Derivative Financial Instruments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011 Item
Derivative Financial Instruments
Aggregate foreign currency exchange loss		$ 0.2	$ 0.3	$ 0.7
Forward contracts losses (gains) included in aggregate foreign currency exchange losses		0.3	0.1	(0.5)
Number of outstanding contracts					0
Notional amount of monthly forward contracts	3.7		3.7
Weighted average notional amount of derivative contracts	$ 2.2		$ 2.4