Employee Benefit Plans Level 4 (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Pension Benefits [Member]
Component of periodic benefit cost
Defined Benefit Plan, Service Cost	$ 1	$ 1	$ 1	$ 1
Interest cost	59	58	118	117
Expected return on plan assets	(76)	(78)	(153)	(156)
Amortization of prior service credit	0	0	0	0
Amortization of actuarial loss	13	14	27	29
Net periodic benefit cost	(3)	(5)	(7)	(9)
Other Postretirement Benefits [Member]
Component of periodic benefit cost
Defined Benefit Plan, Service Cost	0	0	0	0
Interest cost	3	3	6	6
Expected return on plan assets	(3)	(3)	(5)	(6)
Amortization of prior service credit	1	1	3	3
Amortization of actuarial loss	1	1	2	2
Net periodic benefit cost	$ 0	$ 0	$ 0	$ (1)