10-K Filing

CENTURY ALUMINUM CO CIK: 949157 FY 2023

Filing Information

Form Type	10-K
Accession Number	`0000949157-24-000028`
Period End Date	20231231
Filing Date	20240315
Fiscal Year	2023
Fiscal Period	FY
XBRL Instance	cenx-20231231_htm.xml

Filing Contents

This filing contains the following financial statements:

Balance Sheet 73 Income Statement 66 Cash Flow Statement 128 Stockholders Equity 23 Comprehensive Income 36

Balance Sheet 73 line items

Line Item	Tag	Value	Unit	Period
Cash and cash equivalents	`CashAndCashEquivalentsAtCarryingValue`	$54.30M	USD	Point-in-time
Cash and cash equivalents	`CashAndCashEquivalentsAtCarryingValue`	$88.80M	USD	Point-in-time
Restricted cash	`RestrictedCashAndCashEquivalents`	$1.20M	USD	Point-in-time
Restricted cash	`RestrictedCashAndCashEquivalents`	$1.50M	USD	Point-in-time
Accounts receivable - net	`AccountsReceivableNetCurrent`	$66.90M	USD	Point-in-time
Accounts receivable - net	`AccountsReceivableNetCurrent`	$53.70M	USD	Point-in-time
Non-trade receivables	`NontradeReceivablesCurrent`	$36.20M	USD	Point-in-time
Non-trade receivables	`NontradeReceivablesCurrent`	-	USD	Point-in-time
Manufacturing credit receivable	`ManufacturingCreditReceivableCurrent`	$59.30M	USD	Point-in-time
Manufacturing credit receivable	`ManufacturingCreditReceivableCurrent`	-	USD	Point-in-time
Inventories	`InventoryNet`	$398.80M	USD	Point-in-time
Inventories	`InventoryNet`	$477.00M	USD	Point-in-time
Derivative assets	`DerivativeAssetsCurrent`	$127.30M	USD	Point-in-time
Derivative assets	`DerivativeAssetsCurrent`	$2.90M	USD	Point-in-time
Prepaid and other current assets	`PrepaidExpenseAndOtherAssetsCurrent`	$24.50M	USD	Point-in-time
Prepaid and other current assets	`PrepaidExpenseAndOtherAssetsCurrent`	$27.50M	USD	Point-in-time
Total current assets	`AssetsCurrent`	$767.10M	USD	Point-in-time
Total current assets	`AssetsCurrent`	$677.80M	USD	Point-in-time
Property, plant and equipment - net	`PropertyPlantAndEquipmentNet`	$744.40M	USD	Point-in-time
Property, plant and equipment - net	`PropertyPlantAndEquipmentNet`	$1.00B	USD	Point-in-time
Other assets	`OtherAssetsNoncurrent`	$75.20M	USD	Point-in-time
Other assets	`OtherAssetsNoncurrent`	$49.80M	USD	Point-in-time
TOTAL	`Assets`	$1.85B	USD	Point-in-time
TOTAL	`Assets`	$1.47B	USD	Point-in-time
TOTAL	`Assets`	$1.57B	USD	Point-in-time
Accounts payable, trade	`AccountsPayableTradeCurrent`	$167.30M	USD	Point-in-time
Accounts payable, trade	`AccountsPayableTradeCurrent`	$249.50M	USD	Point-in-time
Accrued compensation and benefits	`AccruedEmployeeBenefitsCurrent`	$38.10M	USD	Point-in-time
Accrued compensation and benefits	`AccruedEmployeeBenefitsCurrent`	$33.00M	USD	Point-in-time
Accrued and other current liabilities	`AccruedLiabilitiesCurrent`	$50.90M	USD	Point-in-time
Accrued and other current liabilities	`AccruedLiabilitiesCurrent`	$37.60M	USD	Point-in-time
Derivative liabilities	`DerivativeLiabilitiesCurrent`	$1.40M	USD	Point-in-time
Derivative liabilities	`DerivativeLiabilitiesCurrent`	$9.70M	USD	Point-in-time
Deferred credit - preliminary bargain purchase gain	`BusinessCombinationBargainPurchaseGain`	$273.40M	USD	Point-in-time
Deferred credit - preliminary bargain purchase gain	`BusinessCombinationBargainPurchaseGain`	-	USD	Point-in-time
