Strategic Investments (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Schedule of Investments [Line Items]
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity	$ 308
Equity method investments	270	$ 303
Measurement alternative investments (1)	173	94
Notes receivable	23	26
Investments	$ 468	$ 424

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Difference between amount at which an investment accounted for under the equity method of accounting is carried (reported) on the balance sheet and amount of underlying equity in net assets the reporting Entity has in the investee.

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This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

+ References

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Amount of investment in equity security without readily determinable fair value.

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Sum of the carrying amounts as of the balance sheet date of all investments.

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