Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 158.8	$ 85.2	$ 282.7	$ 203.5
Other comprehensive loss, net of tax:
Gain (loss) on cash flow hedges, net of tax (expense) benefit of ($0.1), $0.4, $2.2, and $0.7, respectively	0.4	(1.0)	(6.1)	(1.9)
Comprehensive income	$ 159.2	$ 84.2	$ 276.6	$ 201.6