Derivative Instruments, Cash Flow Hedges and Offsetting of Derivatives (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		3 Months Ended						3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Foreign Exchange Contract [Member] Cash Flow Hedging [Member]	Mar. 31, 2012 Foreign Exchange Contract [Member] Cash Flow Hedging [Member]	Mar. 31, 2013 Other Current Assets [Member] Foreign Exchange Contract [Member] Cash Flow Hedging [Member]	Dec. 31, 2012 Other Current Assets [Member] Foreign Exchange Contract [Member] Cash Flow Hedging [Member]	Mar. 31, 2013 Other Current Liabilities [Member] Foreign Exchange Contract [Member] Cash Flow Hedging [Member]	Dec. 31, 2012 Other Current Liabilities [Member] Foreign Exchange Contract [Member] Cash Flow Hedging [Member]	Mar. 31, 2013 Operating expense [Member] Foreign Exchange Contract [Member] Cash Flow Hedging [Member]	Mar. 31, 2012 Operating expense [Member] Foreign Exchange Contract [Member] Cash Flow Hedging [Member]
Derivatives, Fair Value [Line Items]
Maximum Length of Time Hedged in Cash Flow Hedge	1 year
Derivative Asset Designated as Hedging Instrument, Fair Value					$ 1.6	$ 3.5
Derivative Liability Designated as Hedging Instrument, Fair Value							1.1	0.1
Derivative Instruments, Loss Recognized in Other Comprehensive Income (Loss), Effective Portion			2.1
Derivative Instruments, Gain Recognized in Other Comprehensive Income (Loss), Effective Portion				6.0
Derivative Instruments, Gain Reclassified from Accumulated OCI into Income, Effective Portion									1.4
Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion										3.5
Amount of derivative asset offset under a master netting arrangement	0.2	0.1
Amount of derivative liability offset under a master netting arrangement	0.2	0.1
Net derivative assets	1.4	3.4
Net derivative liabilities	$ 0.9