Ak Steel Holding (AKS) 10-Q 4 Nov 14 2014 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information Document	9 Months Ended
	Sep. 30, 2014	Oct. 31, 2014
Document and Entity Information [Abstract]	'	'
Entity Registrant Name	'AK STEEL HOLDING CORP	'
Entity Central Index Key	'0000918160	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Accelerated Filer	'
Document Type	'10-Q	'
Document Period End Date	30-Sep-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q3	'
Amendment Flag	'false	'
Entity Common Stock, Shares Outstanding	'	177,074,749

CONDENSED_CONSOLIDATED_STATEME

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (unaudited) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Net sales	$1,593.80	$1,331.30	$4,508.10	$4,105.60
Cost of products sold (exclusive of items shown separately below)	1,438.90	1,222.40	4,191.40	3,783.90
Selling and administrative expenses (exclusive of items shown separately below)	65.6	51.5	179.7	153.3
Depreciation	49.1	48.4	146.3	144.9
Pension and OPEB expense (income)	-23.5	-16.9	-74.2	-49.3
Total operating costs	1,530.10	1,305.40	4,443.20	4,032.80
Operating profit	63.7	25.9	64.9	72.8
Interest expense	35.6	32.1	101	95.1
Other income (expense)	-15.3	-2.8	-20.2	1.5
Income (loss) before income taxes	12.8	-9	-56.3	-20.8
Income tax expense	3.9	6.7	7.5	13.6
Net income (loss)	8.9	-15.7	-63.8	-34.4
Less: Net income attributable to noncontrolling interests	16.1	16	46.6	47.6
Net income (loss) attributable to AK Steel Holding Corporation	($7.20)	($31.70)	($110.40)	($82)
Basic and diluted earnings per share:	'	'	'	'
Net income (loss) attributable to AK Steel Holding Corporation common stockholders (in dollars per share)	($0.05)	($0.23)	($0.79)	($0.60)

CONDENSED_CONSOLIDATED_STATEME1

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (unaudited) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Net income (loss)	$8.90	($15.70)	($63.80)	($34.40)
Other comprehensive income (loss), before tax:	'	'	'	'
Foreign currency translation gain (loss)	-2.5	1.2	-2.6	0.5
Cash flow hedges:	'	'	'	'
Gains (losses) arising in period	-2.7	10.3	-9.6	0.6
Reclassification of losses (gains) to net income (loss)	3.9	-5.9	-0.1	-20.5
Unrealized holding gains (losses) on securities:	'	'	'	'
Unrealized holding gains (losses) arising in period	0	0	0	0.2
Pension and OPEB plans:	'	'	'	'
Prior service credit (cost) arising in period	-2.1	-6.1	-2.1	-6.1
Gains (losses) arising in period	-3	9.6	-8.3	9.6
Reclassification of prior service cost (credits) included in net income (loss)	-17.2	-19.1	-51.7	-57.3
Reclassification of losses (gains) included in net income (loss)	1	6.6	0.4	21
Other comprehensive income (loss), before tax	-22.6	-3.4	-74	-52
Income tax expense related to items of comprehensive income (loss)	0	0	0	0
Other comprehensive income (loss)	-22.6	-3.4	-74	-52
Comprehensive income (loss)	-13.7	-19.1	-137.8	-86.4
Less: Comprehensive income attributable to noncontrolling interests	16.1	16	46.6	47.6
Comprehensive income (loss) attributable to AK Steel Holding Corporation	($29.80)	($35.10)	($184.40)	($134)

CONDENSED_CONSOLIDATED_BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (unaudited) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$60.80	$45.30
Accounts receivable, net	707.6	525.2
Inventory, net	1,126	586.6
Deferred tax assets, current	74.7	69.6
Other current assets	76.3	46.5
Total current assets	2,045.40	1,273.20
Property, plant and equipment	6,335.90	5,871.90
Accumulated depreciation	-4,120.80	-3,991.80
Property, plant and equipment, net	2,215.10	1,880.10
Other non-current assets:	'	'
Investments in affilates	396.5	209.8
Other non-current assets	228.4	242.6
TOTAL ASSETS	4,885.40	3,605.70
Current liabilities:	'	'
Accounts payable	812.3	601.8
Accrued liabilities	281.7	142.9
Current portion of long-term debt	0.2	0.8
Current portion of pension and other postretirement benefit obligations	62.2	85.9
Total current liabilities	1,156.40	831.4
Non-current liabilities:	'	'
Long-term debt	2,406.40	1,506.20
Pension and other postretirement benefit obligations	832.4	965.4
Other non-current liabilities	124.4	110
TOTAL LIABILITIES	4,519.60	3,413
Exchangeable notes exchange feature	31	0
Equity:	'	'
Common stock, authorized 300,000,000 shares of $0.01 par value each; issued 177,216,956 and 149,691,388 shares in 2014 and 2013; outstanding 177,073,715 and 136,380,078 shares in 2014 and 2013	1.8	1.5
Additional paid-in capital	2,226.40	2,079.20
Treasury stock, common shares at cost, 143,241 and 13,311,310 shares in 2014 and 2013	-1	-174
Accumulated deficit	-2,561.50	-2,451.10
Accumulated other comprehensive income	249.4	323.4
Total stockholders' equity (deficit)	-84.9	-221
Noncontrolling interests	419.7	413.7
TOTAL EQUITY	334.8	192.7
TOTAL LIABILITIES AND EQUITY	4,885.40	3,605.70
Variable Interest Entity, Primary Beneficiary [Member] | SunCoke Middletown [Member]	'	'
Current assets:	'	'
Cash and cash equivalents	16.3	14.2
Inventory, net	30.6	22.1
Property, plant and equipment	419.5	418.5
Accumulated depreciation	-39.7	-29
Other assets (liabilities), net	-1	-0.7
Current liabilities:	'	'
Accounts payable	8.6	13.3
Equity:	'	'
Noncontrolling interests	417.9	411.8
Variable Interest Entity, Primary Beneficiary [Member] | Other Variable Interest Entities [Member]	'	'
Current assets:	'	'
Cash and cash equivalents	0.8	1
Property, plant and equipment	11.4	11.5
Accumulated depreciation	-9.2	-9.2
Other assets (liabilities), net	0.6	0.6
Equity:	'	'
Noncontrolling interests	$1.80	$1.90

CONDENSED_CONSOLIDATED_BALANCE1

CONDENSED CONSOLIDATED BALANCE SHEETS (unaudited) Parentheticals (USD $)	Sep. 30, 2014	Dec. 31, 2013
Common Stock, Shares Authorized	300,000,000	'
Common Stock, Par Value Per Share	$0.01	$0.01
Common Stock, Shares, Issued	177,216,956	149,691,388
Common Stock, Shares, Outstanding	177,073,715	136,380,078
Treasury Stock, Shares	143,241	13,311,310

CONDENSED_CONSOLIDATED_STATEME2

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (unaudited) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Cash flows from operating activities:	'	'
Net income (loss)	($63.80)	($34.40)
Depreciation	146.3	144.9
Amortization	15.9	15.1
Deferred income taxes	6.3	11
Pension and OPEB expense (income)	-74.2	-49.3
Contributions to pension trust	-196.5	-140.2
Other postretirement benefit payments	-48.8	-47.2
Other operating items, net	-14.1	-0.1
Net cash flows from operating activities	-380.6	-223.7
Cash flows from investing activities:	'	'
Capital investments	-39.3	-48.1
Investments in Magnetation joint venture	-90	-50
Investment in acquired business, net of cash acquired	-677.2	0
Other investing items, net	15.4	15.1
Net cash flows from investing activities	-791.1	-83
Cash flows from financing activities:	'	'
Net borrowings under credit facility	470	185
Proceeds from issuance of long-term debt	427.1	31.9
Redemption of long-term debt	-0.6	-27.2
Proceeds from issuance of common stock	345.3	0
Debt issuance costs	-10.6	-3.1
SunCoke Middletown distributions to noncontrolling interest owners	-40.6	-41.1
Other financing items, net	-3.4	-0.1
Net cash flows from financing activities	1,187.20	145.4
Net increase (decrease) in cash and cash equivalents	15.5	-161.3
Cash and cash equivalents, beginning of period	45.3	227
Cash and cash equivalents, end of period	60.8	65.7
Consolidated Entity Excluding Variable Interest Entities (VIE) [Member]	'	'
Cash flows from operating activities:	'	'
Depreciation	135.6	134.4
Changes in working capital	-134.9	-91.7
Cash flows from investing activities:	'	'
Capital investments	-38.2	-45.3
Variable Interest Entity, Primary Beneficiary [Member] | SunCoke Middletown [Member]	'	'
Cash flows from operating activities:	'	'
Depreciation	10.7	10.5
Changes in working capital	-13.7	-1
Net cash flows from operating activities	43.8	57.3
Cash flows from investing activities:	'	'
Capital investments	-1.1	-2.8
Cash flows from financing activities:	'	'
SunCoke Middletown distributions to noncontrolling interest owners	-40.6	-41.1
Cash and cash equivalents, beginning of period	14.2	'
Cash and cash equivalents, end of period	16.3	'
Butler and Zanesville Works Retiree Healthcare Benefits Litigation [Member]	'	'
Cash flows from operating activities:	'	'
Contributions to retirees VEBAs	($3.10)	($30.80)

CONDENSED_CONSOLIDATED_STATEME3

CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (DEFICIT) (unaudited) (USD $)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interests [Member]
In Millions
Balance at Dec. 31, 2012	($91)	$1.50	$2,069.70	($173.30)	($2,404.30)	$1.10	$414.30
Net income (loss)	-34.4	'	'	'	-82	'	47.6
Share-based compensation	7.4	'	7.4	'	'	'	'
Purchase of treasury stock	-0.7	'	'	-0.7	'	'	'
Change in accumulated other comprehensive income (loss)	-52	'	'	'	'	-52	'
Net distributions to noncontrolling interests	-41.1	'	'	'	'	'	-41.1
Balance at Sep. 30, 2013	-211.8	1.5	2,077.10	-174	-2,486.30	-50.9	420.8
Balance at Dec. 31, 2013	192.7	1.5	2,079.20	-174	-2,451.10	323.4	413.7
Net income (loss)	-63.8	'	'	'	-110.4	'	46.6
Issuance of common stock	345.3	0.4	344.9	'	'	'	'
Retirement of treasury stock	0	-0.1	-173.9	174	'	'	'
Share-based compensation	7.2	'	7.2	'	'	'	'
Exchangeable notes exchange feature	-31	'	-31	'	'	'	'
Purchase of treasury stock	-1	'	'	-1	'	'	'
Change in accumulated other comprehensive income (loss)	-74	'	'	'	'	-74	'
Net distributions to noncontrolling interests	-40.6	'	'	'	'	'	-40.6
Balance at Sep. 30, 2014	$334.80	$1.80	$2,226.40	($1)	($2,561.50)	$249.40	$419.70

Basis_of_Presentation_Notes

Basis of Presentation (Notes)	9 Months Ended
	Sep. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Basis of Presentation	'
	Basis of Presentation
	In the opinion of the management of AK Steel Holding Corporation (“AK Holding”) and its wholly-owned subsidiary, AK Steel Corporation (“AK Steel”, and together with AK Holding, the “Company”), the accompanying condensed consolidated financial statements contain all adjustments, consisting of normal recurring adjustments, necessary to present fairly the financial position of the Company as of September 30, 2014, the results of its operations for the three and nine months ended September 30, 2014 and 2013, and its cash flows for the nine months ended September 30, 2014 and 2013. The results of operations for the three and nine months ended September 30, 2014 are not necessarily indicative of the results to be expected for the full year ending December 31, 2014. These condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements of the Company for the year ended December 31, 2013, included in the Company’s Form 10‑K for the year ended December 31, 2013, and the unaudited condensed consolidated financial statements included in any subsequent Quarterly Reports on Form 10-Q.

Acquisition_of_Dearborn_Notes

Acquisition of Dearborn (Notes)	9 Months Ended
	Sep. 30, 2014
Business Combinations [Abstract]	'
Business Combination Disclosure [Text Block]	'
	Acquisition of Dearborn
	On September 16, 2014, the Company acquired Severstal Dearborn, LLC (“Dearborn”) from Severstal Columbus Holdings, LLC (“Severstal”). The assets acquired from Severstal included the integrated steelmaking assets located in Dearborn, Michigan (“Dearborn Works”), the Mountain State Carbon, LLC (“Mountain State Carbon”) cokemaking facility located in Follansbee, West Virginia, and interests in joint ventures that process flat-rolled steel products. The Company acquired Dearborn to increase scale and enhance its ability to better serve customers, further its automotive strategy, strengthen its carbon steelmaking footprint and achieve additional operational flexibility. In addition, the Company acquired highly modernized and upgraded steelmaking equipment and facilities and the opportunity to earn significant cost-based synergies. Immediately after the acquisition, Dearborn was merged with and into AK Steel.
	The initial purchase price was $706.5 and was paid in cash, but that amount is subject to a customary working capital adjustment based on the final closing date net working capital. As of September 30, 2014, the Company has recorded a liability to Severstal of $14.5 for its current estimate of the final working capital adjustment, although this estimate is subject to revision. In conjunction with the acquisition, AK Steel issued $430.0 of 7.625% Senior Notes due October 2021 at a price of 99.325% of par to pay part of the purchase price and used a portion of the net proceeds from the issuance of 40.25 million shares of AK Holding common stock at a price of $9.00 per share to pay the balance of the purchase price. The Company used the additional proceeds from the issuance of AK Holding common stock to repay a portion of outstanding borrowings under its asset-backed revolving credit facility (“Credit Facility”) and for general corporate purposes. For the three and nine months ended September 30, 2014, the Company incurred acquisition costs of $6.3 and $7.3, respectively. Acquisition costs are primarily comprised of transaction fees and direct costs, including legal, finance, consulting and other professional fees. These costs are included in selling and administrative expenses in the Condensed Consolidated Statements of Operations. In addition, the Company incurred $12.6 of costs in the three and nine months ended September 30, 2014 for committed bridge financing that the Company arranged in connection with the acquisition of Dearborn, but which was unused because of the Company’s successful financing of the acquisition through the debt and common stock offerings discussed above. As a result, these costs were expensed in the third quarter and are included in other income (expense) in the Condensed Consolidated Statements of Operations. Subsequent to the acquisition, the Company incurred severance costs of $2.6 for certain employees of Dearborn, which are included in selling and administrative expenses in the Condensed Consolidated Statements of Operations for the three and nine months ended September 30, 2014, and an income tax charge of $2.1 related to changes in the value of deferred tax assets resulting from the acquisition.
	A summary of the preliminary purchase price allocation for the fair value of the assets acquired and the obligations assumed at the date of the acquisition is presented below. The purchase price allocation is preliminary and is subject to the completion of several items, including consideration of final valuations and the final determination of post-closing purchase price adjustments relating to working capital.
	Cash and cash equivalents	$	29.3
	Accounts receivable	152.2
	Inventory	362.2
	Other current assets	3.6
	Property, plant and equipment	446.3
	Investment in affiliates	97.5
	Total assets acquired	1,091.10
	Accounts payable	(204.3		)
	Accrued liabilities	(36.9		)
	Other postretirement benefit obligations	(121.8		)
	Other non-current liabilities	(7.1		)
	Total liabilities assumed	(370.1		)
	Preliminary purchase price (including estimate for working capital adjustment)	$	721
	The condensed consolidated financial statements reflect the effects of the acquisition and Dearborn’s financial results beginning September 16, 2014. The following table summarizes selected unaudited pro forma consolidated statements of operations data for the nine months ended September 30, 2014 and 2013 as if the acquisition had been completed at the beginning of each year.
			Nine Months Ended September 30,
			2014			2013
	Net sales		$	5,945.10		$	5,612.40
	Operating profit (loss)		(889.3		)	131.1
	This selected unaudited pro forma consolidated financial data is included only for the purpose of illustration and does not necessarily indicate what the operating results would have been if the acquisition had been completed on that date. Moreover, this information does not indicate what the Company’s future operating results will be. This information includes actual data in 2014 for the period subsequent to the date of the acquisition. The Condensed Consolidated Statement of Operations for the three and nine months ended September 30, 2014 include net sales and operating profit of $90.0 and $2.1, respectively, attributable to Dearborn since the acquisition. The estimated weighted-average life of Dearborn’s machinery and equipment is approximately 20 years. Pro forma operating profit (loss) for the nine months ended September 30, 2014, includes charges for fixed asset impairments of $1,005.1 recorded by Severstal prior to the acquisition.

Inventories_Notes

Inventories (Notes)	9 Months Ended
	Sep. 30, 2014
Inventory Disclosure [Abstract]	'
Inventories	'
	Inventories
		September 30,			December 31, 2013
		2014
	Finished and semi-finished	$	1,103.30		$	722.2
	Raw materials	403.5			260.9
	Total cost	1,506.80			983.1
	Adjustment to state inventories at LIFO value	(380.8		)	(396.5		)
	Inventory, net	$	1,126.00		$	586.6

Investments_in_Affiliates_Note

Investments in Affiliates (Notes)	9 Months Ended
	Sep. 30, 2014
Equity Method Investments and Joint Ventures [Abstract]	'
Investments in Affiliates	'
	Investments in Affiliates
	The Company has investments in several businesses accounted for using the equity method of accounting. The investees and equity ownership percentages are presented below:
			Equity Ownership %
	Combined Metals of Chicago, LLC		40	%
	Delaco Processing, LLC		49	%
	Double Eagle Steel Coating Company (a)		50	%
	Magnetation LLC		49.9	%
	Rockport Roll Shop LLC		50	%
	Spartan Steel Coating, LLC		48	%
	(a)	Double Eagle Steel Coating Company (“DESCO”) is a joint venture between United States Steel Corporation (“US Steel”) and AK Steel that was acquired as part of the Dearborn acquisition. On April 1, 2013, Dearborn sent to US Steel a notice of dissolution of the joint venture in accordance with the terms of the joint venture agreement. The notice provided that the joint venture would dissolve two years from the date of the notice. On September 16, 2014, the Company acquired Dearborn, which included Dearborn’s 50% interest in DESCO. Shortly prior to the Company’s acquisition of Dearborn, US Steel notified the Company that it believed it had a right under the joint venture agreement to purchase Dearborn’s interest in DESCO prior to it being sold to the Company. US Steel has taken the position that the Company now must sell to it the 50% ownership interest in DESCO formerly owned by Dearborn. The Company has notified US Steel that the Company rejects US Steel’s position, but the Company is willing to discuss a potential sale of its ownership interest in DESCO to US Steel in lieu of proceeding with the dissolution of the joint venture. US Steel and the Company are engaged in discussions to resolve this dispute.
	The Company’s share of income (loss) related to Magnetation LLC (“Magnetation”) was included in other income (expense) and totaled $(2.2) and $(3.4) for the three months ended September 30, 2014 and 2013, respectively, and $(6.0) and $(2.3) for the nine months ended September 30, 2014 and 2013, respectively. The Company did not record any income (loss) related to DESCO for the period. The Company’s share of income from the remaining investees are included in cost of products sold since they are part of the Company’s integrated operations and totaled $3.4 and $1.8 for the three months ended September 30, 2014 and 2013, respectively, and $8.5 and $5.9 for the nine months ended September 30, 2014 and 2013, respectively.
	Summarized financial statement data for all investees is presented below. The financial results for the acquired joint ventures are only included for the period since the acquisition.
			Three Months Ended September 30,				Nine Months Ended September 30,
			2014		2013		2014		2013
	Revenue		$	87.4	$	76.2	$	245.1	$	220.1
	Gross profit		25.3		26.4		73.3		77.9
	Net income		7.3		0.7		17.7		17.2
	Magnetation
	Magnetation utilizes advanced magnetic separation technology to recover iron ore from existing stockpiles of previously-mined material, such as tailings basins. Magnetation controls substantial volumes of these existing stockpiles, as well as other resources with significant amounts of iron content that could allow it to eventually recover iron ore from traditional mining operations. Traditional mining operations are not currently anticipated to be necessary for the foreseeable future, depending upon factors such as the recovery yield of Magnetation’s concentrate plants and future acquisitions of additional tailings basins and other iron-bearing resources. Through a pellet purchase agreement, AK Steel will have the right to purchase all of the pellets produced by Magnetation’s iron ore pelletizing plant, which began producing iron ore pellets in September 2014.
	AK Steel committed to an investment of capital in Magnetation totaling $297.5. AK Steel contributed $90.0 in the nine months ended September 30, 2014, and made an additional contribution of $10.0 in October 2014 following the startup of Magnetation’s pellet plant, which completes the Company’s required capital contributions. AK Steel has no legal or contractual obligation to provide further financing to Magnetation. As of September 30, 2014, the Company’s carrying cost of the investment exceeded its share of the underlying equity in net assets of Magnetation, recorded using historical carrying amounts, by $116.2. This difference is being amortized through equity in earnings and its amortization is included in the Company’s share of income (loss) amounts above.

Income_Taxes_Notes

Income Taxes (Notes)	9 Months Ended
	Sep. 30, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	Income taxes recorded through September 30, 2014 and 2013 were estimated using the discrete method. Current year income taxes are based on the actual year-to-date pre-tax loss through September 30, 2014, as well as the related change in the valuation allowance on deferred tax assets. The Company is unable to estimate pre-tax income for the remainder of 2014 with sufficient precision for purposes of the effective tax rate method, which requires consideration of a projection of full-year income and the expected change in the valuation allowance. The estimated annual effective tax rate method was not reliable due to its sensitivity to small changes to forecasted annual pre-tax earnings and the effect of the Company’s valuation allowance, which create results with significant variations in the customary relationship between income tax expense and pre-tax income for the interim periods. As a result, the Company determined that the use of the discrete method is more appropriate than the annual effective tax rate method. The Company has estimated the change in valuation allowances required based on the year-to-date pre-tax loss and the change in value of the identified tax-planning strategy, which is determined based on year-to-date LIFO income. Income tax expense for the three and nine months ended September 30, 2014 includes non-cash charges of $6.4 and $45.5, respectively, for the change in the valuation allowance on the Company’s deferred tax assets, which offsets the income tax benefit related to the Company’s pre-tax loss. Income tax expense for the three and nine months ended September 30, 2013 includes non-cash charges of $15.3 and $37.1, respectively. The Company incurred an income tax charge of $2.1 for the three and nine months ended September 30, 2014, related to changes in the value of deferred tax assets resulting from the Dearborn acquisition.

Longterm_Debt_and_Other_Financ

Long-term Debt and Other Financing (Notes)	9 Months Ended
	Sep. 30, 2014
Debt Disclosure [Abstract]	'
Long-term Debt and Other Financing	'
	Long-term Debt and Other Financing
	The Company’s debt balances, including current portions, were as follows:
		September 30,			December 31, 2013
		2014
	Credit Facility	$	560		$	90
	8.75% Senior Secured Notes due December 2018	380			380
	5.00% Exchangeable Senior Notes due November 2019 (effective rate of 10.8%)	150			150
	7.625% Senior Notes due May 2020	529.8			529.8
	7.625% Senior Notes due October 2021	430			—
	8.375% Senior Notes due April 2022	290.2			290.2
	Industrial Revenue Bonds due 2014 through 2030	99.5			100.1
	Unamortized debt (discount) premium, net	(32.9		)	(33.1		)
	Total debt	2,406.60			1,507.00
	Less:
	Current portion of long-term debt	0.2			0.8
	Total long-term debt	$	2,406.40		$	1,506.20
	During the nine months ended September 30, 2014, the Company was in compliance with all the terms and conditions of its debt agreements.
	Senior Notes due October 2021
	In September 2014, AK Steel issued $430.0 of 7.625% Senior Notes due October 2021 (the “2021 Notes”) at a price of 99.325% of par, generating net proceeds of $418.6 after underwriting discounts and other fees. The Company used the net proceeds from the issuance of the 2021 Notes, plus a portion of the net proceeds from a concurrent public offering of AK Holding common stock, for the purchase price of Dearborn. AK Holding, in addition to AK Tube LLC (“AK Tube”) and AK Steel Properties, Inc. (“AK Properties”), two 100%-owned subsidiaries of AK Steel, each fully and unconditionally, jointly and severally, guarantee the payment of interest, principal and premium, if any, on the 2021 Notes. The 2021 Notes were issued under a supplemental indenture, which includes covenants and restrictions substantially similar to the existing indentures governing the 7.625% Senior Notes due 2020 and the 8.375% Senior Notes due 2022 and are equal in right of payment to those notes. Prior to October 1, 2017, AK Steel may redeem the 2021 Notes at a price equal to par plus a make-whole premium and all accrued and unpaid interest to the date of redemption. Subsequent to that date, they are redeemable at 103.813% until October 1, 2018, 101.906% thereafter until October 1, 2019 and 100.0% thereafter, together with all accrued and unpaid interest to the date of redemption.
	Credit Facility
	Upon the acquisition of Dearborn on September 16, 2014, the Company amended its Credit Facility that it entered into in March 2014 with a group of lenders. The amendment to the Credit Facility, among other things, increases the aggregate principal amount of commitments under the Credit Facility to $1.5 billion in order to provide additional liquidity, increases availability thresholds, and amends certain covenants to increase the operational and strategic flexibility of AK Steel and its subsidiaries. In addition, the amended Credit Facility requires the maintenance of a minimum fixed charge coverage ratio of one to one if availability under the Credit Facility is less than $150.0. The Credit Facility, which expires in March 2019, replaced AK Steel’s prior $1.1 billion asset-backed revolving credit facility (“Replaced Credit Facility”), and is secured by the same classes of assets as the Replaced Credit Facility. The Credit Facility contains common restrictions similar to the Replaced Credit Facility, including limitations on, among other things, distributions and dividends, acquisitions and investments, indebtedness, liens and affiliate transactions. Availability is calculated as the lesser of the Credit Facility commitment or the Company’s eligible collateral after advance rates, less in either case outstanding revolver borrowings and letters of credit. The Company’s obligations under its Credit Facility are secured by its inventory and accounts receivable, and availability under the Credit Facility fluctuates monthly based on the varying levels of eligible collateral. The Credit Facility provides the Company with enhanced liquidity and greater financial and strategic flexibility. The Credit Facility includes a separate “first-in, last-out”, or “FILO” tranche, which allows the Company to maximize its eligible collateral at higher advance rates. In April 2014, in order to provide additional collateral to the borrowing base and increase the Company’s availability under the Credit Facility, thereby enhancing its liquidity, the Company added AK Tube and AK Properties as guarantors under the Credit Facility. AK Steel’s parent company, AK Holding, also guarantees the Credit Facility. Immediately after the acquisition, Dearborn was merged with and into AK Steel and thus the eligible assets of Dearborn Works are included in the eligible collateral under the Credit Facility.
	At September 30, 2014, the Company’s eligible collateral, after application of applicable advance rates, was $1.5 billion. As of September 30, 2014, there were outstanding Credit Facility borrowings of $560.0. Availability as of September 30, 2014 was further reduced by $71.4 of outstanding letters of credit, resulting in remaining availability of $868.6.
	Exchangeable Notes
	AK Steel has $150.0 of outstanding 5.00% Senior Exchangeable Notes due November 2019 (the “Exchangeable Notes”). Among other things, the indenture governing the Exchangeable Notes provides noteholders with an exchange right at the option of the noteholders, in the event that the closing price of the Company’s common stock is greater than or equal to $7.02 per share (130% of the exchange price of the Exchangeable Notes) for at least 20 trading days during the last 30 consecutive trading days of a calendar quarter. As of October 1, 2014, this exchange right was triggered for the quarter ended September 30, 2014, and will remain available until December 31, 2014. Thereafter, the triggering condition will be reassessed at the beginning of each quarter while any Exchangeable Notes remain outstanding. The Company would be required to pay noteholders cash for the principal amount of the Exchangeable Notes and to pay cash or issue AK Holding common stock (at AK Steel’s option) for the premium if they elect to exchange their Exchangeable Notes during the fourth quarter of 2014. As a result, a portion of the equity component of the Exchangeable Notes, calculated as the difference between the principal amount of the Exchangeable Notes and the carrying amount of the liability component of the Exchangeable Notes, was considered redeemable and classified as temporary equity of $31.0 on the Condensed Consolidated Balance Sheets at September 30, 2014. In the event that holders of Exchangeable Notes elect to exchange, the Company expects to fund any cash settlement from cash or borrowings under its Credit Facility or both. There have been no exchanges as of the date of this filing.

