Financial Instruments - Information on Available-for-sale Investments (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Debt securities, amortized cost	$ 76		$ 76		$ 1,768
Debt securities, unrealized gains	0		0		17
Debt securities, unrealized losses	0		0		0
Debt securities, fair value	76		76		1,785
Publicly traded equity securities, fair value	1,307		1,307		838
Total debt and publicly traded equity securities, fair value	1,383		1,383		2,623
Unrealized net losses (gains)	(464)	$ 39	(469)	$ (75)
U.S. government and agency securities
Debt Securities, Available-for-sale [Line Items]
Debt securities, amortized cost	74		74		266
Debt securities, unrealized gains	0		0		3
Debt securities, unrealized losses	0		0		0
Debt securities, fair value	74		74		269
Foreign government bonds
Debt Securities, Available-for-sale [Line Items]
Debt securities, amortized cost	2		2		0
Debt securities, unrealized gains	0		0		0
Debt securities, unrealized losses	0		0		0
Debt securities, fair value	2		2		0
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Debt securities, amortized cost	0		0		668
Debt securities, unrealized gains	0		0		0
Debt securities, unrealized losses	0		0		0
Debt securities, fair value	0		0		668
Corporate notes and bonds
Debt Securities, Available-for-sale [Line Items]
Debt securities, amortized cost	0		0		608
Debt securities, unrealized gains	0		0		13
Debt securities, unrealized losses	0		0		0
Debt securities, fair value	0		0		621
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Debt securities, amortized cost	0		0		226
Debt securities, unrealized gains	0		0		1
Debt securities, unrealized losses	0		0		0
Debt securities, fair value	$ 0		$ 0		$ 227

Debt Securities and Equity Securities, FV-NI

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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).

+ References

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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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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 (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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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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