Supplemental Cash Flow Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Supplemental disclosure of cash flow information:
Interest paid			$ 14.4	$ 5.4
Income taxes paid	0.5	0.4	1.8	0.9
Supplemental disclosure of non-cash transactions:
Non-cash capital expenditures			3.5	1.2
Capital leases acquired			$ 0.2	$ 0