Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 57.7	$ 45.5	$ 33.5
Other comprehensive (loss) income, net of tax:
Defined benefit plan adjustments (Note 16)	(0.2)	(0.2)	11.0
Foreign currency translation gain (loss), net (Note 16)	2.9	(5.5)	1.1
Other comprehensive income (loss), net of tax	2.7	(5.7)	12.1
Comprehensive income	$ 60.4	$ 39.8	$ 45.6