Supplemental Cash Flow Information (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Supplemental Cash Flow Information
Interest paid	$ 0.8	$ 0.6	$ 0.8
Income taxes paid	16.4	12.2	11.1
Decrease in accounts payable and accrued liabilities for changes in unpaid capital expenditures	$ 1.0	$ 0.7