Financial Instruments - Investments (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Debt Securities, Held-to-maturity, Maturity, Fair Value [Abstract]
Debt securities, amortized cost	$ 8,380	$ 16,920
Debt securities, gross unrealized gains	6	8
Debt securities, gross unrealized losses	(47)	(85)
Debt securities maturities, within 1 year, fair value	7,984
Debt securities maturities, over 1 to 5 years, fair value	322
Debt securities maturities, over 5 years, fair value	35
Debt Securities, Available-for-sale and Held-to-maturity, fair value	8,340	16,842
Government and agency debt - non-U.S. [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Available-for-sale debt securities, amortized cost	4,895	9,754
Available-for-sale debt securities, gross unrealized gain	6	7
Available-for-sale debt securities, gross unrealized loss	(38)	(58)
Available-for-sale securities, debt maturities	4,863	9,703
Available-for-sale Securities, Debt Maturities [Abstract]
Available-for-sale securities, debt maturities, within 1 year, fair value	4,863
Available-for-sale securities, debt maturities, over 1 to 5 years, fair value	0
Available-for-sale securities, debt maturities, over 5 years, fair value	0
Available-for-sale securities, debt maturities	4,863	9,703
Debt Securities, Held-to-maturity, Maturity [Abstract]
Held-to-maturity securities, amortized cost	803	592
Held-to-maturity securities, gross unrealized gains	0	0
Held-to-maturity securities, gross unrealized losses	0	0
Held-to-maturity securities, fair value	803	592
Debt Securities, Held-to-maturity, Maturity, Fair Value [Abstract]
Held-to-maturity securities, debt maturities, within 1 year, fair value	798
Held-to-maturity securities, debt maturities, over 1 to 5 years, fair value	0
Held-to-maturity securities, debt maturities, over 5 years, fair value	4
Government and agency - U.S. [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Available-for-sale debt securities, amortized cost	1,120	3,804
Available-for-sale debt securities, gross unrealized gain	0	0
Available-for-sale debt securities, gross unrealized loss	(6)	(23)
Available-for-sale securities, debt maturities	1,114	3,782
Available-for-sale Securities, Debt Maturities [Abstract]
Available-for-sale securities, debt maturities, within 1 year, fair value	811
Available-for-sale securities, debt maturities, over 1 to 5 years, fair value	303
Available-for-sale securities, debt maturities, over 5 years, fair value	0
Available-for-sale securities, debt maturities	1,114	3,782
Corporate and Other [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Available-for-sale debt securities, amortized cost	1,027	2,101
Available-for-sale debt securities, gross unrealized gain	0	0
Available-for-sale debt securities, gross unrealized loss	(2)	(4)
Available-for-sale securities, debt maturities	1,025	2,097
Available-for-sale Securities, Debt Maturities [Abstract]
Available-for-sale securities, debt maturities, within 1 year, fair value	1,014
Available-for-sale securities, debt maturities, over 1 to 5 years, fair value	11
Available-for-sale securities, debt maturities, over 5 years, fair value	0
Available-for-sale securities, debt maturities	1,025	2,097
Time deposits and other [Member]
Debt Securities, Held-to-maturity, Maturity [Abstract]
Held-to-maturity securities, amortized cost	535	668
Held-to-maturity securities, gross unrealized gains	0	0
Held-to-maturity securities, gross unrealized losses	0	0
Held-to-maturity securities, fair value	535	$ 668
Debt Securities, Held-to-maturity, Maturity, Fair Value [Abstract]
Held-to-maturity securities, debt maturities, within 1 year, fair value	498
Held-to-maturity securities, debt maturities, over 1 to 5 years, fair value	7
Held-to-maturity securities, debt maturities, over 5 years, fair value	$ 30

Available-for-sale Securities, Debt Maturities, After Year Five, Fair Value

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Debt Securities, Accumulated Gross Unrealized Gain

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Debt Securities, Accumulated Gross Unrealized Loss

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Debt Securities Maturities, After Year Five, Fair Value

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Debt Securities Maturities, Next Twelve Months, Fair Value

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Debt Securities Maturities, Year Two Through Five, Fair Value

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Held-to-maturity Securities, Debt Maturities, After Year Five, Fair Value

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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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Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), maturing in next fiscal year following latest fiscal year. Excludes interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

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Amount of investment in debt security measured at amortized cost (held-to-maturity) and 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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