Investments in Affiliates (Schedule of Balances with Affiliates) (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Investments in and Advances to Affiliates, Schedule of Investments [Abstract]
Non-trade receivables		$ 21	$ 26
Total due from affiliates		21	26
Short-term borrowings	[1]	32	17
Trade payables		36	45
Current Other liabilities		8	8
Total due to affiliates		$ 76	$ 70

[1] The Company has agreements with certain affiliates whereby excess affiliate cash is lent to and managed by the Company at variable interest rates governed by those agreements.