Marketable Securities (current and non-current) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Marketable securities
Current marketable securities	$ 380	$ 1,076
Non-current marketable securities	37	27
Total marketable securities	417	1,103
Corporate debt securities
Marketable securities
Current marketable securities		14
Commercial paper
Marketable securities
Current marketable securities	366	899
Certificates of deposit/time deposits
Marketable securities
Current marketable securities	10	76
U.S. municipal securities
Marketable securities
Current marketable securities	3	3
Non-current marketable securities	37	27
Asset-backed securities total
Marketable securities
Current marketable securities	1	84
Asset-backed securities Automobile loan related
Marketable securities
Current marketable securities	$ 1	16
Asset-backed securities Credit card related
Marketable securities
Current marketable securities		$ 68

Amount of investment in marketable security.

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