XML 87 R59.htm IDEA: XBRL DOCUMENT v2.4.1.9

Business acquisitions Acquisition of Sebree aluminum smelter (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended					12 Months Ended				3 Months Ended	19 Months Ended
	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2014	Dec. 31, 2013		Dec. 31, 2012	Jun. 30, 2014	Dec. 31, 2014	Jun. 01, 2013 t
Business Acquisition [Line Items]
Purchase price cash paid						$ 1,042us-gaap_PaymentsToAcquireBusinessesGross	$ 48,058us-gaap_PaymentsToAcquireBusinessesGross		$ 0us-gaap_PaymentsToAcquireBusinessesGross
Gain on fair value of contingent consideration	7,943us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsRevenuesAndGainsRecognized					7,943us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsRevenuesAndGainsRecognized	0us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsRevenuesAndGainsRecognized		0us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsRevenuesAndGainsRecognized
Gain on bargain purchase					5,253us-gaap_BusinessCombinationBargainPurchaseGainRecognizedAmount	0us-gaap_BusinessCombinationBargainPurchaseGainRecognizedAmount	5,253us-gaap_BusinessCombinationBargainPurchaseGainRecognizedAmount		0us-gaap_BusinessCombinationBargainPurchaseGainRecognizedAmount
Sebree power contract amortization		5,534cenx_AmortizationofAssumedPowerContract	16,570cenx_AmortizationofAssumedPowerContract	11,720cenx_AmortizationofAssumedPowerContract	2,741cenx_AmortizationofAssumedPowerContract	5,534cenx_AmortizationofAssumedPowerContract	31,031cenx_AmortizationofAssumedPowerContract		0cenx_AmortizationofAssumedPowerContract
Sebree Smelter [Member]
Business Acquisition [Line Items]
Primary aluminum capacity (in tonnes)												205,000cenx_Primaryaluminumcapacity / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember
Purchase price												61,000cenx_BusinessAcquisitionPurchasePrice / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember
Purchase price cash paid											49,035us-gaap_PaymentsToAcquireBusinessesGross / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember
Gain on fair value of contingent consideration										965us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsRevenuesAndGainsRecognized / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember
Gain on bargain purchase											5,253us-gaap_BusinessCombinationBargainPurchaseGainRecognizedAmount / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember
Cash											48,083us-gaap_BusinessCombinationConsiderationTransferred1 / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember
Deferred purchase price											1,910cenx_BusinessCombinationDeferredPurchasePrice / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember
Inventories	59,018us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember					59,018us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember					59,018us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember
Prepaid and other current assets	2,273us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember					2,273us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember					2,273us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember
Property, plant and equipment – net	55,520us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember					55,520us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember					55,520us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember
Total assets acquired	116,811us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember					116,811us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember					116,811us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember
Accrued and other current liabilities	43,316us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember					43,316us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember					43,316us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember
Accrued pension benefit costs	996cenx_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedPensionBenefitCosts / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember					996cenx_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedPensionBenefitCosts / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember					996cenx_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedPensionBenefitCosts / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember
Accrued postretirement benefit costs	6,544cenx_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedPostRetirementBenefits / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember					6,544cenx_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedPostRetirementBenefits / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember					6,544cenx_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedPostRetirementBenefits / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember
Other liabilities	7,476us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember					7,476us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember					7,476us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember
Deferred taxes	3,233us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilitiesNoncurrent / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember					3,233us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilitiesNoncurrent / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember					3,233us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilitiesNoncurrent / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember
Total liabilities assumed	61,565us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember					61,565us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember					61,565us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember
Sebree revenue							247,178us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember
Sebree income from continuing operations (1)							8,705us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember	[1]
Sebree power contract amortization						5,534cenx_AmortizationofAssumedPowerContract / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember	31,031cenx_AmortizationofAssumedPowerContract / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember
Pro forma revenues							1,662,707us-gaap_BusinessAcquisitionsProFormaRevenue / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember		1,755,196us-gaap_BusinessAcquisitionsProFormaRevenue / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember
Pro forma loss from continuing operations							$ (83,035)us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember		$ (260,505)us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember
Pro forma loss per common share, basic							$ (0.94)us-gaap_BusinessAcquisitionProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTaxPerShareBasic / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember		$ (2.94)us-gaap_BusinessAcquisitionProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTaxPerShareBasic / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember
Pro forma loss per common share, diluted							$ (0.94)us-gaap_BusinessAcquisitionProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTaxPerShareDiluted / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember		$ (2.94)us-gaap_BusinessAcquisitionProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTaxPerShareDiluted / us-gaap_BusinessAcquisitionAxis = cenx_SebreeSmelterMember
[1] Our net income for the years ended December 31, 2014 and 2013, includes a non-recurring credit for the amortization of the deferred power contract liability of $5,534 and $31,031, respectively, related to the amortization of an unfavorable power contract assumed as part of the Sebree acquisition resulting in a credit to our depreciation and amortization expense within cost of goods sold on the consolidated statement of operations for the first quarter of 2014. The power contract terminated on January 31, 2014.