Total current liabilities	`LiabilitiesCurrent`	$763.00M	USD	Point-in-time
Total current liabilities	`LiabilitiesCurrent`	$410.70M	USD	Point-in-time
Long-term debt	`LongTermDebtNoncurrent`	$381.60M	USD	Point-in-time
Long-term debt	`LongTermDebtNoncurrent`	$430.90M	USD	Point-in-time
Accrued benefits costs - less current portion	`DefinedBenefitPensionPlanLiabilitiesNoncurrent`	$118.00M	USD	Point-in-time
Accrued benefits costs - less current portion	`DefinedBenefitPensionPlanLiabilitiesNoncurrent`	$120.30M	USD	Point-in-time
Other liabilities	`OtherLiabilitiesNoncurrent`	$66.30M	USD	Point-in-time
Other liabilities	`OtherLiabilitiesNoncurrent`	$31.40M	USD	Point-in-time
Deferred taxes	`DeferredIncomeTaxLiabilitiesNet`	$72.40M	USD	Point-in-time
Deferred taxes	`DeferredIncomeTaxLiabilitiesNet`	$103.10M	USD	Point-in-time
Asset retirement obligations - less current portion	`AssetRetirementObligationsNoncurrent`	$19.60M	USD	Point-in-time
Asset retirement obligations - less current portion	`AssetRetirementObligationsNoncurrent`	$49.50M	USD	Point-in-time
Total noncurrent liabilities	`LiabilitiesNoncurrent`	$739.40M	USD	Point-in-time
Total noncurrent liabilities	`LiabilitiesNoncurrent`	$662.00M	USD	Point-in-time
COMMITMENTS AND CONTINGENCIES (NOTE 17)	`CommitmentsAndContingencies`	-	USD	Point-in-time
COMMITMENTS AND CONTINGENCIES (NOTE 17)	`CommitmentsAndContingencies`	-	USD	Point-in-time
Preferred stock (Note 9)	`PreferredStockValue`	-	USD	Point-in-time
Preferred stock (Note 9)	`PreferredStockValue`	-	USD	Point-in-time
Common stock (Note 9)	`CommonStockValue`	$1.00M	USD	Point-in-time
Common stock (Note 9)	`CommonStockValue`	$1.00M	USD	Point-in-time
Additional paid-in capital	`AdditionalPaidInCapital`	$2.54B	USD	Point-in-time
Additional paid-in capital	`AdditionalPaidInCapital`	$2.54B	USD	Point-in-time
Treasury stock, at cost	`TreasuryStockValue`	$86.30M	USD	Point-in-time
Treasury stock, at cost	`TreasuryStockValue`	$86.30M	USD	Point-in-time
Accumulated other comprehensive loss	`AccumulatedOtherComprehensiveIncomeLossNetOfTax`	$-94.00M	USD	Point-in-time
Accumulated other comprehensive loss	`AccumulatedOtherComprehensiveIncomeLossNetOfTax`	$-97.90M	USD	Point-in-time
Accumulated deficit	`RetainedEarningsAccumulatedDeficit`	$-2.00B	USD	Point-in-time
Accumulated deficit	`RetainedEarningsAccumulatedDeficit`	$-1.96B	USD	Point-in-time
Total Century shareholders equity	`StockholdersEquity`	$399.30M	USD	Point-in-time
Total Century shareholders equity	`StockholdersEquity`	$355.60M	USD	Point-in-time
Noncontrolling interest	`MinorityInterest`	-	USD	Point-in-time
Noncontrolling interest	`MinorityInterest`	$-11.50M	USD	Point-in-time
Total equity	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$421.00M	USD	Point-in-time
Total equity	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$344.10M	USD	Point-in-time
Total equity	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$546.10M	USD	Point-in-time
Total equity	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$399.30M	USD	Point-in-time
TOTAL	`LiabilitiesAndStockholdersEquity`	$1.47B	USD	Point-in-time
TOTAL	`LiabilitiesAndStockholdersEquity`	$1.85B	USD	Point-in-time

