Debt (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
Summary of Long-term debt
Total debt	$ 72.5	$ 59.8	$ 67.7
Less current portion	0.4	0.6	0.3
Long-term debt	72.1	59.2	67.4
Revolving credit facility [Member]
Summary of Long-term debt
Total debt	72.0	59.1	67.2
Other obligations [Member]
Summary of Long-term debt
Total debt	$ 0.5	$ 0.7	$ 0.5