Restructuring And Other Charges (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring And Other Charges [Abstract]
Restructuring reserve		$ 2	$ 15	$ 18
Payment of restructuring costs	$ 35
Restructuring charges		87	168	35
Transformation costs		8	46	23
Pension/OPEB special termination benefit enhancements			44
Severance costs		7	38	$ 12
Consulting and advisory costs		$ 72	$ 40