Pension_and_Other_Postretireme

Pension and Other Postretirement Benefits (Notes)	9 Months Ended
	Sep. 30, 2014
General Discussion of Pension and Other Postretirement Benefits [Abstract]	'
Pension and Other Postretirement Benefits	'
	Pension and Other Postretirement Benefits
	The Company provides noncontributory pension and various healthcare and life insurance benefits to most employees and retirees. The pension plan is not fully funded. The Company has contributed $196.5 to the master pension trust during 2014 and does not expect to make any additional contributions during 2014.
	Net periodic benefit cost (income) for pension and other postretirement benefits were as follows:
		Three Months Ended September 30,						Nine Months Ended September 30,
		2014			2013			2014			2013
	Pension Benefits
	Service cost	$	0.5		$	0.7		$	1.2		$	1.9
	Interest cost	36.6			34.7			109.6			104.1
	Expected return on assets	(50.7		)	(46.2		)	(152.1		)	(138.3		)
	Amortization of prior service cost	1.1			0.9			3.2			2.7
	Amortization of (gain) loss	1.1			6.7			1.2			20
	Settlement (gain) loss	0.2			(0.8		)	0.2			(0.8		)
	Net periodic benefit cost (income)	$	(11.2	)	$	(4.0	)	$	(36.7	)	$	(10.4	)
	Other Postretirement Benefits
	Service cost	$	1.1		$	1.1		$	3.1		$	3.5
	Interest cost	5.2			5.3			15.3			15.8
	Amortization of prior service cost (credit)	(18.3		)	(20.0		)	(54.9		)	(60.0		)
	Amortization of (gain) loss	(0.3		)	0.7			(1.0		)	1.8
	Net periodic benefit cost (income)	$	(12.3	)	$	(12.9	)	$	(37.5	)	$	(38.9	)
	The Company assumed Dearborn’s other postretirement benefits as of the acquisition on September 16, 2014, and recorded an initial liability of $121.8. The discount rate used for this measurement was 4.45%. Net periodic benefit cost (income) for the Dearborn plan is estimated to be $2.4 for the remainder of 2014 after the acquisition date.
	During the first and third quarters of 2014, the Company performed remeasurements of an unfunded supplemental retirement plan as a result of lump sum benefit payments made to retired participants.

Environmental_and_Legal_Contin

Environmental and Legal Contingencies (Notes)	9 Months Ended
	Sep. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Environmental and Legal Contingencies	'
	Environmental and Legal Contingencies
	Environmental Contingencies
	AK Steel and its predecessors have been conducting steel manufacturing and related operations since 1900. Although the Company believes its operating practices have been consistent with prevailing industry standards during this time, hazardous materials may have been released in the past at one or more operating sites or third-party sites, including operating sites that the Company no longer owns. To the extent reasonably estimable, the Company has estimated potential remediation expenditures for those sites where future remediation efforts are probable based on identified conditions, regulatory requirements or contractual obligations arising from the sale of a business or facility. In the case of sites involving governmentally-required investigations, an estimate of potential remediation expenditures is typically made only after the investigation is complete and the nature and scope of the remediation is better understood. In general, the material components of these accruals include the costs associated with investigations, delineations, risk assessments, remedial work, governmental response and oversight costs, site monitoring, and preparation of reports to the appropriate environmental agencies. Liabilities recorded on the Company’s Condensed Consolidated Balance Sheets for such estimated probable costs relating to environmental matters are presented below:
		September 30,		December 31, 2013
		2014
	Accrued liabilities	$	16.3	$	9.5
	Other non-current liabilities	34.3		34.1
	The ultimate costs to the Company with respect to each site cannot be predicted with certainty because of the evolving nature of the investigation and remediation process. Rather, to develop the estimates of the probable costs, the Company must make certain assumptions. The most significant of these assumptions relate to the nature and scope of the work that will be necessary to investigate and remediate a particular site and the cost of that work. Other significant assumptions include the cleanup technology that will be used, whether and to what extent any other parties will participate in paying the investigation and remediation costs, reimbursement of past response and future oversight costs by governmental agencies, and the reaction of the governing environmental agencies to the proposed work plans. Costs of future expenditures are not discounted to their present value. To the extent that the Company has been able to reasonably estimate its future liabilities, the Company does not believe that there is a reasonable possibility that a loss or losses exceeding the amounts accrued will be incurred in connection with the environmental matters discussed below that would, either individually or in the aggregate, have a material adverse effect on the Company’s consolidated financial condition, results of operations or cash flows. However, since amounts recognized in the consolidated financial statements in accordance with accounting principles generally accepted in the United States exclude potential losses that are not probable or that may not be currently estimable, the ultimate costs of these environmental proceedings may be higher than those currently recorded in the Company’s consolidated financial statements.
	Except as expressly noted below, the Company does not currently anticipate any material effect on the Company’s consolidated financial position, results of operations or cash flows as a result of its compliance with current environmental regulations. Moreover, because all domestic steel producers operate under the same set of federal environmental regulations, the Company does not believe that it is disadvantaged relative to its domestic competitors by the need to comply with these regulations. Some foreign competitors may benefit from less stringent environmental requirements in the countries in which they produce, resulting in lower compliance costs and providing those foreign competitors with a cost advantage on their products.
	Pursuant to the Resource Conservation and Recovery Act (“RCRA”), which governs the treatment, handling and disposal of hazardous waste, the United States Environmental Protection Agency (“EPA”) and authorized state environmental agencies may conduct inspections of RCRA-regulated facilities to identify areas where there have been releases of hazardous waste or hazardous constituents into the environment and may order the facilities to take corrective action to remediate such releases. AK Steel’s major steelmaking facilities are subject to RCRA inspections by environmental regulators. While the Company cannot predict the future actions of these regulators, it is possible that they may identify conditions in future inspections of these facilities which they believe require corrective action.
	Under authority conferred by the Comprehensive Environmental Response, Compensation and Liability Act (“CERCLA”), the EPA and state environmental authorities have conducted site investigations at certain of AK Steel’s facilities and other third-party facilities, portions of which previously may have been used for disposal of materials that are currently subject to regulation. The results of these investigations are still pending, and AK Steel could be directed to expend funds for remedial activities at the former disposal areas. Because of the uncertain status of these investigations, however, the Company cannot reliably predict whether or when such expenditures might be required, their magnitude or the timeframe during which these potential costs would be incurred.
	As previously reported, on July 27, 2001, AK Steel received a Special Notice Letter from the EPA requesting that AK Steel agree to conduct a Remedial Investigation/Feasibility Study (“RI/FS”) and enter into an administrative order on consent pursuant to Section 122 of CERCLA regarding the former Hamilton Plant located in New Miami, Ohio. The Hamilton Plant ceased operations in 1990, and all of its former structures have been demolished and removed. Although AK Steel did not believe that a site-wide RI/FS was necessary or appropriate, in April 2002 it entered into a mutually agreed-upon administrative order on consent to perform such an investigation and study of the Hamilton Plant site. The site-wide investigation portion of the RI/FS has been submitted. A supplemental study is projected to be completed in 2014. AK Steel currently has accrued $0.7 for the remaining cost of the RI/FS. Until the RI/FS is completed, AK Steel cannot reliably estimate the additional costs, if any, associated with any potentially required remediation of the site or the timeframe during which these potential costs would be incurred.
	As previously reported, on September 30, 1998, AK Steel’s predecessor, Armco Inc., received an order from the EPA under Section 3013 of RCRA requiring it to develop a plan for investigation of eight areas of Mansfield Works that allegedly could be sources of contamination. A site investigation began in November 2000 and is continuing. AK Steel cannot reliably estimate at this time how long it will take to complete this site investigation. AK Steel currently has accrued approximately $1.1 for the projected cost of the study at Mansfield Works. Until the site investigation is completed, AK Steel cannot reliably estimate the additional costs, if any, associated with any potentially required remediation of the site or the timeframe during which these potential costs would be incurred.
	As previously noted, on September 26, 2012, the EPA issued an order under Section 3013 of RCRA requiring the Company to develop a plan for investigation of four areas at AK Steel’s Ashland Works Coke Plant. A site investigation plan was submitted to the EPA on October 25, 2012, revised most recently on May 29, 2014 and approved by the EPA on June 27, 2014. AK Steel cannot reliably estimate at this time how long it will take to complete the site investigation. AK Steel currently has accrued approximately $0.5 for the projected cost of the investigation. Until the site investigation is completed, AK Steel cannot reliably estimate the additional costs, if any, associated with any potentially required remediation of the site or the timeframe during which these potential costs would be incurred.
	As previously reported, on August 3, 2011, September 29, 2011, and June 28, 2012, the EPA issued Notice of Violations (“NOV”) with respect to the coke plant at AK Steel’s Middletown Works alleging violations of pushing and combustion stack limits. The Company is investigating these claims and is working with the EPA to attempt to resolve them. AK Steel believes it will reach a settlement in this matter, but it cannot be certain that a settlement will be reached and cannot reliably estimate at this time how long it will take to reach a settlement or what all of its terms might be. AK Steel will vigorously contest any claims which cannot be resolved through a settlement. Until it has reached a settlement with the EPA or the claims that are the subject of the NOVs are otherwise resolved, AK Steel cannot reliably estimate the costs, if any, associated with any potentially required operational changes at the battery or the timeframe over which any potential costs would be incurred.
	As previously reported, on July 15, 2009, AK Steel and the Pennsylvania Department of Environmental Protection (“PADEP”) entered into a Consent Order and Agreement (the “Consent Order”) to resolve an alleged unpermitted discharge of wastewater from the closed Hillside Landfill at the former Ambridge Works. Under the terms of the Consent Order, AK Steel paid a penalty and also agreed to implement various corrective actions, including an investigation of the area where activities were conducted regarding the landfill, submission of a plan to collect and treat surface waters and seep discharges, and upon approval from PADEP, implementation of that plan. The Company has accrued approximately $2.2 for the current phase of remedial work required under the Consent Order. However, the design plan for this phase has not yet been developed or approved. Until that design plan is approved, the Company cannot reliably determine the actual cost of this phase, but it is expected to be at least the amount of the current accrual. The Company currently estimates that the remaining work required for this phase will be completed in 2016, but that estimated timeframe is subject to the potential for delays, such as delays due to work plan approval and/or permitting delays. Additional work in the form of monitoring likely will be required after completion of the current phase, but the Company cannot reliably determine the cost of that work or the timeframe for its completion until the design phase has been approved.
	As previously reported, on June 29, 2000, the United States filed a complaint on behalf of the EPA against AK Steel in the U.S. District Court for the Southern District of Ohio, Case No. C-1-00530, for alleged violations of the Clean Air Act, the Clean Water Act and RCRA at the Middletown Works. Subsequently, the State of Ohio, the Sierra Club and the National Resources Defense Council intervened. On May 15, 2006, a Consent Decree in Partial Resolution of Pending Claims (the “Consent Decree”) was entered by the court. Under the Consent Decree, the Company paid a civil penalty and performed a supplemental environmental project to remove ozone-depleting refrigerants from certain equipment. The Company further agreed to undertake a comprehensive RCRA facility investigation at its Middletown Works and, as appropriate, complete a corrective measures study. In accordance with the Consent Decree, the Company also was required to implement certain RCRA corrective action interim measures to address polychlorinated biphenyls (“PCBs”) in sediments and soils relating to Dicks Creek and certain other specified surface waters, adjacent floodplain areas and other previously identified geographic areas. The Company has completed the remedial activity at Dicks Creek, but continues to work on the RCRA facility investigation and certain interim measures. The Company currently has accrued approximately $13.8 for the cost of known work required under the Consent Decree for the RCRA facility investigation and remaining interim measures.
	As previously reported, on October 17, 2012, the EPA issued an NOV and Notice of Intent to File a Civil Administrative Complaint to AK Steel’s Mansfield Works alleging violations of RCRA primarily relating to the Company’s management of electric arc furnace dust at the facility. The Company is investigating these claims and is working with the EPA to attempt to resolve them. The NOV proposed a civil penalty of approximately $0.3. AK Steel believes it will reach a settlement in this matter, but it cannot be certain that a settlement will be reached and cannot reliably estimate at this time how long it will take to reach a settlement or what all of its terms might be. AK Steel will vigorously contest any claims which cannot be resolved through a settlement.
	The following new matters have been added to AK Steel’s prior environmental contingency disclosures as a result of the recent acquisition by AK Steel of Dearborn.
	On May 12, 2014, the Michigan Department of Environmental Quality (“MDEQ”) issued to Dearborn Works an Air Permit to Install No. 182-05C (the “PTI”) to increase the emission limits for the blast furnace and other emission sources. The PTI was issued as a correction to a prior permit to install based on information that was not available during the prior permitting process. On July 10, 2014, the South Dearborn Environmental Improvement Association (“SDEIA”), Detroiters Working for Environmental Justice, Original United Citizens of Southwest Detroit and Sierra Club filed a Claim of Appeal of the PTI in the State of Michigan Wayne County Circuit, Case No. 14-008887-AA. Appellants and the MDEQ stipulated to the intervention of Severstal in this action as an additional appellee. The appellants allege multiple deficiencies with the permit and the permitting process. On October 9, 2014, the appellants filed a Motion for Peremptory Reversal of the MDEQ’s decision to issue the PTI. The hearing on appellants’ motion is scheduled for December 12, 2014. AK Steel believes that the MDEQ issued this permit properly in compliance with applicable law and will vigorously contest this appeal. On October 17, 2014, AK Steel filed a motion to dismiss the appeal of SDEIA. The hearing on AK Steel’s motion is scheduled for November 21, 2014. Until the appeal is resolved, AK Steel cannot determine what the ultimate permit limits will be. Until the permit limits are determined and final, AK Steel cannot reliably estimate the costs, if any, which it will incur in the event that the permit limits are changed as a result of the appeal. Nor can it determine if such costs will be material or the timeframe over which any potential costs would be incurred.
	On August 21, 2014, the SDEIA filed a Complaint under the Michigan Environmental Protection Act (“MEPA”) in the State of Michigan, Wayne County Circuit Case No. 14-010875-CE. The plaintiffs allege that the air emissions from the Dearborn Works are impacting the air, water and other natural resources, as well as the public trust in such resources. The plaintiffs are requesting, among other requested relief, that the court assess the limitations in the PTI to determine their sufficiency. On October 15, 2014, the court ordered a stay of the proceedings until a final order is issued in Wayne County Circuit Court Case No. 14-008887-AA (discussed above). Upon resumption, AK Steel will vigorously contest these claims. Until the claims that are the subject of this Complaint are resolved, AK Steel cannot reliably estimate the costs, if any, associated with the claims or the timeframe over which any potential costs would be incurred.
	Between 2008 and the end of 2013, MDEQ and the EPA issued multiple NOVs to Dearborn Works covering a wide range of alleged environmental violations, mostly regarding the Clean Air Act. The United States Department of Justice and MDEQ have proposed a settlement to AK Steel to resolve the alleged violations contained in the NOVs and the parties are currently negotiating the terms of a proposed Consent Decree to resolve this dispute. AK Steel believes it has the potential to reach a settlement in this matter, but it cannot be certain that a settlement will be reached or reliably estimate at this time how long it will take to reach a settlement or the terms of such a settlement. AK Steel will vigorously contest any claims which cannot be resolved through a settlement. AK Steel cannot reliably estimate at this time whether it will reach a settlement of this matter or, if a settlement is reached, how long it will take to reach that settlement, the costs or fines associated with the settlement, or what its other terms will be. Nor can AK Steel reliably estimate whether it will incur any costs or fines in the event a settlement is not reached, or the amount or timeframe relating to any such potential costs or fines.
	On April 9, 2014, SDEIA sent a Notice of Intent to Sue under the Clean Air Act to Dearborn with respect to Dearborn Works. On June 18, 2014, SDEIA filed a complaint under the citizen enforcement action provisions of the Clean Air Act against Dearborn in the United States District Court for the Eastern District of Michigan, Case No. 2:14-cv-12387-GER-PJK. The complaint alleges violations nearly identical to those alleged in the NOVs arising under the Clean Air Act that were issued to Dearborn Works by MDEQ and EPA between 2008 and 2013 and are the subject of ongoing settlement negotiations. On August 29, 2014, AK Steel moved to dismiss many of the counts in the complaint. On October 9, 2014, plaintiff filed an amended complaint which removed two of the counts in the original complaint. AK Steel filed an answer to plaintiff’s amended complaint on October 24, 2014. AK Steel refiled its motion for partial dismissal and that motion is still pending before the court. AK Steel will vigorously contest these claims. Until the claims that are the subject of the amended complaint are resolved, AK Steel cannot reliably estimate the costs, if any, associated with the claims or the timeframe over which any potential costs would be incurred.
	On April 27, 2000, MDEQ issued a RCRA Corrective Action Order No. 111-04-00-07E to Rouge Steel Company and Ford Motor Company for the property that includes the Dearborn Works. The Corrective Action Order has been amended five times. Dearborn became a party to the Corrective Action Order via an amendment dated January 24, 2004 as a result of becoming the successor-in-interest to Rouge Steel Company for certain matters. AK Steel is the successor to Dearborn by virtue of its recent acquisition of Dearborn. The Corrective Action Order requires the site-wide investigation and where appropriate, remediation, of the facility. The site investigation and remediation is ongoing. AK Steel cannot reliably estimate at this time how long it will take to complete this site investigation and remediation. To date, Ford Motor Company has incurred most of the costs of the investigation and remediation due to its prior ownership of the steelmaking operations at Dearborn Works. AK Steel has accrued approximately $0.4 for the projected cost of the continuing investigation. Until the site investigation is completed, AK Steel cannot reliably estimate the additional costs, if any, associated with any potentially required remediation of the site or the timeframe during which these potential costs would be incurred.
	On August 29, 2013, the West Virginia Department of Environmental Protection (“WVDEP”) issued to Mountain State Carbon a renewal National Pollution Discharge Elimination System (“NPDES”) permit for wastewater discharge from the facility to the Ohio River. The new NPDES permit included numerous new, and more stringent, effluent limitations. On October 7, 2013, Mountain State Carbon appealed the permit to the Environmental Quality Board, Appeal No. 13-25-EQB. AK Steel believes it has the potential to reach a settlement in this matter, but it cannot be certain that a settlement will be reached or reliably estimate at this time how long it will take to reach a settlement or the terms of such a settlement. AK Steel will vigorously contest any claims which cannot be resolved through a settlement. Until it has reached a settlement with WVDEP or the issues that are the subject of the appeal are otherwise resolved, AK Steel cannot determine what the ultimate permit limits will be. Until the permit limits are determined and final, AK Steel cannot reliably estimate the costs, if any, which it will incur in the event that the permit limits are changed as a result of the appeal. Nor can it determine if such costs will be material or the timeframe over which any potential costs would be incurred.
	On February 6, 2012, the United States and the WVDEP filed a Complaint under the Clean Air Act and RCRA against Mountain State Carbon in the United States District Court for the Northern District for West Virginia, Civil Action No. 5:12-CV-19. On March 6, 2012, WVDEP voluntarily dismissed its claims against Mountain State Carbon. The case proceeded to a bench trial in May 2014, during which the United States pursued three main claims alleging: (1) excess opacity at the combustion stack caused by deficient thru walls; (2) excess hydrogen sulfide emissions due to a deficient primary cooler; and (3) various RCRA violations. The government sought injunctive relief on each claim, and a civil penalty of $10.6. On July 17, 2014, the court issued its Findings of Facts, Conclusions of Law and Memorandum Order and dismissed most of the United States’ claims in their entirety. The court did, however, assess a civil penalty of approximately $2.4 and order three injunctive relief measures: (1) the assessment by both parties’ experts of the sufficiency of the cokemaking facility’s thru walls and the submission to the court of a report by October 15, 2014, following which the replacement of some thru walls could be required; (2) the requirement for Mountain State Carbon to install and utilize an automated system that tracks oven charging times at Battery 8 to identify ovens that cause opacity violations; and (3) the requirement for Mountain State Carbon to clean all spiral heat exchangers as soon as practicable and establish a regular cleaning schedule. On August 21, 2014, the court issued an Order in response to the Plaintiff’s Motion for Entry of Judgment, memorializing the judgment identified in the Findings of Fact, Conclusions of Law and Memorandum Order. On October 17, 2014, the United States appealed the judgment to the United States Court of Appeals for the Fourth Circuit. AK Steel will vigorously defend the judgment in such appeal.
	In addition to the foregoing matters, AK Steel is or may be involved in proceedings with various regulatory authorities that may require AK Steel to pay fines, comply with more rigorous standards or other requirements or incur capital and operating expenses for environmental compliance. The Company believes that the ultimate disposition of the proceedings will not have, individually or in the aggregate, a material adverse effect on its consolidated financial condition, results of operations or cash flows.
	Legal Contingencies
	As previously reported, since 1990, AK Steel (or its predecessor, Armco Inc.) has been named as a defendant in numerous lawsuits alleging personal injury as a result of exposure to asbestos. The great majority of these lawsuits have been filed on behalf of people who claim to have been exposed to asbestos while visiting the premises of a current or former AK Steel facility. The majority of asbestos cases pending in which AK Steel is a defendant do not include a specific dollar claim for damages. In the cases that do include specific dollar claims for damages, the complaint typically includes a monetary claim for compensatory damages and a separate monetary claim in an equal amount for punitive damages, and does not attempt to allocate the total monetary claim among the various defendants.
	Information on asbestos cases pending at September 30, 2014 is presented below:
			Asbestos Cases Pending at
			September 30, 2014
	Cases with specific dollar claims for damages:
	Claims up to $0.2		114
	Claims above $0.2 to $5.0		6
	Claims above $5.0 to $15.0		2
	Claims above $15.0 to $20.0		2
	Total claims with specific dollar claims for damages (a)		124
	Cases without a specific dollar claim for damages		314
	Total asbestos cases pending		438
	(a)	Involve a total of 2,332 plaintiffs and 16,631 defendants
	In each case, the amount described is per plaintiff against all of the defendants, collectively. Thus, it usually is not possible at the outset of a case to determine the specific dollar amount of a claim against AK Steel. In fact, it usually is not even possible at the outset to determine which of the plaintiffs actually will pursue a claim against AK Steel. Typically, that can only be determined through written interrogatories or other discovery after a case has been filed. Thus, in a case involving multiple plaintiffs and multiple defendants, AK Steel initially only accounts for the lawsuit as one claim against it. After AK Steel has determined through discovery whether a particular plaintiff will pursue a claim against it, it makes an appropriate adjustment to statistically account for that specific claim. It has been AK Steel’s experience to date that only a small percentage of asbestos plaintiffs ultimately identify AK Steel as a target defendant from whom they actually seek damages and most of these claims ultimately are either dismissed or settled for a small fraction of the damages initially claimed. Set forth below is a chart showing the number of new claims filed (accounted for as described above), the number of pending claims disposed of (i.e., settled or otherwise dismissed), and the approximate net amount of dollars paid on behalf of AK Steel in settlement of asbestos-related claims in the three and nine months ended September 30, 2014 and 2013.
		Three Months Ended September 30,				Nine Months Ended September 30,
		2014		2013		2014		2013
	New Claims Filed	16		10		40		34
	Pending Claims Disposed Of	10		5		38		30
	Total Amount Paid in Settlements	$	0.1	$	—	$	0.6	$	0.9
	Since the onset of asbestos claims against AK Steel in 1990, five asbestos claims against it have proceeded to trial in four separate cases. All five concluded with a verdict in favor of AK Steel. AK Steel intends to continue to vigorously defend the asbestos claims asserted against it. Based upon its present knowledge, and the factors set forth above, the Company believes it is unlikely that the resolution in the aggregate of the asbestos claims against AK Steel will have a materially adverse effect on the Company’s consolidated results of operations, cash flows or financial condition. However, predictions as to the outcome of pending litigation, particularly claims alleging asbestos exposure, are subject to substantial uncertainties. These uncertainties include (1) the significantly variable rate at which new claims may be filed, (2) the effect of bankruptcies of other companies currently or historically defending asbestos claims, (3) the uncertainties surrounding the litigation process from jurisdiction to jurisdiction and from case to case, (4) the type and severity of the disease alleged to be suffered by each claimant, and (5) the potential for enactment of legislation affecting asbestos litigation.
	As previously reported, in September and October 2008, several companies filed purported class actions in the United States District Court for the Northern District of Illinois against nine steel manufacturers, including AK Holding. The case numbers for these actions are 08CV5214, 08CV5371, 08CV5468, 08CV5633, 08CV5700, 08CV5942 and 08CV6197. An additional action, case number 10CV04236, was filed in the same federal district court on July 8, 2010. On December 28, 2010, another action, case number 32,321, was filed in state court in the Circuit Court for Cocke County, Tennessee. The defendants removed the Tennessee case to federal court and filed a motion to transfer the case to the Northern District of Illinois. That motion was granted on March 28, 2012. The plaintiffs in the various pending actions are companies which claim to have purchased steel products, directly or indirectly, from one or more of the defendants and they purport to file the actions on behalf of all persons and entities who purchased steel products for delivery or pickup in the United States from any of the named defendants at any time from at least as early as January 2005. The complaints allege that the defendant steel producers have conspired in violation of antitrust laws to restrict output and to fix, raise, stabilize and maintain artificially high prices with respect to steel products in the United States. Discovery has commenced but only with respect to issues relating to class certification. On May 24, 2012, the direct purchaser plaintiffs filed a motion for class certification. On February 28, 2013, the defendants filed a memorandum in opposition to the motion for class certification and motions to exclude the opinions of the plaintiffs’ experts. An evidentiary hearing on the motion for class certification and the motions to exclude the opinions of the plaintiffs’ experts was held commencing on March 15, 2014. No trial date has been set. Prior to that hearing, AK Holding reached an agreement with the direct purchaser plaintiffs to tentatively settle the claims asserted against AK Holding, subject to certain court approvals set forth below. Pursuant to that settlement, AK Holding agreed to pay $5.8 to the plaintiff class of direct purchasers in exchange for a complete release of all claims from the members of that class. AK Holding continues to believe that the claims asserted against it lack any merit, but it elected to enter into the settlement in order to avoid the ongoing expense of defending itself in this protracted and expensive antitrust litigation. The tentative settlement received preliminary approval by the court on April 11, 2014. Following such preliminary approval, notice of the proposed settlement was provided to members of the settlement class. After receipt of such notice, several class members elected to opt out of the class settlement. In order to become final, the settlement must receive a second approval by the court following a fairness hearing which occurred on October 17, 2014. On October 21, 2014, the Court entered an order and judgment approving the settlement and dismissing all of the direct plaintiffs’ claims against the Company with prejudice as to the settlement class. The Company recorded a charge during the first quarter of 2014 in the amount of the tentative settlement with the direct purchaser plaintiff class. At this stage, the Company does not have adequate information available to determine that a loss is probable or to reliably or accurately estimate its potential loss, if any, with respect to the remaining indirect purchaser plaintiff class members and any direct purchaser class members that have opted out of the class (hereinafter collectively referred to as the “Remaining Plaintiff Class Members.”). Because the Company has been unable to determine that a potential loss in this case with respect to the Remaining Plaintiff Class Members is probable or estimable, it has not recorded an accrual related to this matter for them. In the event that the Company’s assumptions used to evaluate whether a loss in this matter is either probable or estimable with respect to the Remaining Plaintiff Class Members prove to be incorrect or change in future periods, the Company may be required to record a charge for their claims at a later date.
	As previously reported, on January 20, 2010, ArcelorMittal France and ArcelorMittal Atlantique et Lorraine (collectively “ArcelorMittal”) filed an action in the United States District Court for the District of Delaware, Case No. 10-050-SLR against AK Steel, Dearborn, and Wheeling-Nisshan Inc., who is indemnified by Dearborn in this action. AK Steel is the successor to Dearborn by virtue of its recent acquisition of Dearborn. By virtue of its responsibility as a successor-in-interest to Dearborn and an indemnitor of Wheeling-Nisshan Inc, AK Steel now has complete responsibility for the defense of this action. The three named defendants thus are collectively referred to hereafter as “AK Steel,” though the precise claims against each separate defendant may vary. The complaint alleges that AK Steel is infringing the claims of U.S. Patent No. 6,296,805 (the “Patent”) in making pre-coated cold-rolled boron steel sheet and seeks injunctive relief and unspecified compensatory damages. AK Steel filed an answer in which it denied ArcelorMittal’s claims and raised various affirmative defenses. AK Steel also filed counterclaims against ArcelorMittal for a declaratory judgment that AK Steel is not infringing the Patent and that the Patent is invalid. Subsequently, the trial court bifurcated the issues of liability and damages. The case proceeded with a trial to a jury on the issue of liability during the week of January 15, 2011. The jury returned a verdict that AK Steel did not infringe the Patent and that the Patent was invalid. Judgment subsequently was entered in favor of AK Steel. ArcelorMittal filed an appeal with the United States Court of Appeals for the Federal Circuit. On November 30, 2012, the court of appeals issued a decision reversing certain findings related to claim construction and the validity of the Patent and remanded the case to the trial court for further proceedings. On January 30, 2013, ArcelorMittal filed a motion for rehearing with the court of appeals. On March 20, 2013, the court of appeals denied ArcelorMittal’s motion for rehearing. The case then was remanded to the trial court for further proceedings. On April 16, 2013, pursuant to a petition previously filed by ArcelorMittal and ArcelorMittal USA LLC, the U.S. Patent and Trademark Office reissued the Patent as U.S. Reissue Patent RE44,153 (the “Reissued Patent”). Also on April 16, 2013, ArcelorMittal filed a second action against the defendants in the United States District Court for the District of Delaware, Case Nos. 1:13-cv-00685 and 1:13-cv-00686 (collectively the “Second Action”). The complaint filed in the Second Action alleges that AK Steel is infringing the claims of the Reissued Patent and seeks injunctive relief and unspecified compensatory damages. On April 23, 2013, AK Steel filed a motion to dismiss key elements of the complaint filed in the Second Action. In addition, the parties briefed related non-infringement and claims construction issues in the original action. On October 25, 2013, the district court granted summary judgment in favor of AK Steel, confirming that AK Steel’s product does not infringe the original Patent or the Reissued Patent. The court further ruled that ArcelorMittal’s Reissued Patent was invalid due to ArcelarMittal’s deliberate violation of a statutory prohibition on broadening a patent through reissue more than two years after the original Patent was granted and that the original Patent had been surrendered when the Reissued Patent was issued and thus is no longer in effect. Final Judgment was entered on October 31, 2013. On November 6, 2013, ArcelorMittal filed a motion to clarify or, in the alternative, to alter or amend the October 31, 2013 judgment. The defendants opposed the motion. On December 5, 2013, the court issued a memorandum and order denying the motion and entering final judgment in favor of defendants, including AK Steel, and against ArcelorMittal, specifically ruling that all claims of ArcelorMittal’s Reissued Patent are invalid as violative of 35 U.S.C. §251(d). On December 30, 2013, ArcelorMittal filed notices of appeal to the Federal Circuit Court of Appeals. The appeal has been fully briefed and is set for hearing on November 4, 2014. AK Steel intends to continue to contest this matter vigorously. At this time, the Company has not made a determination that a loss is probable and it does not have adequate information to reliably or accurately estimate its potential loss in the event that ArcelorMittal were to prevail in its appeal in this dispute. Because the Company has been unable to determine that the potential loss in this case is probable or estimable, it has not recorded an accrual related to this matter. In the event that the Company’s assumptions used to evaluate whether a loss in this matter is either probable or estimable prove to be incorrect or change in future periods, the Company may be required to record a liability for an adverse outcome.
	Trade Cases
	As previously reported, on June 1, 2009, the Chinese Ministry of Commerce (“MOFCOM”) initiated antidumping and countervailing duty investigations of imports of grain-oriented electrical steel (“GOES”) from Russia and the United States. China initiated the investigations based on a petition filed by two Chinese steelmakers. These two steelmakers alleged that AK Steel and Allegheny Technologies Inc. of the United States and Novolipetsk Steel of Russia exported GOES to China at less than fair value, and that the production of GOES in the United States has been subsidized by the U.S. government. On December 9, 2009, MOFCOM issued its preliminary determination that GOES producers in the United States and Russia had been dumping in the China market and that GOES producers in the United States had received subsidies from the U.S. government. The Chinese authorities imposed provisional additional duties on future imports of GOES from Russia and/or the United States to China. On or about April 10, 2010, MOFCOM issued a final determination of dumping and subsidization against GOES producers in the United States and Russia. On September 16, 2010, the Office of the United States Trade Representative (“USTR”) filed a complaint with the World Trade Organization (the “WTO”) against China for violating the WTO’s rules by imposing antidumping and countervailing duties against imports of GOES from the United States. After conducting several rounds of hearings, on June 15, 2012, a panel (the “Panel”) composed by the WTO to decide the case issued its final decision in the case. In its decision, the Panel concluded that MOFCOM imposed antidumping and countervailing duties on imports of GOES from the United States in a manner that was inconsistent with China’s WTO obligations. On July 20, 2012, China filed an appeal of the Panel’s decision to the WTO Appellate Body. On October 18, 2012, the Appellate Body upheld the decisions of the Panel. On November 16, 2012, the WTO Dispute Settlement Body adopted the decisions of the Panel. Subsequently, a WTO Arbitrator determined that China should implement the WTO decision by July 31, 2013. In its final determination issued on July 31, 2013, MOFCOM reduced the countervailing duty rate applicable to AK Steel from 11.7 percent to 3.4 percent and determined that the antidumping duty rate applicable to AK Steel will remain at 7.8 percent, for a total of 11.2 percent. AK Steel does not believe that China has remedied the flaws that the WTO identified in MOFCOM’s material injury finding. In late February, 2014, at USTR’s request, the WTO Dispute Settlement Body announced its decision to form a compliance panel to investigate China's failure to implement the WTO’s recommendations and rulings. Proceedings before the compliance panel are underway. AK Steel also has urged USTR to ask that WTO Dispute Settlement Body for permission to impose trade sanctions. AK Steel intends to continue to fully support the USTR in this matter.
	On September 18, 2013, AK Steel, along with another domestic producer and the United Steelworkers (collectively, the “Petitioners”), filed trade cases against imports of GOES from seven countries. Antidumping (“AD”) petitions were filed against China, the Czech Republic, Germany, Japan, Poland, Russia and South Korea and a countervailing duty (“CVD”) petition was filed against China charging that unfairly traded imports of GOES from those seven countries are causing material injury to the domestic industry. The United States Department of Commerce (“DOC”) initiated the cases on October 24, 2013. On November 19, 2013, the International Trade Commission (“ITC”) made a preliminary determination that there is a reasonable indication that GOES imports caused or threaten to cause material injury. On March 5, 2014, the DOC preliminarily determined that GOES imports from China benefit from subsidies by the Government of China, resulting in a preliminary CVD rate of 49.15 percent of the value of the GOES imports. As a result of the preliminary affirmative CVD determination, importers are required to post cash deposits with U.S. Customs and Border Protection on imports of GOES from China based on the CVD preliminary rate. On May 5, 2014, the DOC issued preliminary determinations that imports of GOES from China, the Czech Republic, Germany, Japan, Poland, Russia and South Korea are being dumped in the United States. On July 17, 2014, the DOC issued final dumping determinations with respect to imports of GOES from Germany, Japan, and Poland, affirming the preliminary dumping margins for these three countries. As a result of the preliminary dumping determinations on China, the Czech Republic, Russia, and South Korea, and final dumping determinations on Germany, Japan and Poland, importers were required to post cash deposits with U.S. Customs and Border Protection on imports of GOES from these seven countries (in addition to any deposits required by the preliminary affirmative CVD determinations). The DOC also reached affirmative preliminary critical circumstances findings with respect to Poland and Russia. In separate decisions issued on August 27, 2014 and October 23, 2014, the ITC issued its final determination with respect to imports of GOES from China, the Czech Republic,Germany, Japan, Poland, Russia and South Korea. In each of these decisions, the ITC determined in a 5-1 vote that the United States steel industry is neither materially injured nor threatened with material injury by reason of those imports. These two ITC decisions nullify the DOC’s preliminary assessment of dumping duties on GOES imports from each of the countries against which the trade petition was filed, as well as a CVD determination with respect to China.  On September 16, 2014, the Petitioners filed an appeal of the ITC’s August 27, 2014 decision to the Court of International Trade. The petitioners have stated that they intend to file an appeal from the ITC’s October 23, 2014 decision. AK Steel expects a decision in those appeals in approximately one year.
	On September 30, 2013, AK Steel filed trade cases against imports of non-oriented electrical steel (“NOES”) from six countries. AD petitions were filed against China, Germany, Japan, South Korea, Sweden and Taiwan and CVD petitions were filed against China, South Korea and Taiwan charging that unfairly traded imports of NOES from those six countries are causing material injury to the domestic industry. The DOC initiated the cases on November 7, 2013. On December 3, 2013, the ITC made a preliminary determination that there is a reasonable indication that NOES imports caused or threaten to cause material injury. On March 19, 2014, the DOC issued preliminary determinations with respect to AK Steel’s CVD petitions against China, South Korea and Taiwan. The DOC preliminarily determined that NOES imports from China benefit from subsidies by the Government of China, resulting in a preliminary CVD rate of 125.83 percent of the value of the NOES imports. With respect to South Korea, the DOC calculated a de minimis preliminary CVD rate, resulting in a preliminary negative determination for South Korea. With respect to Taiwan, the DOC preliminarily determined that certain NOES imports from Taiwan benefit from subsidies by the Government of Taiwan, resulting in (a) a preliminary CVD rate of 12.82 percent for Leicong Industrial Company, Ltd., (b) a de minimis preliminary CVD rate for China Steel Corporation and certain of its affiliates, and (c) a preliminary CVD rate of 6.41 percent for all other producers in Taiwan. On May 16, 2014, the DOC issued preliminary determinations that imports of NOES from China, Germany, Japan, South Korea, Sweden and Taiwan are being dumped in the United States. As a result of the preliminary dumping determinations, importers were required to post cash deposits with U.S. Customs and Border Protection on imports of NOES from these six countries (in addition to any deposits required by the preliminary affirmative CVD determinations).
	On October 7, 2014, the DOC issued its final dumping determinations as to all six subject countries as follows:
	Country		NOES Dumping Margins
	China		407.52%
	Germany		86.29% — 98.84%
	Japan		135.59% — 204.79%
	South Korea		6.91%
	Sweden		98.46% — 126.72%
	Taiwan		28.14% — 52.23%
	In addition, the DOC issued a final CVD determination with respect to China at the rate of 158.88 percent. With respect to South Korea, the DOC affirmed its preliminary de minimis CVD determination. With respect to Taiwan, the DOC (a) affirmed its de minimis CVD determination with respect to China Steel Corporation and certain of its affiliates, (b) issued a final CVD determination with respect to Leicong Industrial Company, Ltd. at the rate of 17.12 percent, and (c) issued a final CVD determination with respect to all other Taiwanese producers at the rate of 8.80 percent. U.S. Customs and Border Protection will require that importers post cash deposits on imports of NOES from the subject countries at the above rates. A final injury determination for all six subject countries is expected from the ITC in November 2014.
The following new matters have been added to AK Steel’s prior legal contingency disclosures as a result of the recent acquisition by AK Steel of Dearborn.
On June 13, 2013, Cliffs Sales Company (“Cliffs”) filed an action in the United States District Court for the Northern District of Ohio, Civil Action No. 1:13 cv 1308, against Dearborn pertaining to Dearborn Works. Cliffs claims that Dearborn breached a May 21, 2008 Agreement for Sale of Reclaimed Iron Units, as amended (the “Iron Unit Agreement”). Cliffs claims that Dearborn breached the Iron Unit Agreement by failing to purchase the required amount of pellets, chips and fines as allegedly required. Dearborn filed an answer denying the material allegations of the complaint and asserting several affirmative defenses. In January of 2014, the presiding judge ordered a stay of the proceedings until Cliffs and Dearborn completed an arbitration of a separate dispute. That arbitration is now concluded and it is anticipated that the stay of the litigation will be lifted. Discovery is expected to re-commence in the near future. AK Steel, as successor-in-interest to Dearborn, intends to contest this matter vigorously. At this time, AK Steel has not made a determination that a loss is probable and it does not have adequate information to reliably or accurately estimate its potential loss in the event that Cliffs were to prevail in this lawsuit. Because AK Steel has been unable to determine that a loss is probable or estimable, it has not recorded an accrual related to this matter. In the event that AK Steel’s assumptions used to evaluate whether a loss in this matter is either probable or estimable prove to be incorrect or change in future periods, AK Steel may be required to record a liability for an adverse outcome.
On August 29, 2014, Dearborn served a private arbitration demand and asserted a breach of contract claim against PCI Enterprises Company (“PCI”) with respect to Dearborn Works. In its demand, Dearborn sought a declaration that it properly terminated a Pulverized Coal Supply Agreement with PCI (the “PCI Agreement”) and damages in the amount of $11.8. On the same date, PCI served a statement of claim against Dearborn alleging that it breached the PCI Agreement and seeking damages in an amount between $12.0 and $14.0. Discovery has commenced. AK Steel, as successor-in-interest to Dearborn, intends to vigorously defend against PCI’s counterclaim. At this time, AK Steel has not made a determination that a loss is probable and it does not have adequate information to reliably or accurately estimate its potential loss in the event that PCI were to prevail on its counterclaim. Because AK Steel has been unable to determine that a loss is probable or estimable, it has not recorded an accrual related to this matter. In the event that AK Steel’s assumptions used to evaluate whether a loss in this matter is either probable or estimable prove to be incorrect or change in future periods, AK Steel may be required to record a liability for an adverse outcome.
Other Contingencies
In addition to the matters discussed above, there are various pending and potential claims against AK Steel and its subsidiaries involving product liability, commercial, employee benefits and other matters arising in the ordinary course of business. Because of the considerable uncertainties which exist with respect to any claim, it is difficult to reliably or accurately estimate what would be the amount of a loss in the event that a claimant(s) were to prevail. In the event that material assumptions or factual understandings relied upon by the Company to evaluate its exposure with respect to these contingencies prove to be inaccurate or otherwise change in the future, the Company may be required to record a liability for an adverse outcome. To the extent, however, that the Company has been able to reasonably evaluate its potential future liabilities with respect to all of these contingencies, including those described more specifically above, it is the Company’s opinion, unless otherwise noted, that the ultimate liability resulting from these contingencies, individually and in the aggregate, should not have a material effect on the Company’s consolidated financial position, results of operations or cash flows.

