CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 47.1	$ 42.0
Accounts receivable, net	565.6	564.2
Inventory, net	727.8	418.7
Deferred tax assets, current	32.7	216.5
Other current assets	33.7	33.0
Total current assets	1,406.9	1,274.4
Property, plant and equipment	5,984.5	5,967.2
Accumulated depreciation	(3,942.5)	(3,797.0)
Property, plant and equipment, net	2,042.0	2,170.2
Other non-current assets:
Investment in AFSG Holdings, Inc.	55.6	55.6
Investment in Magnetation LLC	129.6	101.2
Goodwill	37.1	37.1
Deferred tax assets, non-current	146.6	716.5
Other non-current assets	102.9	94.9
Total other non-current assets	471.8	1,005.3
TOTAL ASSETS	3,920.7	4,449.9
Current liabilities:
Short-term borrowings under credit facility	42.0	250.0
Accounts payable	603.2	583.6
Accrued liabilities	185.6	172.8
Current portion of long-term debt	0.7	0.7
Current portion of pension and other postretirement benefit obligations	125.4	130.0
Total current liabilities	956.9	1,137.1
Non-current liabilities:
Long-term debt, including $400.0 of credit facility borrowings at September 30, 2012	1,349.5	650.0
Pension and other postretirement benefit obligations	1,503.4	1,744.8
Other non-current liabilities	524.8	540.8
Total non-current liabilities	3,377.7	2,935.6
TOTAL LIABILITIES	4,334.6	4,072.7
Commitments and contingencies
Equity (deficit):
Preferred stock, authorized 25,000,000 shares	0	0
Common stock, authorized 200,000,000 shares of $.01 par value each; issued 123,779,646 and 123,229,210 shares in 2012 and 2011; outstanding 110,630,790 and 110,284,228 shares in 2012 and 2011	1.2	1.2
Additional paid-in capital	1,933.7	1,922.2
Treasury stock, common shares at cost, 13,148,856 and 12,944,982 shares in 2012 and 2011	(173.3)	(171.6)
Accumulated deficit	(2,173.9)	(1,366.0)
Accumulated other comprehensive income (loss)	(22.2)	2.7
TOTAL STOCKHOLDERS' EQUITY (DEFICIT)	(434.5)	388.5
Noncontrolling interests	20.6	(11.3)
TOTAL EQUITY (DEFICIT)	(413.9)	377.2
TOTAL LIABILITIES AND EQUITY (DEFICIT)	3,920.7	4,449.9
Variable Interest Entity, Primary Beneficiary [Member] | SunCoke Middletown [Member]
Current assets:
Accounts receivable, net	23.7	0.6
Inventory, net	28.2	23.8
Property, plant and equipment	413.3	432.3
Accumulated depreciation	(11.6)	(1.4)
Current liabilities:
Accounts payable	12.5	29.8
Accrued liabilities	1.1	2.1
Non-current liabilities:
Other non-current liabilities	421.7	436.8
Equity (deficit):
Noncontrolling interests	18.3	(13.4)
Variable Interest Entity, Primary Beneficiary [Member] | Other Variable Interest Entities [Member]
Current assets:
Property, plant and equipment	11.4	11.2
Accumulated depreciation	(8.8)	(8.6)
Other assets (liabilities), net	2.1	1.6
Equity (deficit):
Noncontrolling interests	$ 2.3	$ 2.1