Derivative Financial Instruments and Risk Management (Details 5) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Offsetting Assets and Liabilities [Abstract]
Gross Amount of Recognized Assets	$ 53	$ 72
Gross Amounts Offset	0	0
Net Amount of Assets	53	72
Gross Amounts Not Offset	(8)	(7)
Net Amount	45	65
Gross Amount of Recognized Liabilities	(50)	(8)
Gross Amounts Offset	0	0
Net Amount of Liabilities	(50)	(8)
Gross Amounts Not Offset	8	7
Net Amount	$ (42)	$ (1)