Common_Stock_Notes

Common Stock (Notes)	9 Months Ended
	Sep. 30, 2014
Equity [Abstract]	'
Stockholders' Equity Note Disclosure	'
	Common Stock
	On September 16, 2014, AK Holding issued 40.25 million shares of common stock at $9.00 per share. Net proceeds were $345.3 after underwriting discounts and other fees. AK Holding used the net proceeds from the issuance of common stock to pay a portion of the purchase price for the acquisition of Dearborn, to repay borrowings under the Credit Facility and for general corporate purposes.
	At the 2014 Annual Meeting held on May 29, 2014, the stockholders of the Company approved an amendment to its Restated Certificate of Incorporation to increase the authorized shares of the Company’s common stock from 200 million to 300 million shares.
	In January 2014, the Board of Directors authorized the formal retirement of 13,311,310 shares of common stock held by AK Holding as treasury stock. The retirement had no effect on the number of shares authorized or outstanding or on total stockholders’ equity.

Sharebased_Compensation_Notes

Share-based Compensation (Notes)	9 Months Ended
	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Share-based Compensation	'
	Share-based Compensation
	AK Holding’s Stock Incentive Plan permits the granting of nonqualified stock option, restricted stock, performance share and restricted stock unit awards to Directors, officers and other employees of the Company. At the 2014 Annual Meeting held on May 29, 2014, the stockholders of the Company approved an amendment to the Stock Incentive Plan to increase the shares authorized for issuance under the plan by 4.0 million shares. The following table summarizes information about share-based compensation expense, which the Company has estimated will be $8.7 for 2014:
		Three Months Ended September 30,				Nine Months Ended September 30,
	Share-based Compensation Expense	2014		2013		2014		2013
	Stock options	$	0.2	$	0.1	$	1.5	$	1.2
	Restricted stock	0.4		0.3		2.7		2.5
	Restricted stock units issued to Directors	0.4		0.3		0.9		0.7
	Performance shares	0.6		1		2.1		3
	Total share-based compensation expense	$	1.6	$	1.7	$	7.2	$	7.4
	The Company granted stock options on 551,740 shares during the nine months ended September 30, 2014, at a weighted-average fair value of $3.50 per share of stock option. There have been 11,881 options exercised in 2014.
	The Company granted restricted stock awards of 487,290 shares during the nine months ended September 30, 2014, at a weighted-average fair value of $6.67 per share. The total intrinsic value of restricted stock awards that vested (i.e., restrictions lapsed) during the nine months ended September 30, 2014 was $2.8.
	The Company granted performance share awards of 512,400 shares during the nine months ended September 30, 2014, at a weighted-average fair value of $6.40 per share.

Comprehensive_Income_Loss_Note

Comprehensive Income (Loss) (Notes)	9 Months Ended
	Sep. 30, 2014
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]	'
Comprehensive Income (Loss)	'
	Comprehensive Income (Loss)
	The details of other comprehensive income (loss), net of tax, are as follows:
			Three Months Ended September 30,						Nine Months Ended September 30,
			2014			2013			2014			2013
	Foreign currency translation
	Balance at beginning of period		$	4.6		$	2.8		$	4.7		$	3.5
	Other comprehensive income (loss):
	Foreign currency translation gain (loss)		(2.5		)	1.2			(2.6		)	0.5
	Balance at end of period		$	2.1		$	4		$	2.1		$	4
	Cash flow hedges
	Balance at beginning of period		$	7.4		$	7.4		$	18.3		$	31.7
	Other comprehensive income (loss):
	Gains (losses) arising in period		(2.7		)	10.3			(9.6		)	0.6
	Income tax expense		—			—			—			—
	Gains (losses) arising in period, net of tax		(2.7		)	10.3			(9.6		)	0.6
	Reclassification of losses (gains) to net income (loss):
	Hot roll carbon steel coil contracts (a)		—			—			—			(0.4		)
	Other commodity contracts (b)		3.9			(5.9		)	(0.1		)	(20.1		)
	Subtotal		3.9			(5.9		)	(0.1		)	(20.5		)
	Income tax expense		—			—			—			—
	Net amount of reclassification of losses (gains) to net income (loss)		3.9			(5.9		)	(0.1		)	(20.5		)
	Total other comprehensive income (loss), net of tax		1.2			4.4			(9.7		)	(19.9		)
	Balance at end of period		$	8.6		$	11.8		$	8.6		$	11.8
	Unrealized holding gains (losses) on securities
	Balance at beginning of period		$	0.4		$	0.5		$	0.4		$	0.3
	Other comprehensive income (loss):
	Unrealized holding gains arising in period		—			—			—			0.2
	Income tax expense		—			—			—			—
	Unrealized holding gains (losses) arising in period, net of tax		—			—			—			0.2
	Balance at end of period		$	0.4		$	0.5		$	0.4		$	0.5
	Pension and OPEB plans
	Balance at beginning of period		$	259.6		$	(58.2	)	$	300		$	(34.4	)
	Other comprehensive income (loss):
	Prior service credit (cost) arising in period		(2.1		)	(6.1		)	(2.1		)	(6.1		)
	Gains (losses) arising in period		(3.0		)	9.6			(8.3		)	9.6
	Income tax expense		—			—			—			—
	Gains (losses) arising in period, net of tax		(5.1		)	3.5			(10.4		)	3.5
	Reclassification to net income (loss):
	Prior service costs (credits) (c)		(17.2		)	(19.1		)	(51.7		)	(57.3		)
	Actuarial (gains) losses (c)		1			6.6			0.4			21
	Subtotal		(16.2		)	(12.5		)	(51.3		)	(36.3		)
	Income tax expense		—			—			—			—
	Amount of reclassification to net income (loss), net of tax		(16.2		)	(12.5		)	(51.3		)	(36.3		)
	Total other comprehensive income (loss), net of tax		(21.3		)	(9.0		)	(61.7		)	(32.8		)
	Balance at end of period		$	238.3		$	(67.2	)	$	238.3		$	(67.2	)
	(a)	Amounts are included in net sales on the Condensed Consolidated Statements of Operations.
	(b)	Amounts are included in cost of products sold on the Condensed Consolidated Statements of Operations.
	(c)	Amounts are included in pension and OPEB expense (income) on the Condensed Consolidated Statements of Operations.

Earnings_Per_Share_Notes

Earnings Per Share (Notes)	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Earnings Per Share	'
	Earnings per Share
	Earnings per share are calculated using the “two-class” method. Under the “two-class” method, undistributed earnings are allocated to both common shares and participating securities. The sum of distributed earnings to common stockholders and undistributed earnings allocated to common stockholders is divided by the weighted-average number of common shares outstanding during the period. The restricted stock granted by AK Holding is entitled to non-forfeitable dividends, if declared, and meets the criteria of a participating security.
		Three Months Ended September 30,						Nine Months Ended September 30,
		2014			2013			2014			2013
	Net income (loss) attributable to AK Steel Holding Corporation	$	(7.2	)	$	(31.7	)	$	(110.4	)	$	(82.0	)
	Less: distributed earnings to common stockholders and holders of certain stock compensation awards	—			—			—			—
	Undistributed earnings (loss)	$	(7.2	)	$	(31.7	)	$	(110.4	)	$	(82.0	)
	Common stockholders earnings—basic and diluted:
	Distributed earnings to common stockholders	$	—		$	—		$	—		$	—
	Undistributed earnings (loss) to common stockholders	(7.2		)	(31.6		)	(110.0		)	(81.7		)
	Common stockholders earnings (loss)—basic and diluted	$	(7.2	)	$	(31.6	)	$	(110.0	)	$	(81.7	)
	Common shares outstanding (weighted-average shares in millions):
	Common shares outstanding for basic earnings per share	142.8			135.9			138.4			135.8
	Effect of exchangeable debt	—			—			—			—
	Effect of dilutive stock-based compensation	—			—			—			—
	Common shares outstanding for diluted earnings per share	142.8			135.9			138.4			135.8
	Basic and diluted earnings per share:
	Distributed earnings	$	—		$	—		$	—		$	—
	Undistributed earnings (loss)	(0.05		)	(0.23		)	(0.79		)	(0.60		)
	Basic and diluted earnings (loss) per share	$	(0.05	)	$	(0.23	)	$	(0.79	)	$	(0.60	)
	Potentially issuable common shares (in millions) excluded from earnings per share calculation due to anti-dilutive effect	13.3			2.5			10.6			2.5

Variable_Interest_Entities_Not

Variable Interest Entities (Notes)	9 Months Ended
	Sep. 30, 2014
Variable Interest Entity, Primary Beneficiary, Does Not Hold Majority Voting Interest, Disclosures [Abstract]	'
Variable Interest Entities	'
	Variable Interest Entities
	SunCoke Middletown
	The Company purchases all of the coke and electrical power generated from SunCoke Middletown’s plant under long-term supply agreements. SunCoke Middletown is deemed to be a variable interest entity because the Company has committed to purchase all of the expected production from the facility through at least 2031 and the Company has been determined to be the primary beneficiary. Thus, the financial results of SunCoke Middletown are required to be consolidated with the results of the Company with recognition of a noncontrolling interest, even though the Company has no ownership interest in SunCoke Middletown. Included in consolidated income (loss) before taxes was income before taxes related to SunCoke Middletown of $16.2 and $15.9 for the three months ended September 30, 2014 and 2013, respectively, and of $46.8 and $47.8 for the nine months ended September 30, 2014 and 2013, respectively.
	Vicksmetal/Armco Associates
	The Company owns a 50% interest in Vicksmetal/Armco Associates (“VAA”), a joint venture with Vicksmetal Company, which is owned by Sumitomo Corporation. VAA slits electrical steel primarily for AK Steel, though also for third parties. AK Steel has determined that VAA meets the definition of a variable interest entity and the financial results of VAA are consolidated with the results of the Company, as the primary beneficiary.

Fair_Value_Measurements_Notes

Fair Value Measurements (Notes)	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	Fair Value Measurements
	The Company measures certain assets and liabilities at fair value. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (i.e., the “exit price”) in an orderly transaction between market participants at the measurement date. In determining fair value, the Company uses various valuation approaches. The hierarchy of those valuation approaches is broken down into three levels based on the reliability of inputs as follows:
	•	Level 1 inputs are quoted prices in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date.
	•	Level 2 inputs are inputs, other than quoted prices, that are directly or indirectly observable for the asset or liability. Level 2 inputs include model-generated values that rely on inputs either directly observed or readily-derived from available market data sources, such as Bloomberg or other news and data vendors. They include quoted prices for similar assets or liabilities in active markets, inputs other than quoted prices that are observable for the asset or liability (e.g., interest rates and yield curves observable at commonly quoted intervals or current market) and contractual prices for the underlying financial instrument, as well as other relevant economic factors. Fair values of the Company’s derivative commodity contracts and foreign currency forward contracts are generated using forward prices that are derived from observable futures prices relating to the respective commodity or currency from sources such as the New York Mercantile Exchange (NYMEX) or the London Metal Exchange (LME). In cases where the derivative is an option contract (including caps, floors and collars), the Company’s valuations reflect adjustments made to valuations generated by the derivative’s counterparty. After validating that the counterparty’s assumptions relating to implied volatilities are in line with an independent source for these implied volatilities, the Company discounts these model-generated future values with discount factors designed to reflect the credit quality of the party obligated to pay under the derivative contract. Differing discount rates are applied to different contracts as a function of differing maturities and different counterparties. As of September 30, 2014, a spread over benchmark rates of less than 3.0% was used for derivatives valued as assets and for derivatives valued as liabilities. The Company has estimated the fair value of long-term debt based upon quoted market prices for the same or similar issues or on the current interest rates available to the Company for debt of similar terms and maturities.
	•	Level 3 inputs are unobservable inputs for the asset or liability. Unobservable inputs are used to measure fair value to the extent that observable inputs are not available, thereby allowing for situations in which there is little, if any, market activity for the asset or liability at the measurement date. This level of categorization is not applicable to the Company’s valuations on a normal recurring basis other than for an immaterial portion of its pension assets.
	The following table presents information about the Company’s assets and liabilities measured at fair value on a recurring basis:
		September 30, 2014								December 31, 2013
		Level 1		Level 2			Total			Level 1		Level 2			Total
	Assets measured at fair value
	Cash and cash equivalents	$	60.8	$	—		$	60.8		$	45.3	$	—		$	45.3
	Other current assets:
	Foreign exchange contracts	—		1.4			1.4			—		—			—
	Commodity hedge contracts	—		3			3			—		4.9			4.9
	Other non-current assets:
	Available for sale investments—cash and cash equivalents	3.3		—			3.3			18.6		—			18.6
	Assets measured at fair value	$	64.1	$	4.4		$	68.5		$	63.9	$	4.9		$	68.8
	Liabilities measured at fair value
	Accrued liabilities:
	Foreign exchange contracts	$	—	$	—		$	—		$	—	$	(0.7	)	$	(0.7	)
	Commodity hedge contracts	—		(26.8		)	(26.8		)	—		(0.4		)	(0.4		)
	Other non-current liabilities—commodity hedge contracts	—		(1.3		)	(1.3		)	—		(0.1		)	(0.1		)
	Liabilities measured at fair value	$	—	$	(28.1	)	$	(28.1	)	$	—	$	(1.2	)	$	(1.2	)
	Liabilities measured at other than fair value
	Long-term debt, including current portions:
	Fair value	$	—	$	(2,573.6	)	$	(2,573.6	)	$	—	$	(1,659.9	)	$	(1,659.9	)
	Carrying amount	—		(2,406.6		)	(2,406.6		)	—		(1,507.0		)	(1,507.0		)
	The carrying amounts of the Company’s other financial instruments do not differ materially from their estimated fair values at September 30, 2014 and December 31, 2013.

