Income Taxes And Tax-Related Items Income Taxes And Tax-Related Items (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Unrecognized tax benefits	$ 19	$ 17
Tax-related interest and penalties payable	6	8
Net deferred tax assets	(13)	(42)
State net operating loss carryforwards	3	3
Valuation allowance for deferred tax assets	$ 3	$ 3
Minimum
Years state net operating loss carryforwards expire	Dec. 31, 2020
Maximum
Years state net operating loss carryforwards expire	Dec. 31, 2029