Condensed Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement of Comprehensive Income [Abstract]
Net income	$ 12.3	$ 10.5	$ 26.6	$ 24.2
Other comprehensive income (loss), net of tax:
Minimum pension liability adjustment	0	0	0.2	0.1
Foreign currency translation adjustment gains (losses)	0.6	0.7	(0.7)	0.7
Total other comprehensive income (loss), net of tax	0.6	0.7	(0.5)	0.8
Comprehensive income	$ 12.9	$ 11.2	$ 26.1	$ 25.0