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	$ 107	$ 111
Projected benefit obligation	112	119
Funded status	(5)	(8)
Amounts Recognized on the Consolidated Balance Sheets
Other liabilities	(5)	(8)
Net amount recognized	$ (5)	$ (8)
Weighted-Average Assumptions, Benefit obligations:
Weighted-average discount rate	4.50%	4.00%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Weighted-average discount rate	4.00%	4.50%
Expected return on plan assets	4.50%	4.75%
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 8	$ 7
Projected benefit obligation	10	12
Funded status	(2)	(5)
Amounts Recognized on the Consolidated Balance Sheets
Other liabilities	(2)	(5)
Net amount recognized	$ (2)	$ (5)
Weighted-Average Assumptions, Benefit obligations:
Weighted-average discount rate	4.50%	4.00%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Weighted-average discount rate	4.00%	4.50%
Expected return on plan assets	6.50%	6.50%