Planned Divestiture Of Northwest Operations (Schedule Of Assets And Liabilities Held For Sale) (Details) $ in Millions	Sep. 30, 2019 USD ($)
Planned Divestiture Of Northwest Operations [Abstract]
Accounts receivable, less allowances of $7	$ 51
Prepaid expenses	2
Contract acquisition costs	10
Other current assets	3
Property, plant and equipment, net	1,021
Goodwill	658
Other intangibles, net	30
Other assets	26
Valuation allowance on assets held for sale	(399)
Total assets held for sale	1,402
Accounts payable	10
Advanced billings	18
Accrued other taxes	13
Other current liabilities	23
Total liabilities held for sale	134
Pension and other postretirement benefits	30
Other liabilities	40
Allowance for accounts receivable, classified as held for sale	7
Pension liability	146
Pension asset to transfer	$ 87
Percent of pension liability to transfer	60