Derivative Instruments - Change in Unrealized Gains (Losses) in AOCI (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	$ 1,098	$ (194)	$ 571	$ 536
Change in fair value, net of tax			(124)
Reclassification into earnings, net of tax			(3)
Ending Balance	1,331	268	1,331	268
Cash Flow Hedges | Foreign exchange forward contracts
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	14	(5)	14	2
Change in fair value, net of tax	3	2	8	(7)
Reclassification into earnings, net of tax	(5)	2	(10)	4
Ending Balance	12	(1)	12	(1)
Cash Flow Hedges | Interest rate swap contracts
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	2	0	0	0
Change in fair value, net of tax	(157)	0	(155)	0
Reclassification into earnings, net of tax	0	0	0	0
Ending Balance	(155)	0	(155)	0
Net Investment Hedges
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	(70)	16	(81)	(8)
Change in fair value, net of tax	8	(16)	19	8
Reclassification into earnings, net of tax	3	0	3	0
Ending Balance	$ (59)	$ 0	$ (59)	$ 0