Commitments (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Commitments [Abstract]
Lease expenses	$ 36.3	$ 34.2	$ 34.6
Business acquisition, contingent consideration, at fair value	$ 376.1