Employee Benefit Plans (Details 7) - Level 3 [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
The effect of fair-value measurements using significant unobservable inputs on changes in Level 3 plan assets for the period are outlined below
Beginning Balance	$ 1,951	$ 1,772
Actual Return on Plan Assets:
Assets held at the reporting date	(85)	145
Assets sold during the period	122	23
Purchases, Sales and Settlements	(207)	11
Transfers in and/or out of Level 3	0	0
Ending Balance	1,781	1,951
Corporate [Member]
The effect of fair-value measurements using significant unobservable inputs on changes in Level 3 plan assets for the period are outlined below
Beginning Balance	25	22
Actual Return on Plan Assets:
Assets held at the reporting date	1	(3)
Assets sold during the period	0	0
Purchases, Sales and Settlements	(7)	6
Transfers in and/or out of Level 3	0	0
Ending Balance	19	25
Bank Loans [Member]
The effect of fair-value measurements using significant unobservable inputs on changes in Level 3 plan assets for the period are outlined below
Beginning Balance	0	0
Actual Return on Plan Assets:
Assets held at the reporting date	0	0
Assets sold during the period	0	0
Purchases, Sales and Settlements	11	0
Transfers in and/or out of Level 3	0	0
Ending Balance	11	0
Real Estate [Member]
The effect of fair-value measurements using significant unobservable inputs on changes in Level 3 plan assets for the period are outlined below
Beginning Balance	1,872	1,693
Actual Return on Plan Assets:
Assets held at the reporting date	(85)	149
Assets sold during the period	121	23
Purchases, Sales and Settlements	(210)	7
Transfers in and/or out of Level 3	0	0
Ending Balance	1,698	1,872
Other [Member]
The effect of fair-value measurements using significant unobservable inputs on changes in Level 3 plan assets for the period are outlined below
Beginning Balance	54	57
Actual Return on Plan Assets:
Assets held at the reporting date	(1)	(1)
Assets sold during the period	1	0
Purchases, Sales and Settlements	(1)	(2)
Transfers in and/or out of Level 3	0	0
Ending Balance	$ 53	$ 54