Income Statement 66 line items

Line Item	Tag	Value	Unit	Period
Total net sales	`RevenueFromContractWithCustomerExcludingAssessedTax`	$2.78B	USD	Annual
Total net sales	`RevenueFromContractWithCustomerExcludingAssessedTax`	$2.19B	USD	Annual
Total net sales	`RevenueFromContractWithCustomerExcludingAssessedTax`	$2.21B	USD	Annual
Cost of goods sold	`CostOfGoodsAndServicesSold`	$2.09B	USD	Annual
Cost of goods sold	`CostOfGoodsAndServicesSold`	$2.73B	USD	Annual
Cost of goods sold	`CostOfGoodsAndServicesSold`	$2.09B	USD	Annual
Gross profit	`GrossProfit`	$91.90M	USD	Annual
Gross profit	`GrossProfit`	$124.20M	USD	Annual
Gross profit	`GrossProfit`	$46.70M	USD	Annual
Selling, general and administrative expenses	`SellingGeneralAndAdministrativeExpense`	$44.30M	USD	Annual
Selling, general and administrative expenses	`SellingGeneralAndAdministrativeExpense`	$57.60M	USD	Annual
Selling, general and administrative expenses	`SellingGeneralAndAdministrativeExpense`	$37.50M	USD	Annual
Asset impairment	`AssetImpairmentCharges`	$159.40M	USD	Annual
Asset impairment	`AssetImpairmentCharges`	-	USD	Annual
Asset impairment	`AssetImpairmentCharges`	-	USD	Annual
Other operating expense - net	`OtherOperatingIncomeExpenseNet`	-	USD	Annual
Other operating expense - net	`OtherOperatingIncomeExpenseNet`	$-15.80M	USD	Annual
Other operating expense - net	`OtherOperatingIncomeExpenseNet`	$-600.00K	USD	Annual
Operating income (loss)	`OperatingIncomeLoss`	$66.00M	USD	Annual
Operating income (loss)	`OperatingIncomeLoss`	$-150.20M	USD	Annual
Operating income (loss)	`OperatingIncomeLoss`	$31.80M	USD	Annual
Interest income	`InterestIncomeOther`	$2.00M	USD	Annual
Interest income	`InterestIncomeOther`	$800.00K	USD	Annual
Interest income	`InterestIncomeOther`	$500.00K	USD	Annual
Net (loss) gain on forward and derivative contracts	`GainLossOnDerivativeInstrumentsNetPretax`	$-212.40M	USD	Annual
Net (loss) gain on forward and derivative contracts	`GainLossOnDerivativeInstrumentsNetPretax`	$197.10M	USD	Annual
Net (loss) gain on forward and derivative contracts	`GainLossOnDerivativeInstrumentsNetPretax`	$-61.80M	USD	Annual
Loss on early extinguishment of debt	`GainsLossesOnExtinguishmentOfDebt`	-	USD	Annual
Loss on early extinguishment of debt	`GainsLossesOnExtinguishmentOfDebt`	-	USD	Annual
Loss on early extinguishment of debt	`GainsLossesOnExtinguishmentOfDebt`	$-24.70M	USD	Annual
Other (loss) income - net	`OtherNonoperatingIncomeExpense`	$15.30M	USD	Annual
Other (loss) income - net	`OtherNonoperatingIncomeExpense`	$-3.30M	USD	Annual
Other (loss) income - net	`OtherNonoperatingIncomeExpense`	$3.10M	USD	Annual
(Loss) income before income taxes	`IncomeLossIncludingPortionAttributableToNoncontrollingInterest`	$-66.80M	USD	Annual
(Loss) income before income taxes	`IncomeLossIncludingPortionAttributableToNoncontrollingInterest`	$-197.60M	USD	Annual
(Loss) income before income taxes	`IncomeLossIncludingPortionAttributableToNoncontrollingInterest`	$33.40M	USD	Annual
Income tax benefit (expense)	`IncomeTaxExpenseBenefit`	$-14.60M	USD	Annual
Income tax benefit (expense)	`IncomeTaxExpenseBenefit`	$-30.60M	USD	Annual
Income tax benefit (expense)	`IncomeTaxExpenseBenefit`	$47.40M	USD	Annual
Loss before equity in earnings of joint ventures	`IncomeLossAfterIncomeTaxesBeforeIncomeLossFromEquityMethodInvestments`	$-14.00M	USD	Annual
Loss before equity in earnings of joint ventures	`IncomeLossAfterIncomeTaxesBeforeIncomeLossFromEquityMethodInvestments`	$-52.20M	USD	Annual
Loss before equity in earnings of joint ventures	`IncomeLossAfterIncomeTaxesBeforeIncomeLossFromEquityMethodInvestments`	$-167.00M	USD	Annual
Equity in losses of joint ventures	`IncomeLossFromEquityMethodInvestments`	$-100.00K	USD	Annual
Equity in losses of joint ventures	`IncomeLossFromEquityMethodInvestments`	$-100.00K	USD	Annual
Equity in losses of joint ventures	`IncomeLossFromEquityMethodInvestments`	$-100.00K	USD	Annual
Net loss	`ProfitLoss`	$-14.10M	USD	Annual
Net loss	`ProfitLoss`	$-52.30M	USD	Annual
Net loss	`ProfitLoss`	$-167.10M	USD	Annual
Net loss attributable to noncontrolling interests	`NetIncomeLossAttributableToNoncontrollingInterest`	$-9.20M	USD	Annual
Net loss attributable to noncontrolling interests	`NetIncomeLossAttributableToNoncontrollingInterest`	-	USD	Annual
Net loss attributable to noncontrolling interests	`NetIncomeLossAttributableToNoncontrollingInterest`	-	USD	Annual
Net loss	`NetIncomeLoss`	$-14.10M	USD	Annual
Net loss	`NetIncomeLoss`	$-167.10M	USD	Annual
Net loss	`NetIncomeLoss`	$-43.10M	USD	Annual
Basic (in dollars per share)	`EarningsPerShareBasic`	$-0.47	USD	Annual
Basic (in dollars per share)	`EarningsPerShareBasic`	$-0.15	USD	Annual
Basic (in dollars per share)	`EarningsPerShareBasic`	$-1.85	USD	Annual
Diluted (in dollars per share)	`EarningsPerShareDiluted`	$-1.85	USD	Annual
Diluted (in dollars per share)	`EarningsPerShareDiluted`	$-0.47	USD	Annual
Diluted (in dollars per share)	`EarningsPerShareDiluted`	$-0.15	USD	Annual
Basic (in shares)	`WeightedAverageNumberOfSharesOutstandingBasic`	90.20M	shares	Annual
Basic (in shares)	`WeightedAverageNumberOfSharesOutstandingBasic`	92.40M	shares	Annual
Basic (in shares)	`WeightedAverageNumberOfSharesOutstandingBasic`	91.40M	shares	Annual
Diluted (in shares)	`WeightedAverageNumberOfDilutedSharesOutstanding`	92.40M	shares	Annual
Diluted (in shares)	`WeightedAverageNumberOfDilutedSharesOutstanding`	91.40M	shares	Annual
Diluted (in shares)	`WeightedAverageNumberOfDilutedSharesOutstanding`	90.20M	shares	Annual

