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)	(785,435)				(785,435)				(785,435)
Unrealized foreign currency translation adjustment, net of tax						(3,986)
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						(4,433)			(4,433)
Unrealized holding gains arising during the period, net of tax							20,736
Less: Reclassification adjustment for net gains included in net income, net of tax							(1,250)
Net unrealized gain on investments, net of tax							19,486		19,486
Comprehensive Income (Loss) Net of Tax									(770,382)
Sherman unrealized loss included in net loss								(16,761)	16,761
Repurchases of common stock under incentive plans			(2,484)	108					(2,376)
Issuance of common stock - stock offering		50		526,135					526,185
Issuance of common stock under benefit plans				1,938					1,938
Amortization of restricted stock				2,854					2,854
Stock-based compensation expense				191					191
Dividends declared					(536)				(536)
Balance, at Jun. 30, 2010		150	(891,980)	1,894,481	816,172	13,852	(53,316)	270	1,779,629
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)	240,121				240,121				240,121
Unrealized foreign currency translation adjustment, net of tax						6,520
Less: Reclassification adjustment for liquidation of foreign subsidiary and net gains on sales, net of tax						27,954
Net foreign currency translation adjustment, net of tax						(21,434)			(21,434)
Unrealized holding gains arising during the period, net of tax							13,615
Less: Reclassification adjustment for net gains included in net income, net of tax							(34,938)
Net unrealized gain on investments, net of tax							48,553		48,553
Comprehensive Income (Loss) Net of Tax									267,240
Repurchases of common stock under incentive plans			(24)						(24)
Issuance of common stock under benefit plans		1		404					405
Amortization of restricted stock				1,603					1,603
Additional convertible debt issuance costs, net				(22)					(22)
Stock-based compensation expense				995					995
Dividends declared				(333)	(334)				(667)
Balance, at Jun. 30, 2011	$ 1,129,310	$ 151	$ (892,036)	$ 1,965,739	$ 34,861	$ (340)	$ 20,696	$ 239	$ 1,129,310