Income Taxes (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Tax Disclosure [Abstract]
Income tax expense	$ 15	$ 12	$ 38	$ 56
Loss before income taxes	58	567	145	1,481
Tax Credit Carryforward, Valuation Allowance		$ 20		$ 20
Unrecognized Tax Benefits	241		241
Decrease in Unrecognized Tax Benefits is Reasonably Possible	13		$ 13
Income Tax Credits and Adjustments	$ 13