Stockholders' Equity - Summary of Changes in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			$ 22,525
Net current period other comprehensive income (loss)	$ 24	$ (28)	(15)	$ 22
Ending balance	18,027		18,027
Foreign Currency Translation
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			53	47
Net unrealized gain (loss)			(35)	8
Reclassifications to net income			0	0
Net current period other comprehensive income (loss)			(35)	8
Ending balance	18	55	18	55
Unrealized Gains and Losses on Available-for-Sale Debt Securities
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			1	(52)
Net unrealized gain (loss)			51	49
Reclassifications to net income			(13)	0
Net current period other comprehensive income (loss)			38	49
Ending balance	39	(3)	39	(3)
Unrealized Gains and Losses on Cash Flow Hedges
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			31	85
Net unrealized gain (loss)			21	29
Reclassifications to net income			(39)	(64)
Net current period other comprehensive income (loss)			(18)	(35)
Ending balance	13	50	13	50
Accumulated Other Comprehensive Income
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			85	80
Net unrealized gain (loss)			37	86
Reclassifications to net income			(52)	(64)
Net current period other comprehensive income (loss)	24	(28)	(15)	22
Ending balance	$ 70	$ 102	$ 70	$ 102

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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

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

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

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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