Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance beginning	$ 134.2	$ 127.3	$ 165.0
Foreign currency translation adjustment	1.0	(1.7)	2.9
Amortization related to derivatives securities, before tax	3.0	2.8	2.6
Tax impact	(0.6)	(0.4)	(0.8)
Other comprehensive income	3.4	0.7	4.7
Balance end	114.5	134.2	127.3
Foreign currency translation adjustment
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance beginning	1.8	3.5	0.6
Foreign currency translation adjustment	1.0	(1.7)	2.9
Amortization related to derivatives securities, before tax	0.0
Tax impact	0.0
Other comprehensive income	1.0	(1.7)	2.9
Balance end	2.8	1.8	3.5
Valuation and amortization of derivative securities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance beginning	(22.7)	(25.1)	(26.9)
Foreign currency translation adjustment	0.0
Amortization related to derivatives securities, before tax	3.0	2.8	2.6
Tax impact	(0.6)	(0.4)	(0.8)
Other comprehensive income	2.4	2.4	1.8
Balance end	(20.3)	(22.7)	(25.1)
AOCI
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance beginning	(20.9)	(21.6)	(26.3)
Balance end	$ (17.5)	$ (20.9)	$ (21.6)