Marketable Securities (current and non-current) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Marketable Securities
Current marketable securities	$ 604	$ 1,076
Non-current marketable securities	27	27
Total marketable securities	631	1,103
Corporate debt securities
Marketable Securities
Current marketable securities	20	14
Commercial paper
Marketable Securities
Current marketable securities	495	899
Certificates of deposit/time deposits
Marketable Securities
Current marketable securities	59	76
U.S. municipal securities
Marketable Securities
Current marketable securities	3	3
Non-current marketable securities	27	27
Asset-backed securities total
Marketable Securities
Current marketable securities	27	84
Asset-backed securities Automobile loan related
Marketable Securities
Current marketable securities	8	16
Asset-backed securities Credit card related
Marketable Securities
Current marketable securities	$ 19	$ 68

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Total debt and equity financial instruments including: (1) securities held-to-maturity, (2) trading securities, and (3) securities available-for-sale.

+ References

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Total debt and equity financial instruments including: (1) securities held-to-maturity and (2) securities available-for-sale that will be held for the long-term.

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