Cash Flow Statement 128 line items

Line Item	Tag	Value	Unit	Period
Net loss	`ProfitLoss`	$-14.10M	USD	Annual
Net loss	`ProfitLoss`	$-52.30M	USD	Annual
Net loss	`ProfitLoss`	$-167.10M	USD	Annual
Lower of cost or NRV inventory adjustment	`InventoryWriteDown`	-	USD	Annual
Lower of cost or NRV inventory adjustment	`InventoryWriteDown`	$39.60M	USD	Annual
Lower of cost or NRV inventory adjustment	`InventoryWriteDown`	-	USD	Annual
Unrealized loss (gain) on derivative instruments	`UnrealizedGainLossOnDerivatives`	$201.50M	USD	Annual
Unrealized loss (gain) on derivative instruments	`UnrealizedGainLossOnDerivatives`	$-102.90M	USD	Annual
Unrealized loss (gain) on derivative instruments	`UnrealizedGainLossOnDerivatives`	$-87.10M	USD	Annual
Depreciation, depletion and amortization	`DepreciationDepletionAndAmortization`	$74.70M	USD	Annual
Depreciation, depletion and amortization	`DepreciationDepletionAndAmortization`	$73.40M	USD	Annual
Depreciation, depletion and amortization	`DepreciationDepletionAndAmortization`	$82.60M	USD	Annual
Change in deferred tax (benefit) provision	`DeferredIncomeTaxesAndTaxCredits`	$-30.60M	USD	Annual
Change in deferred tax (benefit) provision	`DeferredIncomeTaxesAndTaxCredits`	$44.20M	USD	Annual
Change in deferred tax (benefit) provision	`DeferredIncomeTaxesAndTaxCredits`	$-30.80M	USD	Annual
Asset impairment	`AssetImpairmentCharges`	$159.40M	USD	Annual
Asset impairment	`AssetImpairmentCharges`	-	USD	Annual
Asset impairment	`AssetImpairmentCharges`	-	USD	Annual
Other postretirement benefits gain, net	`OtherPostretirementBenefitsExpenseReversalOfExpenseNoncash`	-	USD	Annual
Other postretirement benefits gain, net	`OtherPostretirementBenefitsExpenseReversalOfExpenseNoncash`	$-8.90M	USD	Annual
Other postretirement benefits gain, net	`OtherPostretirementBenefitsExpenseReversalOfExpenseNoncash`	-	USD	Annual
Loss on early extinguishment of debt	`GainLossOnExtinguishmentOfDebtNet`	-	USD	Annual
Loss on early extinguishment of debt	`GainLossOnExtinguishmentOfDebtNet`	$-24.70M	USD	Annual
Loss on early extinguishment of debt	`GainLossOnExtinguishmentOfDebtNet`	-	USD	Annual
Other non-cash items - net	`OtherNoncashIncomeExpense`	$22.80M	USD	Annual
Other non-cash items - net	`OtherNoncashIncomeExpense`	$-3.40M	USD	Annual
Other non-cash items - net	`OtherNoncashIncomeExpense`	$1.70M	USD	Annual
Accounts receivable - net	`IncreaseDecreaseInAccountsReceivable`	$-13.70M	USD	Annual
Accounts receivable - net	`IncreaseDecreaseInAccountsReceivable`	$16.20M	USD	Annual
Accounts receivable - net	`IncreaseDecreaseInAccountsReceivable`	$-36.90M	USD	Annual
Non-trade receivables	`IncreaseDecreaseInNontradeReceivables`	-	USD	Annual
Non-trade receivables	`IncreaseDecreaseInNontradeReceivables`	$-4.10M	USD	Annual
Non-trade receivables	`IncreaseDecreaseInNontradeReceivables`	-	USD	Annual
Manufacturing credit receivable	`IncreaseDecreaseInManufacturingCreditsReceivable`	-	USD	Annual
Manufacturing credit receivable	`IncreaseDecreaseInManufacturingCreditsReceivable`	$59.30M	USD	Annual
Manufacturing credit receivable	`IncreaseDecreaseInManufacturingCreditsReceivable`	-	USD	Annual
Due from affiliates	`IncreaseDecreaseInDueFromRelatedPartiesCurrent`	$-700.00K	USD	Annual
Due from affiliates	`IncreaseDecreaseInDueFromRelatedPartiesCurrent`	$-3.60M	USD	Annual
Due from affiliates	`IncreaseDecreaseInDueFromRelatedPartiesCurrent`	$15.50M	USD	Annual
Inventories	`IncreaseDecreaseInInventories`	$-25.80M	USD	Annual
Inventories	`IncreaseDecreaseInInventories`	$134.50M	USD	Annual
Inventories	`IncreaseDecreaseInInventories`	$12.80M	USD	Annual
Prepaid and other current assets	`IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets`	$-2.90M	USD	Annual
Prepaid and other current assets	`IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets`	$-5.60M	USD	Annual
Prepaid and other current assets	`IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets`	$13.40M	USD	Annual
Accounts payable, trade	`IncreaseDecreaseInAccountsPayableTrade`	$44.80M	USD	Annual
