Derivatives and Hedging Activities (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2012 Forward contracts [Member] Prepaid expenses and other assets [Member]	Dec. 31, 2011 Forward contracts [Member] Prepaid expenses and other assets [Member]	Mar. 31, 2012 Forward contracts [Member] Other assets [Member]	Dec. 31, 2011 Forward contracts [Member] Other assets [Member]	Mar. 31, 2012 Forward contracts [Member] Accrued expenses [Member]	Dec. 31, 2011 Forward contracts [Member] Accrued expenses [Member]	Mar. 31, 2012 Forward contracts [Member] Other non-current liabilities [Member]	Dec. 31, 2011 Forward contracts [Member] Other non-current liabilities [Member]
Fair value of forward contract recorded in balance sheet
Fair value of derivative assets			$ 28.7	$ 15.8	$ 33.2	$ 19.8
Fair value of derivative liabilities							6.1	16.0	11.6	26.1
Amounts recognized in other comprehensive income and reclassified from AOCI into earnings
Amount of gain/(loss) recognized in OCI, net of tax of ($16.2) and ($22.7), respectively	35.2	48.0
Amount of gain/(loss) reclassified from AOCI into earnings	$ 0.7	$ 1.2