Fair Value of Financial Instruments (Unaudited) (Details 1) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable Securities	$ 353	$ 335
Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable Securities	337	319
Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable Securities	0	1
Fair Value, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable Securities	337	320
Derivatives	(8)	(10)
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable Securities	337	319
Derivatives	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable Securities	0	1
Derivatives	(8)	(10)
Fair Value, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable Securities	$ 16	15
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable Securities
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable Securities