Accounts payable, trade	`IncreaseDecreaseInAccountsPayableTrade`	$-15.80M	USD	Annual
Accounts payable, trade	`IncreaseDecreaseInAccountsPayableTrade`	$-19.40M	USD	Annual
Due to affiliates	`IncreaseDecreaseInDueToRelatedPartiesCurrent`	$38.30M	USD	Annual
Due to affiliates	`IncreaseDecreaseInDueToRelatedPartiesCurrent`	$51.70M	USD	Annual
Due to affiliates	`IncreaseDecreaseInDueToRelatedPartiesCurrent`	$-43.50M	USD	Annual
Accrued and other current liabilities	`IncreaseDecreaseInAccruedLiabilities`	$5.00M	USD	Annual
Accrued and other current liabilities	`IncreaseDecreaseInAccruedLiabilities`	$8.80M	USD	Annual
Accrued and other current liabilities	`IncreaseDecreaseInAccruedLiabilities`	-	USD	Annual
Ravenswood retiree legal settlement	`IncreaseDecreaseinEstimatedLitigationLiability`	$-2.00M	USD	Annual
Ravenswood retiree legal settlement	`IncreaseDecreaseinEstimatedLitigationLiability`	$-2.00M	USD	Annual
Ravenswood retiree legal settlement	`IncreaseDecreaseinEstimatedLitigationLiability`	$-2.00M	USD	Annual
PBGC settlement	`PensionExpenseReversalOfExpenseNoncash`	$-4.50M	USD	Annual
PBGC settlement	`PensionExpenseReversalOfExpenseNoncash`	$-2.40M	USD	Annual
PBGC settlement	`PensionExpenseReversalOfExpenseNoncash`	-	USD	Annual
Other - net	`IncreaseDecreaseInOtherOperatingCapitalNet`	$-2.80M	USD	Annual
Other - net	`IncreaseDecreaseInOtherOperatingCapitalNet`	$-1.40M	USD	Annual
Other - net	`IncreaseDecreaseInOtherOperatingCapitalNet`	$-1.80M	USD	Annual
Net cash provided by (used in) operating activities	`NetCashProvidedByUsedInOperatingActivities`	$-64.70M	USD	Annual
Net cash provided by (used in) operating activities	`NetCashProvidedByUsedInOperatingActivities`	$25.90M	USD	Annual
Net cash provided by (used in) operating activities	`NetCashProvidedByUsedInOperatingActivities`	$105.60M	USD	Annual
Purchase of property, plant and equipment	`PaymentsToAcquirePropertyPlantAndEquipment`	$86.30M	USD	Annual
Purchase of property, plant and equipment	`PaymentsToAcquirePropertyPlantAndEquipment`	$95.00M	USD	Annual
Purchase of property, plant and equipment	`PaymentsToAcquirePropertyPlantAndEquipment`	$83.00M	USD	Annual
Proceeds from sale of property, plant and equipment	`ProceedsFromSaleOfPropertyPlantAndEquipment`	$800.00K	USD	Annual
Proceeds from sale of property, plant and equipment	`ProceedsFromSaleOfPropertyPlantAndEquipment`	$25.70M	USD	Annual
Proceeds from sale of property, plant and equipment	`ProceedsFromSaleOfPropertyPlantAndEquipment`	$400.00K	USD	Annual
Acquisition of subsidiary net of cash acquired	`PaymentsToAcquireBusinessesNetOfCashAcquired`	-	USD	Annual
Acquisition of subsidiary net of cash acquired	`PaymentsToAcquireBusinessesNetOfCashAcquired`	$-11.50M	USD	Annual
Acquisition of subsidiary net of cash acquired	`PaymentsToAcquireBusinessesNetOfCashAcquired`	-	USD	Annual
Net cash used in investing activities	`NetCashProvidedByUsedInInvestingActivities`	$-85.50M	USD	Annual
Net cash used in investing activities	`NetCashProvidedByUsedInInvestingActivities`	$-57.80M	USD	Annual
Net cash used in investing activities	`NetCashProvidedByUsedInInvestingActivities`	$-82.60M	USD	Annual
Repayment of Senior Notes due 2025	`RepaymentsOfSeniorDebt`	-	USD	Annual
Repayment of Senior Notes due 2025	`RepaymentsOfSeniorDebt`	$250.00M	USD	Annual
Repayment of Senior Notes due 2025	`RepaymentsOfSeniorDebt`	-	USD	Annual
Early redemption and tender premiums paid	`PaymentsOfDebtExtinguishmentCosts`	-	USD	Annual
Early redemption and tender premiums paid	`PaymentsOfDebtExtinguishmentCosts`	-	USD	Annual
Early redemption and tender premiums paid	`PaymentsOfDebtExtinguishmentCosts`	$18.10M	USD	Annual
Proceeds from issuance of Senior Notes due 2028	`ProceedsFromIssuanceOfSeniorLongTermDebt`	$250.00M	USD	Annual
Proceeds from issuance of Senior Notes due 2028	`ProceedsFromIssuanceOfSeniorLongTermDebt`	-	USD	Annual
Proceeds from issuance of Senior Notes due 2028	`ProceedsFromIssuanceOfSeniorLongTermDebt`	-	USD	Annual
