Income Taxes (Current and deferred components of the Company's income tax (expense) benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Current tax expense	$ (180)	$ (269)	$ (171)
Deferred tax benefit	49	46	20
Income tax expense	$ (131)	$ (223)	$ (151)