Employee Benefit Plans Level 4 (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Settlements, Benefit Obligation	$ 1,600,000,000
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements			$ 747,000,000	$ 0
Defined Benefit Plan, Contributions by Employer	300
Component of periodic benefit cost
Interest cost	9,000,000		18,000,000
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements	$ 750,000,000	$ 0	750,000,000	0
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	3.58%
Weighted Average Discount Rate, Percent	4.22%
Component of periodic benefit cost
Defined Benefit Plan, Service Cost	$ 1,000,000	1,000,000	2,000,000	1,000,000
Interest cost	49,000,000	59,000,000	98,000,000	118,000,000
Expected return on plan assets	(80,000,000)	(76,000,000)	(159,000,000)	(153,000,000)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	0	0	0	0
Amortization of actuarial loss	15,000,000	13,000,000	30,000,000	27,000,000
Net periodic benefit cost	$ 735,000,000	(3,000,000)	721,000,000	(7,000,000)
Other Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	3.55%
Weighted Average Discount Rate, Percent	4.19%
Other Postretirement Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements	$ 0	0	0	0
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	3.13%
Weighted Average Discount Rate, Percent	3.97%
Component of periodic benefit cost
Defined Benefit Plan, Service Cost	$ 0	0	0	0
Interest cost	2,000,000	3,000,000	4,000,000	6,000,000
Expected return on plan assets	(2,000,000)	(3,000,000)	(4,000,000)	(5,000,000)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	(2,000,000)	(1,000,000)	(3,000,000)	(3,000,000)
Amortization of actuarial loss	1,000,000	1,000,000	2,000,000	2,000,000
Net periodic benefit cost	(1,000,000)	$ 0	$ (1,000,000)	$ 0
Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements	144,000,000
After Tax [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements	$ 488,000,000