Changes in Accumulated Other Comprehensive (Loss) Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Changes in Other Comprehensive income
Balances as of start of period			$ (2,784)
Increase (decrease) due to amounts reclassified into earnings		$ 3
Net unrealized Pension and other postretirement benefits, net of tax	$ 7	7	8	$ 39
Balances as of end of period	(2,316)		(2,316)
Tax impact for the changes in each component of accumulated other comprehensive (loss) income
Investment securities	(1)	(9)	2	(7)
Foreign currency translation adjustments	(25)	(6)	(204)	30
Cash Flow Hedges	(99)	(18)	(306)	7
Pension and other postretirement benefits	(2)	7	(10)	36
Total tax impact	(127)	(26)	(518)	66
Tax Benefit Recognized in the period			289
Accumulated Other Comprehensive Loss [Member]
Changes in Other Comprehensive income
Balances as of start of period	(2,428)	(2,621)	(2,784)	(2,534)
Net unrealized gains	(2)	(14)	4	(5)
Increase (decrease) due to amounts reclassified into earnings	(1)	(1)	(1)	(3)
Net translation gain of investments in foreign operations	292	29	972	(140)
Net losses related to hedges of investment in foreign operations	(184)	(18)	(515)	25
Net unrealized Pension and other postretirement benefits, net of tax	7	7	8	39
Net change in accumulated other comprehensive income (loss)	112	3	468	(84)
Balances as of end of period	(2,316)	(2,618)	(2,316)	(2,618)
Net Unrealized Gains (Losses) on Investment Securities [Member]
Changes in Other Comprehensive income
Balances as of start of period	13	65	7	58
Net unrealized gains	(2)	(14)	4	(5)
Increase (decrease) due to amounts reclassified into earnings	0	(1)	0	(3)
Net translation gain of investments in foreign operations	0	0	0	0
Net losses related to hedges of investment in foreign operations	0	0	0	0
Net unrealized Pension and other postretirement benefits, net of tax	0	0	0	0
Net change in accumulated other comprehensive income (loss)	(2)	(15)	4	(8)
Balances as of end of period	11	50	11	50
Foreign Currency Translation Adjustments [Member]
Changes in Other Comprehensive income
Balances as of start of period	(1,913)	(2,170)	(2,262)	(2,044)
Net unrealized gains	0	0	0	0
Increase (decrease) due to amounts reclassified into earnings	(1)	0	(1)	0
Net translation gain of investments in foreign operations	292	29	972	(140)
Net losses related to hedges of investment in foreign operations	(184)	(18)	(515)	25
Net unrealized Pension and other postretirement benefits, net of tax	0	0	0	0
Net change in accumulated other comprehensive income (loss)	107	11	456	(115)
Balances as of end of period	(1,806)	(2,159)	(1,806)	(2,159)
Net Unrealized Pension and Other Postretirement Gains (Losses) [Member]
Changes in Other Comprehensive income
Balances as of start of period	(528)	(516)	(529)	(548)
Net unrealized gains	0	0	0	0
Increase (decrease) due to amounts reclassified into earnings	0	0	0	0
Net translation gain of investments in foreign operations	0	0	0	0
Net losses related to hedges of investment in foreign operations	0	0	0	0
Net unrealized Pension and other postretirement benefits, net of tax	7	7	8	39
Net change in accumulated other comprehensive income (loss)	7	7	8	39
Balances as of end of period	$ (521)	$ (509)	$ (521)	$ (509)