Proceeds from issuance of Convertible Senior Notes	`ProceedsFromConvertibleDebt`	$86.30M	USD	Annual
Proceeds from issuance of Convertible Senior Notes	`ProceedsFromConvertibleDebt`	-	USD	Annual
Proceeds from issuance of Convertible Senior Notes	`ProceedsFromConvertibleDebt`	-	USD	Annual
Repayments under Hawesville Term Loan	`RepaymentsOfTermLoan`	$20.00M	USD	Annual
Repayments under Hawesville Term Loan	`RepaymentsOfTermLoan`	-	USD	Annual
Repayments under Hawesville Term Loan	`RepaymentsOfTermLoan`	-	USD	Annual
Debt issuance cost	`PaymentsOfDebtIssuanceCosts`	-	USD	Annual
Debt issuance cost	`PaymentsOfDebtIssuanceCosts`	$7.40M	USD	Annual
Debt issuance cost	`PaymentsOfDebtIssuanceCosts`	$1.50M	USD	Annual
Purchase of capped calls related to Convertible Senior Notes	`PaymentForOptionIndexedToIssuersEquity`	$5.70M	USD	Annual
Purchase of capped calls related to Convertible Senior Notes	`PaymentForOptionIndexedToIssuersEquity`	-	USD	Annual
Purchase of capped calls related to Convertible Senior Notes	`PaymentForOptionIndexedToIssuersEquity`	-	USD	Annual
Carbon credit proceeds	`ProceedsFromCreditSaleFinancingActivities`	-	USD	Annual
Carbon credit proceeds	`ProceedsFromCreditSaleFinancingActivities`	-	USD	Annual
Carbon credit proceeds	`ProceedsFromCreditSaleFinancingActivities`	$36.80M	USD	Annual
Net cash (used in) provided by financing activities	`NetCashProvidedByUsedInFinancingActivities`	$103.70M	USD	Annual
Net cash (used in) provided by financing activities	`NetCashProvidedByUsedInFinancingActivities`	$-13.00M	USD	Annual
Net cash (used in) provided by financing activities	`NetCashProvidedByUsedInFinancingActivities`	$74.40M	USD	Annual
CHANGE IN CASH, CASH EQUIVALENTS, AND RESTRICTED CASH	`CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect`	$14.80M	USD	Annual
CHANGE IN CASH, CASH EQUIVALENTS, AND RESTRICTED CASH	`CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect`	$-43.60M	USD	Annual
CHANGE IN CASH, CASH EQUIVALENTS, AND RESTRICTED CASH	`CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect`	$34.80M	USD	Annual
Cash, cash equivalents and restricted cash, beginning of year	`CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents`	$84.30M	USD	Point-in-time
Cash, cash equivalents and restricted cash, beginning of year	`CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents`	$55.50M	USD	Point-in-time
Cash, cash equivalents and restricted cash, beginning of year	`CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents`	$90.30M	USD	Point-in-time
Cash, cash equivalents and restricted cash, beginning of year	`CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents`	$40.70M	USD	Point-in-time
Cash, cash equivalents and restricted cash, end of year	`CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents`	$84.30M	USD	Point-in-time
Cash, cash equivalents and restricted cash, end of year	`CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents`	$55.50M	USD	Point-in-time
Cash, cash equivalents and restricted cash, end of year	`CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents`	$90.30M	USD	Point-in-time
Cash, cash equivalents and restricted cash, end of year	`CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents`	$40.70M	USD	Point-in-time
Interest	`InterestPaidNet`	$27.00M	USD	Annual
Interest	`InterestPaidNet`	$35.20M	USD	Annual
Interest	`InterestPaidNet`	$36.80M	USD	Annual
Taxes, net of refunds	`IncomeTaxesPaidNet`	$900.00K	USD	Annual
Taxes, net of refunds	`IncomeTaxesPaidNet`	$5.90M	USD	Annual
Taxes, net of refunds	`IncomeTaxesPaidNet`	$3.10M	USD	Annual
Capital expenditures	`CapitalExpendituresIncurredButNotYetPaid`	$3.70M	USD	Annual
Capital expenditures	`CapitalExpendituresIncurredButNotYetPaid`	$10.70M	USD	Annual
Capital expenditures	`CapitalExpendituresIncurredButNotYetPaid`	$7.10M	USD	Annual
Capitalized interest	`InterestPaidCapitalized`	$4.20M	USD	Annual
Capitalized interest	`InterestPaidCapitalized`	$1.60M	USD	Annual
Capitalized interest	`InterestPaidCapitalized`	$6.00M	USD	Annual

