Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 12.7	$ 178.8	$ 37.0	$ 211.6
Other comprehensive income (loss):
Foreign currency translation	0.0	(0.5)	0.1	(2.8)
Total comprehensive income	$ 12.7	$ 178.3	$ 37.1	$ 208.8