Statement of Shareholders Equity (USD $)	Total	Common Stock [Member]	Retained Earnings [Member]	Treasury Stock [Member]
Beginning Balance at Dec. 31, 2010	$ 1,138,976,000	$ 426,779,000	$ 712,197,000	$ 0
Beginning Balance, Shares at Dec. 31, 2010		152,568,000
Stock options exercised	9,928,000	9,928,000
Stock options exercised, Shares		672,000
Employee stock plan grants	700,000			700,000
Employee stock plan grants, Shares		150,000
Shares re-issued from treasury	0	(686,000)	(4,531,000)	5,217,000
Shares repurchased	(20,868,000)			(20,868,000)
Shares repurchased, Shares		(588,000)
Net share settlements	(15,429,000)		(15,429,000)
Net share settlements, Shares		(325,000)
Fair value of employee stock plan grants	20,988,000	20,988,000
Tax benefit of stock options exercised	6,212,000	6,212,000
Comprehensive earnings:
Net earnings (loss)	453,202,000		453,202,000
Ending Balance at Dec. 31, 2011	1,593,709,000	463,221,000	1,145,439,000	(14,951,000)
Ending Balance, Shares at Dec. 31, 2011		152,477,000
Stock options exercised	632,000	632,000
Stock options exercised, Shares		34,000
Employee stock plan grants	613,000	613,000
Employee stock plan grants, Shares		708,000
Shares re-issued from treasury	0	(1,245,000)	(14,793,000)	16,038,000
Shares repurchased	(1,100,000)			(1,100,000)
Shares repurchased, Shares		(50,000)
Net share settlements	(5,618,000)		(5,618,000)
Net share settlements, Shares		(239,000)
Fair value of employee stock plan grants	15,222,000	15,222,000
Tax benefit of stock options exercised	(4,427,000)	(4,427,000)
Comprehensive earnings:
Net earnings (loss)	(2,176,898,000)		(2,176,898,000)
Ending Balance at Dec. 31, 2012	(577,867,000)	474,016,000	(1,051,870,000)	(13,000)
Ending Balance, Shares at Dec. 31, 2012		152,930,000
Stock options exercised	11,000	11,000
Stock options exercised, Shares		1,000
Employee stock plan grants	700,000	700,000
Employee stock plan grants, Shares		347,000
Shares re-issued from treasury	0	(711,000)	(652,000)	1,363,000
Shares repurchased	(3,311,000)			(3,311,000)
Shares repurchased, Shares		(165,000)
Net share settlements	(2,118,000)		(2,118,000)
Net share settlements, Shares		(122,000)
Fair value of employee stock plan grants	13,257,000	13,257,000
Comprehensive earnings:
Net earnings (loss)	237,838,000		237,838,000
Ending Balance at Dec. 31, 2013	$ (331,490,000)	$ 487,273,000	$ (816,802,000)	$ (1,961,000)
Ending Balance, Shares at Dec. 31, 2013		152,991,000