Foreign Currency Exchange Rate Risk Foreign Currency Exchange Rate Risk (Details textual) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended		3 Months Ended
	Jun. 30, 2012	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2011 Maximum
Derivative [Line Items]
Net gain (loss)	$ (1.4)	$ 0.3	$ (4.5)	$ (0.1)
Maturities of foreign currency forward contracts	45 days or less	45 days or less