Derivative_Instruments_and_Hed

Derivative Instruments and Hedging Activities (Notes)	9 Months Ended
	Sep. 30, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivative Instruments and Hedging Activities	'
	Derivative Instruments and Hedging Activities
	The Company is subject to fluctuations of exchange rates on a portion of intercompany receivables that are denominated in foreign currencies and uses forward currency contracts to manage exposures to certain of these currency price fluctuations. These contracts have not been designated as hedges for accounting purposes and gains or losses are reported in earnings on a current basis in other income (expense).
	The Company is exposed to fluctuations in market prices of raw materials and energy sources, as well as to the effect of market prices on the sale of certain commodity steel (hot roll carbon steel coils). The Company may use cash-settled commodity price swaps and options (including collars) to hedge the market risk associated with the purchase of certain of its raw materials and energy requirements and the sale of hot roll carbon steel coils. With respect to input commodities, these derivatives are typically used for a portion of the Company’s natural gas, nickel, iron ore, aluminum, zinc and electricity requirements. The Company’s hedging strategy is designed to mitigate the effect on earnings from the price volatility of these various commodity exposures. Independent of any hedging activities, price changes in any of these commodity markets could negatively affect operating costs or selling prices.
	All commodity derivatives are marked to market and recognized as an asset or liability at fair value. The effective gains and losses for commodity derivatives designated as cash flow hedges of forecasted purchases of raw materials and energy sources are recorded in accumulated other comprehensive income (loss) on the Consolidated Balance Sheets and reclassified into cost of products sold in the same period as the earnings recognition of the associated underlying transaction. The effective gains and losses for hot roll carbon steel coils derivatives designated as cash flow hedges of forecasted sales are recorded in accumulated other comprehensive income on the Consolidated Balance Sheets and reclassified into net sales in the same period as the earnings recognition of the associated underlying transaction. Gains and losses on these designated derivatives arising from either hedge ineffectiveness or related to components excluded from the assessment of effectiveness are recognized in current earnings under cost of products sold or net sales, as appropriate. All gains or losses from derivatives for which hedge accounting treatment has not been elected are also reported in earnings on a current basis in net sales or cost of products sold.
	The Company had the following outstanding commodity price swaps and options and forward foreign exchange contracts:
	Commodity		September 30,				December 31, 2013
			2014
	Nickel (in lbs)		382,400				763,300
	Natural gas (in MMBTUs)		17,232,500				3,240,000
	Zinc (in lbs)		15,000,000				12,000,000
	Electricity (in MWHs)		767,000				—
	Iron ore (in metric tons)		1,084,200				190,735
	Hot roll carbon steel coils (in short tons)		87,800				74,147
	Foreign exchange contracts (in euros)		€	19,640,000			€	17,730,000
	The following table presents the fair value of derivative instruments in the Condensed Consolidated Balance Sheets:
	Asset (liability)		September 30,				December 31, 2013
			2014
	Derivatives designated as hedging instruments:
	Other current assets—commodity contracts		$	2.3			$	2.6
	Accrued liabilities—commodity contracts		(6.7		)		—
	Other non-current liabilities—commodity contracts		(0.8		)		—
	Derivatives not designated as hedging instruments:
	Other current assets:
	Foreign exchange contracts		1.4				—
	Commodity contracts		0.7				2.3
	Accrued liabilities:
	Foreign exchange contracts		—				(0.7		)
	Commodity contracts		(20.1		)		(0.4		)
	Other noncurrent liabilities—commodity contracts		(0.5		)		(0.1		)
	The following table presents gains (losses) on derivative instruments included in the Condensed Consolidated Statements of Operations:
			Three Months Ended September 30,							Nine Months Ended September 30,
	Gain (loss)		2014				2013			2014			2013
	Derivatives designated as cash flow hedges—
	Commodity contracts:
	Reclassified from accumulated other comprehensive income into net sales (effective portion)		$	—			$	—		$	—		$	0.4
	Reclassified from accumulated other comprehensive income into cost of products sold (effective portion)		(3.9		)		5.9			0.1			20.1
	Recognized in cost of products sold (ineffective portion and amount excluded from effectiveness testing)		(3.8		)		(3.1		)	(4.5		)	3.3
	Derivatives not designated as hedging instruments:
	Foreign exchange contracts—recognized in other income (expense)		(0.2		)		(0.7		)	0.7			(0.2		)
	Commodity contracts:
	Recognized in net sales		(1.8		)		0.2			(6.0		)	0.4
	Recognized in cost of products sold		(11.2		)		0.6			(30.4		)	0.4
	The following table lists the amount of gains (losses) before tax expected to be reclassified into cost of products sold within the next twelve months for the Company’s existing commodity contracts that qualify for hedge accounting, as well as the period of time over which the Company is hedging its exposure to the volatility in future cash flows:
	Commodity Hedge	Settlement Dates		Gains (losses)
	Natural gas	October 2014 to December 2016		$	2.8
	Zinc	October 2014 to December 2016		0.3
	Electricity	October 2014 to December 2015		1.2
	Iron ore	October 2014 to November 2016		(10.9		)

Supplemental_Cash_Flow_Informa

Supplemental Cash Flow Information (Notes)	9 Months Ended
	Sep. 30, 2014
Supplemental Cash Flow Information [Abstract]	'
Supplemental Cash Flow Information	'
	Supplemental Cash Flow Information
	The following table presents the net cash paid (received) during the period for interest, net of capitalized interest, and income taxes:
		Nine Months Ended September 30,
		2014			2013
	Net cash paid (received) during the period for:
	Interest, net of capitalized interest	$	62.9		$	60
	Income taxes	(0.5		)	1.1
	Included in net cash flows from operations was cash provided by SunCoke Middletown of $43.8 and $57.3 for the nine months ended September 30, 2014 and 2013, respectively. Consolidated cash and cash equivalents at September 30, 2014 and December 31, 2013, includes $16.3 and $14.2, respectively, of cash and cash equivalents of SunCoke Middletown. There are no compensating balance arrangements or legal restrictions on the cash and cash equivalents of SunCoke Middletown, however, it is not available for the Company’s use.
	The Company had non-cash capital investments during the nine months ended September 30, 2014 and 2013, that had not been paid as of the end of the respective period. These amounts are included in accounts payable and accrued liabilities and have been excluded from the Condensed Consolidated Statements of Cash Flows. The Company also granted restricted stock to certain employees and restricted stock units to directors under the Stock Incentive Plan. The amounts of non-cash investing and financing activities were as follows:
		Nine Months Ended September 30,
		2014			2013
	Capital investments	$	7.6		$	5.4
	Issuance of restricted stock and restricted stock units	4			2.7

Union_Contracts_Notes

Union Contracts (Notes)	9 Months Ended
	Sep. 30, 2014
Union Contracts [Abstract]	'
Union Contracts	'
	Union Contracts
	In June 2014, members of the International Association of Machinists and Aerospace Workers, Local 1943, ratified a 42-month labor agreement covering approximately 1,640 employees at the Middletown Works. The new agreement was reached early. It will replace the current agreement, which was set to expire on September 15, 2014. The new agreement took effect on September 15, 2014 and will expire on March 15, 2018.
	The United Steelworkers, Local 1190, has been recognized as the bargaining agent for approximately 220 hourly employees at Mountain State Carbon, LLC. AK Steel will be bargaining in good faith in efforts to reach an initial labor agreement.
	An agreement with the United Steelworkers, Local 1915, which represents approximately 110 employees at AK Tube in Walbridge, Ohio, is scheduled to expire on January 22, 2015. An agreement with the United Steelworkers, Local 1865, which represents approximately 820 employees at the Ashland Works, is scheduled to expire on March 1, 2015. An agreement with the United Automobile Workers, Local 4104, which represents approximately 130 employees at the Zanesville Works, is scheduled to expire on May 20, 2015.

New_Accounting_Pronouncements_

New Accounting Pronouncements (Notes)	9 Months Ended
	Sep. 30, 2014
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]	'
New Accounting Pronouncements	'
	New Accounting Pronouncements
	The Financial Accounting Standards Board issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606), during the second quarter of 2014. Topic 606 affects virtually all aspects of an entity’s revenue recognition, including determining the measurement of revenue and the timing of when it is recognized for the transfer of goods or services to customers. Topic 606 is effective for annual reporting periods beginning after December 15, 2016. The Company is currently evaluating the effect of the adoption of Topic 606 on its financial position and results of operations.

Supplemental_Guarantor_Informa

Supplemental Guarantor Information (Notes)	9 Months Ended
	Sep. 30, 2014
Supplemental Guarantor Information [Abstract]	'
Supplemental Guarantor Information	'
	Supplemental Guarantor Information
	AK Steel’s 8.75% Senior Secured Notes due December 2018, 7.625% Senior Notes due May 2020, 7.625% Senior Notes due October 2021, 8.375% Senior Notes due April 2022 (collectively, the “Senior Notes”) and 5.00% Exchangeable Senior Notes due November 2019 (the “Exchangeable Notes”) are governed by indentures entered into by AK Holding and its 100%-owned subsidiary, AK Steel. In April 2014, the Company designated two 100%-owned subsidiaries, AK Tube and AK Properties, as guarantor subsidiaries of the Senior Notes (other than the 7.625% Senior Notes due October 2021, which were subsequently issued and as to which AK Tube and AK Properties were guarantor subsidiaries from issuance). Under the terms of the indentures, AK Holding and the guarantor subsidiaries each fully and unconditionally, jointly and severally, guarantee the payment of interest, principal and premium, if any, on each of the notes comprising the Senior Notes.
	With respect to the Exchangeable Notes, under the terms of the indenture AK Holding fully and unconditionally, jointly and severally, guarantees the payment of interest, principal and premium, if any, on such notes. AK Holding remains the sole guarantor of the Exchangeable Notes.
	The presentation of the supplemental guarantor information reflects all investments in subsidiaries under the equity method of accounting. Net income (loss) of the subsidiaries accounted for under the equity method is therefore reflected in their parents’ investment accounts. The principal elimination entries eliminate investments in subsidiaries and inter-company balances and transactions. The following supplemental condensed consolidating financial statements present information about AK Holding, AK Steel, the guarantor subsidiaries of the Senior Notes and the other non-guarantor subsidiaries after the addition of AK Tube and AK Steel Properties as guarantors in April 2014.
	Condensed Consolidated Statements of Comprehensive Income (Loss)
	Three Months Ended September 30, 2014
		AK			AK			Guarantor Subsidiaries of the Senior Notes			Other Non-Guarantor Subsidiaries			Eliminations			Consolidated Company
		Holding			Steel
	Net sales	$	—		$	1,552.50		$	69.7		$	135.7		$	(164.1	)	$	1,593.80
	Cost of products sold (exclusive of items shown separately below)	—			1,433.10			50.1			104.4			(148.7		)	1,438.90
	Selling and administrative expenses (exclusive of items shown separately below)	1			65.2			2.9			7.7			(11.2		)	65.6
	Depreciation	—			42.7			1.1			5.3			—			49.1
	Pension and OPEB expense (income)	—			(23.5		)	—			—			—			(23.5		)
	Total operating costs	1			1,517.50			54.1			117.4			(159.9		)	1,530.10
	Operating profit (loss)	(1.0		)	35			15.6			18.3			(4.2		)	63.7
	Interest expense	—			34.8			—			0.8			—			35.6
	Other income (expense)	—			(15.8		)	1.6			(1.1		)	—			(15.3		)
	Income (loss) before income taxes	(1.0		)	(15.6		)	17.2			16.4			(4.2		)	12.8
	Income tax expense (benefit)	—			(1.5		)	6.9			0.2			(1.7		)	3.9
	Equity in net income (loss) of subsidiaries	(6.2		)	7.9			—			—			(1.7		)	—
	Net income (loss)	(7.2		)	(6.2		)	10.3			16.2			(4.2		)	8.9
	Less: Net income attributable to noncontrolling interests	—			—			—			16.1			—			16.1
	Net income (loss) attributable to AK Steel Holding Corporation	(7.2		)	(6.2		)	10.3			0.1			(4.2		)	(7.2		)
	Other comprehensive income (loss)	(22.6		)	(22.6		)	—			(2.5		)	25.1			(22.6		)
	Comprehensive income (loss) attributable to AK Steel Holding Corporation	$	(29.8	)	$	(28.8	)	$	10.3		$	(2.4	)	$	20.9		$	(29.8	)
	Condensed Consolidated Statements of Comprehensive Income (Loss)
	Three Months Ended September 30, 2013
		AK			AK			Guarantor Subsidiaries of the Senior Notes			Other Non-Guarantor Subsidiaries			Eliminations			Consolidated Company
		Holding			Steel
	Net sales	$	—		$	1,284.10		$	63		$	137.3		$	(153.1	)	$	1,331.30
	Cost of products sold (exclusive of items shown separately below)	—			1,206.40			45.9			112.5			(142.4		)	1,222.40
	Selling and administrative expenses (exclusive of items shown separately below)	1			50.8			2.6			6.8			(9.7		)	51.5
	Depreciation	—			43.1			1.2			4.1			—			48.4
	Pension and OPEB expense (income)	—			(16.9		)	—			—			—			(16.9		)
	Total operating costs	1			1,283.40			49.7			123.4			(152.1		)	1,305.40
	Operating profit (loss)	(1.0		)	0.7			13.3			13.9			(1.0		)	25.9
	Interest expense	—			31.7			—			0.4			—			32.1
	Other income (expense)	—			(1.9		)	1.5			(2.4		)	—			(2.8		)
	Income (loss) before income taxes	(1.0		)	(32.9		)	14.8			11.1			(1.0		)	(9.0		)
	Income tax expense (benefit)	—			3.6			5.5			(1.9		)	(0.5		)	6.7
	Equity in net income (loss) of subsidiaries	(30.7		)	5.8			—			—			24.9			—
	Net income (loss)	(31.7		)	(30.7		)	9.3			13			24.4			(15.7		)
	Less: Net income attributable to noncontrolling interests	—			—			—			16			—			16
	Net income (loss) attributable to AK Steel Holding Corporation	(31.7		)	(30.7		)	9.3			(3.0		)	24.4			(31.7		)
	Other comprehensive income (loss)	(3.4		)	(3.4		)	—			1.2			2.2			(3.4		)
	Comprehensive income (loss) attributable to AK Steel Holding Corporation	$	(35.1	)	$	(34.1	)	$	9.3		$	(1.8	)	$	26.6		$	(35.1	)
	Condensed Consolidated Statements of Comprehensive Income (Loss)
	Nine Months Ended September 30, 2014
		AK			AK			Guarantor Subsidiaries of the Senior Notes			Other Non-Guarantor Subsidiaries			Eliminations			Consolidated Company
		Holding			Steel
	Net sales	$	—		$	4,350.70		$	209.8		$	393.7		$	(446.1	)	$	4,508.10
	Cost of products sold (exclusive of items shown separately below)	—			4,141.10			151.6			309			(410.3		)	4,191.40
	Selling and administrative expenses (exclusive of items shown separately below)	3.6			177.9			8.6			22.3			(32.7		)	179.7
	Depreciation	—			127.5			3.1			15.7			—			146.3
	Pension and OPEB expense (income)	—			(74.2		)	—			—			—			(74.2		)
	Total operating costs	3.6			4,372.30			163.3			347			(443.0		)	4,443.20
	Operating profit (loss)	(3.6		)	(21.6		)	46.5			46.7			(3.1		)	64.9
	Interest expense	—			99			—			2			—			101
	Other income (expense)	—			(23.5		)	4.9			(1.6		)	—			(20.2		)
	Income (loss) before income taxes	(3.6		)	(144.1		)	51.4			43.1			(3.1		)	(56.3		)
	Income tax expense (benefit)	—			(10.8		)	20.6			(1.0		)	(1.3		)	7.5
	Equity in net income (loss) of subsidiaries	(106.8		)	26.5			—			—			80.3			—
	Net income (loss)	(110.4		)	(106.8		)	30.8			44.1			78.5			(63.8		)
Less: Net income attributable to noncontrolling interests	—			—			—			46.6			—			46.6
Net income (loss) attributable to AK Steel Holding Corporation	(110.4		)	(106.8		)	30.8			(2.5		)	78.5			(110.4		)
Other comprehensive income (loss)	(74.0		)	(74.0		)	—			(2.6		)	76.6			(74.0		)
Comprehensive income (loss) attributable to AK Steel Holding Corporation	$	(184.4	)	$	(180.8	)	$	30.8		$	(5.1	)	$	155.1		$	(184.4	)
Condensed Consolidated Statements of Comprehensive Income (Loss)
Nine Months Ended September 30, 2013
	AK			AK			Guarantor Subsidiaries of the Senior Notes			Other Non-Guarantor Subsidiaries			Eliminations			Consolidated Company
	Holding			Steel
Net sales	$	—		$	3,917.30		$	196.6		$	430		$	(438.3	)	$	4,105.60
Cost of products sold (exclusive of items shown separately below)	—			3,688.80			142.2			360.8			(407.9		)	3,783.90
Selling and administrative expenses (exclusive of items shown separately below)	3.5			152.2			7.9			20			(30.3		)	153.3
Depreciation	—			129.8			3.4			11.7			—			144.9
Pension and OPEB expense (income)	—			(49.3		)	—			—			—			(49.3		)
Total operating costs	3.5			3,921.50			153.5			392.5			(438.2		)	4,032.80
Operating profit (loss)	(3.5		)	(4.2		)	43.1			37.5			(0.1		)	72.8
Interest expense	—			94.1			—			1			—			95.1
Other income (expense)	—			(2.6		)	4.6			(0.5		)	—			1.5
Income (loss) before income taxes	(3.5		)	(100.9		)	47.7			36			(0.1		)	(20.8		)
Income tax expense (benefit)	—			(0.6		)	18.7			(4.4		)	(0.1		)	13.6
Equity in net income (loss) of subsidiaries	(78.5		)	21.8			—			—			56.7			—
Net income (loss)	(82.0		)	(78.5		)	29			40.4			56.7			(34.4		)
Less: Net income attributable to noncontrolling interests	—			—			—			47.6			—			47.6
Net income (loss) attributable to AK Steel Holding Corporation	(82.0		)	(78.5		)	29			(7.2		)	56.7			(82.0		)
Other comprehensive income (loss)	(52.0		)	(52.0		)	—			0.5			51.5			(52.0		)
Comprehensive income (loss) attributable to AK Steel Holding Corporation	$	(134.0	)	$	(130.5	)	$	29		$	(6.7	)	$	108.2		$	(134.0	)
Condensed Consolidated Balance Sheets
September 30, 2014
	AK			AK			Guarantor Subsidiaries of the Senior Notes			Other Non-Guarantor Subsidiaries			Eliminations			Consolidated Company
	Holding			Steel
ASSETS
Current assets:
Cash and cash equivalents	$	—		$	21		$	0.2		$	39.6		$	—		$	60.8
Accounts receivable, net	—			673.7			32.7			33.3			(32.1		)	707.6
Inventory, net	—			1,031.20			31			78.1			(14.3		)	1,126.00
Deferred tax assets, current	—			74.5			—			0.2			—			74.7
Other current assets	0.3			72.6			0.3			3.1			—			76.3
Total current assets	0.3			1,873.00			64.2			154.3			(46.4		)	2,045.40
Property, plant and equipment	—			5,646.80			96.1			593			—			6,335.90
Accumulated depreciation	—			(3,993.0		)	(70.9		)	(56.9		)	—			(4,120.8		)
Property, plant and equipment, net	—			1,653.80			25.2			536.1			—			2,215.10
Other non-current assets:
Investments in affiliates	—			97.8			—			298.7			—			396.5
Investment in subsidiaries	(2,223.7		)	1,571.30			—			—			652.4			—
Inter-company accounts	2,138.50			(3,078.5		)	1,306.30			(403.0		)	36.7			—
Other non-current assets	—			130.8			33			64.6			—			228.4
TOTAL ASSETS	$	(84.9	)	$	2,248.20		$	1,428.70		$	650.7		$	642.7		$	4,885.40
LIABILITIES AND EQUITY
Current liabilities:
Accounts payable	$	—		$	759.8		$	9.7		$	43.6		$	(0.8	)	$	812.3
Accrued liabilities	—			260.6			3.1			18			—			281.7
Current portion of long-term debt	—			0.2			—			—			—			0.2
Current portion of pension and other postretirement benefit obligations	—			61.8			—			0.4			—			62.2
Total current liabilities	—			1,082.40			12.8			62			(0.8		)	1,156.40
Non-current liabilities:
Long-term debt	—			2,406.40			—			—			—			2,406.40
Pension and other postretirement benefit obligations	—			828.3			—			4.1			—			832.4
Other non-current liabilities	—			123.8			—			0.6			—			124.4
TOTAL LIABILITIES	—			4,440.90			12.8			66.7			(0.8		)	4,519.60
Exchangeable notes exchange feature	—			31			—			—			—			31
Equity:
Total stockholders’ equity (deficit)	(84.9		)	(2,223.7		)	1,415.90			164.3			643.5			(84.9		)
Noncontrolling interests	—			—			—			419.7			—			419.7
TOTAL EQUITY	(84.9		)	(2,223.7		)	1,415.90			584			643.5			334.8
TOTAL LIABILITIES AND EQUITY	$	(84.9	)	$	2,248.20		$	1,428.70		$	650.7		$	642.7		$	4,885.40
Condensed Consolidated Balance Sheets
December 31, 2013
	AK			AK			Guarantor Subsidiaries of the Senior Notes			Other Non-Guarantor Subsidiaries			Eliminations			Consolidated Company
	Holding			Steel
ASSETS
Current assets:
Cash and cash equivalents	$	—		$	16.8		$	—		$	28.5		$	—		$	45.3
Accounts receivable, net	—			492.4			25.2			35.9			(28.3		)	525.2
Inventory, net	—			520			19.2			58.5			(11.1		)	586.6
Deferred tax assets, current	—			69.4			—			0.2			—			69.6
Other current assets	0.3			43.9			0.2			2.1			—			46.5
Total current assets	0.3			1,142.50			44.6			125.2			(39.4		)	1,273.20
Property, plant and equipment	—			5,258.40			94.9			518.6			—			5,871.90
Accumulated depreciation	—			(3,881.7		)	(67.9		)	(42.2		)	—			(3,991.8		)
Property, plant and equipment, net	—			1,376.70			27			476.4			—			1,880.10
Other non-current assets:
Investments in affiliates	—			—			—			209.8			—			209.8
Investment in subsidiaries	(2,772.4		)	1,393.80			—			—			1,378.60			—
Inter-company accounts	2,551.10			(3,479.7		)	1,269.60			(372.9		)	31.9			—
Other non-current assets	—			141			33			68.6			—			242.6
TOTAL ASSETS	$	(221.0	)	$	574.3		$	1,374.20		$	507.1		$	1,371.10		$	3,605.70
LIABILITIES AND EQUITY
Current liabilities:
Accounts payable	$	—		$	550.5		$	6.3		$	45.6		$	(0.6	)	$	601.8
Accrued liabilities	—			133.6			2.9			6.4			—			142.9
Current portion of long-term debt	—			0.8			—			—			—			0.8
Current portion of pension and other postretirement benefit obligations	—			85.4			—			0.5			—			85.9
Total current liabilities	—			770.3			9.2			52.5			(0.6		)	831.4
Non-current liabilities:
Long-term debt	—			1,506.20			—			—			—			1,506.20
Pension and other postretirement benefit obligations	—			960.6			—			4.8			—			965.4
Other non-current liabilities	—			109.6			—			0.4			—			110
TOTAL LIABILITIES	—			3,346.70			9.2			57.7			(0.6		)	3,413.00
Equity:
Total stockholders’ equity (deficit)	(221.0		)	(2,772.4		)	1,365.00			35.7			1,371.70			(221.0		)
Noncontrolling interests	—			—			—			413.7			—			413.7
TOTAL EQUITY	(221.0		)	(2,772.4		)	1,365.00			449.4			1,371.70			192.7
TOTAL LIABILITIES AND EQUITY	$	(221.0	)	$	574.3		$	1,374.20		$	507.1		$	1,371.10		$	3,605.70
Condensed Consolidated Statements of Cash Flows
Nine Months Ended September 30, 2014
	AK			AK			Guarantor Subsidiaries of the Senior Notes			Other Non-Guarantor Subsidiaries			Eliminations			Consolidated Company
	Holding			Steel
Net cash flows from operating activities	$	1.2		$	(476.2	)	$	18.7		$	70.7		$	5		$	(380.6	)
Cash flows from investing activities:
Capital investments	—			(25.2		)	(1.9		)	(12.2		)	—			(39.3		)
Investments in Magnetation joint venture	—			—			—			(90.0		)	—			(90.0		)
Investment in acquired business, net of cash acquired	—			(677.2		)	—			—			—			(677.2		)
Other investing items, net	—			15.4			—			—			—			15.4
Net cash flows from investing activities	—			(687.0		)	(1.9		)	(102.2		)	—			(791.1		)
Cash flows from financing activities:
Net borrowings under credit facility	—			470			—			—			—			470
Proceeds from issuance of long-term debt	—			427.1			—			—			—			427.1
Redemption of long-term debt	—			(0.6		)	—			—			—			(0.6		)
Proceeds from issuance of common stock	345.3			—			—			—			—			345.3
Debt issuance costs	—			(10.6		)	—			—			—			(10.6		)
Inter-company activity	(345.6		)	281.4			(16.6		)	85.8			(5.0		)	—
SunCoke Middletown distributions to noncontrolling interest owners	—			—			—			(40.6		)	—			(40.6		)
Other financing items, net	(0.9		)	0.1			—			(2.6		)	—			(3.4		)
Net cash flows from financing activities	(1.2		)	1,167.40			(16.6		)	42.6			(5.0		)	1,187.20
Net increase (decrease) in cash and cash equivalents	—			4.2			0.2			11.1			—			15.5
Cash and equivalents, beginning of period	—			16.8			—			28.5			—			45.3
Cash and equivalents, end of period	$	—		$	21		$	0.2		$	39.6		$	—		$	60.8
Condensed Consolidated Statements of Cash Flows
Nine Months Ended September 30, 2013
	AK			AK			Guarantor Subsidiaries of the Senior Notes			Other Non-Guarantor Subsidiaries			Eliminations			Consolidated Company
	Holding			Steel
Net cash flows from operating activities	$	(2.8	)	$	(325.4	)	$	37.3		$	73.1		$	(5.9	)	$	(223.7	)
Cash flows from investing activities:
Capital investments	—			(31.6		)	(0.7		)	(15.8		)	—			(48.1		)
Investments in Magnetation joint venture	—			—						(50.0		)	—			(50.0		)
Other investing items, net	—			4.8			(0.3		)	10.6			—			15.1
Net cash flows from investing activities	—			(26.8		)	(1.0		)	(55.2		)	—			(83.0		)
Cash flows from financing activities:
Net borrowings under credit facility	—			185			—			—			—			185
Proceeds from issuance of long-term debt	—			31.9			—			—			—			31.9
Redemption of long-term debt	—			(27.2		)	—			—			—			(27.2		)
Debt issuance costs	—			(3.1		)	—			—			—			(3.1		)
Inter-company activity	3.5			(9.9		)	(36.2		)	36.7			5.9			—
SunCoke Middletown distributions to noncontrolling interest owners	—			—			—			(41.1		)	—			(41.1		)
Other financing items, net	(0.7		)	—			—			0.6			—			(0.1		)
Net cash flows from financing activities	2.8			176.7			(36.2		)	(3.8		)	5.9			145.4
Net increase (decrease) in cash and cash equivalents	—			(175.5		)	0.1			14.1			—			(161.3		)
Cash and equivalents, beginning of period	—			203.6			—			23.4			—			227
Cash and equivalents, end of period	$	—		$	28.1		$	0.1		$	37.5		$	—		$	65.7

Basis_of_Presentation_Policies

Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Basis of Accounting, Policy	'
	In the opinion of the management of AK Steel Holding Corporation (“AK Holding”) and its wholly-owned subsidiary, AK Steel Corporation (“AK Steel”, and together with AK Holding, the “Company”), the accompanying condensed consolidated financial statements contain all adjustments, consisting of normal recurring adjustments, necessary to present fairly the financial position of the Company as of September 30, 2014, the results of its operations for the three and nine months ended September 30, 2014 and 2013, and its cash flows for the nine months ended September 30, 2014 and 2013. The results of operations for the three and nine months ended September 30, 2014 are not necessarily indicative of the results to be expected for the full year ending December 31, 2014. These condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements of the Company for the year ended December 31, 2013, included in the Company’s Form 10‑K for the year ended December 31, 2013, and the unaudited condensed consolidated financial statements included in any subsequent Quarterly Reports on Form 10-Q.

Earnings_Per_Share_Policies

Earnings Per Share (Policies)	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Earnings Per Share, Policy	'
	Earnings per share are calculated using the “two-class” method. Under the “two-class” method, undistributed earnings are allocated to both common shares and participating securities. The sum of distributed earnings to common stockholders and undistributed earnings allocated to common stockholders is divided by the weighted-average number of common shares outstanding during the period. The restricted stock granted by AK Holding is entitled to non-forfeitable dividends, if declared, and meets the criteria of a participating security.

