Employee Benefit Plans - Schedule of Amounts Recognized in Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Defined Pension Benefits
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Other assets	$ 57	$ 48
Other liabilities	(11)	(11)
Net amount recognized as of December 31,	46	37
Other Postretirement Benefits
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Other assets	0	0
Other liabilities	(33)	(40)
Net amount recognized as of December 31,	$ (33)	$ (40)