CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Comprehensive income:
Net income	$ 117.4	$ 95.9	$ 224.4	$ 209.1
Other comprehensive income
Reclassifications of loss to net income, net of tax of $—	0.1	0.0	0.1	0.0
Reclassification of losses to net income, net of tax of $—, $0.1, $0.1 and $0.1, respectively	0.2	0.2	0.4	0.4
Total other comprehensive income	0.3	0.2	0.5	0.4
Total comprehensive income	$ 117.7	$ 96.1	$ 224.9	$ 209.5