Employee Benefit Plans Level 4 (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Component of periodic benefit cost
Interest cost	$ 9
Pension Plan [Member]
Component of periodic benefit cost
Defined Benefit Plan, Service Cost	1	$ 0
Interest cost	49	59
Expected return on plan assets	(79)	(77)
Amortization of prior service credit	0	0
Amortization of actuarial loss	15	14
Net periodic benefit cost	$ (14)	(4)
Interest Cost Discount Rate	3.58%
Weighted Average Discount Rate, Percent	4.22%
Other Pension Plan [Member]
Component of periodic benefit cost
Interest Cost Discount Rate	3.55%
Weighted Average Discount Rate, Percent	4.19%
Other Postretirement Benefit Plan [Member]
Component of periodic benefit cost
Defined Benefit Plan, Service Cost	$ 0	0
Interest cost	2	3
Expected return on plan assets	(2)	(2)
Amortization of prior service credit	1	2
Amortization of actuarial loss	1	1
Net periodic benefit cost	$ 0	$ 0
Interest Cost Discount Rate	3.13%
Weighted Average Discount Rate, Percent	3.97%