Consolidated Statements of Changes in Stockholders' Equity (Unaudited) (USD $) In Thousands, except Share data	Total USD ($)	Total Stockholders' Equity USD ($)	Common Stock USD ($)	Common Stock Shares Outstanding	Additional Paid-In Capital USD ($)	Accumulated Other Comprehensive Income (Loss) USD ($)	Retained Earnings USD ($)	Treasury Stock USD ($)	Noncontrolling Interest USD ($)	Preferred stock [Member] USD ($)	Series A Preferred Stock USD ($)	Series A Preferred Stock Total Stockholders' Equity USD ($)	Series A Preferred Stock Retained Earnings USD ($)	Series B Preferred Stock USD ($)	Series B Preferred Stock Total Stockholders' Equity USD ($)	Series B Preferred Stock Retained Earnings USD ($)	Series C Preferred Stock USD ($)	Series C Preferred Stock Total Stockholders' Equity USD ($)	Series C Preferred Stock Retained Earnings USD ($)
Beginning Balance, value at Dec. 31, 2009	$ 5,278,622	$ 5,278,609	$ 110,444		$ 5,090,891	$ (40,825)	$ 604,467	$ (1,861,738)	$ 13	$ 1,375,370
Beginning Balance, shares at Dec. 31, 2009			552,219,576	484,997,634				(67,221,942)		8,110,370
Comprehensive income:
Net income (loss)	577,958	577,958					577,958
Other comprehensive income, net of tax:
Change in unrealized gains (losses) on investments, net of tax	1,678	1,678				1,678
Change in unrealized gains (losses) on derivatives, net of tax	(4,151)	(4,151)				(4,151)
Defined benefit pension plans adjustment	(35)	(35)				(35)
Comprehensive income	575,450	575,450
Cash dividends:
Preferred stock											(5,750)	(5,750)	(5,750)	(1,969)	(1,969)	(1,969)	(29,376)	(29,376)	(29,376)
Restricted stock dividend	(11)	(11)					(11)
Issuance of common shares	10,437	10,437	271		10,166
Issuance of common shares, shares			1,351,808	1,351,808
Preferred stock issuance costs and related amortization					294		(294)
Tax benefit related to employee stock option and purchase plans	(4,805)	(4,805)			(4,805)
Stock-based compensation expense	26,037	26,037			26,037
Cumulative effect of accounting change	(753,856)	(753,856)					(753,856)
Repurchase of common shares:
Benefit plans	(8,022)	(8,022)						(8,022)
Benefit plans, shares				(552,860)				(552,860)
Noncontrolling interest - other	(9)								(9)
Ending Balance, value at Jun. 30, 2010	5,086,748	5,086,744	110,715		5,122,583	(43,333)	391,169	(1,869,760)	4	1,375,370
Ending Balance, shares at Jun. 30, 2010			553,571,384	485,796,582				(67,774,802)		8,110,370
Beginning Balance, value at Mar. 31, 2010	4,755,696	4,755,677	110,682		5,106,094	(42,511)	72,062	(1,866,020)	19	1,375,370
Beginning Balance, shares at Mar. 31, 2010			553,407,785	485,843,997				(67,563,788)		8,110,370
Comprehensive income:
Net income (loss)	337,818	337,818					337,818
Other comprehensive income, net of tax:
Change in unrealized gains (losses) on investments, net of tax	1,615	1,615				1,615
Change in unrealized gains (losses) on derivatives, net of tax	(2,439)	(2,439)				(2,439)
Defined benefit pension plans adjustment	2	2				2
Comprehensive income	336,996	336,996
Cash dividends:
Preferred stock											(2,875)	(2,875)	(2,875)	(1,014)	(1,014)	(1,014)	(14,688)	(14,688)	(14,688)
Issuance of common shares	3,798	3,798	33		3,765
Issuance of common shares, shares			163,599	163,599
Preferred stock issuance costs and related amortization					134		(134)
Tax benefit related to employee stock option and purchase plans	(1,212)	(1,212)			(1,212)
Stock-based compensation expense	13,802	13,802			13,802
Repurchase of common shares:
Benefit plans	(3,740)	(3,740)						(3,740)
Benefit plans, shares				(211,014)				(211,014)
Noncontrolling interest - other	(15)								(15)