Acquisition_of_Dearborn_Prelim

Acquisition of Dearborn Preliminary Purchase Price Allocation (Tables)	9 Months Ended
	Sep. 30, 2014
Business Combinations [Abstract]	'
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]	'
	A summary of the preliminary purchase price allocation for the fair value of the assets acquired and the obligations assumed at the date of the acquisition is presented below. The purchase price allocation is preliminary and is subject to the completion of several items, including consideration of final valuations and the final determination of post-closing purchase price adjustments relating to working capital.
	Cash and cash equivalents	$	29.3
	Accounts receivable	152.2
	Inventory	362.2
	Other current assets	3.6
	Property, plant and equipment	446.3
	Investment in affiliates	97.5
	Total assets acquired	1,091.10
	Accounts payable	(204.3		)
	Accrued liabilities	(36.9		)
	Other postretirement benefit obligations	(121.8		)
	Other non-current liabilities	(7.1		)
	Total liabilities assumed	(370.1		)
	Preliminary purchase price (including estimate for working capital adjustment)	$	721
Business Acquisition, Pro Forma Information [Table Text Block]	'
	The following table summarizes selected unaudited pro forma consolidated statements of operations data for the nine months ended September 30, 2014 and 2013 as if the acquisition had been completed at the beginning of each year.
			Nine Months Ended September 30,
			2014			2013
	Net sales		$	5,945.10		$	5,612.40
	Operating profit (loss)		(889.3		)	131.1

Inventories_Tables

Inventories (Tables)	9 Months Ended
	Sep. 30, 2014
Inventory Disclosure [Abstract]	'
Detail of inventories	'
		September 30,			December 31, 2013
		2014
	Finished and semi-finished	$	1,103.30		$	722.2
	Raw materials	403.5			260.9
	Total cost	1,506.80			983.1
	Adjustment to state inventories at LIFO value	(380.8		)	(396.5		)
	Inventory, net	$	1,126.00		$	586.6

Investments_in_Affiliates_Tabl

Investments in Affiliates (Tables)	9 Months Ended
	Sep. 30, 2014
Equity Method Investments and Joint Ventures [Abstract]	'
Equity Method Investments [Table Text Block]	'
	Summarized financial statement data for all investees is presented below. The financial results for the acquired joint ventures are only included for the period since the acquisition.
			Three Months Ended September 30,				Nine Months Ended September 30,
			2014		2013		2014		2013
	Revenue		$	87.4	$	76.2	$	245.1	$	220.1
	Gross profit		25.3		26.4		73.3		77.9
	Net income		7.3		0.7		17.7		17.2
	The investees and equity ownership percentages are presented below:
			Equity Ownership %
	Combined Metals of Chicago, LLC		40	%
	Delaco Processing, LLC		49	%
	Double Eagle Steel Coating Company (a)		50	%
	Magnetation LLC		49.9	%
	Rockport Roll Shop LLC		50	%
	Spartan Steel Coating, LLC		48	%
	(a)	Double Eagle Steel Coating Company (“DESCO”) is a joint venture between United States Steel Corporation (“US Steel”) and AK Steel that was acquired as part of the Dearborn acquisition. On April 1, 2013, Dearborn sent to US Steel a notice of dissolution of the joint venture in accordance with the terms of the joint venture agreement. The notice provided that the joint venture would dissolve two years from the date of the notice. On September 16, 2014, the Company acquired Dearborn, which included Dearborn’s 50% interest in DESCO. Shortly prior to the Company’s acquisition of Dearborn, US Steel notified the Company that it believed it had a right under the joint venture agreement to purchase Dearborn’s interest in DESCO prior to it being sold to the Company. US Steel has taken the position that the Company now must sell to it the 50% ownership interest in DESCO formerly owned by Dearborn. The Company has notified US Steel that the Company rejects US Steel’s position, but the Company is willing to discuss a potential sale of its ownership interest in DESCO to US Steel in lieu of proceeding with the dissolution of the joint venture. US Steel and the Company are engaged in discussions to resolve this dispute.

Longterm_Debt_and_Other_Financ1

Long-term Debt and Other Financing (Tables)	9 Months Ended
	Sep. 30, 2014
Debt Disclosure [Abstract]	'
Schedule of Long-term Debt Instruments	'
	The Company’s debt balances, including current portions, were as follows:
		September 30,			December 31, 2013
		2014
	Credit Facility	$	560		$	90
	8.75% Senior Secured Notes due December 2018	380			380
	5.00% Exchangeable Senior Notes due November 2019 (effective rate of 10.8%)	150			150
	7.625% Senior Notes due May 2020	529.8			529.8
	7.625% Senior Notes due October 2021	430			—
	8.375% Senior Notes due April 2022	290.2			290.2
	Industrial Revenue Bonds due 2014 through 2030	99.5			100.1
	Unamortized debt (discount) premium, net	(32.9		)	(33.1		)
	Total debt	2,406.60			1,507.00
	Less:
	Current portion of long-term debt	0.2			0.8
	Total long-term debt	$	2,406.40		$	1,506.20

Pension_and_Other_Postretireme1

Pension and Other Postretirement Benefits (Tables)	9 Months Ended
	Sep. 30, 2014
General Discussion of Pension and Other Postretirement Benefits [Abstract]	'
Schedule of Defined Benefit Plans Disclosures	'
	Net periodic benefit cost (income) for pension and other postretirement benefits were as follows:
		Three Months Ended September 30,						Nine Months Ended September 30,
		2014			2013			2014			2013
	Pension Benefits
	Service cost	$	0.5		$	0.7		$	1.2		$	1.9
	Interest cost	36.6			34.7			109.6			104.1
	Expected return on assets	(50.7		)	(46.2		)	(152.1		)	(138.3		)
	Amortization of prior service cost	1.1			0.9			3.2			2.7
	Amortization of (gain) loss	1.1			6.7			1.2			20
	Settlement (gain) loss	0.2			(0.8		)	0.2			(0.8		)
	Net periodic benefit cost (income)	$	(11.2	)	$	(4.0	)	$	(36.7	)	$	(10.4	)
	Other Postretirement Benefits
	Service cost	$	1.1		$	1.1		$	3.1		$	3.5
	Interest cost	5.2			5.3			15.3			15.8
	Amortization of prior service cost (credit)	(18.3		)	(20.0		)	(54.9		)	(60.0		)
	Amortization of (gain) loss	(0.3		)	0.7			(1.0		)	1.8
	Net periodic benefit cost (income)	$	(12.3	)	$	(12.9	)	$	(37.5	)	$	(38.9	)

Environmental_and_Legal_Contin1

Environmental and Legal Contingencies (Tables)	9 Months Ended
	Sep. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Schedule of Accrual of Liabilities Related to Environmental Loss Contingencies	'
	Liabilities recorded on the Company’s Condensed Consolidated Balance Sheets for such estimated probable costs relating to environmental matters are presented below:
		September 30,		December 31, 2013
		2014
	Accrued liabilities	$	16.3	$	9.5
	Other non-current liabilities	34.3		34.1
Schedule of Information on Pending Asbestos Cases	'
	Information on asbestos cases pending at September 30, 2014 is presented below:
			Asbestos Cases Pending at
			September 30, 2014
	Cases with specific dollar claims for damages:
	Claims up to $0.2		114
	Claims above $0.2 to $5.0		6
	Claims above $5.0 to $15.0		2
	Claims above $15.0 to $20.0		2
	Total claims with specific dollar claims for damages (a)		124
	Cases without a specific dollar claim for damages		314
	Total asbestos cases pending		438
	(a)	Involve a total of 2,332 plaintiffs and 16,631 defendants
Schedule of Number of New Asbestos Claims Filed, Number of Pending Asbestos Claims Disposed, And Amount Paid in Settlements	'
	Set forth below is a chart showing the number of new claims filed (accounted for as described above), the number of pending claims disposed of (i.e., settled or otherwise dismissed), and the approximate net amount of dollars paid on behalf of AK Steel in settlement of asbestos-related claims in the three and nine months ended September 30, 2014 and 2013.
		Three Months Ended September 30,				Nine Months Ended September 30,
		2014		2013		2014		2013
	New Claims Filed	16		10		40		34
	Pending Claims Disposed Of	10		5		38		30
	Total Amount Paid in Settlements	$	0.1	$	—	$	0.6	$	0.9
Schedule Of Percentages To Calculate Cash Deposits On Imports Of NOES From Foreign Countries To US [Table Text Block]	'
	As a result of the preliminary dumping determinations, importers were required to post cash deposits with U.S. Customs and Border Protection on imports of NOES from these six countries (in addition to any deposits required by the preliminary affirmative CVD determinations).
	On October 7, 2014, the DOC issued its final dumping determinations as to all six subject countries as follows:
	Country		NOES Dumping Margins
	China		407.52%
	Germany		86.29% — 98.84%
	Japan		135.59% — 204.79%
	South Korea		6.91%
	Sweden		98.46% — 126.72%
	Taiwan		28.14% — 52.23%

Sharebased_Compensation_Tables

Share-based Compensation (Tables)	9 Months Ended
	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Schedule about share-based compensation expense	'
	The following table summarizes information about share-based compensation expense, which the Company has estimated will be $8.7 for 2014:
		Three Months Ended September 30,				Nine Months Ended September 30,
	Share-based Compensation Expense	2014		2013		2014		2013
	Stock options	$	0.2	$	0.1	$	1.5	$	1.2
	Restricted stock	0.4		0.3		2.7		2.5
	Restricted stock units issued to Directors	0.4		0.3		0.9		0.7
	Performance shares	0.6		1		2.1		3
	Total share-based compensation expense	$	1.6	$	1.7	$	7.2	$	7.4

Comprehensive_Income_Loss_Tabl

Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 30, 2014
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]	'
Accumulated Other Comprehensive Income (Loss), Net of T ax	'
	The details of other comprehensive income (loss), net of tax, are as follows:
			Three Months Ended September 30,						Nine Months Ended September 30,
			2014			2013			2014			2013
	Foreign currency translation
	Balance at beginning of period		$	4.6		$	2.8		$	4.7		$	3.5
	Other comprehensive income (loss):
	Foreign currency translation gain (loss)		(2.5		)	1.2			(2.6		)	0.5
	Balance at end of period		$	2.1		$	4		$	2.1		$	4
	Cash flow hedges
	Balance at beginning of period		$	7.4		$	7.4		$	18.3		$	31.7
	Other comprehensive income (loss):
	Gains (losses) arising in period		(2.7		)	10.3			(9.6		)	0.6
	Income tax expense		—			—			—			—
	Gains (losses) arising in period, net of tax		(2.7		)	10.3			(9.6		)	0.6
	Reclassification of losses (gains) to net income (loss):
	Hot roll carbon steel coil contracts (a)		—			—			—			(0.4		)
	Other commodity contracts (b)		3.9			(5.9		)	(0.1		)	(20.1		)
	Subtotal		3.9			(5.9		)	(0.1		)	(20.5		)
	Income tax expense		—			—			—			—
	Net amount of reclassification of losses (gains) to net income (loss)		3.9			(5.9		)	(0.1		)	(20.5		)
	Total other comprehensive income (loss), net of tax		1.2			4.4			(9.7		)	(19.9		)
	Balance at end of period		$	8.6		$	11.8		$	8.6		$	11.8
	Unrealized holding gains (losses) on securities
	Balance at beginning of period		$	0.4		$	0.5		$	0.4		$	0.3
	Other comprehensive income (loss):
	Unrealized holding gains arising in period		—			—			—			0.2
	Income tax expense		—			—			—			—
	Unrealized holding gains (losses) arising in period, net of tax		—			—			—			0.2
	Balance at end of period		$	0.4		$	0.5		$	0.4		$	0.5
	Pension and OPEB plans
	Balance at beginning of period		$	259.6		$	(58.2	)	$	300		$	(34.4	)
	Other comprehensive income (loss):
	Prior service credit (cost) arising in period		(2.1		)	(6.1		)	(2.1		)	(6.1		)
	Gains (losses) arising in period		(3.0		)	9.6			(8.3		)	9.6
	Income tax expense		—			—			—			—
	Gains (losses) arising in period, net of tax		(5.1		)	3.5			(10.4		)	3.5
	Reclassification to net income (loss):
	Prior service costs (credits) (c)		(17.2		)	(19.1		)	(51.7		)	(57.3		)
	Actuarial (gains) losses (c)		1			6.6			0.4			21
	Subtotal		(16.2		)	(12.5		)	(51.3		)	(36.3		)
	Income tax expense		—			—			—			—
	Amount of reclassification to net income (loss), net of tax		(16.2		)	(12.5		)	(51.3		)	(36.3		)
	Total other comprehensive income (loss), net of tax		(21.3		)	(9.0		)	(61.7		)	(32.8		)
	Balance at end of period		$	238.3		$	(67.2	)	$	238.3		$	(67.2	)
	(a)	Amounts are included in net sales on the Condensed Consolidated Statements of Operations.
	(b)	Amounts are included in cost of products sold on the Condensed Consolidated Statements of Operations.
	(c)	Amounts are included in pension and OPEB expense (income) on the Condensed Consolidated Statements of Operations.

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Earnings per share	'
		Three Months Ended September 30,						Nine Months Ended September 30,
		2014			2013			2014			2013
	Net income (loss) attributable to AK Steel Holding Corporation	$	(7.2	)	$	(31.7	)	$	(110.4	)	$	(82.0	)
	Less: distributed earnings to common stockholders and holders of certain stock compensation awards	—			—			—			—
	Undistributed earnings (loss)	$	(7.2	)	$	(31.7	)	$	(110.4	)	$	(82.0	)
	Common stockholders earnings—basic and diluted:
	Distributed earnings to common stockholders	$	—		$	—		$	—		$	—
	Undistributed earnings (loss) to common stockholders	(7.2		)	(31.6		)	(110.0		)	(81.7		)
	Common stockholders earnings (loss)—basic and diluted	$	(7.2	)	$	(31.6	)	$	(110.0	)	$	(81.7	)
	Common shares outstanding (weighted-average shares in millions):
	Common shares outstanding for basic earnings per share	142.8			135.9			138.4			135.8
	Effect of exchangeable debt	—			—			—			—
	Effect of dilutive stock-based compensation	—			—			—			—
	Common shares outstanding for diluted earnings per share	142.8			135.9			138.4			135.8
	Basic and diluted earnings per share:
	Distributed earnings	$	—		$	—		$	—		$	—
	Undistributed earnings (loss)	(0.05		)	(0.23		)	(0.79		)	(0.60		)
	Basic and diluted earnings (loss) per share	$	(0.05	)	$	(0.23	)	$	(0.79	)	$	(0.60	)
	Potentially issuable common shares (in millions) excluded from earnings per share calculation due to anti-dilutive effect	13.3			2.5			10.6			2.5

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair value assets and liabilities measured on a recurring basis	'
	The following table presents information about the Company’s assets and liabilities measured at fair value on a recurring basis:
		September 30, 2014								December 31, 2013
		Level 1		Level 2			Total			Level 1		Level 2			Total
	Assets measured at fair value
	Cash and cash equivalents	$	60.8	$	—		$	60.8		$	45.3	$	—		$	45.3
	Other current assets:
	Foreign exchange contracts	—		1.4			1.4			—		—			—
	Commodity hedge contracts	—		3			3			—		4.9			4.9
	Other non-current assets:
	Available for sale investments—cash and cash equivalents	3.3		—			3.3			18.6		—			18.6
	Assets measured at fair value	$	64.1	$	4.4		$	68.5		$	63.9	$	4.9		$	68.8
	Liabilities measured at fair value
	Accrued liabilities:
	Foreign exchange contracts	$	—	$	—		$	—		$	—	$	(0.7	)	$	(0.7	)
	Commodity hedge contracts	—		(26.8		)	(26.8		)	—		(0.4		)	(0.4		)
	Other non-current liabilities—commodity hedge contracts	—		(1.3		)	(1.3		)	—		(0.1		)	(0.1		)
	Liabilities measured at fair value	$	—	$	(28.1	)	$	(28.1	)	$	—	$	(1.2	)	$	(1.2	)
	Liabilities measured at other than fair value
	Long-term debt, including current portions:
	Fair value	$	—	$	(2,573.6	)	$	(2,573.6	)	$	—	$	(1,659.9	)	$	(1,659.9	)
	Carrying amount	—		(2,406.6		)	(2,406.6		)	—		(1,507.0		)	(1,507.0		)

Derivative_Instruments_and_Hed1

Derivative Instruments and Hedging Activities (Tables)	9 Months Ended
	Sep. 30, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Outstanding commodity price swaps and options and forward foreign exchange contracts	'
	The Company had the following outstanding commodity price swaps and options and forward foreign exchange contracts:
	Commodity		September 30,				December 31, 2013
			2014
	Nickel (in lbs)		382,400				763,300
	Natural gas (in MMBTUs)		17,232,500				3,240,000
	Zinc (in lbs)		15,000,000				12,000,000
	Electricity (in MWHs)		767,000				—
	Iron ore (in metric tons)		1,084,200				190,735
	Hot roll carbon steel coils (in short tons)		87,800				74,147
	Foreign exchange contracts (in euros)		€	19,640,000			€	17,730,000
Fair value of derivative instruments in the Condensed Consolidated Balance Sheets	'
	The following table presents the fair value of derivative instruments in the Condensed Consolidated Balance Sheets:
	Asset (liability)		September 30,				December 31, 2013
			2014
	Derivatives designated as hedging instruments:
	Other current assets—commodity contracts		$	2.3			$	2.6
	Accrued liabilities—commodity contracts		(6.7		)		—
	Other non-current liabilities—commodity contracts		(0.8		)		—
	Derivatives not designated as hedging instruments:
	Other current assets:
	Foreign exchange contracts		1.4				—
	Commodity contracts		0.7				2.3
	Accrued liabilities:
	Foreign exchange contracts		—				(0.7		)
	Commodity contracts		(20.1		)		(0.4		)
	Other noncurrent liabilities—commodity contracts		(0.5		)		(0.1		)
Gains (losses) on derivative instruments included in the Condensed Consolidated Statements of Operations	'
	The following table presents gains (losses) on derivative instruments included in the Condensed Consolidated Statements of Operations:
			Three Months Ended September 30,							Nine Months Ended September 30,
	Gain (loss)		2014				2013			2014			2013
	Derivatives designated as cash flow hedges—
	Commodity contracts:
	Reclassified from accumulated other comprehensive income into net sales (effective portion)		$	—			$	—		$	—		$	0.4
	Reclassified from accumulated other comprehensive income into cost of products sold (effective portion)		(3.9		)		5.9			0.1			20.1
	Recognized in cost of products sold (ineffective portion and amount excluded from effectiveness testing)		(3.8		)		(3.1		)	(4.5		)	3.3
	Derivatives not designated as hedging instruments:
	Foreign exchange contracts—recognized in other income (expense)		(0.2		)		(0.7		)	0.7			(0.2		)
	Commodity contracts:
	Recognized in net sales		(1.8		)		0.2			(6.0		)	0.4
	Recognized in cost of products sold		(11.2		)		0.6			(30.4		)	0.4
Amount of gains (losses) expected to be reclassified into earnings within the next twelve months	'
	The following table lists the amount of gains (losses) before tax expected to be reclassified into cost of products sold within the next twelve months for the Company’s existing commodity contracts that qualify for hedge accounting, as well as the period of time over which the Company is hedging its exposure to the volatility in future cash flows:
	Commodity Hedge	Settlement Dates		Gains (losses)
	Natural gas	October 2014 to December 2016		$	2.8
	Zinc	October 2014 to December 2016		0.3
	Electricity	October 2014 to December 2015		1.2
	Iron ore	October 2014 to November 2016		(10.9		)

Supplemental_Cash_Flow_Informa1

Supplemental Cash Flow Information (Tables)	9 Months Ended
	Sep. 30, 2014
Supplemental Cash Flow Information [Abstract]	'
Schedule of cash flow, supplemental disclosures	'
	The following table presents the net cash paid (received) during the period for interest, net of capitalized interest, and income taxes:
		Nine Months Ended September 30,
		2014			2013
	Net cash paid (received) during the period for:
	Interest, net of capitalized interest	$	62.9		$	60
	Income taxes	(0.5		)	1.1
Schedule of non-cash investing and financing activities	'
	The amounts of non-cash investing and financing activities were as follows:
		Nine Months Ended September 30,
		2014			2013
	Capital investments	$	7.6		$	5.4
	Issuance of restricted stock and restricted stock units	4			2.7

Supplemental_Guarantor_Informa1

Supplemental Guarantor Information (Tables)	9 Months Ended
	Sep. 30, 2014
Supplemental Guarantor Information [Abstract]	'
Schedule of Condensed Comprehensive Income (Loss)	'
	Condensed Consolidated Statements of Comprehensive Income (Loss)
	Three Months Ended September 30, 2014
		AK			AK			Guarantor Subsidiaries of the Senior Notes			Other Non-Guarantor Subsidiaries			Eliminations			Consolidated Company
		Holding			Steel
	Net sales	$	—		$	1,552.50		$	69.7		$	135.7		$	(164.1	)	$	1,593.80
	Cost of products sold (exclusive of items shown separately below)	—			1,433.10			50.1			104.4			(148.7		)	1,438.90
	Selling and administrative expenses (exclusive of items shown separately below)	1			65.2			2.9			7.7			(11.2		)	65.6
	Depreciation	—			42.7			1.1			5.3			—			49.1
	Pension and OPEB expense (income)	—			(23.5		)	—			—			—			(23.5		)
	Total operating costs	1			1,517.50			54.1			117.4			(159.9		)	1,530.10
	Operating profit (loss)	(1.0		)	35			15.6			18.3			(4.2		)	63.7
	Interest expense	—			34.8			—			0.8			—			35.6
	Other income (expense)	—			(15.8		)	1.6			(1.1		)	—			(15.3		)
	Income (loss) before income taxes	(1.0		)	(15.6		)	17.2			16.4			(4.2		)	12.8
	Income tax expense (benefit)	—			(1.5		)	6.9			0.2			(1.7		)	3.9
	Equity in net income (loss) of subsidiaries	(6.2		)	7.9			—			—			(1.7		)	—
	Net income (loss)	(7.2		)	(6.2		)	10.3			16.2			(4.2		)	8.9
	Less: Net income attributable to noncontrolling interests	—			—			—			16.1			—			16.1
	Net income (loss) attributable to AK Steel Holding Corporation	(7.2		)	(6.2		)	10.3			0.1			(4.2		)	(7.2		)
	Other comprehensive income (loss)	(22.6		)	(22.6		)	—			(2.5		)	25.1			(22.6		)
	Comprehensive income (loss) attributable to AK Steel Holding Corporation	$	(29.8	)	$	(28.8	)	$	10.3		$	(2.4	)	$	20.9		$	(29.8	)
	Condensed Consolidated Statements of Comprehensive Income (Loss)
	Three Months Ended September 30, 2013
		AK			AK			Guarantor Subsidiaries of the Senior Notes			Other Non-Guarantor Subsidiaries			Eliminations			Consolidated Company
		Holding			Steel
	Net sales	$	—		$	1,284.10		$	63		$	137.3		$	(153.1	)	$	1,331.30
	Cost of products sold (exclusive of items shown separately below)	—			1,206.40			45.9			112.5			(142.4		)	1,222.40
	Selling and administrative expenses (exclusive of items shown separately below)	1			50.8			2.6			6.8			(9.7		)	51.5
	Depreciation	—			43.1			1.2			4.1			—			48.4
	Pension and OPEB expense (income)	—			(16.9		)	—			—			—			(16.9		)
	Total operating costs	1			1,283.40			49.7			123.4			(152.1		)	1,305.40
	Operating profit (loss)	(1.0		)	0.7			13.3			13.9			(1.0		)	25.9
	Interest expense	—			31.7			—			0.4			—			32.1
	Other income (expense)	—			(1.9		)	1.5			(2.4		)	—			(2.8		)
	Income (loss) before income taxes	(1.0		)	(32.9		)	14.8			11.1			(1.0		)	(9.0		)
	Income tax expense (benefit)	—			3.6			5.5			(1.9		)	(0.5		)	6.7
	Equity in net income (loss) of subsidiaries	(30.7		)	5.8			—			—			24.9			—
	Net income (loss)	(31.7		)	(30.7		)	9.3			13			24.4			(15.7		)
	Less: Net income attributable to noncontrolling interests	—			—			—			16			—			16
	Net income (loss) attributable to AK Steel Holding Corporation	(31.7		)	(30.7		)	9.3			(3.0		)	24.4			(31.7		)
	Other comprehensive income (loss)	(3.4		)	(3.4		)	—			1.2			2.2			(3.4		)
	Comprehensive income (loss) attributable to AK Steel Holding Corporation	$	(35.1	)	$	(34.1	)	$	9.3		$	(1.8	)	$	26.6		$	(35.1	)
	Condensed Consolidated Statements of Comprehensive Income (Loss)
	Nine Months Ended September 30, 2014
		AK			AK			Guarantor Subsidiaries of the Senior Notes			Other Non-Guarantor Subsidiaries			Eliminations			Consolidated Company
		Holding			Steel
	Net sales	$	—		$	4,350.70		$	209.8		$	393.7		$	(446.1	)	$	4,508.10
	Cost of products sold (exclusive of items shown separately below)	—			4,141.10			151.6			309			(410.3		)	4,191.40
	Selling and administrative expenses (exclusive of items shown separately below)	3.6			177.9			8.6			22.3			(32.7		)	179.7
	Depreciation	—			127.5			3.1			15.7			—			146.3
	Pension and OPEB expense (income)	—			(74.2		)	—			—			—			(74.2		)
	Total operating costs	3.6			4,372.30			163.3			347			(443.0		)	4,443.20
	Operating profit (loss)	(3.6		)	(21.6		)	46.5			46.7			(3.1		)	64.9
	Interest expense	—			99			—			2			—			101
	Other income (expense)	—			(23.5		)	4.9			(1.6		)	—			(20.2		)
	Income (loss) before income taxes	(3.6		)	(144.1		)	51.4			43.1			(3.1		)	(56.3		)
	Income tax expense (benefit)	—			(10.8		)	20.6			(1.0		)	(1.3		)	7.5
	Equity in net income (loss) of subsidiaries	(106.8		)	26.5			—			—			80.3			—
	Net income (loss)	(110.4		)	(106.8		)	30.8			44.1			78.5			(63.8		)
	Less: Net income attributable to noncontrolling interests	—			—			—			46.6			—			46.6
	Net income (loss) attributable to AK Steel Holding Corporation	(110.4		)	(106.8		)	30.8			(2.5		)	78.5			(110.4		)
	Other comprehensive income (loss)	(74.0		)	(74.0		)	—			(2.6		)	76.6			(74.0		)
	Comprehensive income (loss) attributable to AK Steel Holding Corporation	$	(184.4	)	$	(180.8	)	$	30.8		$	(5.1	)	$	155.1		$	(184.4	)
Condensed Consolidated Statements of Comprehensive Income (Loss)
Nine Months Ended September 30, 2013
	AK			AK			Guarantor Subsidiaries of the Senior Notes			Other Non-Guarantor Subsidiaries			Eliminations			Consolidated Company
	Holding			Steel
Net sales	$	—		$	3,917.30		$	196.6		$	430		$	(438.3	)	$	4,105.60
Cost of products sold (exclusive of items shown separately below)	—			3,688.80			142.2			360.8			(407.9		)	3,783.90
Selling and administrative expenses (exclusive of items shown separately below)	3.5			152.2			7.9			20			(30.3		)	153.3
Depreciation	—			129.8			3.4			11.7			—			144.9
Pension and OPEB expense (income)	—			(49.3		)	—			—			—			(49.3		)
Total operating costs	3.5			3,921.50			153.5			392.5			(438.2		)	4,032.80
Operating profit (loss)	(3.5		)	(4.2		)	43.1			37.5			(0.1		)	72.8
Interest expense	—			94.1			—			1			—			95.1
Other income (expense)	—			(2.6		)	4.6			(0.5		)	—			1.5
Income (loss) before income taxes	(3.5		)	(100.9		)	47.7			36			(0.1		)	(20.8		)
Income tax expense (benefit)	—			(0.6		)	18.7			(4.4		)	(0.1		)	13.6
Equity in net income (loss) of subsidiaries	(78.5		)	21.8			—			—			56.7			—
Net income (loss)	(82.0		)	(78.5		)	29			40.4			56.7			(34.4		)
Less: Net income attributable to noncontrolling interests	—			—			—			47.6			—			47.6
Net income (loss) attributable to AK Steel Holding Corporation	(82.0		)	(78.5		)	29			(7.2		)	56.7			(82.0		)
Other comprehensive income (loss)	(52.0		)	(52.0		)	—			0.5			51.5			(52.0		)
Comprehensive income (loss) attributable to AK Steel Holding Corporation	$	(134.0	)	$	(130.5	)	$	29		$	(6.7	)	$	108.2		$	(134.0	)
Condensed Balance Sheet [Table Text Block]	'
	Condensed Consolidated Balance Sheets
	September 30, 2014
		AK			AK			Guarantor Subsidiaries of the Senior Notes			Other Non-Guarantor Subsidiaries			Eliminations			Consolidated Company
		Holding			Steel
	ASSETS
	Current assets:
	Cash and cash equivalents	$	—		$	21		$	0.2		$	39.6		$	—		$	60.8
	Accounts receivable, net	—			673.7			32.7			33.3			(32.1		)	707.6
	Inventory, net	—			1,031.20			31			78.1			(14.3		)	1,126.00
	Deferred tax assets, current	—			74.5			—			0.2			—			74.7
	Other current assets	0.3			72.6			0.3			3.1			—			76.3
	Total current assets	0.3			1,873.00			64.2			154.3			(46.4		)	2,045.40
	Property, plant and equipment	—			5,646.80			96.1			593			—			6,335.90
	Accumulated depreciation	—			(3,993.0		)	(70.9		)	(56.9		)	—			(4,120.8		)
	Property, plant and equipment, net	—			1,653.80			25.2			536.1			—			2,215.10
	Other non-current assets:
	Investments in affiliates	—			97.8			—			298.7			—			396.5
	Investment in subsidiaries	(2,223.7		)	1,571.30			—			—			652.4			—
	Inter-company accounts	2,138.50			(3,078.5		)	1,306.30			(403.0		)	36.7			—
	Other non-current assets	—			130.8			33			64.6			—			228.4
	TOTAL ASSETS	$	(84.9	)	$	2,248.20		$	1,428.70		$	650.7		$	642.7		$	4,885.40
	LIABILITIES AND EQUITY
	Current liabilities:
	Accounts payable	$	—		$	759.8		$	9.7		$	43.6		$	(0.8	)	$	812.3
	Accrued liabilities	—			260.6			3.1			18			—			281.7
	Current portion of long-term debt	—			0.2			—			—			—			0.2
	Current portion of pension and other postretirement benefit obligations	—			61.8			—			0.4			—			62.2
	Total current liabilities	—			1,082.40			12.8			62			(0.8		)	1,156.40
	Non-current liabilities:
	Long-term debt	—			2,406.40			—			—			—			2,406.40
	Pension and other postretirement benefit obligations	—			828.3			—			4.1			—			832.4
	Other non-current liabilities	—			123.8			—			0.6			—			124.4
	TOTAL LIABILITIES	—			4,440.90			12.8			66.7			(0.8		)	4,519.60
	Exchangeable notes exchange feature	—			31			—			—			—			31
	Equity:
	Total stockholders’ equity (deficit)	(84.9		)	(2,223.7		)	1,415.90			164.3			643.5			(84.9		)
	Noncontrolling interests	—			—			—			419.7			—			419.7
	TOTAL EQUITY	(84.9		)	(2,223.7		)	1,415.90			584			643.5			334.8
	TOTAL LIABILITIES AND EQUITY	$	(84.9	)	$	2,248.20		$	1,428.70		$	650.7		$	642.7		$	4,885.40
	Condensed Consolidated Balance Sheets
	December 31, 2013
		AK			AK			Guarantor Subsidiaries of the Senior Notes			Other Non-Guarantor Subsidiaries			Eliminations			Consolidated Company
		Holding			Steel
	ASSETS
	Current assets:
	Cash and cash equivalents	$	—		$	16.8		$	—		$	28.5		$	—		$	45.3
	Accounts receivable, net	—			492.4			25.2			35.9			(28.3		)	525.2
	Inventory, net	—			520			19.2			58.5			(11.1		)	586.6
	Deferred tax assets, current	—			69.4			—			0.2			—			69.6
	Other current assets	0.3			43.9			0.2			2.1			—			46.5
	Total current assets	0.3			1,142.50			44.6			125.2			(39.4		)	1,273.20
	Property, plant and equipment	—			5,258.40			94.9			518.6			—			5,871.90
	Accumulated depreciation	—			(3,881.7		)	(67.9		)	(42.2		)	—			(3,991.8		)
	Property, plant and equipment, net	—			1,376.70			27			476.4			—			1,880.10
	Other non-current assets:
	Investments in affiliates	—			—			—			209.8			—			209.8
	Investment in subsidiaries	(2,772.4		)	1,393.80			—			—			1,378.60			—
	Inter-company accounts	2,551.10			(3,479.7		)	1,269.60			(372.9		)	31.9			—
	Other non-current assets	—			141			33			68.6			—			242.6
	TOTAL ASSETS	$	(221.0	)	$	574.3		$	1,374.20		$	507.1		$	1,371.10		$	3,605.70
	LIABILITIES AND EQUITY
	Current liabilities:
	Accounts payable	$	—		$	550.5		$	6.3		$	45.6		$	(0.6	)	$	601.8
Accrued liabilities	—			133.6			2.9			6.4			—			142.9
Current portion of long-term debt	—			0.8			—			—			—			0.8
Current portion of pension and other postretirement benefit obligations	—			85.4			—			0.5			—			85.9
Total current liabilities	—			770.3			9.2			52.5			(0.6		)	831.4
Non-current liabilities:
Long-term debt	—			1,506.20			—			—			—			1,506.20
Pension and other postretirement benefit obligations	—			960.6			—			4.8			—			965.4
Other non-current liabilities	—			109.6			—			0.4			—			110
TOTAL LIABILITIES	—			3,346.70			9.2			57.7			(0.6		)	3,413.00
Equity:
Total stockholders’ equity (deficit)	(221.0		)	(2,772.4		)	1,365.00			35.7			1,371.70			(221.0		)
Noncontrolling interests	—			—			—			413.7			—			413.7
TOTAL EQUITY	(221.0		)	(2,772.4		)	1,365.00			449.4			1,371.70			192.7
TOTAL LIABILITIES AND EQUITY	$	(221.0	)	$	574.3		$	1,374.20		$	507.1		$	1,371.10		$	3,605.70
Schedule of Condensed Cash Flow Statement	'
	Condensed Consolidated Statements of Cash Flows
	Nine Months Ended September 30, 2014
		AK			AK			Guarantor Subsidiaries of the Senior Notes			Other Non-Guarantor Subsidiaries			Eliminations			Consolidated Company
		Holding			Steel
	Net cash flows from operating activities	$	1.2		$	(476.2	)	$	18.7		$	70.7		$	5		$	(380.6	)
	Cash flows from investing activities:
	Capital investments	—			(25.2		)	(1.9		)	(12.2		)	—			(39.3		)
	Investments in Magnetation joint venture	—			—			—			(90.0		)	—			(90.0		)
	Investment in acquired business, net of cash acquired	—			(677.2		)	—			—			—			(677.2		)
	Other investing items, net	—			15.4			—			—			—			15.4
	Net cash flows from investing activities	—			(687.0		)	(1.9		)	(102.2		)	—			(791.1		)
	Cash flows from financing activities:
	Net borrowings under credit facility	—			470			—			—			—			470
	Proceeds from issuance of long-term debt	—			427.1			—			—			—			427.1
	Redemption of long-term debt	—			(0.6		)	—			—			—			(0.6		)
	Proceeds from issuance of common stock	345.3			—			—			—			—			345.3
	Debt issuance costs	—			(10.6		)	—			—			—			(10.6		)
	Inter-company activity	(345.6		)	281.4			(16.6		)	85.8			(5.0		)	—
	SunCoke Middletown distributions to noncontrolling interest owners	—			—			—			(40.6		)	—			(40.6		)
	Other financing items, net	(0.9		)	0.1			—			(2.6		)	—			(3.4		)
	Net cash flows from financing activities	(1.2		)	1,167.40			(16.6		)	42.6			(5.0		)	1,187.20
	Net increase (decrease) in cash and cash equivalents	—			4.2			0.2			11.1			—			15.5
	Cash and equivalents, beginning of period	—			16.8			—			28.5			—			45.3
	Cash and equivalents, end of period	$	—		$	21		$	0.2		$	39.6		$	—		$	60.8
	Condensed Consolidated Statements of Cash Flows
	Nine Months Ended September 30, 2013
		AK			AK			Guarantor Subsidiaries of the Senior Notes			Other Non-Guarantor Subsidiaries			Eliminations			Consolidated Company
		Holding			Steel
	Net cash flows from operating activities	$	(2.8	)	$	(325.4	)	$	37.3		$	73.1		$	(5.9	)	$	(223.7	)
	Cash flows from investing activities:
	Capital investments	—			(31.6		)	(0.7		)	(15.8		)	—			(48.1		)
	Investments in Magnetation joint venture	—			—						(50.0		)	—			(50.0		)
	Other investing items, net	—			4.8			(0.3		)	10.6			—			15.1
	Net cash flows from investing activities	—			(26.8		)	(1.0		)	(55.2		)	—			(83.0		)
	Cash flows from financing activities:
	Net borrowings under credit facility	—			185			—			—			—			185
	Proceeds from issuance of long-term debt	—			31.9			—			—			—			31.9
	Redemption of long-term debt	—			(27.2		)	—			—			—			(27.2		)
	Debt issuance costs	—			(3.1		)	—			—			—			(3.1		)
	Inter-company activity	3.5			(9.9		)	(36.2		)	36.7			5.9			—
	SunCoke Middletown distributions to noncontrolling interest owners	—			—			—			(41.1		)	—			(41.1		)
	Other financing items, net	(0.7		)	—			—			0.6			—			(0.1		)
	Net cash flows from financing activities	2.8			176.7			(36.2		)	(3.8		)	5.9			145.4
	Net increase (decrease) in cash and cash equivalents	—			(175.5		)	0.1			14.1			—			(161.3		)
	Cash and equivalents, beginning of period	—			203.6			—			23.4			—			227
	Cash and equivalents, end of period	$	—		$	28.1		$	0.1		$	37.5		$	—		$	65.7

