Retirement and Deferred Compensation Plans (Benefit Plans' Assets and Obligations) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 1,433	$ 1,434
Projected benefit obligation	1,593	1,607
Funded status of plan	(160)	(173)
Amounts Recognized on the Consolidated Balance Sheets
Other assets	26	28
Other liabilities	(186)	(201)
Net amount recognized	$ (160)	$ (173)
Weighted-Average Assumptions, Benefit obligations:
Weighted-average discount rate	4.03%	4.29%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Weighted-average discount rate	4.29%	3.88%
Expected return on plan assets	6.99%	6.87%
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 56	$ 52
Projected benefit obligation	84	97
Funded status of plan	(28)	(45)
Amounts Recognized on the Consolidated Balance Sheets
Other assets		2
Other liabilities	(28)	(47)
Net amount recognized	$ (28)	$ (45)
Weighted-Average Assumptions, Benefit obligations:
Weighted-average discount rate	4.50%	4.50%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Weighted-average discount rate	4.50%	4.00%
Expected return on plan assets	6.50%	6.50%