CONDENSED CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 642	$ 29	$ 1,049	$ 1,064
Other comprehensive income, net of reclassification adjustments:
Foreign currency translation gain (loss)	(325)	345	(193)	676
Unrealized gains (losses) on investments, net	(2)	(29)	(38)	(49)
Tax benefit (expense) on unrealized gains (losses) on investments, net	0	6	10	18
Unrealized gains (losses) on hedging activities, net	137	(64)	108	(98)
Tax benefit (expense) on unrealized gains (losses) on hedging activities, net	(29)	14	(23)	14
Other comprehensive income, net of tax	(219)	272	(136)	561
Comprehensive income	$ 423	$ 301	$ 913	$ 1,625

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Amount before tax, after reclassification adjustments of gain (loss) on foreign currency translation adjustments, on foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature, attributable to parent entity.

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Amount before tax, after reclassification adjustments, of appreciation (loss) in value of unsold available-for-sale securities. Excludes amounts related to other than temporary impairment (OTTI) loss.

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