Acquisition_of_Dearborn_Detail

Acquisition of Dearborn (Details) (Severstal Dearborn [Member], USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 16, 2014
Severstal Dearborn [Member]	'	'	'
Business Acquisition [Line Items]	'	'	'
Cash and cash equivalents	'	'	$29.30
Accounts receivable	'	'	152.2
Inventory	'	'	362.2
Other current assets	'	'	3.6
Property, plant and equipment	'	'	446.3
Investment in affilates	'	'	97.5
Total assets acquired	'	'	1,091.10
Accounts payable	'	'	-204.3
Accrued liabilities	'	'	-36.9
Other postretirement benefit obligations	'	'	-121.8
Other non-current liabilities	'	'	-7.1
Total liabilities assumed	'	'	-370.1
Preliminary purchase price (including estimate for working capital adjustment)	'	'	721
Business Acquisition, Pro Forma Revenue	5,945.10	5,612.40	'
Business Acquisition, Pro Forma Operating Profit (Loss)	($889.30)	$131.10	'

Acquisition_of_Dearborn_Detail1

Acquisition of Dearborn (Details2) (USD $)

0 Months Ended

0 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

In Millions, except Per Share data, unless otherwise specified

Sep. 16, 2014

Sep. 16, 2014

Sep. 16, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Severstal Dearborn [Member]

Severstal Dearborn [Member]

Severstal Dearborn [Member]

Other Income (Expense) [Member]

Other Income (Expense) [Member]

Selling, General and Administrative Expenses [Member]

Selling, General and Administrative Expenses [Member]

Senior Notes Due October 2021 [Member]

Senior Notes Due October 2021 [Member]

Weighted Average [Member]

Severstal Dearborn [Member]

Severstal Dearborn [Member]

Severstal Dearborn [Member]

Severstal Dearborn [Member]

Machinery and Equipment [Member]

Severstal Dearborn [Member]

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Payments to Acquire Businesses, Gross

'

'

$706.50

'

'

'

'

'

'

'

'

'

Business Combination, Contingent Consideration, Liability

'

'

'

14.5

14.5

'

'

'

'

'

'

'

Debt Instrument, Face Amount

'

'

'

'

'

'

'

'

'

430

430

'

Debt Instrument, Interest Rate, Stated Percentage

'

'

'

'

'

'

'

'

'

7.63%

7.63%

'

Debt Instrument, Maturity Date

'

'

'

'

'

'

'

'

'

'

1-Oct-21

'

Debt Instrument Offering Price

'

'

'

'

'

'

'

'

'

99.33%

'

'

Common Stock, Shares, Issued

40.25

'

'

'

'

'

'

'

'

'

'

'

Shares Issued, Price Per Share

'

$9

'

'

'

'

'

'

'

'

'

'

Business Combination, Acquisition Related Costs

'

'

'

'

'

'

'

6.3

7.3

'

'

'

Business Combination, Additional Disclosures, Unused Bridge Commitment Expensed

'

'

'

'

'

12.6

12.6

'

'

'

'

'

Business Combination, Additional Disclosures, Severance Costs Expensed

'

'

'

'

'

'

'

2.6

2.6

'

'

'

Business Combination, Additional Disclosures, Income Tax Charge

'

'

'

2.1

2.1

'

'

'

'

'

'

'

Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual

'

'

'

90

90

'

'

'

'

'

'

'

Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual

'

'

'

2.1

2.1

'

'

'

'

'

'

'

Property, Plant and Equipment, Useful Life

'

'

'

'

'

'

'

'

'

'

'

'20 years

Business Combination, Pro Forma, Asset Impairment Charge

'

'

'

'

$1,005.10

'

'

'

'

'

'

'

Inventories_Details

Inventories (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Inventory Disclosure [Abstract]	'	'
Finished and semi-finished	$1,103.30	$722.20
Raw materials	403.5	260.9
Total cost	1,506.80	983.1
Adjustment to state inventories at LIFO value	-380.8	-396.5
Inventory, net	$1,126	$586.60

Investments_in_Affiliates_Deta

Investments in Affiliates (Details) (USD $)

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

9 Months Ended

1 Months Ended

In Millions, unless otherwise specified

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Oct. 04, 2011

Sep. 30, 2014

Sep. 30, 2014

Oct. 31, 2014

Other Nonoperating Income (Expense) [Member]

Other Nonoperating Income (Expense) [Member]

Other Nonoperating Income (Expense) [Member]

Other Nonoperating Income (Expense) [Member]

Cost of Sales [Member]

Cost of Sales [Member]

Cost of Sales [Member]

Cost of Sales [Member]

Combined Metals of Chicago, LLC [Member]

Delaco Processing, LLC [Member]

Double Eagle Steel Coating Company [Member]

Magnetation LLC [Member]

Magnetation LLC [Member]

Rockport Roll Shop LLC [Member]

Spartan Steel Coating, LLC [Member]

Subsequent Event [Member]

Magnetation LLC [Member]

Schedule of Equity Method Investments [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Equity Method Investment, Ownership Percentage

'

'

'

'

'

'

'

'

'

'

'

'

40.00%

49.00%

50.00%

[1]

49.90%

'

50.00%

48.00%

'

Income (Loss) from Equity Method Investments

'

'

'

'

($2.20)

($3.40)

($6)

($2.30)

$3.40

$1.80

$8.50

$5.90

'

'

'

'

'

'

'

'

Revenue

87.4

76.2

245.1

220.1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Gross profit

25.3

26.4

73.3

77.9

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net income

7.3

0.7

17.7

17.2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Other Commitment

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

297.5

'

'

'

Payments to Acquire Equity Method Investments

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

90

'

'

'

10

Equity Method Investment, Difference Between Carrying Amount and Underlying Equity

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$116.20

'

'

'

'

[1]

Double Eagle Steel Coating Company (bDESCOb) is a joint venture between United States Steel Corporation (bUS Steelb) and AK Steel that was acquired as part of the Dearborn acquisition. On April 1, 2013, Dearborn sent to US Steel a notice of dissolution of the joint venture in accordance with the terms of the joint venture agreement. The notice provided that the joint venture would dissolve two years from the date of the notice. On September 16, 2014, the Company acquired Dearborn, which included Dearbornbs 50% interest in DESCO. Shortly prior to the Companybs acquisition of Dearborn, US Steel notified the Company that it believed it had a right under the joint venture agreement to purchase Dearbornbs interest in DESCO prior to it being sold to the Company. US Steel has taken the position that the Company now must sell to it the 50% ownership interest in DESCO formerly owned by Dearborn. The Company has notified US Steel that the Company rejects US Steelbs position, but the Company is willing to discuss a potential sale of its ownership interest in DESCO to US Steel in lieu of proceeding with the dissolution of the joint venture. US Steel and the Company are engaged in discussions to resolve this dispute.

Income_Taxes_Details

Income Taxes (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Tax Disclosure [Abstract]	'	'	'	'
Valuation allowance charge	$6.40	$15.30	$45.50	$37.10
Severstal Dearborn [Member]	'	'	'	'
Income Tax Disclosure [Abstract]	'	'	'	'
Business Combination, Additional Disclosures, Income Tax Charge	$2.10	'	$2.10	'

Longterm_Debt_and_Other_Financ2

Long-term Debt and Other Financing Long-term debt table (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Debt Instrument [Line Items]	'	'
Unamortized debt (discount) premium, net	($32.90)	($33.10)
Total debt	2,406.60	1,507
Current portion of long-term debt	0.2	0.8
Total long-term debt	2,406.40	1,506.20
Senior Secured Notes Due December 2018 [Member]	'	'
Debt Instrument [Line Items]	'	'
Long-term Debt, Gross	380	380
Debt Instrument, Interest Rate, Stated Percentage	8.75%	8.75%
Exchangeable Senior Notes Due November 2019 [Member]	'	'
Debt Instrument [Line Items]	'	'
Long-term Debt, Gross	150	150
Debt Instrument, Interest Rate, Stated Percentage	5.00%	5.00%
Debt Instrument, Interest Rate, Effective Percentage	10.80%	10.80%
Debt Instrument, Convertible, Terms of Conversion Feature	'Among other things, the indenture governing the Exchangeable Notes provides noteholders with an exchange right at the option of the noteholders, in the event that the closing price of the Companybs common stock is greater than or equal to $7.02 per share (130% of the exchange price of the Exchangeable Notes) for at least 20 trading days during the last 30 consecutive trading days of a calendar quarter.	'
Senior Notes Due May 2020 [Member]	'	'
Debt Instrument [Line Items]	'	'
Long-term Debt, Gross	529.8	529.8
Debt Instrument, Interest Rate, Stated Percentage	7.63%	7.63%
Senior Notes Due October 2021 [Member]	'	'
Debt Instrument [Line Items]	'	'
Long-term Debt, Gross	430	0
Debt Instrument, Interest Rate, Stated Percentage	7.63%	'
Senior Notes Due April 2022 [Member]	'	'
Debt Instrument [Line Items]	'	'
Long-term Debt, Gross	290.2	290.2
Debt Instrument, Interest Rate, Stated Percentage	8.38%	8.38%
Industrial Revenue Bonds [Member]	'	'
Debt Instrument [Line Items]	'	'
Long-term Debt, Gross	99.5	100.1
Revolving Credit Facility [Member]	'	'
Debt Instrument [Line Items]	'	'
Credit Facility	$560	$90

Longterm_Debt_and_Other_Financ3

Long-term Debt and Other Financing (Details2) (USD $)

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Mar. 31, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Replaced Credit Facility [Member]

Senior Notes Due October 2021 [Member]

Senior Notes Due October 2021 [Member]

Exchangeable Senior Notes Due November 2019 [Member]

Exchangeable Senior Notes Due November 2019 [Member]

Senior Notes Due May 2020 [Member]

Senior Notes Due May 2020 [Member]

Senior Notes Due April 2022 [Member]

Senior Notes Due April 2022 [Member]

Debt Instrument, Redemption, Period One [Member]

Debt Instrument, Redemption, Period Two [Member]

Debt Instrument, Redemption, Period Three [Member]

Debt Instrument, Redemption, Period Four [Member]

Senior Notes Due October 2021 [Member]

Senior Notes Due October 2021 [Member]

Senior Notes Due October 2021 [Member]

Senior Notes Due October 2021 [Member]

Line of Credit Facility [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Face Amount

'

'

'

'

'

$430,000,000

$430,000,000

$150,000,000

'

'

'

'

'

'

'

'

'

Debt Instrument, Interest Rate, Stated Percentage

'

'

'

'

'

7.63%

7.63%

5.00%

5.00%

7.63%

7.63%

8.38%

8.38%

'

'

'

'

Debt Instrument, Maturity Date

'

'

'

'

'

'

1-Oct-21

15-Nov-19

'

'

'

'

'

'

'

'

'

Debt Instrument Offering Price

'

'

'

'

'

99.33%

'

'

'

'

'

'

'

'

'

'

'

Proceeds from Debt, Net of Issuance Costs

'

'

'

'

'

418,600,000

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Redemption, Description

'

'

'

'

'

'

'

'

'

'

'

'

'

'Prior to October 1, 2017, AK Steel may redeem the 2021 Notes at a price equal to par plus a make-whole premium and all accrued and unpaid interest to the date of redemption.

'

'

'

Debt Instrument, Redemption Period, Start Date

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1-Oct-17

1-Oct-18

1-Oct-19

Debt Instrument, Redemption Period, End Date

'

'

'

'

'

'

'

'

'

'

'

'

'

30-Sep-17

30-Sep-18

30-Sep-19

30-Sep-20

Debt Instrument, Redemption Price, Percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

'

103.81%

101.91%

100.00%

Line of credit facility, maximum borrowing capacity

'

'

1,500,000,000

'

1,100,000,000

'

'

'

'

'

'

'

'

'

'

'

'

Minimum amount of borrowing capacity for a fixed charge coverage ratio applies

'

'

150,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Line of Credit Facility, Expiration Date

'

'

31-Mar-19

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Line of Credit Facility, Current Borrowing Capacity

'

'

1,500,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Outstanding borrowings on revolving credit facility

'

'

560,000,000

90,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Letters of credit, outstanding

'

'

71,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Line of credit facility, remaining borrowing capacity

'

'

868,600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Convertible, Terms of Conversion Feature

'

'

'

'

'

'

'

'Among other things, the indenture governing the Exchangeable Notes provides noteholders with an exchange right at the option of the noteholders, in the event that the closing price of the Companybs common stock is greater than or equal to $7.02 per share (130% of the exchange price of the Exchangeable Notes) for at least 20 trading days during the last 30 consecutive trading days of a calendar quarter.

'

'

'

'

'

'

'

'

'

Debt Instrument, Convertible, Stock Price Trigger

'

'

'

'

'

'

'

$7.02

'

'

'

'

'

'

'

'

'

Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger

'

'

'

'

'

'

'

130.00%

'

'

'

'

'

'

'

'

'

Debt Instrument, Convertible, Threshold Trading Days

'

'

'

'

'

'

'

20

'

'

'

'

'

'

'

'

'

Debt Instrument, Convertible, Threshold Consecutive Trading Days

'

'

'

'

'

'

'

'30 days

'

'

'

'

'

'

'

'

'

Exchangeable notes exchange feature

$31,000,000

$0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Pension_and_Other_Postretireme2

Pension and Other Postretirement Benefits (Details) (USD $)

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

In Millions, unless otherwise specified

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 16, 2014

Pension Plans, Defined Benefit [Member]

Pension Plans, Defined Benefit [Member]

Pension Plans, Defined Benefit [Member]

Pension Plans, Defined Benefit [Member]

Other Postretirement Benefit Plans, Defined Benefit [Member]

Other Postretirement Benefit Plans, Defined Benefit [Member]

Other Postretirement Benefit Plans, Defined Benefit [Member]

Other Postretirement Benefit Plans, Defined Benefit [Member]

Severstal Dearborn [Member]

Severstal Dearborn [Member]

Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Pension plan contributions

$196.50

$140.20

'

'

$196.50

'

'

'

'

'

'

'

Other Postretirement Defined Benefit Plan, Liabilities

'

'

'

'

'

'

'

'

'

'

'

121.8

Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate

'

'

'

'

'

'

'

'

'

'

4.45%

'

Net periodic benefit cost (income) [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

Service cost

'

'

0.5

0.7

1.2

1.9

1.1

1.1

3.1

3.5

'

'

Interest cost

'

'

36.6

34.7

109.6

104.1

5.2

5.3

15.3

15.8

'

'

Expected return on assets

'

'

-50.7

-46.2

-152.1

-138.3

'

'

'

'

'

'

Amortization of prior service cost (credit)

'

'

1.1

0.9

3.2

2.7

-18.3

-20

-54.9

-60

'

'

Amortization of (gain) loss

'

'

1.1

6.7

1.2

20

-0.3

0.7

-1

1.8

'

'

Settlement (gain)

'

'

-0.2

0.8

-0.2

0.8

'

'

'

'

'

'

Net periodic benefit cost (income)

'

'

-11.2

-4

-36.7

-10.4

-12.3

-12.9

-37.5

-38.9

'

'

Estimated Increase (Decrease) in Pension and Other Postretirement Benefit Expense After Business Combination

'

'

'

'

'

'

'

'

'

'

'

$2.40

Environmental_and_Legal_Contin2

Environmental and Legal Contingencies (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]	'	'
Accrued liabilities	$16.30	$9.50
Other non-current liabilities	$34.30	$34.10

Environmental_and_Legal_Contin3

Environmental and Legal Contingencies (Details 2) (USD $)	Sep. 30, 2014	Sep. 30, 2014	Oct. 17, 2012	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014	Jul. 17, 2014	31-May-14
In Millions, unless otherwise specified	Hamilton Plant [Member]	Mansfield OH Works [Member]	Mansfield OH Works [Member]	Ashland coke plant [Member]	Ambridge Works [Member]	Middletown Works RCRA Site [Member]	Dearborn Works [Member]	Mountain State Carbon, LLC [Member]	Mountain State Carbon, LLC [Member]
Site Contingency [Line Items]	'	'	'	'	'	'	'	'	'
Site contingency accrual, undiscounted amount	$0.70	$1.10	'	$0.50	$2.20	$13.80	$0.40	'	'
Proposed civil penalty related to environmental issue	'	'	$0.30	'	'	'	'	$2.40	$10.60

Environmental_and_Legal_Contin4

Environmental and Legal Contingencies (Details 3) (USD $)	3 Months Ended			9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013	Sep. 30, 2014		Sep. 30, 2013
	claims-lawsuits		claims-lawsuits	claims-lawsuits		claims-lawsuits
Asbestos Claims With Specific Dollar Claim For Damages [Member]	'		'	'		'
Information on pending asbestos cases [Line Items]	'		'	'		'
Number of asbestos cases pending	124	[1]	'	124	[1]	'
Claims with specific dollar claims for damages [Abstract]	'		'	'		'
Asbestos Lawsuits Pending With Dollars Number Of Plaintiffs	'		'	2,332		'
Asbestos Lawsuits Pending With Dollars Number Of Defendants	'		'	16,631		'
Asbestos Claims With Specific Dollar Claim For Damages [Member] | Asbestos claims up to $0.2 [Member]	'		'	'		'
Information on pending asbestos cases [Line Items]	'		'	'		'
Number of asbestos cases pending	114		'	114		'
Claims with specific dollar claims for damages [Abstract]	'		'	'		'
Amount claimed per plaintiff, lower range	'		'	$0		'
Amount claimed per plaintiff, upper range	'		'	200,000		'
Asbestos Claims With Specific Dollar Claim For Damages [Member] | Asbestos above $0.2 to $5.0 [Member]	'		'	'		'
Information on pending asbestos cases [Line Items]	'		'	'		'
Number of asbestos cases pending	6		'	6		'
Claims with specific dollar claims for damages [Abstract]	'		'	'		'
Amount claimed per plaintiff, lower range	'		'	200,000		'
Amount claimed per plaintiff, upper range	'		'	5,000,000		'
Asbestos Claims With Specific Dollar Claim For Damages [Member] | Asbestos above $5.0 to $15.0 [Member]	'		'	'		'
Information on pending asbestos cases [Line Items]	'		'	'		'
Number of asbestos cases pending	2		'	2		'
Claims with specific dollar claims for damages [Abstract]	'		'	'		'
Amount claimed per plaintiff, lower range	'		'	5,000,000		'
Amount claimed per plaintiff, upper range	'		'	15,000,000		'
Asbestos Claims With Specific Dollar Claim For Damages [Member] | Asbestos above $15.0 to $20.0 [Member]	'		'	'		'
Information on pending asbestos cases [Line Items]	'		'	'		'
Number of asbestos cases pending	2		'	2		'
Claims with specific dollar claims for damages [Abstract]	'		'	'		'
Amount claimed per plaintiff, lower range	'		'	15,000,000		'
Amount claimed per plaintiff, upper range	'		'	20,000,000		'
Asbestos Claims Without Specific Dollar Claim For Damages [Member]	'		'	'		'
Information on pending asbestos cases [Line Items]	'		'	'		'
Number of asbestos cases pending	314		'	314		'
Asbestos Issue [Member]	'		'	'		'
Information on pending asbestos cases [Line Items]	'		'	'		'
Number of asbestos cases pending	438		'	438		'
Claims with specific dollar claims for damages [Abstract]	'		'	'		'
Loss Contingency, New Claims Filed, Number	16		10	40		34
Loss Contingency, Claims Settled and Dismissed, Number	10		5	38		30
Amounts paid in asbestos settlements	$100,000		$0	$600,000		$900,000
[1]	Involve a total of 2,332 plaintiffs and 16,631 defendants

Environmental_and_Legal_Contin5

Environmental and Legal Contingencies (Details 4) (USD $)

