Condensed Consolidated Statements Of Changes In Shareholders' Equity (USD $) In Thousands	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings (Deficit) [Member]	Total
Balance at Dec. 31, 2010	$ 214	$ (7,479)	$ 3,151,513	$ (1,603,696)	$ 1,540,552
Balance (in shares) at Dec. 31, 2010	213,736	(539)
Issuance of common stock	0		7,327		7,327
Issuance of common stock (in shares)	551
Share-based compensation			4,048		4,048
Common stock dividends				(8,547)	(8,547)
Net income (loss)				21,941	21,941
Balance at Mar. 31, 2011	214	(7,479)	3,162,888	(1,590,302)	1,565,321
Balance (in shares) at Mar. 31, 2011	214,287	(539)
Balance at Dec. 31, 2011	215	(7,479)	3,181,063	(1,615,467)	1,558,332
Balance (in shares) at Dec. 31, 2011	217,245	(539)
Issuance of common stock	0		19		19
Issuance of common stock (in shares)	2
Share-based compensation			4,795		4,795
Restricted stock cancellations	0				0
Restricted stock cancellations (in shares)	(49)
Common stock dividends				(8,663)	(8,663)
Net income (loss)				(281,649)	(281,649)
Balance at Mar. 31, 2012	$ 215	$ (7,479)	$ 3,185,877	$ (1,905,779)	$ 1,272,834
Balance (in shares) at Mar. 31, 2012	217,198	(539)