Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 13.2	$ 12.0	$ 18.7	$ 14.4
Other comprehensive income (loss), net of tax:
Defined benefit plan adjustments	0.0	0.1	0.1	0.1
Foreign currency translation gain (loss)	0.5	1.2	(2.2)	(0.1)
Other comprehensive income (loss), net of tax	0.5	1.3	(2.1)	0.0
Comprehensive income	$ 13.7	$ 13.3	$ 16.6	$ 14.4