Condensed Consolidated Statements of Changes in Common Stockholders' Equity (USD $) In Thousands	Total	Common Stock	Treasury Stock	Additional Paid-in Capital	Retained Earnings	Foreign Currency Translation Adjustment	Unrealized Holding Gains/(Losses)	Other Change in Stockholders Equity [Member]	Total Stockholders Equity
Balance, at Dec. 31, 2009		$ 100	$ (889,496)	$ 1,363,255	$ 1,602,143	$ 18,285	$ (72,802)	$ (16,491)	$ 2,004,994
Comprehensive Income (Loss)
Net income (loss)	(673,250)				(673,250)				(673,250)
Unrealized foreign currency translation adjustment, net of tax						2,280
Less: Reclassification adjustment for liquidation of foreign subsidiary and net gains on sales, net of tax						(447)
Net foreign currency translation adjustment, net of tax						1,833			1,833
Unrealized holding gains (losses) arising during the period, net of tax							48,681
Less: Reclassification adjustment for net gains (losses) included in net income, net of tax							3,099
Net unrealized gain on investments, net of tax							51,780		51,780
Comprehensive Income (Loss) Net of Tax									(619,637)
Sherman unrealized loss included in net loss								16,761	16,761
Repurchases of common stock under incentive plans			(2,493)	108					(2,385)
Issuance of common stock - stock offering		50		525,837					525,887
Issuance of common stock under benefit plans				3,035					3,035
Amortization of restricted stock				3,084					3,084
Stock-based compensation expense				749					749
Dividends declared					(868)				(868)
Balance, at Sep. 30, 2010		150	(891,989)	1,896,068	928,025	20,118	(21,022)	270	1,931,620
Balance, at Dec. 31, 2010	859,780	150	(892,012)	1,963,092	(204,926)	21,094	(27,857)	239	859,780
Comprehensive Income (Loss)
Net income (loss)	423,689				423,689				423,689
Unrealized foreign currency translation adjustment, net of tax						6,519
Less: Reclassification adjustment for liquidation of foreign subsidiary and net gains on sales, net of tax						27,599
Net foreign currency translation adjustment, net of tax						(21,080)			(21,080)
Unrealized holding gains (losses) arising during the period, net of tax							(9,856)
Less: Reclassification adjustment for net gains (losses) included in net income, net of tax							(33,449)
Net unrealized gain on investments, net of tax							23,593		23,593
Comprehensive Income (Loss) Net of Tax									426,202
Repurchases of common stock under incentive plans			(40)						(40)
Issuance of common stock under benefit plans		1		707					708
Amortization of restricted stock				1,665					1,665
Additional convertible debt issuance costs, net				(22)					(22)
Stock-based compensation expense				1,144					1,144
Dividends declared				(333)	(668)				(1,001)
Balance, at Sep. 30, 2011	$ 1,288,436	$ 151	$ (892,052)	$ 1,966,253	$ 218,095	$ 14	$ (4,264)	$ 239	$ 1,288,436