Stockholders Equity 23 line items

Line Item	Tag	Value	Unit	Period
Beginning balance	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$421.00M	USD	Point-in-time
Beginning balance	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$344.10M	USD	Point-in-time
Beginning balance	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$546.10M	USD	Point-in-time
Beginning balance	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$399.30M	USD	Point-in-time
Beginning balance (in shares)	`CommonStockSharesOutstanding`	92.69M	shares	Point-in-time
Beginning balance (in shares)	`CommonStockSharesOutstanding`	92.32M	shares	Point-in-time
Net loss	`ProfitLoss`	$-14.10M	USD	Annual
Net loss	`ProfitLoss`	$-52.30M	USD	Annual
Net loss	`ProfitLoss`	$-167.10M	USD	Annual
Other comprehensive income (loss)	`OtherComprehensiveIncomeLossNetOfTax`	$36.50M	USD	Annual
Other comprehensive income (loss)	`OtherComprehensiveIncomeLossNetOfTax`	$-11.70M	USD	Annual
Other comprehensive income (loss)	`OtherComprehensiveIncomeLossNetOfTax`	$-3.90M	USD	Annual
Share-based compensation	`AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue`	$4.10M	USD	Annual
Share-based compensation	`AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue`	$3.30M	USD	Annual
Share-based compensation	`AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue`	$10.10M	USD	Annual
Capped call premiums	`AdjustmentsToAdditionalPaidInCapitalOptionIndexedToIssuersEquityCappedCallPremium`	$4.60M	USD	Annual
Noncontrolling interest of business acquired	`NoncontrollingInterestDecreaseFromBusinessCombination`	$2.30M	USD	Annual
Ending balance	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$421.00M	USD	Point-in-time
Ending balance	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$344.10M	USD	Point-in-time
Ending balance	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$546.10M	USD	Point-in-time
Ending balance	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$399.30M	USD	Point-in-time
Ending balance (in shares)	`CommonStockSharesOutstanding`	92.69M	shares	Point-in-time
Ending balance (in shares)	`CommonStockSharesOutstanding`	92.32M	shares	Point-in-time