9 Months Ended

3 Months Ended

In Millions, unless otherwise specified

Sep. 30, 2014

Jul. 31, 2013

Jul. 31, 2013

Jul. 31, 2013

Jul. 31, 2013

Mar. 05, 2014

Mar. 19, 2014

Mar. 19, 2014

Mar. 19, 2014

Sep. 30, 2014

Oct. 07, 2014

Oct. 07, 2014

Oct. 07, 2014

Oct. 07, 2014

Oct. 07, 2014

Oct. 07, 2014

Oct. 07, 2014

Oct. 07, 2014

Oct. 07, 2014

Oct. 07, 2014

Oct. 07, 2014

Oct. 07, 2014

Oct. 07, 2014

Oct. 07, 2014

Oct. 07, 2014

Antitrust Case [Member]

MOFCOM [Member]

MOFCOM [Member]

MOFCOM [Member]

MOFCOM [Member]

US Trade Case - GOES [Member]

US Trade Case - NOES [Member]

US Trade Case - NOES [Member]

US Trade Case - NOES [Member]

Breach Of Contract Case [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Maximum [Member]

Maximum [Member]

Maximum [Member]

Maximum [Member]

Maximum [Member]

Maximum [Member]

Minimum [Member]

Minimum [Member]

Minimum [Member]

Minimum [Member]

Minimum [Member]

Minimum [Member]

Preliminary [Member]

Final [Member]

Final [Member]

Final [Member]

Preliminary [Member]

Preliminary [Member]

Preliminary [Member]

Preliminary [Member]

US Trade Case - NOES [Member]

US Trade Case - NOES [Member]

US Trade Case - NOES [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Countervailing Duty [Member]

CHINA

Antidumping Duty [Member]

Countervailing Duty [Member]

Countervailing Duty [Member]

Countervailing Duty [Member]

Countervailing Duty [Member]

Countervailing Duty [Member]

Final [Member]

Final [Member]

Final [Member]

US Trade Case - NOES [Member]

US Trade Case - NOES [Member]

US Trade Case - NOES [Member]

US Trade Case - NOES [Member]

US Trade Case - NOES [Member]

US Trade Case - NOES [Member]

US Trade Case - NOES [Member]

US Trade Case - NOES [Member]

US Trade Case - NOES [Member]

US Trade Case - NOES [Member]

US Trade Case - NOES [Member]

US Trade Case - NOES [Member]

CHINA

CHINA

CHINA

CHINA

CHINA

Leicong Industrial Company [Member]

All Other Producers [Member]

Countervailing Duty [Member]

Countervailing Duty [Member]

Countervailing Duty [Member]

Final [Member]

Final [Member]

Final [Member]

Final [Member]

Final [Member]

Final [Member]

Final [Member]

Final [Member]

Final [Member]

Final [Member]

Final [Member]

Final [Member]

TAIWAN, PROVINCE OF CHINA

TAIWAN, PROVINCE OF CHINA

CHINA

Leicong Industrial Company [Member]

All Other Producers [Member]

Antidumping Duty [Member]

Antidumping Duty [Member]

Antidumping Duty [Member]

Antidumping Duty [Member]

Antidumping Duty [Member]

Antidumping Duty [Member]

Antidumping Duty [Member]

Antidumping Duty [Member]

Antidumping Duty [Member]

Antidumping Duty [Member]

Antidumping Duty [Member]

Antidumping Duty [Member]

TAIWAN, PROVINCE OF CHINA

TAIWAN, PROVINCE OF CHINA

CHINA

GERMANY

JAPAN

KOREA, REPUBLIC OF

SWEDEN

TAIWAN, PROVINCE OF CHINA

CHINA

GERMANY

JAPAN

KOREA, REPUBLIC OF

SWEDEN

TAIWAN, PROVINCE OF CHINA

Loss Contingencies [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Payment in Litigation Settlement

$5.80

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Duty Rate

'

11.70%

11.20%

7.80%

3.40%

49.15%

125.83%

12.82%

6.41%

'

158.88%

17.12%

8.80%

407.52%

98.84%

204.79%

6.91%

126.72%

52.23%

407.52%

86.29%

135.59%

6.91%

98.46%

28.14%

Loss Contingency, Damages Sought, Value

'

'

'

'

'

'

'

'

'

11.8

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Loss Contingency, Range of Possible Loss, Minimum

'

'

'

'

'

'

'

'

'

12

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Loss Contingency, Range of Possible Loss, Maximum

'

'

'

'

'

'

'

'

'

$14

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common_Stock_Details

Common Stock (Details) (USD $)	0 Months Ended	1 Months Ended	9 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 16, 2014	Jan. 31, 2014	Sep. 30, 2014	Sep. 30, 2013	Sep. 16, 2014	29-May-14	28-May-14
Equity [Abstract]	'	'	'	'	'	'	'
Common Stock, Shares, Issued	40,250,000	'	'	'	'	'	'
Shares Issued, Price Per Share	'	'	'	'	$9	'	'
Proceeds from issuance of common stock	$345.30	'	$345.30	$0	'	'	'
Common Stock, Shares Authorized	'	'	300,000,000	'	'	300,000,000	200,000,000
Treasury Stock, Shares, Retired	'	13,311,310	'	'	'	'	'

Sharebased_Compensation_Detail

Share-based Compensation (Details) (USD $)	0 Months Ended	3 Months Ended		9 Months Ended
In Millions, except Share data, unless otherwise specified	29-May-14	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized	4,000,000	'	'	'	'
Estimated share-based compensation expense	'	$8.70	'	$8.70	'
Share-based Compensation Expense [Abstract]	'	'	'	'	'
Share-based Compensation Expense	'	1.6	1.7	7.2	7.4
Number of options granted (in shares)	'	'	'	551,740	'
Weighted-average grant-date fair value per share of options granted (dollars per share)	'	'	'	$3.50	'
Number of options exercised (in shares)	'	'	'	11,881	'
Stock Options [Member]	'	'	'	'	'
Share-based Compensation Expense [Abstract]	'	'	'	'	'
Share-based Compensation Expense	'	0.2	0.1	1.5	1.2
Restricted Stock [Member]	'	'	'	'	'
Share-based Compensation Expense [Abstract]	'	'	'	'	'
Share-based Compensation Expense	'	0.4	0.3	2.7	2.5
Number of shares granted (in shares)	'	'	'	487,290	'
Weighted average grant date fair value, granted (dollars per share)	'	'	'	$6.67	'
Intrinsic value of shares vested/restrictions lapsed during the period	'	'	'	2.8	'
Restricted Stock Units Issued to Directors [Member]	'	'	'	'	'
Share-based Compensation Expense [Abstract]	'	'	'	'	'
Share-based Compensation Expense	'	0.4	0.3	0.9	0.7
Performance Share Awards [Member]	'	'	'	'	'
Share-based Compensation Expense [Abstract]	'	'	'	'	'
Share-based Compensation Expense	'	$0.60	$1	$2.10	$3
Number of shares granted (in shares)	'	'	'	512,400	'
Weighted average grant date fair value, granted (dollars per share)	'	'	'	$6.40	'

Comprehensive_Income_Loss_Deta

Comprehensive Income (Loss) (Details) (USD $)	3 Months Ended				9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Schedule of Accumulated Comprehensive Income [Line Items]	'		'		'		'
Balance at beginning of period	$4.60		$2.80		$4.70		$3.50
Other comprehensive income (loss):	'		'		'		'
Foreign currency translation gain (loss)	-2.5		1.2		-2.6		0.5
Balance at end of period	2.1		4		2.1		4
Cash flow hedges	'		'		'		'
Balance at beginning of period	7.4		7.4		18.3		31.7
Other comprehensive income (loss):	'		'		'		'
Gains (losses) arising in period	-2.7		10.3		-9.6		0.6
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	0		0		0		0
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	-2.7		10.3		-9.6		0.6
Reclassification of losses (gains) to net income (loss):	'		'		'		'
Reclassification of losses (gains) to net income (loss)	3.9		-5.9		-0.1		-20.5
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax	0		0		0		0
Net amount of reclassification of losses (gains) to net income (loss)	3.9		-5.9		-0.1		-20.5
Total other comprehensive income (loss), net of tax	1.2		4.4		-9.7		-19.9
Balance at end of period	8.6		11.8		8.6		11.8
Unrealized holding gains (losses) on securities	'		'		'		'
Balance at beginning of period	0.4		0.5		0.4		0.3
Other comprehensive income (loss):	'		'		'		'
Unrealized holding gains (losses) arising in period	0		0		0		0.2
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax	0		0		0		0
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax	0		0		0		0.2
Balance at end of period	0.4		0.5		0.4		0.5
Pension and OPEB plans	'		'		'		'
Balance at beginning of period	259.6		-58.2		300		-34.4
Other comprehensive income (loss):	'		'		'		'
Prior service credit (cost) arising in period	-2.1		-6.1		-2.1		-6.1
Gains (losses) arising in period	-3		9.6		-8.3		9.6
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, before Reclassification Adjustments, Tax	0		0		0		0
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Reclassification Adjustments, Net of Tax	-5.1		3.5		-10.4		3.5
Reclassification to net income (loss):	'		'		'		'
Reclassification of prior service cost (credits) included in net income (loss)	-17.2		-19.1		-51.7		-57.3
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), before Tax	1		6.6		0.4		21
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, before Tax	-16.2		-12.5		-51.3		-36.3
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Tax	0		0		0		0
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Net of Tax	-16.2		-12.5		-51.3		-36.3
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	-21.3		-9		-61.7		-32.8
Balance at end of period	238.3		-67.2		238.3		-67.2
Sales [Member] | Hot roll carbon steel coils [Member]	'		'		'		'
Reclassification of losses (gains) to net income (loss):	'		'		'		'
Reclassification of losses (gains) to net income (loss)	0	[1]	0	[1]	0	[1]	-0.4	[1]
Cost of Sales [Member] | Other Contract [Member]	'		'		'		'
Reclassification of losses (gains) to net income (loss):	'		'		'		'
Reclassification of losses (gains) to net income (loss)	3.9	[2]	-5.9	[2]	-0.1	[2]	-20.1	[2]
Pension and OPEB Expense (Income) [Member]	'		'		'		'
Reclassification to net income (loss):	'		'		'		'
Reclassification of prior service cost (credits) included in net income (loss)	-17.2	[3]	-19.1	[3]	-51.7	[3]	-57.3	[3]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), before Tax	$1	[3]	$6.60	[3]	$0.40	[3]	$21	[3]
[1]	Amounts are included in net sales on the Condensed Consolidated Statements of Operations.
[2]	Amounts are included in cost of products sold on the Condensed Consolidated Statements of Operations.
[3]	Amounts are included in pension and OPEB expense (income) on the Condensed Consolidated Statements of Operations.

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share [Abstract]	'	'	'	'
Net income (loss) attributable to AK Steel Holding Corporation	($7.20)	($31.70)	($110.40)	($82)
Less: distributed earnings to common stockholders and holders of certain stock compensation awards	0	0	0	0
Undistributed Earnings Attributable To Parent	-7.2	-31.7	-110.4	-82
Common stockholders earnings - basic [Abstract]	'	'	'	'
Distributed earnings to common stockholders - basic	0	0	0	0
Undistributed earnings (loss) to common stockholders - basic	-7.2	-31.6	-110	-81.7
Common stockholders earnings (loss) - basic	-7.2	-31.6	-110	-81.7
Common stockholders earnings - diluted [Abstract]	'	'	'	'
Distributed earnings to common stockholders - diluted	0	0	0	0
Undistributed earnings (loss) to common stockholders - diluted	-7.2	-31.6	-110	-81.7
Common stockholders earnings (loss) - diluted	($7.20)	($31.60)	($110)	($81.70)
Common shares outstanding (weighted-average shares in millions) [Abstract]	'	'	'	'
Common shares outstanding for basic earnings per share (in shares)	142.8	135.9	138.4	135.8
Effect of exchangeable debt (in shares)	0	0	0	0
Effect of dilutive stock-based compensation (in shares)	0	0	0	0
Common shares outstanding for diluted earnings per share (in shares)	142.8	135.9	138.4	135.8
Basic earnings per share [Abstract]	'	'	'	'
Distributed earnings - basic (in dollars per share)	$0	$0	$0	$0
Undistributed earnings (loss) - basic (in dollars per share)	($0.05)	($0.23)	($0.79)	($0.60)
Basic earnings (loss) per share (in dollars per share)	($0.05)	($0.23)	($0.79)	($0.60)
Diluted earnings per share [Abstract]	'	'	'	'
Distributed earnings - diluted (in dollars per share)	$0	$0	$0	$0
Undistributed earnings (loss) - diluted (in dollars per share)	($0.05)	($0.23)	($0.79)	($0.60)
Diluted earnings (loss) per share (in dollars per share)	($0.05)	($0.23)	($0.79)	($0.60)
Potentially issuable common shares (in millions) excluded from earnings per share calculation due to anti-dilutive effect (in shares)	13.3	2.5	10.6	2.5

Variable_Interest_Entities_Det

Variable Interest Entities (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Variable Interest Entity [Line Items]	'	'	'	'
Income (loss) before income taxes	$12.80	($9)	($56.30)	($20.80)
SunCoke Middletown [Member] | Variable Interest Entity, Primary Beneficiary [Member]	'	'	'	'
Variable Interest Entity [Line Items]	'	'	'	'
Variable interest entity, ownership percentage (in hundredths)	'	'	0.00%	'
Income (loss) before income taxes	$16.20	$15.90	$46.80	$47.80
Vicksmetal Armco Associates [Member] | Variable Interest Entity, Primary Beneficiary [Member]	'	'	'	'
Variable Interest Entity [Line Items]	'	'	'	'
Variable interest entity, ownership percentage (in hundredths)	'	'	50.00%	'

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2014

In Millions, unless otherwise specified

Estimate of Fair Value, Fair Value Disclosure [Member]

Estimate of Fair Value, Fair Value Disclosure [Member]

Estimate of Fair Value, Fair Value Disclosure [Member]

Estimate of Fair Value, Fair Value Disclosure [Member]

Estimate of Fair Value, Fair Value Disclosure [Member]

Estimate of Fair Value, Fair Value Disclosure [Member]

Carrying (Reported) Amount, Fair Value Disclosure [Member]

Carrying (Reported) Amount, Fair Value Disclosure [Member]

Carrying (Reported) Amount, Fair Value Disclosure [Member]

Carrying (Reported) Amount, Fair Value Disclosure [Member]

Carrying (Reported) Amount, Fair Value Disclosure [Member]

Carrying (Reported) Amount, Fair Value Disclosure [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Assets [Member]

Liability [Member]

Fair Value, Inputs, Level 1 [Member]

Fair Value, Inputs, Level 1 [Member]

Fair Value, Inputs, Level 2 [Member]

Fair Value, Inputs, Level 2 [Member]

Fair Value, Inputs, Level 1 [Member]

Fair Value, Inputs, Level 1 [Member]

Fair Value, Inputs, Level 2 [Member]

Fair Value, Inputs, Level 2 [Member]

Fair Value, Inputs, Level 1 [Member]

Fair Value, Inputs, Level 1 [Member]

Fair Value, Inputs, Level 2 [Member]

Fair Value, Inputs, Level 2 [Member]

Cash and Cash Equivalents [Member]

Cash and Cash Equivalents [Member]

Cash and Cash Equivalents [Member]

Cash and Cash Equivalents [Member]

Cash and Cash Equivalents [Member]

Cash and Cash Equivalents [Member]

Other Current Assets [Member]

Other Current Assets [Member]

Other Current Assets [Member]

Other Current Assets [Member]

Other Current Assets [Member]

Other Current Assets [Member]

Other Noncurrent Assets [Member]

Other Noncurrent Assets [Member]

Other Noncurrent Assets [Member]

Other Noncurrent Assets [Member]

Other Noncurrent Assets [Member]

Other Noncurrent Assets [Member]

Accrued Liabilities [Member]

Accrued Liabilities [Member]

Accrued Liabilities [Member]

Accrued Liabilities [Member]

Accrued Liabilities [Member]

Accrued Liabilities [Member]

Other Noncurrent Liabilities [Member]

Other Noncurrent Liabilities [Member]

Other Noncurrent Liabilities [Member]

Other Noncurrent Liabilities [Member]

Other Noncurrent Liabilities [Member]

Other Noncurrent Liabilities [Member]

Maximum [Member]

Maximum [Member]

Fair Value, Inputs, Level 1 [Member]

Fair Value, Inputs, Level 1 [Member]

Fair Value, Inputs, Level 2 [Member]

Fair Value, Inputs, Level 2 [Member]

Fair Value, Inputs, Level 1 [Member]

Fair Value, Inputs, Level 1 [Member]

Fair Value, Inputs, Level 2 [Member]

Fair Value, Inputs, Level 2 [Member]

Fair Value, Inputs, Level 1 [Member]

Fair Value, Inputs, Level 1 [Member]

Fair Value, Inputs, Level 2 [Member]

Fair Value, Inputs, Level 2 [Member]

Fair Value, Inputs, Level 1 [Member]

Fair Value, Inputs, Level 1 [Member]

Fair Value, Inputs, Level 2 [Member]

Fair Value, Inputs, Level 2 [Member]

Fair Value, Inputs, Level 1 [Member]

Fair Value, Inputs, Level 1 [Member]

Fair Value, Inputs, Level 2 [Member]

Fair Value, Inputs, Level 2 [Member]

Fair Value, Inputs, Level 2 [Member]

Fair Value, Inputs, Level 2 [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Benchmark interest rates for contracts (in hundredths)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3.00%

3.00%

Assets measured at fair value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash and cash equivalents

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$60.80

$45.30

$60.80

$45.30

$0

$0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Foreign exchange contracts - current

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1.4

0

0

0

1.4

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Commodity hedge contracts - current

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3

4.9

0

0

3

4.9

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Available for sale investments-cash and cash equivalents

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3.3

18.6

3.3

18.6

0

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Assets measured at fair value

'

'

'

'

'

'

'

'

'

'

'

'

68.5

68.8

64.1

63.9

4.4

4.9

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Liabilities measured at fair value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Foreign exchange contracts

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0

-0.7

0

0

0

-0.7

'

'

'

'

'

'

'

'

Commodity hedge contracts - current

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-26.8

-0.4

0

0

-26.8

-0.4

'

'

'

'

'

'

'

'

Commodity hedge contracts - noncurrent

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-1.3

-0.1

0

0

-1.3

-0.1

'

'

Liabilities measured at fair value

'

'

'

'

'

'

'

'

'

'

'

'

-28.1

-1.2

0

0

-28.1

-1.2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Fair Value Disclosure

($2,573.60)

($1,659.90)

$0

$0

($2,573.60)

($1,659.90)

($2,406.60)

($1,507)

$0

$0

($2,406.60)

($1,507)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Derivative_Instruments_and_Hed2

Derivative Instruments and Hedging Activities (Details)

9 Months Ended

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Natural Gas [Member]

Zinc [Member]

Electricity [Member]

Iron Ore [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Foreign Exchange Contract [Member]

Foreign Exchange Contract [Member]

USD ($)

USD ($)

USD ($)

USD ($)

Nickel [Member]

Nickel [Member]

Natural Gas [Member]

Natural Gas [Member]

Zinc [Member]

Zinc [Member]

Electricity [Member]

Electricity [Member]

Iron Ore [Member]

Iron Ore [Member]

Hot roll carbon steel coils [Member]

Hot roll carbon steel coils [Member]

EUR (€)

EUR (€)

lb

lb

MMBTU

MMBTU

lb

lb

MW

MW

t

t

T

T

Derivative [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Nonmonetary Notional Amount of Derivatives

'

'

'

'

382,400

763,300

17,232,500

3,240,000

15,000,000

12,000,000

767,000

0

1,084,200

190,735

87,800

74,147

'

'

Derivative, Notional Amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

€ 19,640,000

€ 17,730,000

Beginning Settlement Date

31-Oct-14

31-Oct-14

31-Oct-14

31-Oct-14

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Ending Settlement Date

31-Dec-16

31-Dec-16

31-Dec-15

30-Nov-16

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Gains (losses) expected to be reclassified into cost of products sold within the next twelve months

$2,800,000

$300,000

$1,200,000

($10,900,000)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Derivative_Instruments_and_Hed3

Derivative Instruments and Hedging Activities (Details 2) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Designated as Hedging Instrument [Member] | Commodity Contract [Member] | Other Current Assets [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Current	$2.30	$2.60
Designated as Hedging Instrument [Member] | Commodity Contract [Member] | Accrued Liabilities [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Liability, Current	-6.7	0
Designated as Hedging Instrument [Member] | Commodity Contract [Member] | Other Noncurrent Liabilities [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Liability, Noncurrent	-0.8	0
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Other Current Assets [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Current	1.4	0
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Accrued Liabilities [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Liability, Current	0	-0.7
Not Designated as Hedging Instrument [Member] | Commodity Contract [Member] | Other Current Assets [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Current	0.7	2.3
Not Designated as Hedging Instrument [Member] | Commodity Contract [Member] | Accrued Liabilities [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Liability, Current	-20.1	-0.4
Not Designated as Hedging Instrument [Member] | Commodity Contract [Member] | Other Noncurrent Liabilities [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Liability, Noncurrent	($0.50)	($0.10)

Derivative_Instruments_and_Hed4

Derivative Instruments and Hedging Activities (Details 3) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Sales [Member] | Commodity Contract [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	($1.80)	$0.20	($6)	$0.40
Other Income [Member] | Foreign Exchange Contract [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	-0.2	-0.7	0.7	-0.2
Cost of Products Sold [Member] | Commodity Contract [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	-11.2	0.6	-30.4	0.4
Cash Flow Hedging [Member] | Sales [Member] | Commodity Contract [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Reclassified from accumulated other comprehensive income (loss) into income (effective portion)	0	0	0	0.4
Cash Flow Hedging [Member] | Cost of Products Sold [Member] | Commodity Contract [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Reclassified from accumulated other comprehensive income (loss) into income (effective portion)	-3.9	5.9	0.1	20.1
Recognized in cost of products sold (ineffective portion and amount excluded from effectiveness testing)	($3.80)	($3.10)	($4.50)	$3.30

Supplemental_Cash_Flow_Informa2

Supplemental Cash Flow Information (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Dec. 31, 2012
Supplemental cash flow, net cash paid (received) during the period for: [Abstract]	'	'	'	'
Interest, net of capitalized interest	$62.90	$60	'	'
Income taxes	-0.5	1.1	'	'
Net Cash Provided by (Used in) Operating Activities	-380.6	-223.7	'	'
Cash and Cash Equivalents, at Carrying Value	60.8	65.7	45.3	227
Supplemental cash flow, noncash investing and financing activities [Abstract]	'	'	'	'
Capital investments	7.6	5.4	'	'
Restricted Stock and Restricted Stock Units [Member]	'	'	'	'
Supplemental cash flow, noncash investing and financing activities [Abstract]	'	'	'	'
Issuance of restricted stock and restricted stock units	4	2.7	'	'
Variable Interest Entity, Primary Beneficiary [Member] | SunCoke Middletown [Member]	'	'	'	'
Supplemental cash flow, net cash paid (received) during the period for: [Abstract]	'	'	'	'
Net Cash Provided by (Used in) Operating Activities	43.8	57.3	'	'
Cash and Cash Equivalents, at Carrying Value	$16.30	'	$14.20	'

Union_Contracts_Details

Union Contracts (Details)	Sep. 30, 2014
	employees
Middletown OH Works [Member]	'
Concentration Risk [Line Items]	'
Entity Number of Employees	1,640
Mountain State Carbon, LLC [Member]	'
Concentration Risk [Line Items]	'
Entity Number of Employees	220
Walbridge Tube [Member]	'
Concentration Risk [Line Items]	'
Entity Number of Employees	110
Ashland Works [Member]	'
Concentration Risk [Line Items]	'
Entity Number of Employees	820
Zanesville Works [Member]	'
Concentration Risk [Line Items]	'
Entity Number of Employees	130

