Other Long-Term Liabilities (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Other Long-Term Liabilities
Deferred taxes and other tax liabilities	$ 258.9	$ 253.8
Pension and other post-retirement obligations	17.8	19.1
Deferred credits	8.8	9.1
Deferred compensation	6.6	5.5
Other	2.4	2.8
Other long-term liabilities	$ 294.5	$ 290.3