Summary of Significant Accounting Policies - Changes in the Components of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accounting Policies [Abstract]
Pension and OPEB liability adjustments, pre-tax	$ 1.9	$ (12.7)	$ 19.8
Unrealized gain (loss) on financial instruments, pre-tax	(13.6)	(0.4)	(4.9)
Unrealized foreign currency translation adjustments, pre-tax	(54.4)	(63.0)	4.0
Total other comprehensive income (loss), pre-tax	(66.1)	(76.1)	18.9
Pension and OPEB liability adjustments, Tax	0.9	4.4	(6.7)
Unrealized gain (loss) on financial instruments, Tax	0.3	0.2	(1.8)
Unrealized foreign currency translation adjustments, Tax	0.0	0.0	0.0
Total other comprehensive income (loss), Tax	1.2	4.6	(8.5)
Pension and OPEB liability adjustments, Net of Tax	2.8	(8.3)	13.1
Unrealized gain (loss) on financial instruments, Net of Tax	(13.3)	(0.2)	(6.7)
Unrealized foreign currency translation adjustments, Net of Tax	(54.4)	(63.0)	4.0
Other Comprehensive Income (Loss)	$ (64.9)	$ (71.5)	$ 10.4