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
Comprehensive income:
Net income	$ 218.4	$ 204.5	$ 455.2	$ 444.8
Derivative instruments:
Reclassification of loss to net income, net of tax of $0.1, $0.1, $0.3 and $0.3, respectively	0.3	0.3	0.9	0.9
Tax	0.1	0.1	0.3	0.3
Total other comprehensive income	0.3	0.3	0.9	0.9
Total comprehensive income	$ 218.7	$ 204.8	$ 456.1	$ 445.7