Employee Benefit Plans - Schedule of Net Periodic Benefit Costs and Other Amounts Recognized in Other Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Pension Benefits
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 2	$ 2	$ 1
Interest cost	7	7	8
Expected return on plan assets	(14)	(14)	(15)
Amortization of transition obligation, prior service credit, and net actuarial loss (gain)	1	1	1
Net periodic benefit gain	(4)	(4)	(5)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax	16	4	(5)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, before Tax	1	1	1
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	17	5	(4)
Other Postretirement Benefits
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	0	0	0
Interest cost	2	2	2
Expected return on plan assets	0	0	0
Amortization of transition obligation, prior service credit, and net actuarial loss (gain)	(6)	(6)	(4)
Net periodic benefit gain	(4)	(4)	(2)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax	4	5	7
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, before Tax	(6)	(6)	(4)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	$ (2)	$ (1)	$ 3