Shareholders' Equity (Details) (USD $) Share data in Thousands, unless otherwise specified	1 Months Ended	3 Months Ended		9 Months Ended
	Oct. 31, 2008	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Stock Repurchase Programs
Authorized common stock repurchase program	$ 50,000,000
Shares repurchased		536
Amount of shares repurchased		20,000,000		20,000,000
Amount available to repurchase shares under stock repurchase program		30,000,000
Accumulated other comprehensive loss
Balance at the beginning of the period				(16,018,000)
Other comprehensive loss		111,000	(652,000)	(9,060,000)	(8,731,000)
Balance at the end of the period		(25,078,000)		(25,078,000)
Foreign Currency Translation Adjustments
Accumulated other comprehensive loss
Balance at the beginning of the period				(16,130,000)
Other comprehensive loss				(8,975,000)
Balance at the end of the period		(25,105,000)		(25,105,000)
Cash Flow Hedges
Accumulated other comprehensive loss
Balance at the beginning of the period				112,000
Other comprehensive loss				(85,000)
Balance at the end of the period		$ 27,000		$ 27,000