X

- Definition

The aggregate benefit recognized in earnings to allocate the assumed power contract liability in a systematic and rational manner over the contract period. As a noncash benefit, this element is subtracted from net income when calculating cash provided by or used in operations using the indirect method.

+ References

No definition available.

+ Details

Name:	cenx_AmortizationofAssumedPowerContract
Namespace Prefix:	cenx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

This amount represents the purchase price of the business acquisition.

+ References

No definition available.

+ Details

Name:	cenx_BusinessAcquisitionPurchasePrice
Namespace Prefix:	cenx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

This amount represents deferred purchase price as a result of certain working capital adjustments due to the previous owner.

+ References

No definition available.

+ Details

Name:	cenx_BusinessCombinationDeferredPurchasePrice
Namespace Prefix:	cenx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

The amount of acquisition cost of a business combination allocated to pension benefit costs of the acquired entity.

+ References

No definition available.

+ Details

Name:	cenx_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedPensionBenefitCosts
Namespace Prefix:	cenx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

The amount of acquisition cost of a business combination allocated to post retirement benefits of the acquired entity.

+ References

No definition available.

+ Details

Name:	cenx_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedPostRetirementBenefits
Namespace Prefix:	cenx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Annual production capacity of primary aluminum (in tonnes).

+ References

No definition available.

+ Details

Name:	cenx_Primaryaluminumcapacity
Namespace Prefix:	cenx_
Data Type:	num:massItemType
Balance Type:	na
Period Type:	instant

X

- Details

Name:	us-gaap_BusinessAcquisitionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The pro forma income from continuing operations before changes in accounting and extraordinary items, net of tax effect per basic share of common stock for a period as if the business combination or combinations had been completed at the beginning of a period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(2)-(3)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

+ Details

Name:	us-gaap_BusinessAcquisitionProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTaxPerShareBasic
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The pro forma income from continuing operations before changes in accounting and extraordinary items, net of tax effect, per diluted share of common stock for a period as if the business combination or combinations had been completed at the beginning of a period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(2)-(3)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

+ Details

Name:	us-gaap_BusinessAcquisitionProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTaxPerShareDiluted
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The pro forma income from continuing operations before changes in accounting and extraordinary items, net of tax effect, for the period as if the business combination or combinations had been completed at the beginning of a period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(2)-(3)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

+ Details

Name:	us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(2)-(3)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

+ Details

Name:	us-gaap_BusinessAcquisitionsProFormaRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

In a business combination in which the amount of net identifiable assets acquired and liabilities assumed exceeds the aggregate consideration transferred or to be transferred (as defined), this element represents the amount of gain recognized by the entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (f)(1)

-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 30

-Paragraph 6

-URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6571-128477



Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 30

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6527-128477



Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 25

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6396-128476



Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 25

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6387-128476



Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 25

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6393-128476

+ Details

Name:	us-gaap_BusinessCombinationBargainPurchaseGainRecognizedAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 30

-Paragraph 7

-URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6578-128477



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 30

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6613-128477



Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479

+ Details

Name:	us-gaap_BusinessCombinationConsiderationTransferred1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

This element represents the amount of earnings or loss of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(1)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

+ Details

Name:	us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

This element represents the amount of revenue of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(1)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

+ Details

Name:	us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount of assets acquired at the acquisition date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=39739317&loc=d3e4845-128472

+ Details

Name:	us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Amount of asset related to consideration paid in advance for costs that provide economic benefits in future periods, and amount of other assets that are expected to be realized or consumed within one year or the normal operating cycle, if longer, acquired at the acquisition date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=39739317&loc=d3e4845-128472

+ Details

Name:	us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Amount of other liabilities due within one year or within the normal operating cycle, if longer, assumed at the acquisition date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=39739317&loc=d3e4845-128472

+ Details

Name:	us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Amount of deferred tax liability attributable to taxable temporary differences due after one year or the normal operating cycle, if longer, assumed at the acquisition date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=39739317&loc=d3e4845-128472

+ Details

Name:	us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilitiesNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

The amount of inventory recognized as of the acquisition date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=39739317&loc=d3e4845-128472



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 55

-Paragraph 37

-URI http://asc.fasb.org/extlink&oid=35744172&loc=d3e2207-128464

+ Details

Name:	us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Amount of liabilities assumed at the acquisition date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=39739317&loc=d3e4845-128472

+ Details

Name:	us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Amount of other liabilities due after one year or the normal operating cycle, if longer, assumed at the acquisition date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=39739317&loc=d3e4845-128472

+ Details

Name:	us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

The amount of property, plant, and equipment recognized as of the acquisition date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=39739317&loc=d3e4845-128472



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 55

-Paragraph 37

-URI http://asc.fasb.org/extlink&oid=35744172&loc=d3e2207-128464

+ Details

Name:	us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

The revenues and gains recognized recorded for each transaction with the acquiree that is recognized separately from the acquisition of assets and assumptions of liabilities in the business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (e)(3)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

+ Details

Name:	us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsRevenuesAndGainsRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 13

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3213-108585

+ Details

Name:	us-gaap_PaymentsToAcquireBusinessesGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Details

Name:	us-gaap_BusinessAcquisitionAxis=cenx_SebreeSmelterMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: