Equity - Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	$ 34,499	$ 35,013
Other comprehensive income (loss) before reclassifications	(272)	171
Amounts reclassified from accumulated other comprehensive income (loss)	11	1
Deferred taxes	(4)	0
Other comprehensive income (loss)	(265)	172
Less: Other comprehensive income (loss) attributable to noncontrolling interests	(97)	87
Ending Balance	17,985	35,086
Investment Securities, Parent
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	1	0
Ending Balance	0	1
Investment Securities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Other comprehensive income (loss) before reclassifications	(2)	2
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Deferred taxes	0	0
Other comprehensive income (loss)	(2)	2
Investment Securities, Noncontrolling Interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Less: Other comprehensive income (loss) attributable to noncontrolling interests	(1)	1
Foreign Currency Translation Adjustment, Parent
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	(1,436)	(1,152)
Ending Balance	(1,612)	(1,070)
Foreign Currency Translation Adjustments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Other comprehensive income (loss) before reclassifications	(277)	166
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Deferred taxes	0	0
Other comprehensive income (loss)	(277)	166
Foreign Currency Translation Adjustments, Noncontrolling Interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Less: Other comprehensive income (loss) attributable to noncontrolling interests	(101)	84
Cash Flow Hedges, Parent
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	6	(1)
Ending Balance	1
Cash Flow Hedges
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Other comprehensive income (loss) before reclassifications	(9)	5
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Deferred taxes	1	(1)
Other comprehensive income (loss)	(8)	4
Ending Balance		1
Cash Flow Hedges, Noncontrolling Interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Less: Other comprehensive income (loss) attributable to noncontrolling interests	(3)	2
Benefit Plans, Parent
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	(207)	(66)
Ending Balance	(193)	(66)
Benefit Plans
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Other comprehensive income (loss) before reclassifications	16	(2)
Amounts reclassified from accumulated other comprehensive income (loss)	11	1
Deferred taxes	(5)	1
Other comprehensive income (loss)	22	0
Benefit Plans, Noncontrolling Interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Less: Other comprehensive income (loss) attributable to noncontrolling interests	8	0
Accumulated Other Comprehensive Loss
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	(1,636)	(1,219)
Other comprehensive income (loss)	(168)	85
Ending Balance	$ (1,804)	$ (1,134)

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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