Retirement and Deferred Compensation Plans (Benefit Plans' Assets and Obligations) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 1,356	$ 1,566
Projected benefit obligation	1,477	1,674
Funded status	(121)	(108)
Amounts Recognized on the Consolidated Balance Sheets
Other assets	52	45
Other liabilities	(173)	(153)
Net amount recognized	$ (121)	$ (108)
Weighted-Average Assumptions, Benefit obligations:
Weighted-average discount rate	4.14%	3.62%
Weighted-Average Assumptions, Net periodic benefit cost:
Weighted-average discount rate	3.75%	4.01%
Expected return on plan assets	6.46%	6.71%
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 64	$ 60
Projected benefit obligation	74	87
Funded status	(10)	(27)
Amounts Recognized on the Consolidated Balance Sheets
Other liabilities	(10)	(27)
Net amount recognized	$ (10)	$ (27)
Weighted-Average Assumptions, Benefit obligations:
Weighted-average discount rate	4.50%	4.00%
Weighted-Average Assumptions, Net periodic benefit cost:
Weighted-average discount rate	4.00%	4.50%
Expected return on plan assets	6.50%	6.50%