Business Segment Information (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended								6 Months Ended		12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Jul. 18, 2011	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Reconciliation of Adjusted EBITDA to net income
Adjusted EBITDA attributable to SunCoke Energy, Inc.											$ 173.9		$ 262.7		$ 142.8
Add: Adjusted EBITDA attributable to noncontrolling interest(1)											41.2	[1]	3.0	[1]	(4.0)	[1]
Adjusted EBITDA											215.1		265.7		138.8
Subtract:
Adjustment to unconsolidated affiliate earnings(2)											3.2	[2]	0	[2]	0	[2]
Depreciation, depletion and amortization											96.0		80.8		58.4
Financing expense, net											52.3		47.8		1.4
Income tax expense											6.7		23.4		7.2
Sales discount provided to customers due to sharing of nonconventional fuel tax credits											6.8		11.2		12.9
Net income	$ 18.7	$ 12.3	$ 12.7	$ 6.4	$ 29.0	$ 32.9	$ 24.0	$ 16.6	$ 23.3	$ 35.6	$ 50.1		$ 102.5		$ 58.9

[1] Reflects non-controlling interest in Indiana Harbor and the portion of the Partnership owned by public unitholders

[2] (2)Reflects estimated share of interest, taxes, depreciation and amortization related to VISA SunCoke