Comprehensive Income (Loss) - Components of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
AOCI Attributable to Parent, Net of Tax [Roll Forward]
December 31, 2016	$ 268.4
Change in other comprehensive income (loss)	(0.1)	$ (0.1)
March 31, 2017	275.4
Total Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
December 31, 2016	(1.4)
March 31, 2017	(1.5)
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
December 31, 2016	(1.4)
Change in other comprehensive income (loss)	0.0
March 31, 2017	(1.4)
Effective Portion of Unrealized Gain (Loss) on Cash Flow Hedge
AOCI Attributable to Parent, Net of Tax [Roll Forward]
December 31, 2016	0.0
Change in other comprehensive income (loss)	(0.1)
March 31, 2017	$ (0.1)