Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at the beginning of the period	$ (1.4)
Change in other comprehensive income (loss)	0.2	$ (0.3)	$ (0.9)
Balance at the end of the period	(1.2)	(1.4)
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at the beginning of the period	(1.4)	(1.1)	(0.2)
Balance at the end of the period	(1.2)	(1.4)	(1.1)
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at the beginning of the period	(1.4)	(1.2)	(0.5)
Change in other comprehensive income (loss)	0.2	(0.2)	(0.7)
Balance at the end of the period	(1.2)	(1.4)	(1.2)
Effective Portion of Unrealized Gain (Loss) on Derivative
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at the beginning of the period	0.0	0.1	0.3
Change in other comprehensive income (loss)	0.0	(0.1)	(0.2)
Balance at the end of the period	$ 0.0	$ 0.0	$ 0.1