Changes in Accumulated Other Comprehensive (Loss) Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Changes in Other Comprehensive income
Balances as of start of period			$ (2,534)
(Decrease) increase due to amounts reclassified into earnings	$ 0			$ 1
Pension and other postretirement benefit gains	6	$ 6	32	29
Balances as of end of period	(2,621)		(2,621)
Accumulated Other Comprehensive Loss [Member]
Changes in Other Comprehensive income
Balances as of start of period	(2,502)	(2,151)	(2,534)	(1,919)
Net unrealized gains (losses)	5	(20)	9	(20)
(Decrease) increase due to amounts reclassified into earnings	0	1	2	1
Net translation loss of investments in foreign operations	(265)	45	(169)	(405)
Net losses gains related to hedges of investment in foreign operations	135	(33)	43	162
Pension and other postretirement benefit gains	6	6	32	29
Net change in accumulated other comprehensive income (loss)	(119)	(3)	(87)	(235)
Balances as of end of period	(2,621)	(2,154)	(2,621)	(2,154)
Net Unrealized Gains (Losses) on Investment Securities [Member]
Changes in Other Comprehensive income
Balances as of start of period	60	96	58	96
Net unrealized gains (losses)	5	(20)	9	(20)
(Decrease) increase due to amounts reclassified into earnings	0	0	(2)
Net translation loss of investments in foreign operations	0	0	0	0
Net losses gains related to hedges of investment in foreign operations	0	0	0	0
Pension and other postretirement benefit gains	0	0	0	0
Net change in accumulated other comprehensive income (loss)	5	(20)	7	(20)
Balances as of end of period	65	76	65	76
Foreign Currency Translation Adjustments [Member]
Changes in Other Comprehensive income
Balances as of start of period	(2,040)	(1,754)	(2,044)	(1,499)
Net unrealized gains (losses)	0	0	0	0
(Decrease) increase due to amounts reclassified into earnings		(1)	0	(1)
Net translation loss of investments in foreign operations	(265)	45	(169)	(405)
Net losses gains related to hedges of investment in foreign operations	135	(33)	43	162
Pension and other postretirement benefit gains	0	0	0	0
Net change in accumulated other comprehensive income (loss)	(130)	11	(126)	(244)
Balances as of end of period	(2,170)	(1,743)	(2,170)	(1,743)
Net Unrealized Pension and Other Postretirement Gains (Losses) [Member]
Changes in Other Comprehensive income
Balances as of start of period	(522)	(493)	(548)	(516)
Net unrealized gains (losses)	0	0	0	0
(Decrease) increase due to amounts reclassified into earnings	0	0	0	0
Net translation loss of investments in foreign operations	0	0	0	0
Net losses gains related to hedges of investment in foreign operations	0	0	0	0
Pension and other postretirement benefit gains	6	6	32	29
Net change in accumulated other comprehensive income (loss)	6	6	32	29
Balances as of end of period	$ (516)	$ (487)	$ (516)	$ (487)