Comprehensive Income 36 line items

Line Item	Tag	Value	Unit	Period
Net loss	`ProfitLoss`	$-14.10M	USD	Annual
Net loss	`ProfitLoss`	$-52.30M	USD	Annual
Net loss	`ProfitLoss`	$-167.10M	USD	Annual
Net loss on foreign currency cash flow hedges reclassified as income	`OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax`	$-200.00K	USD	Annual
Net loss on foreign currency cash flow hedges reclassified as income	`OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax`	$-100.00K	USD	Annual
Net loss on foreign currency cash flow hedges reclassified as income	`OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax`	$-100.00K	USD	Annual
Net (gain) loss arising during the period	`OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax`	$31.60M	USD	Annual
Net (gain) loss arising during the period	`OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax`	$-5.90M	USD	Annual
Net (gain) loss arising during the period	`OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax`	$-10.10M	USD	Annual
OPEB curtailment gain, net	`OtherComprehensiveIncomeLossFinalizationOfPensionAndNonPensionPostretirementPlanValuationBeforeTax`	-	USD	Annual
OPEB curtailment gain, net	`OtherComprehensiveIncomeLossFinalizationOfPensionAndNonPensionPostretirementPlanValuationBeforeTax`	-	USD	Annual
OPEB curtailment gain, net	`OtherComprehensiveIncomeLossFinalizationOfPensionAndNonPensionPostretirementPlanValuationBeforeTax`	$-8.90M	USD	Annual
Amortization of prior service benefit (cost) during the period	`OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax`	$-3.10M	USD	Annual
Amortization of prior service benefit (cost) during the period	`OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax`	$-1.20M	USD	Annual
Amortization of prior service benefit (cost) during the period	`OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax`	$100.00K	USD	Annual
Amortization of net loss during the period	`OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax`	$-4.80M	USD	Annual
Amortization of net loss during the period	`OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax`	$-6.20M	USD	Annual
Amortization of net loss during the period	`OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax`	$-8.40M	USD	Annual
Other comprehensive (loss) income before income tax effect	`OtherComprehensiveIncomeLossBeforeTax`	$36.80M	USD	Annual
Other comprehensive (loss) income before income tax effect	`OtherComprehensiveIncomeLossBeforeTax`	$-11.40M	USD	Annual
Other comprehensive (loss) income before income tax effect	`OtherComprehensiveIncomeLossBeforeTax`	$-3.90M	USD	Annual
Income tax effect	`OtherComprehensiveIncomeLossTax`	$300.00K	USD	Annual
Income tax effect	`OtherComprehensiveIncomeLossTax`	-	USD	Annual
Income tax effect	`OtherComprehensiveIncomeLossTax`	$300.00K	USD	Annual
Other comprehensive (loss) income	`OtherComprehensiveIncomeLossNetOfTax`	$36.50M	USD	Annual
Other comprehensive (loss) income	`OtherComprehensiveIncomeLossNetOfTax`	$-11.70M	USD	Annual
Other comprehensive (loss) income	`OtherComprehensiveIncomeLossNetOfTax`	$-3.90M	USD	Annual
Comprehensive loss	`ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest`	$-56.20M	USD	Annual
Comprehensive loss	`ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest`	$-130.60M	USD	Annual
Comprehensive loss	`ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest`	$-25.80M	USD	Annual
Comprehensive loss attributable to noncontrolling interests	`ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest`	$-9.20M	USD	Annual
Comprehensive loss attributable to noncontrolling interests	`ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest`	-	USD	Annual
Comprehensive loss attributable to noncontrolling interests	`ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest`	-	USD	Annual
Comprehensive loss attributable to Century stockholders	`ComprehensiveIncomeNetOfTax`	$-130.60M	USD	Annual
Comprehensive loss attributable to Century stockholders	`ComprehensiveIncomeNetOfTax`	$-47.00M	USD	Annual
Comprehensive loss attributable to Century stockholders	`ComprehensiveIncomeNetOfTax`	$-25.80M	USD	Annual

Data is extracted from SEC EDGAR XBRL filings. Values shown are as reported in the filing.