Shareholders' Equity (Details) (USD $) In Thousands, except Share data, unless otherwise specified	1 Months Ended		6 Months Ended
	Jun. 30, 2012	Oct. 31, 2011	Jun. 30, 2012
Stockholders' Equity Note [Abstract]
Stock Repurchase Program, Authorized Amount	$ 200,000	$ 150,000
Treasury Stock, Shares, Acquired			4,035,802
Treasury Stock, Value, Acquired, Cost Method			$ 149,664