Derivative Financial Instruments and Risk Management (Details 5) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Offsetting Assets and Liabilities
Gross Amount of Recognized Assets	$ 72	$ 91
Gross Amounts Offset	0	0
Net Amount of Assets	72	91
Gross Amounts Not Offset	(7)	(5)
Net Amount	65	86
Gross Amount of Recognized Liabilities	(8)	(10)
Gross Amounts Offset	0	0
Net Amount of Liabilities	(8)	(10)
Gross Amounts Not Offset	7	5
Net Amount	$ (1)	$ (5)