Employee Benefit Plans - Schedule of Changes in Benefit Obligation and Plan Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Change in plan assets:
Fair value of plan assets as of January 1,	$ 246
Fair value of plan assets as of December 31,	227	$ 246
Defined Pension Benefits
Change in benefit obligation:
Benefit obligation as of January 1,	204	185
Service cost	1	1
Interest cost	8	8
Benefits paid	(15)	(17)
Net actuarial loss (gain)	(13)	27
Benefit obligation as of December 31,	185	204
Change in plan assets:
Fair value of plan assets as of January 1,	239	230
Actual return on plan assets	(3)	25
Employer contributions	1	1
Benefits paid	(15)	(17)
Fair value of plan assets as of December 31,	222	239
Over (under) funded status as of December 31,	37	35
Other Postretirement Benefits
Change in benefit obligation:
Benefit obligation as of January 1,	55	53
Service cost	0	0
Interest cost	2	2
Benefits paid	(3)	(3)
Net actuarial loss (gain)	(9)	3
Benefit obligation as of December 31,	45	55
Change in plan assets:
Fair value of plan assets as of January 1,	7	7
Actual return on plan assets	(1)	0
Employer contributions	2	3
Benefits paid	(3)	(3)
Fair value of plan assets as of December 31,	5	7
Over (under) funded status as of December 31,	$ (40)	$ (48)