Retirement and Deferred Compensation Plans (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit expense (recovery)	$ 8	$ (2)	$ (3)
Expected benefit payments in the next fiscal year	110
Defined contribution plans expense	104	93	88
Deferred compensation plans expense	28	4	$ 35
Elective Contribution [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension contributions	$ 2	$ 8