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Consolidated Statement of Shareholders' Equity (USD $) In Thousands, except Share data	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income	Deferred Equity Compensation
Balance at Dec. 31, 2010	$ 3,733,454	$ 1,837	$ 2,585,423	$ 1,032,445	$ 111,749	$ 2,000
Balance (in shares) at Dec. 31, 2010		183,744,655
Increase (Decrease) in Shareholders' Equity
Net income	859,229			859,229
Dividends ($0.135 per share)	(24,830)			(24,830)
Dividends on restricted stock units			180	(180)
Common stock repurchases	(23,311)	(20)	(23,291)
Common stock repurchases (in shares)		(2,000,000)
Share-based compensation and other	6,861	5	5,356			1,500
Share-based compensation and other (in shares)		477,310
Change in cumulative translation adjustment	(552)				(552)
Change in cash flow hedge	(314)				(314)
Change in unrealized gains (losses) on:
Investments with no other-than-temporary impairment	210,298				210,298
Investments with other-than-temporary impairment	(5,678)				(5,678)
Less: reclassification adjustment for gains (losses) included in net income (loss)	(11,558)				(11,558)
Balance at Sep. 30, 2011	$ 4,766,715	$ 1,822	$ 2,567,668	$ 1,866,664	$ 327,061	$ 3,500
Balance (in shares) at Sep. 30, 2011		182,221,965