Income Taxes And Tax-Related Items Income Taxes And Tax-Related Items (Narrative) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Unrecognized tax benefits	$ 20	$ 19
Unrecognized Tax Benefits, Change Resulting from Settlements with Taxing Authorities	6
Tax-related interest and penalties payable	6	6
Net deferred tax liabilities	(10)
Net deferred tax assets		4
State net operating loss carryforwards	3	3
Valuation allowance for deferred tax assets	3	$ 3
Increase (Decrease) in Deferred Liabilities	$ (14)
Minimum
Operating loss carryforwards, expiration year	2021
Maximum
Operating loss carryforwards, expiration year	2030