Supplemental_Guarantor_Informa2

Supplemental Guarantor Information (Details) (USD $)	0 Months Ended	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 16, 2014	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Dec. 31, 2012
Condensed Consolidated Statements of Comprehensive Income (Loss) [Abstract]	'	'	'	'	'	'	'
Net sales	'	$1,593.80	$1,331.30	$4,508.10	$4,105.60	'	'
Cost of products sold (exclusive of items shown separately below)	'	1,438.90	1,222.40	4,191.40	3,783.90	'	'
Selling and administrative expenses (exclusive of items shown separately below)	'	65.6	51.5	179.7	153.3	'	'
Depreciation	'	49.1	48.4	146.3	144.9	'	'
Pension and OPEB expense (income)	'	-23.5	-16.9	-74.2	-49.3	'	'
Total operating costs	'	1,530.10	1,305.40	4,443.20	4,032.80	'	'
Operating profit (loss)	'	63.7	25.9	64.9	72.8	'	'
Interest expense	'	35.6	32.1	101	95.1	'	'
Other income (expense)	'	-15.3	-2.8	-20.2	1.5	'	'
Income (loss) before income taxes	'	12.8	-9	-56.3	-20.8	'	'
Income tax expense (benefit)	'	3.9	6.7	7.5	13.6	'	'
Equity in net income (loss) of subsidiaries	'	0	0	0	0	'	'
Net income (loss)	'	8.9	-15.7	-63.8	-34.4	'	'
Less: Net income attributable to noncontrolling interests	'	16.1	16	46.6	47.6	'	'
Net income (loss) attributable to AK Steel Holding Corporation	'	-7.2	-31.7	-110.4	-82	'	'
Other comprehensive income (loss)	'	-22.6	-3.4	-74	-52	'	'
Comprehensive income (loss) attributable to AK Steel Holding Corporation	'	-29.8	-35.1	-184.4	-134	'	'
Current assets:	'	'	'	'	'	'	'
Cash and cash equivalents	'	60.8	65.7	60.8	65.7	'	'
Accounts receivable, net	'	707.6	'	707.6	'	525.2	'
Inventory, net	'	1,126	'	1,126	'	586.6	'
Deferred tax assets, current	'	74.7	'	74.7	'	69.6	'
Other current assets	'	76.3	'	76.3	'	46.5	'
Total current assets	'	2,045.40	'	2,045.40	'	1,273.20	'
Property, plant and equipment	'	6,335.90	'	6,335.90	'	5,871.90	'
Accumulated depreciation	'	-4,120.80	'	-4,120.80	'	-3,991.80	'
Property, plant and equipment, net	'	2,215.10	'	2,215.10	'	1,880.10	'
Other non-current assets:	'	'	'	'	'	'	'
Investments in affilates	'	396.5	'	396.5	'	209.8	'
Investment in subsidiaries	'	0	'	0	'	0	'
Inter-company accounts	'	0	'	0	'	0	'
Other non-current assets	'	228.4	'	228.4	'	242.6	'
TOTAL ASSETS	'	4,885.40	'	4,885.40	'	3,605.70	'
Current liabilities:	'	'	'	'	'	'	'
Accounts payable	'	812.3	'	812.3	'	601.8	'
Accrued liabilities	'	281.7	'	281.7	'	142.9	'
Current portion of long-term debt	'	0.2	'	0.2	'	0.8	'
Current portion of pension and other postretirement benefit obligations	'	62.2	'	62.2	'	85.9	'
Total current liabilities	'	1,156.40	'	1,156.40	'	831.4	'
Non-current liabilities:	'	'	'	'	'	'	'
Long-term debt	'	2,406.40	'	2,406.40	'	1,506.20	'
Pension and other postretirement benefit obligations	'	832.4	'	832.4	'	965.4	'
Other non-current liabilities	'	124.4	'	124.4	'	110	'
TOTAL LIABILITIES	'	4,519.60	'	4,519.60	'	3,413	'
Exchangeable notes exchange feature	'	31	'	31	'	0	'
Total stockholders' equity (deficit)	'	-84.9	'	-84.9	'	-221	'
Noncontrolling interests	'	419.7	'	419.7	'	413.7	'
TOTAL EQUITY (DEFICIT)	'	334.8	-211.8	334.8	-211.8	192.7	-91
TOTAL LIABILITIES AND EQUITY	'	4,885.40	'	4,885.40	'	3,605.70	'
Condensed Consolidated Statements of Cash Flows [Abstract]	'	'	'	'	'	'	'
Net cash flows from operating activities	'	'	'	-380.6	-223.7	'	'
Cash flows from investing activities:	'	'	'	'	'	'	'
Capital investments	'	'	'	-39.3	-48.1	'	'
Investments in Magnetation joint venture	'	'	'	-90	-50	'	'
Investment in acquired business, net of cash acquired	'	'	'	-677.2	0	'	'
Other investing items, net	'	'	'	15.4	15.1	'	'
Net cash flows from investing activities	'	'	'	-791.1	-83	'	'
Cash flows from financing activities:	'	'	'	'	'	'	'
Net borrowings under credit facility	'	'	'	470	185	'	'
Proceeds from issuance of long-term debt	'	'	'	427.1	31.9	'	'
Redemption of long-term debt	'	'	'	-0.6	-27.2	'	'
Proceeds from issuance of common stock	345.3	'	'	345.3	0	'	'
Debt issuance costs	'	'	'	-10.6	-3.1	'	'
Inter-company activity	'	'	'	0	0	'	'
SunCoke Middletown distributions to noncontrolling interest owners	'	'	'	-40.6	-41.1	'	'
Other financing items, net	'	'	'	-3.4	-0.1	'	'
Net cash flows from financing activities	'	'	'	1,187.20	145.4	'	'
Net increase (decrease) in cash and cash equivalents	'	'	'	15.5	-161.3	'	'
Cash and cash equivalents, beginning of period	'	'	'	45.3	227	'	'
Cash and cash equivalents, end of period	'	60.8	65.7	60.8	65.7	'	'
AK Holding [Member]	'	'	'	'	'	'	'
Condensed Consolidated Statements of Comprehensive Income (Loss) [Abstract]	'	'	'	'	'	'	'
Net sales	'	0	0	0	0	'	'
Cost of products sold (exclusive of items shown separately below)	'	0	0	0	0	'	'
Selling and administrative expenses (exclusive of items shown separately below)	'	1	1	3.6	3.5	'	'
Depreciation	'	0	0	0	0	'	'
Pension and OPEB expense (income)	'	0	0	0	0	'	'
Total operating costs	'	1	1	3.6	3.5	'	'
Operating profit (loss)	'	-1	-1	-3.6	-3.5	'	'
Interest expense	'	0	0	0	0	'	'
Other income (expense)	'	0	0	0	0	'	'
Income (loss) before income taxes	'	-1	-1	-3.6	-3.5	'	'
Income tax expense (benefit)	'	0	0	0	0	'	'
Equity in net income (loss) of subsidiaries	'	-6.2	-30.7	-106.8	-78.5	'	'
Net income (loss)	'	-7.2	-31.7	-110.4	-82	'	'
Less: Net income attributable to noncontrolling interests	'	0	0	0	0	'	'
Net income (loss) attributable to AK Steel Holding Corporation	'	-7.2	-31.7	-110.4	-82	'	'
Other comprehensive income (loss)	'	-22.6	-3.4	-74	-52	'	'
Comprehensive income (loss) attributable to AK Steel Holding Corporation	'	-29.8	-35.1	-184.4	-134	'	'
Current assets:	'	'	'	'	'	'	'
Cash and cash equivalents	'	0	0	0	0	'	'
Accounts receivable, net	'	0	'	0	'	0	'
Inventory, net	'	0	'	0	'	0	'
Deferred tax assets, current	'	0	'	0	'	0	'
Other current assets	'	0.3	'	0.3	'	0.3	'
Total current assets	'	0.3	'	0.3	'	0.3	'
Property, plant and equipment	'	0	'	0	'	0	'
Accumulated depreciation	'	0	'	0	'	0	'
Property, plant and equipment, net	'	0	'	0	'	0	'
Other non-current assets:	'	'	'	'	'	'	'
Investments in affilates	'	0	'	0	'	0	'
Investment in subsidiaries	'	-2,223.70	'	-2,223.70	'	-2,772.40	'
Inter-company accounts	'	2,138.50	'	2,138.50	'	2,551.10	'
Other non-current assets	'	0	'	0	'	0	'
TOTAL ASSETS	'	-84.9	'	-84.9	'	-221	'
Current liabilities:	'	'	'	'	'	'	'
Accounts payable	'	0	'	0	'	0	'
Accrued liabilities	'	0	'	0	'	0	'
Current portion of long-term debt	'	0	'	0	'	0	'
Current portion of pension and other postretirement benefit obligations	'	0	'	0	'	0	'
Total current liabilities	'	0	'	0	'	0	'
Non-current liabilities:	'	'	'	'	'	'	'
Long-term debt	'	0	'	0	'	0	'
Pension and other postretirement benefit obligations	'	0	'	0	'	0	'
Other non-current liabilities	'	0	'	0	'	0	'
TOTAL LIABILITIES	'	0	'	0	'	0	'
Exchangeable notes exchange feature	'	0	'	0	'	'	'
Total stockholders' equity (deficit)	'	-84.9	'	-84.9	'	-221	'
Noncontrolling interests	'	0	'	0	'	0	'
TOTAL EQUITY (DEFICIT)	'	-84.9	'	-84.9	'	-221	'
TOTAL LIABILITIES AND EQUITY	'	-84.9	'	-84.9	'	-221	'
Condensed Consolidated Statements of Cash Flows [Abstract]	'	'	'	'	'	'	'
Net cash flows from operating activities	'	'	'	1.2	-2.8	'	'
Cash flows from investing activities:	'	'	'	'	'	'	'
Capital investments	'	'	'	0	0	'	'
Investments in Magnetation joint venture	'	'	'	0	0	'	'
Investment in acquired business, net of cash acquired	'	'	'	0	'	'	'
Other investing items, net	'	'	'	0	0	'	'
Net cash flows from investing activities	'	'	'	0	0	'	'
Cash flows from financing activities:	'	'	'	'	'	'	'
Net borrowings under credit facility	'	'	'	0	0	'	'
Proceeds from issuance of long-term debt	'	'	'	0	0	'	'
Redemption of long-term debt	'	'	'	0	0	'	'
Proceeds from issuance of common stock	'	'	'	345.3	'	'	'
Debt issuance costs	'	'	'	0	0	'	'
Inter-company activity	'	'	'	-345.6	3.5	'	'
SunCoke Middletown distributions to noncontrolling interest owners	'	'	'	0	0	'	'
Other financing items, net	'	'	'	-0.9	-0.7	'	'
Net cash flows from financing activities	'	'	'	-1.2	2.8	'	'
Net increase (decrease) in cash and cash equivalents	'	'	'	0	0	'	'
Cash and cash equivalents, beginning of period	'	'	'	0	0	'	'
Cash and cash equivalents, end of period	'	0	0	0	0	'	'
AK Steel [Member]	'	'	'	'	'	'	'
Condensed Consolidated Statements of Comprehensive Income (Loss) [Abstract]	'	'	'	'	'	'	'
Net sales	'	1,552.50	1,284.10	4,350.70	3,917.30	'	'
Cost of products sold (exclusive of items shown separately below)	'	1,433.10	1,206.40	4,141.10	3,688.80	'	'
Selling and administrative expenses (exclusive of items shown separately below)	'	65.2	50.8	177.9	152.2	'	'
Depreciation	'	42.7	43.1	127.5	129.8	'	'
Pension and OPEB expense (income)	'	-23.5	-16.9	-74.2	-49.3	'	'
Total operating costs	'	1,517.50	1,283.40	4,372.30	3,921.50	'	'
Operating profit (loss)	'	35	0.7	-21.6	-4.2	'	'
Interest expense	'	34.8	31.7	99	94.1	'	'
Other income (expense)	'	-15.8	-1.9	-23.5	-2.6	'	'
Income (loss) before income taxes	'	-15.6	-32.9	-144.1	-100.9	'	'
Income tax expense (benefit)	'	-1.5	3.6	-10.8	-0.6	'	'
Equity in net income (loss) of subsidiaries	'	7.9	5.8	26.5	21.8	'	'
Net income (loss)	'	-6.2	-30.7	-106.8	-78.5	'	'
Less: Net income attributable to noncontrolling interests	'	0	0	0	0	'	'
Net income (loss) attributable to AK Steel Holding Corporation	'	-6.2	-30.7	-106.8	-78.5	'	'
Other comprehensive income (loss)	'	-22.6	-3.4	-74	-52	'	'
Comprehensive income (loss) attributable to AK Steel Holding Corporation	'	-28.8	-34.1	-180.8	-130.5	'	'
Current assets:	'	'	'	'	'	'	'
Cash and cash equivalents	'	21	28.1	21	28.1	'	'
Accounts receivable, net	'	673.7	'	673.7	'	492.4	'
Inventory, net	'	1,031.20	'	1,031.20	'	520	'
Deferred tax assets, current	'	74.5	'	74.5	'	69.4	'
Other current assets	'	72.6	'	72.6	'	43.9	'
Total current assets	'	1,873	'	1,873	'	1,142.50	'
Property, plant and equipment	'	5,646.80	'	5,646.80	'	5,258.40	'
Accumulated depreciation	'	-3,993	'	-3,993	'	-3,881.70	'
Property, plant and equipment, net	'	1,653.80	'	1,653.80	'	1,376.70	'
Other non-current assets:	'	'	'	'	'	'	'
Investments in affilates	'	97.8	'	97.8	'	0	'
Investment in subsidiaries	'	1,571.30	'	1,571.30	'	1,393.80	'
Inter-company accounts	'	-3,078.50	'	-3,078.50	'	-3,479.70	'
Other non-current assets	'	130.8	'	130.8	'	141	'
TOTAL ASSETS	'	2,248.20	'	2,248.20	'	574.3	'
Current liabilities:	'	'	'	'	'	'	'
Accounts payable	'	759.8	'	759.8	'	550.5	'
Accrued liabilities	'	260.6	'	260.6	'	133.6	'
Current portion of long-term debt	'	0.2	'	0.2	'	0.8	'
Current portion of pension and other postretirement benefit obligations	'	61.8	'	61.8	'	85.4	'
Total current liabilities	'	1,082.40	'	1,082.40	'	770.3	'
Non-current liabilities:	'	'	'	'	'	'	'
Long-term debt	'	2,406.40	'	2,406.40	'	1,506.20	'
Pension and other postretirement benefit obligations	'	828.3	'	828.3	'	960.6	'
Other non-current liabilities	'	123.8	'	123.8	'	109.6	'
TOTAL LIABILITIES	'	4,440.90	'	4,440.90	'	3,346.70	'
Exchangeable notes exchange feature	'	31	'	31	'	'	'
Total stockholders' equity (deficit)	'	-2,223.70	'	-2,223.70	'	-2,772.40	'
Noncontrolling interests	'	0	'	0	'	0	'
TOTAL EQUITY (DEFICIT)	'	-2,223.70	'	-2,223.70	'	-2,772.40	'
TOTAL LIABILITIES AND EQUITY	'	2,248.20	'	2,248.20	'	574.3	'
Condensed Consolidated Statements of Cash Flows [Abstract]	'	'	'	'	'	'	'
Net cash flows from operating activities	'	'	'	-476.2	-325.4	'	'
Cash flows from investing activities:	'	'	'	'	'	'	'
Capital investments	'	'	'	-25.2	-31.6	'	'
Investments in Magnetation joint venture	'	'	'	0	0	'	'
Investment in acquired business, net of cash acquired	'	'	'	-677.2	'	'	'
Other investing items, net	'	'	'	15.4	4.8	'	'
Net cash flows from investing activities	'	'	'	-687	-26.8	'	'
Cash flows from financing activities:	'	'	'	'	'	'	'
Net borrowings under credit facility	'	'	'	470	185	'	'
Proceeds from issuance of long-term debt	'	'	'	427.1	31.9	'	'
Redemption of long-term debt	'	'	'	-0.6	-27.2	'	'
Proceeds from issuance of common stock	'	'	'	0	'	'	'
Debt issuance costs	'	'	'	-10.6	-3.1	'	'
Inter-company activity	'	'	'	281.4	-9.9	'	'
SunCoke Middletown distributions to noncontrolling interest owners	'	'	'	0	0	'	'
Other financing items, net	'	'	'	0.1	0	'	'
Net cash flows from financing activities	'	'	'	1,167.40	176.7	'	'
Net increase (decrease) in cash and cash equivalents	'	'	'	4.2	-175.5	'	'
Cash and cash equivalents, beginning of period	'	'	'	16.8	203.6	'	'
Cash and cash equivalents, end of period	'	21	28.1	21	28.1	'	'
Guarantor Subsidiaries [Member]	'	'	'	'	'	'	'
Condensed Consolidated Statements of Comprehensive Income (Loss) [Abstract]	'	'	'	'	'	'	'
Net sales	'	69.7	63	209.8	196.6	'	'
Cost of products sold (exclusive of items shown separately below)	'	50.1	45.9	151.6	142.2	'	'
Selling and administrative expenses (exclusive of items shown separately below)	'	2.9	2.6	8.6	7.9	'	'
Depreciation	'	1.1	1.2	3.1	3.4	'	'
Pension and OPEB expense (income)	'	0	0	0	0	'	'
Total operating costs	'	54.1	49.7	163.3	153.5	'	'
Operating profit (loss)	'	15.6	13.3	46.5	43.1	'	'
Interest expense	'	0	0	0	0	'	'
Other income (expense)	'	1.6	1.5	4.9	4.6	'	'
Income (loss) before income taxes	'	17.2	14.8	51.4	47.7	'	'
Income tax expense (benefit)	'	6.9	5.5	20.6	18.7	'	'
Equity in net income (loss) of subsidiaries	'	0	0	0	0	'	'
Net income (loss)	'	10.3	9.3	30.8	29	'	'
Less: Net income attributable to noncontrolling interests	'	0	0	0	0	'	'
Net income (loss) attributable to AK Steel Holding Corporation	'	10.3	9.3	30.8	29	'	'
Other comprehensive income (loss)	'	0	0	0	0	'	'
Comprehensive income (loss) attributable to AK Steel Holding Corporation	'	10.3	9.3	30.8	29	'	'
Current assets:	'	'	'	'	'	'	'
Cash and cash equivalents	'	0.2	0.1	0.2	0.1	'	'
Accounts receivable, net	'	32.7	'	32.7	'	25.2	'
Inventory, net	'	31	'	31	'	19.2	'
Deferred tax assets, current	'	0	'	0	'	0	'
Other current assets	'	0.3	'	0.3	'	0.2	'
Total current assets	'	64.2	'	64.2	'	44.6	'
Property, plant and equipment	'	96.1	'	96.1	'	94.9	'
Accumulated depreciation	'	-70.9	'	-70.9	'	-67.9	'
Property, plant and equipment, net	'	25.2	'	25.2	'	27	'
Other non-current assets:	'	'	'	'	'	'	'
Investments in affilates	'	0	'	0	'	0	'
Investment in subsidiaries	'	0	'	0	'	0	'
Inter-company accounts	'	1,306.30	'	1,306.30	'	1,269.60	'
Other non-current assets	'	33	'	33	'	33	'
TOTAL ASSETS	'	1,428.70	'	1,428.70	'	1,374.20	'
Current liabilities:	'	'	'	'	'	'	'
Accounts payable	'	9.7	'	9.7	'	6.3	'
Accrued liabilities	'	3.1	'	3.1	'	2.9	'
Current portion of long-term debt	'	0	'	0	'	0	'
Current portion of pension and other postretirement benefit obligations	'	0	'	0	'	0	'
Total current liabilities	'	12.8	'	12.8	'	9.2	'
Non-current liabilities:	'	'	'	'	'	'	'
Long-term debt	'	0	'	0	'	0	'
Pension and other postretirement benefit obligations	'	0	'	0	'	0	'
Other non-current liabilities	'	0	'	0	'	0	'
TOTAL LIABILITIES	'	12.8	'	12.8	'	9.2	'
Exchangeable notes exchange feature	'	0	'	0	'	'	'
Total stockholders' equity (deficit)	'	1,415.90	'	1,415.90	'	1,365	'
Noncontrolling interests	'	0	'	0	'	0	'
TOTAL EQUITY (DEFICIT)	'	1,415.90	'	1,415.90	'	1,365	'
TOTAL LIABILITIES AND EQUITY	'	1,428.70	'	1,428.70	'	1,374.20	'
Condensed Consolidated Statements of Cash Flows [Abstract]	'	'	'	'	'	'	'
Net cash flows from operating activities	'	'	'	18.7	37.3	'	'
Cash flows from investing activities:	'	'	'	'	'	'	'
Capital investments	'	'	'	-1.9	-0.7	'	'
Investments in Magnetation joint venture	'	'	'	0	'	'	'
Investment in acquired business, net of cash acquired	'	'	'	0	'	'	'
Other investing items, net	'	'	'	0	-0.3	'	'
Net cash flows from investing activities	'	'	'	-1.9	-1	'	'
Cash flows from financing activities:	'	'	'	'	'	'	'
Net borrowings under credit facility	'	'	'	0	0	'	'
Proceeds from issuance of long-term debt	'	'	'	0	0	'	'
Redemption of long-term debt	'	'	'	0	0	'	'
Proceeds from issuance of common stock	'	'	'	0	'	'	'
Debt issuance costs	'	'	'	0	0	'	'
Inter-company activity	'	'	'	-16.6	-36.2	'	'
SunCoke Middletown distributions to noncontrolling interest owners	'	'	'	0	0	'	'
Other financing items, net	'	'	'	0	0	'	'
Net cash flows from financing activities	'	'	'	-16.6	-36.2	'	'
Net increase (decrease) in cash and cash equivalents	'	'	'	0.2	0.1	'	'
Cash and cash equivalents, beginning of period	'	'	'	0	0	'	'
Cash and cash equivalents, end of period	'	0.2	0.1	0.2	0.1	'	'
Other Non-Guarantor Subsidiaries [Member]	'	'	'	'	'	'	'
Condensed Consolidated Statements of Comprehensive Income (Loss) [Abstract]	'	'	'	'	'	'	'
Net sales	'	135.7	137.3	393.7	430	'	'
Cost of products sold (exclusive of items shown separately below)	'	104.4	112.5	309	360.8	'	'
Selling and administrative expenses (exclusive of items shown separately below)	'	7.7	6.8	22.3	20	'	'
Depreciation	'	5.3	4.1	15.7	11.7	'	'
Pension and OPEB expense (income)	'	0	0	0	0	'	'
Total operating costs	'	117.4	123.4	347	392.5	'	'
Operating profit (loss)	'	18.3	13.9	46.7	37.5	'	'
Interest expense	'	0.8	0.4	2	1	'	'
Other income (expense)	'	-1.1	-2.4	-1.6	-0.5	'	'
Income (loss) before income taxes	'	16.4	11.1	43.1	36	'	'
Income tax expense (benefit)	'	0.2	-1.9	-1	-4.4	'	'
Equity in net income (loss) of subsidiaries	'	0	0	0	0	'	'
Net income (loss)	'	16.2	13	44.1	40.4	'	'
Less: Net income attributable to noncontrolling interests	'	16.1	16	46.6	47.6	'	'
Net income (loss) attributable to AK Steel Holding Corporation	'	0.1	-3	-2.5	-7.2	'	'
Other comprehensive income (loss)	'	-2.5	1.2	-2.6	0.5	'	'
Comprehensive income (loss) attributable to AK Steel Holding Corporation	'	-2.4	-1.8	-5.1	-6.7	'	'
Current assets:	'	'	'	'	'	'	'
Cash and cash equivalents	'	39.6	37.5	39.6	37.5	'	'
Accounts receivable, net	'	33.3	'	33.3	'	35.9	'
Inventory, net	'	78.1	'	78.1	'	58.5	'
Deferred tax assets, current	'	0.2	'	0.2	'	0.2	'
Other current assets	'	3.1	'	3.1	'	2.1	'
Total current assets	'	154.3	'	154.3	'	125.2	'
Property, plant and equipment	'	593	'	593	'	518.6	'
Accumulated depreciation	'	-56.9	'	-56.9	'	-42.2	'
Property, plant and equipment, net	'	536.1	'	536.1	'	476.4	'
Other non-current assets:	'	'	'	'	'	'	'
Investments in affilates	'	298.7	'	298.7	'	209.8	'
Investment in subsidiaries	'	0	'	0	'	0	'
Inter-company accounts	'	-403	'	-403	'	-372.9	'
Other non-current assets	'	64.6	'	64.6	'	68.6	'
TOTAL ASSETS	'	650.7	'	650.7	'	507.1	'
Current liabilities:	'	'	'	'	'	'	'
Accounts payable	'	43.6	'	43.6	'	45.6	'
Accrued liabilities	'	18	'	18	'	6.4	'
Current portion of long-term debt	'	0	'	0	'	0	'
Current portion of pension and other postretirement benefit obligations	'	0.4	'	0.4	'	0.5	'
Total current liabilities	'	62	'	62	'	52.5	'
Non-current liabilities:	'	'	'	'	'	'	'
Long-term debt	'	0	'	0	'	0	'
Pension and other postretirement benefit obligations	'	4.1	'	4.1	'	4.8	'
Other non-current liabilities	'	0.6	'	0.6	'	0.4	'
TOTAL LIABILITIES	'	66.7	'	66.7	'	57.7	'
Exchangeable notes exchange feature	'	0	'	0	'	'	'
Total stockholders' equity (deficit)	'	164.3	'	164.3	'	35.7	'
Noncontrolling interests	'	419.7	'	419.7	'	413.7	'
TOTAL EQUITY (DEFICIT)	'	584	'	584	'	449.4	'
TOTAL LIABILITIES AND EQUITY	'	650.7	'	650.7	'	507.1	'
Condensed Consolidated Statements of Cash Flows [Abstract]	'	'	'	'	'	'	'
Net cash flows from operating activities	'	'	'	70.7	73.1	'	'
Cash flows from investing activities:	'	'	'	'	'	'	'
Capital investments	'	'	'	-12.2	-15.8	'	'
Investments in Magnetation joint venture	'	'	'	-90	-50	'	'
Investment in acquired business, net of cash acquired	'	'	'	0	'	'	'
Other investing items, net	'	'	'	0	10.6	'	'
Net cash flows from investing activities	'	'	'	-102.2	-55.2	'	'
Cash flows from financing activities:	'	'	'	'	'	'	'
Net borrowings under credit facility	'	'	'	0	0	'	'
Proceeds from issuance of long-term debt	'	'	'	0	0	'	'
Redemption of long-term debt	'	'	'	0	0	'	'
Proceeds from issuance of common stock	'	'	'	0	'	'	'
Debt issuance costs	'	'	'	0	0	'	'
Inter-company activity	'	'	'	85.8	36.7	'	'
SunCoke Middletown distributions to noncontrolling interest owners	'	'	'	-40.6	-41.1	'	'
Other financing items, net	'	'	'	-2.6	0.6	'	'
Net cash flows from financing activities	'	'	'	42.6	-3.8	'	'
Net increase (decrease) in cash and cash equivalents	'	'	'	11.1	14.1	'	'
Cash and cash equivalents, beginning of period	'	'	'	28.5	23.4	'	'
Cash and cash equivalents, end of period	'	39.6	37.5	39.6	37.5	'	'
Eliminations [Member]	'	'	'	'	'	'	'
Condensed Consolidated Statements of Comprehensive Income (Loss) [Abstract]	'	'	'	'	'	'	'
Net sales	'	-164.1	-153.1	-446.1	-438.3	'	'
Cost of products sold (exclusive of items shown separately below)	'	-148.7	-142.4	-410.3	-407.9	'	'
Selling and administrative expenses (exclusive of items shown separately below)	'	-11.2	-9.7	-32.7	-30.3	'	'
Depreciation	'	0	0	0	0	'	'
Pension and OPEB expense (income)	'	0	0	0	0	'	'
Total operating costs	'	-159.9	-152.1	-443	-438.2	'	'
Operating profit (loss)	'	-4.2	-1	-3.1	-0.1	'	'
Interest expense	'	0	0	0	0	'	'
Other income (expense)	'	0	0	0	0	'	'
Income (loss) before income taxes	'	-4.2	-1	-3.1	-0.1	'	'
Income tax expense (benefit)	'	-1.7	-0.5	-1.3	-0.1	'	'
Equity in net income (loss) of subsidiaries	'	-1.7	24.9	80.3	56.7	'	'
Net income (loss)	'	-4.2	24.4	78.5	56.7	'	'
Less: Net income attributable to noncontrolling interests	'	0	0	0	0	'	'
Net income (loss) attributable to AK Steel Holding Corporation	'	-4.2	24.4	78.5	56.7	'	'
Other comprehensive income (loss)	'	25.1	2.2	76.6	51.5	'	'
Comprehensive income (loss) attributable to AK Steel Holding Corporation	'	20.9	26.6	155.1	108.2	'	'
Current assets:	'	'	'	'	'	'	'
Cash and cash equivalents	'	0	0	0	0	'	'
Accounts receivable, net	'	-32.1	'	-32.1	'	-28.3	'
Inventory, net	'	-14.3	'	-14.3	'	-11.1	'
Deferred tax assets, current	'	0	'	0	'	0	'
Other current assets	'	0	'	0	'	0	'
Total current assets	'	-46.4	'	-46.4	'	-39.4	'
Property, plant and equipment	'	0	'	0	'	0	'
Accumulated depreciation	'	0	'	0	'	0	'
Property, plant and equipment, net	'	0	'	0	'	0	'
Other non-current assets:	'	'	'	'	'	'	'
Investments in affilates	'	0	'	0	'	0	'
Investment in subsidiaries	'	652.4	'	652.4	'	1,378.60	'
Inter-company accounts	'	36.7	'	36.7	'	31.9	'
Other non-current assets	'	0	'	0	'	0	'
TOTAL ASSETS	'	642.7	'	642.7	'	1,371.10	'
Current liabilities:	'	'	'	'	'	'	'
Accounts payable	'	-0.8	'	-0.8	'	-0.6	'
Accrued liabilities	'	0	'	0	'	0	'
Current portion of long-term debt	'	0	'	0	'	0	'
Current portion of pension and other postretirement benefit obligations	'	0	'	0	'	0	'
Total current liabilities	'	-0.8	'	-0.8	'	-0.6	'
Non-current liabilities:	'	'	'	'	'	'	'
Long-term debt	'	0	'	0	'	0	'
Pension and other postretirement benefit obligations	'	0	'	0	'	0	'
Other non-current liabilities	'	0	'	0	'	0	'
TOTAL LIABILITIES	'	-0.8	'	-0.8	'	-0.6	'
Exchangeable notes exchange feature	'	0	'	0	'	'	'
Total stockholders' equity (deficit)	'	643.5	'	643.5	'	1,371.70	'
Noncontrolling interests	'	0	'	0	'	0	'
TOTAL EQUITY (DEFICIT)	'	643.5	'	643.5	'	1,371.70	'
TOTAL LIABILITIES AND EQUITY	'	642.7	'	642.7	'	1,371.10	'
Condensed Consolidated Statements of Cash Flows [Abstract]	'	'	'	'	'	'	'
Net cash flows from operating activities	'	'	'	5	-5.9	'	'
Cash flows from investing activities:	'	'	'	'	'	'	'
Capital investments	'	'	'	0	0	'	'
Investments in Magnetation joint venture	'	'	'	0	0	'	'
Investment in acquired business, net of cash acquired	'	'	'	0	'	'	'
Other investing items, net	'	'	'	0	0	'	'
Net cash flows from investing activities	'	'	'	0	0	'	'
Cash flows from financing activities:	'	'	'	'	'	'	'
Net borrowings under credit facility	'	'	'	0	0	'	'
Proceeds from issuance of long-term debt	'	'	'	0	0	'	'
Redemption of long-term debt	'	'	'	0	0	'	'
Proceeds from issuance of common stock	'	'	'	0	'	'	'
Debt issuance costs	'	'	'	0	0	'	'
Inter-company activity	'	'	'	-5	5.9	'	'
SunCoke Middletown distributions to noncontrolling interest owners	'	'	'	0	0	'	'
Other financing items, net	'	'	'	0	0	'	'
Net cash flows from financing activities	'	'	'	-5	5.9	'	'
Net increase (decrease) in cash and cash equivalents	'	'	'	0	0	'	'
Cash and cash equivalents, beginning of period	'	'	'	0	0	'	'
Cash and cash equivalents, end of period	'	$0	$0	$0	$0	'	'
Senior Secured Notes Due December 2018 [Member]	'	'	'	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'	'	'	'
Debt Instrument, Interest Rate, Stated Percentage	'	8.75%	'	8.75%	'	8.75%	'
Senior Notes Due May 2020 [Member]	'	'	'	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'	'	'	'
Debt Instrument, Interest Rate, Stated Percentage	'	7.63%	'	7.63%	'	7.63%	'
Senior Notes Due October 2021 [Member]	'	'	'	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'	'	'	'
Debt Instrument, Interest Rate, Stated Percentage	'	7.63%	'	7.63%	'	'	'
Senior Notes Due April 2022 [Member]	'	'	'	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'	'	'	'
Debt Instrument, Interest Rate, Stated Percentage	'	8.38%	'	8.38%	'	8.38%	'
Exchangeable Senior Notes Due November 2019 [Member]	'	'	'	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'	'	'	'
Debt Instrument, Interest Rate, Stated Percentage	'	5.00%	'	5.00%	'	5.00%	'