Fair Value of Financial Instruments (Unaudited) (Details 1) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable Securities	$ 347	$ 352
Derivatives	0	0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable Securities	1	1
Derivatives	1	0
Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable Securities	348	353
Derivatives	$ 1	$ 0