Condensed 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
Statement of Comprehensive Income [Abstract]
Net income	$ 21.4	$ 32.8	$ 44.8	$ 50.3
Other comprehensive income (loss):
Change in foreign currency translation adjustment	1.2	0.8	(4.9)	0.8
Change in unrecognized net actuarial loss and prior service cost related to pension benefit plans, net of income tax expense of $0.2, $0.1, $0.4 and $0.3, respectively	0.9	1.3	2.7	1.5
Change in unrealized gain or loss on interest rate swaps, net of income tax benefit of $0.1, $0.2, $1.1 and $0.4, respectively	(0.3)	(0.7)	(3.4)	(1.2)
Total other comprehensive income (loss)	1.8	1.4	(5.6)	1.1
Comprehensive income	$ 23.2	$ 34.2	$ 39.2	$ 51.4