Consolidated Statements Of Shareholders' Equity (USD $) In Thousands, except Share data	Total		Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings (Accumulated Deficit) [Member]
Shareholders' Equity at Dec. 31, 2010	$ 2,135,167		$ 3,820	$ 2,972,919	$ (1,519)	$ (840,053)
Shareholders' Equity, shares at Dec. 31, 2010			382,028,000
Stock option exercises	0				0	0
Stock awards, net of cancellations, shares			944,000
Stock awards, net of cancellations			10	(10)
Stock repurchases, shares			(364,000)
Stock repurchases	(2,836)		(4)	(3,128)		296
Stock-based compensation	16,459		0	16,459	0	0
Net income (loss)	(210,388)					(210,388)
Other comprehensive income	213				213
Shareholders' Equity at Dec. 31, 2011	1,938,615		3,826	2,986,240	(1,306)	(1,050,145)
Shareholders' Equity, shares at Dec. 31, 2011			382,608,000
Stock option exercises, shares			2,877,000
Stock option exercises	32,809		29	32,780	0	0
Stock awards, net of cancellations, shares			1,228,000
Stock awards, net of cancellations			12	(12)
Stock repurchases, shares			(105,000)
Stock repurchases	(961)		(1)	(813)		(147)
Stock-based compensation	12,694		0	12,694	0	0
Net income (loss)	206,145	[1]				206,145
Other comprehensive income	314				314
Shareholders' Equity at Dec. 31, 2012	2,189,616		3,866	3,030,889	(992)	(844,147)
Shareholders' Equity, shares at Dec. 31, 2012	386,608,436		386,608,000
Stock option exercises, shares			1,432,000
Stock option exercises	19,411		14	19,397	0	0
Stock awards, net of cancellations, shares			1,002,000
Stock awards, net of cancellations			10	(10)
Dividends declared	(57,530)					(57,530)
Stock repurchases, shares			(7,742,000)
Stock repurchases	(127,661)		(77)	(3,063)		(124,521)
Stock-based compensation	14,474			14,474	0	0
Excess tax benefits (deficiencies) from stock-based compensation	(9,671)			(9,671)
Net income (loss)	2,620,116	[1]				2,620,116
Other comprehensive income	197				197
Shareholders' Equity at Dec. 31, 2013	$ 4,648,952		$ 3,813	$ 3,052,016	$ (795)	$ 1,593,918
Shareholders' Equity, shares at Dec. 31, 2013	381,299,600		381,300,000

[1] Due to rounding, the sum of quarterly results may not equal the total for the year. Additionally, quarterly and year-to-date computations of per share amounts are made independently.