Fair Value Measurements (Details 3) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Cost Basis	$ 403	$ 714
Unrealized Gains	9	2
Unrealized Losses	(11)	(28)
Fair Value(3)	401	688
Debt Securities, Available-for-sale [Abstract]
Cost Basis	0	339
Unrealized Gains	0	15
Unrealized Losses	0	(16)
Fair Value	0	338
Short-term cash investments	751	$ 20
Short-term investments held-for-sale	747
Debt securities held-for-sale	$ 135

Cash and Cash Equivalents, Held-for-Sale, Fair Value Disclosure

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Debt Securities, Held-for-sale

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Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on 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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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on 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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Amortized cost 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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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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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Amount of unrealized gain on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Amount of unrealized loss on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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