Financial Instruments (Details 2) (Fair value measured on a recurring basis, USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Total
Assets
Plan asset for deferred compensation	$ 4.0	$ 3.7
Total assets	4.0	3.7
Liabilities
Plan liability for deferred compensation	4.0	3.7
Contingent consideration	1.1	1.9
Total liabilities	5.1	5.6
Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Plan asset for deferred compensation	4.0	3.7
Total assets	4.0	3.7
Liabilities
Plan liability for deferred compensation	4.0	3.7
Total liabilities	4.0	3.7
Significant Unobservable Inputs (Level 3)
Liabilities
Contingent consideration	1.1	1.9
Total liabilities	$ 1.1	$ 1.9