Consolidated Statements of Comprehensive (Loss) Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (31.5)	$ 1.0	$ (89.2)	$ 13.6
Other comprehensive income:
Currency translation adjustment	(0.3)	0.7	(0.2)	1.1
Comprehensive (loss) income	(31.8)	1.7	(89.4)	14.7
Less: Comprehensive (loss) income attributable to noncontrolling interests	(7.3)	5.6	(66.0)	22.3
Comprehensive (loss) income attributable to SunCoke Energy, Inc.	$ (24.5)	$ (3.9)	$ (23.4)	$ (7.6)