Commitments, Contingencies And Guarantees (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Standby letters of credit	$ 55.9	$ 76.9
Average notional amount of open futures contract	34.7	17.7
Net futures activity resulted in losses	1.1	0.8	0.1
Average of contracts to purchase and to sell foreign currency	39.9	49.0
Net gains on foreign exchange contracts	2.2	1.9	1.9
Maximum [Member]
Standby letters of credit	$ 320.1	$ 308.2