Stock Options And Other Stock Plans (Stock Options, Retention Awards And Performance Retention Awards) (Narrative) (Details) $ / shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) $ / shares
Stock Options [Member]
Schedule of Share-based Compensation Arrangements [Line Items]
Contractual term	10 years
Years until vest	3 years
Stock options, subject to performance or market-based vesting conditions | $ / shares	$ 0
Unrecognized compensation expense	$ 16
Expected weighted average period (in years) of nonvested stock options to be recognized	10 months 24 days
Retention Awards [Member]
Schedule of Share-based Compensation Arrangements [Line Items]
Years until vest	4 years
Unrecognized compensation expense	$ 90
Expected weighted average period (in years) of nonvested stock options to be recognized	1 year 4 months 24 days
Performance Retention Awards [Member]
Schedule of Share-based Compensation Arrangements [Line Items]
Operating income growth modifier range	The modifier can be up to +/- 25% of the award earned based on the ROIC achieved.
Requisite service period	37 months
Continued employment requirement	Stock units awarded to selected employees under these grants are subject to continued employment for 37 months and the attainment of certain levels of ROIC, modified for the relative OIG.
Contractual terms of award	We expense the fair value of the units that are probable of being earned based on our forecasted ROIC over the 3-year performance period, and with respect to the third year of the plan, the relative OIG modifier.
ROIC performance period	3 years
Unrecognized compensation expense	$ 24
Expected weighted average period (in years) of nonvested stock options to be recognized	9 months 18 days