CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Comprehensive income:
Net income	$ 78.9	$ 98.0	$ 79.4
Derivative instruments:
Reclassification of loss to net income, net of tax of $0	0.0	0.1	0.0
Other comprehensive income	0.0	0.1	0.0
Comprehensive income	$ 78.9	$ 98.1	$ 79.4