Shareholders' Equity-Common Stock Rollforward (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Repurchases of common stock	6,032,892
Preferred Stock, Shares Authorized	2,000,000
Stock Repurchase Program, Amount Authorized	$ 200,000
Treasury Stock, Value, Acquired, Cost Method	$ 248,571
Common Stock Issued [Member]
Common stock outstanding, Beginning balance	125,424	125,382	125,337
Shares issued for stock-based compensation awards	0	42	45
Repurchases of common stock	0	0	0
Common stock outstanding, Ending balance	125,424	125,424	125,382
Treasury Stock [Member]
Common stock outstanding, Beginning balance	19,423	13,568	10,690
Shares issued for stock-based compensation awards	(2,772)	(1,326)	(2,662)
Repurchases of common stock	8,837	7,181	5,540
Common stock outstanding, Ending balance	25,488	19,423	13,568
Common Stock at Par Value [Member]
Common stock outstanding, Beginning balance	106,001	111,814	114,647
Shares issued for stock-based compensation awards	2,772	1,368	2,707
Repurchases of common stock	(8,837)	(7,181)	(5,540)
Common stock outstanding, Ending balance	99,936	106,001	111,814