Condensed Consolidated Statements of Changes in Shareholders' Equity (Unaudited) (USD $) In Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated (Deficit)	Accumulated Capitalize Other Comprehensive Income [Member]
Beginning Balance at Dec. 31, 2010	$ 2,040,767	$ 893	$ 2,578,206	$ (538,332)
Beginning Balance, Shares at Dec. 31, 2010		89,316
Net income	51,075			51,075
Unrealized loss on marketable securities, net of tax	(1,387)				(1,387)
Common stock issued / cancelled under long-term incentive plans, net	5,141	2	5,139
Common stock issued / cancelled under long-term incentive plans, net, shares		215
Ending Balance at Jun. 30, 2011	$ 2,095,596	$ 895	$ 2,583,345	$ (487,257)	$ (1,387)
Ending Balance, Shares at Jun. 30, 2011		89,531