Retirement Plans and Profit Sharing Arrangements (Benefit Obligations that Exceeded the Fair Value) (Details 4) - Pension Plans [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	$ 1,200	$ 1,100
Plans with accumulated benefit obligations in excess of plan assets:
Accumulated benefit obligation	1,211	875
Fair value of plan assets	905	644
Plans with projected benefit obligations in excess of plan assets:
Projected benefit obligation	1,271	922
Fair value of plan assets	905	644
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Other Change	0	(15)
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Curtailment	$ 0	$ (7)