Changes in Accumulated Other Comprehensive (Loss) Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Changes in Other Comprehensive income
Balances as of start of period			$ (927)
Net unrealized pension and other postretirement benefit gains, net of tax	27	14	54	20
Balances as of end of period	(1,308)		(1,308)
Accumulated Other Comprehensive (Loss) Income [Member]
Changes in Other Comprehensive income
Balances as of start of period	(980)	(777)	(927)	(876)
Net unrealized gains (losses)	(104)	31	(116)	65
Reclassification for realized (gains) losses into earnings	(23)	(20)	(46)	(33)
Net translation of investments in foreign operations	(567)	(475)	(556)	(153)
Net gains (losses) related to hedges of investment in foreign operations	339	276	283	26
Net unrealized pension and other postretirement benefit gains, net of tax	27	14	54	20
Net change in accumulated other comprehensive (loss) income	(328)	(174)	(381)	(75)
Balances as of end of period	(1,308)	(951)	(1,308)	(951)
Net Unrealized Investment Gains (Losses) on Investment Securities [Member]
Changes in Other Comprehensive income
Balances as of start of period	280	308	315	288
Net unrealized gains (losses)	(104)	31	(116)	65
Reclassification for realized (gains) losses into earnings	(23)	(20)	(46)	(34)
Net change in accumulated other comprehensive (loss) income	(127)	11	(162)	31
Balances as of end of period	153	319	153	319
Net Unrealized Gains (Losses) on Cash Flow Hedges [Member]
Changes in Other Comprehensive income
Balances as of start of period	0	0	0	(1)
Reclassification for realized (gains) losses into earnings				1
Net change in accumulated other comprehensive (loss) income	0	0	0	1
Balances as of end of period	0	0	0	0
Foreign Currency Translation Adjustments [Member]
Changes in Other Comprehensive income
Balances as of start of period	(799)	(610)	(754)	(682)
Net translation of investments in foreign operations	(567)	(475)	(556)	(153)
Net gains (losses) related to hedges of investment in foreign operations	339	276	283	26
Net change in accumulated other comprehensive (loss) income	(228)	(199)	(273)	(127)
Balances as of end of period	(1,027)	(809)	(1,027)	(809)
Net Unrealized Pension and Other Postretirement Benefit Losses [Member]
Changes in Other Comprehensive income
Balances as of start of period	(461)	(475)	(488)	(481)
Net unrealized pension and other postretirement benefit gains, net of tax	27	14	54	20
Net change in accumulated other comprehensive (loss) income	27	14	54	20
Balances as of end of period	$ (434)	$ (461)	$ (434)	$ (461)