Divestiture Of Northwest Operations (Narrative) (Details) - USD ($) $ in Millions			3 Months Ended		9 Months Ended
	May 01, 2020	May 28, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Divestiture Of Northwest Operations [Abstract]
Loss on disposal of Northwest Operations				$ 30	$ 160	$ 414
Net proceeds	$ 1,131				1,131
Gross proceeds from divestiture		$ 1,352
Escrow to be disbursed					57
Transition services revenue			$ 15		25
Fair value of transition services			$ 30		30
Property, plant, and equipment, Derecognized	1,084
Goodwill, Derecognized	658
Valuation allowance, Derecognized	603
Defined benefit pension and other postretirement benefit plan obligations, Derecognized	142
Out of period adjustment					$ (27)
Net assets	$ 1,132