Equity (Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	$ (2,595)
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	(396)
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax	(295)
Accumulated Other Comprehensive Income (Loss), Net of Tax	(3,286)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(660)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	50
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(1,019)	$ (494)	$ (334)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	9	(259)	247
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	77	(20)	431
Other Comprehensive Income (Loss), Net of Tax	(933)	(773)	344
Other Comprehensive Income (Loss), Effect of Change in Accounting Principle, Net of Taxes	13
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	(3,256)	(2,595)
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	(353)	(396)
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax	(274)	(295)
Accumulated Other Comprehensive Income (Loss), Net of Tax	(3,883)	(3,286)
Available-for-Sale securities, net
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(674)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0
Other Comprehensive Income (Loss), Effect of Change in Accounting Principle, Net of Taxes	13
Unrealized derivative gains (losses), net
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(5)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	48
Other Comprehensive Income (Loss), Effect of Change in Accounting Principle, Net of Taxes	0
Unfunded pension obligations, net
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	19
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	2
Other Comprehensive Income (Loss), Effect of Change in Accounting Principle, Net of Taxes	0
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(674)	(332)	(227)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	43	(108)	174
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	21	(4)	91
Other Comprehensive Income (Loss), Net of Tax	$ (610)	$ (444)	$ 38