CONDENSED CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 193	$ 133	$ 338	$ 286
Available-for-sale securities:
Unrealized gains, net	42	69	88	163
Reclassification into earnings, net	(6)	(9)	(11)	(18)
Net change from available-for-sale securities	36	60	77	145
Reclassification of foreign currency translation gains	0	0	(2)	0
Other comprehensive income (loss)	36	60	75	145
Comprehensive income	$ 229	$ 193	$ 413	$ 431

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 after tax of reclassification adjustment from accumulated other comprehensive income for translation gain (loss) realized upon the sale or liquidation of an investment in a foreign entity and foreign currency hedges that are designated and qualified as hedging instruments for hedges of the foreign currency exposure of a net investment in a foreign operation.

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