Changes in Accumulated Other Comprehensive (Loss) Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Changes in Other Comprehensive income
Balances as of start of period			$ (1,426)
Pension and other postretirement benefit gains	14	27	41	54
Balances as of end of period	(1,371)		(1,371)
Accumulated Other Comprehensive (Loss) Income [Member]
Changes in Other Comprehensive income
Balances as of start of period	(1,394)	(980)	(1,426)	(927)
Net unrealized gains (losses)	32	(104)	100	(116)
Reclassification for realized (gains) losses into earnings	(26)	(23)	(54)	(46)
Net translation gain (losses) of investments in foreign operations	119	(567)	101	(556)
Net (losses) gains related to hedges of investment in foreign operations	(116)	339	(133)	283
Pension and other postretirement benefit gains	14	27	41	54
Net change in accumulated other comprehensive income (loss)	23	(328)	55	(381)
Balances as of end of period	(1,371)	(1,308)	(1,371)	(1,308)
Net Unrealized Investment Gains (Losses) on Investment Securities [Member]
Changes in Other Comprehensive income
Balances as of start of period	102	280	63	315
Net unrealized gains (losses)	32	(104)	100	(116)
Reclassification for realized (gains) losses into earnings	(29)	(23)	(58)	(46)
Net change in accumulated other comprehensive income (loss)	3	(127)	42	(162)
Balances as of end of period	105	153	105	153
Foreign Currency Translation Adjustments [Member]
Changes in Other Comprehensive income
Balances as of start of period	(1,124)	(799)	(1,090)	(754)
Reclassification for realized (gains) losses into earnings	3		4
Net translation gain (losses) of investments in foreign operations	119	(567)	101	(556)
Net (losses) gains related to hedges of investment in foreign operations	(116)	339	(133)	283
Net change in accumulated other comprehensive income (loss)	6	(228)	(28)	(273)
Balances as of end of period	(1,118)	(1,027)	(1,118)	(1,027)
Net Unrealized Pension and Other Postretirement Benefit Losses [Member]
Changes in Other Comprehensive income
Balances as of start of period	(372)	(461)	(399)	(488)
Pension and other postretirement benefit gains	14	27	41	54
Net change in accumulated other comprehensive income (loss)	14	27	41	54
Balances as of end of period	$ (358)	$ (434)	$ (358)	$ (434)