Ending Balance, value at Jun. 30, 2010	5,086,748	5,086,744	110,715		5,122,583	(43,333)	391,169	(1,869,760)	4	1,375,370
Ending Balance, shares at Jun. 30, 2010			553,571,384	485,796,582				(67,774,802)		8,110,370
Beginning Balance, value at Dec. 31, 2010	5,011,578							(1,876,488)	0	565,000
Beginning Balance, shares at Dec. 31, 2010								(68,319,589)		7,300,000
Cash dividends:
Retirement of common stock in treasury, shares	70,000,000
Retirement of common stock in treasury								1,900,000
Ending Balance, value at Mar. 31, 2011	5,207,087							0		565,000
Ending Balance, shares at Mar. 31, 2011								0		7,300,000
Beginning Balance, value at Dec. 31, 2010	5,011,578	5,011,578	119,053		5,939,838	(44,664)	308,839	(1,876,488)	0	565,000
Beginning Balance, shares at Dec. 31, 2010			595,263,474	526,943,885				(68,319,589)		7,300,000
Comprehensive income:
Net income (loss)	169,046	169,046					169,046
Other comprehensive income, net of tax:
Change in unrealized gains (losses) on investments, net of tax	715	715				715
Change in unrealized gains (losses) on derivatives, net of tax	14,105	14,105				14,105
Defined benefit pension plans adjustment	208	208				208
Comprehensive income	184,074	184,074
Cash dividends:
Common stock ($.10 per share)	(52,253)	(52,253)					(52,253)
Preferred stock											(5,750)	(5,750)	(5,750)	(2,180)	(2,180)	(2,180)
Issuance of common shares	35,240	35,240	687		34,553
Retirement of common stock in treasury, shares			(70,074,369)					70,074,369
Retirement of common stock in treasury			(14,015)		(1,889,891)			1,903,906
Issuance of common shares, shares			3,434,058	3,434,058
Tax benefit related to employee stock option and purchase plans	(7,295)	(7,295)			(7,295)
Stock-based compensation expense	37,061	37,061			37,061
Repurchase of common shares:
Open market	(156,105)	(156,105)						(156,105)
Open market, shares				(9,593,603)				(9,593,603)
Benefit plans	(41,809)	(41,809)						(41,809)
Benefit plans, shares				(2,635,511)				(2,635,511)
Acquisition of noncontrolling interest	8,678
Ending Balance, value at Jun. 30, 2011	5,011,239	5,002,561	105,725		4,114,266	(29,636)	417,702	(170,496)		565,000
Ending Balance, shares at Jun. 30, 2011			528,623,163	518,148,829				(10,474,334)		7,300,000
Beginning Balance, value at Mar. 31, 2011	5,207,087	5,207,087	105,499		4,092,334	(35,401)	479,655	0	0	565,000
Beginning Balance, shares at Mar. 31, 2011			527,493,764	527,493,764				0		7,300,000
Comprehensive income:
Net income (loss)	(5,648)	(5,648)					(5,648)
Other comprehensive income, net of tax:
Change in unrealized gains (losses) on investments, net of tax	1,034	1,034				1,034
Change in unrealized gains (losses) on derivatives, net of tax	4,731	4,731				4,731
Comprehensive income	117	117
Cash dividends:
Common stock ($.10 per share)	(52,253)	(52,253)					(52,253)
Preferred stock											(2,875)	(2,875)	(2,875)	(1,177)	(1,177)	(1,177)
Issuance of common shares	12,305	12,305	226		12,079
Issuance of common shares, shares			1,129,399	1,129,399
Tax benefit related to employee stock option and purchase plans	(2,216)	(2,216)			(2,216)
Stock-based compensation expense	12,069	12,069			12,069
Repurchase of common shares:
Open market	(156,105)	(156,105)						(156,105)
Open market, shares			9,600,000	(9,593,603)				(9,593,603)
Benefit plans	(14,391)	(14,391)						(14,391)
Benefit plans, shares				(880,731)				(880,731)
Acquisition of noncontrolling interest	8,678								8,678
Ending Balance, value at Jun. 30, 2011	$ 5,011,239	$ 5,002,561	$ 105,725		$ 4,114,266	$ (29,636)	$ 417,702	$ (170,496)	$ 8,678	$ 565,000
Ending Balance, shares at Jun. 30, 2011			528,623,163	518,148,829				(10,474,334)		7,300,000