Condensed Consolidated Statements of Changes in Stockholders' Equity (USD $) In Millions, except Share data	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]	Treasury Stock [Member]	Total
Balance at beginning of period at Dec. 31, 2009	$ 5	$ 18,955	$ 10,727	$ 83	$ (3,180)	$ 26,590
Balance at beginning of period (in shares) at Dec. 31, 2009	502,394,396
Cumulative effect from adoption of new consolidation accounting standards			(2,956)	(16)		(2,972)
Comprehensive income:
Net income			1,244			1,244
Other comprehensive income (loss), net of tax:
Change in unrealized gains on securities, net of income taxes				447		447
Other-than-temporary impairment on available-for-sale securities not recognized in earnings, net of taxes				30		30
Defined benefit pension plans				(1)		(1)
Foreign currency translation adjustments				(98)		(98)
Unrealized gains in cash flow hedge instruments, net of taxes				22		22
Other comprehensive income				400		400
Total comprehensive income						1,644
Cash dividends-common stock			(46)			(46)
Purchases of treasury stock					(20)	(20)
Issuances of common stock and restricted stock, net of forfeitures		15				15
Issuances of common stock and restricted stock, net of forfeitures (in shares)	1,600,902
Exercise of stock options and tax benefits of exercises and restricted stock vesting		4				4
Exercise of stock options and tax benefits of exercises and restricted stock vesting (in shares)	478,212
Restricted stock awards and stock options		55				55
Balance at end of period at Jun. 30, 2010	5	19,029	8,969	467	(3,200)	25,270
Balance at end of period (in shares) at Jun. 30, 2010	504,473,510
Balance at beginning of period at Dec. 31, 2010	5	19,084	10,406	248	(3,202)	26,541
Balance at beginning of period (in shares) at Dec. 31, 2010	504,801,064
Cumulative effect from adoption of new consolidation accounting standards						0
Comprehensive income:
Net income			1,927			1,927
Other comprehensive income (loss), net of tax:
Change in unrealized gains on securities, net of income taxes				122		122
Other-than-temporary impairment on available-for-sale securities not recognized in earnings, net of taxes				(7)		(7)
Foreign currency translation adjustments				63		63
Unrealized gains in cash flow hedge instruments, net of taxes				19		19
Other				(3)		(3)
Other comprehensive income				194		194
Total comprehensive income						2,121
Cash dividends-common stock			(46)			(46)
Purchases of treasury stock					(39)	(39)
Issuances of common stock and restricted stock, net of forfeitures		18				18
Issuances of common stock and restricted stock, net of forfeitures (in shares)	1,935,616
Exercise of stock options and tax benefits of exercises and restricted stock vesting		42				42
Exercise of stock options and tax benefits of exercises and restricted stock vesting (in shares)	1,150,307
Restricted stock awards and stock options		44				44
Balance at end of period at Jun. 30, 2011	$ 5	$ 19,188	$ 12,287	$ 442	$ (3,241)	$ 28,681
Balance at end of period (in shares) at Jun. 30, 2011	507,886,987