Income Taxes (Current and deferred components of the Company's income tax (expense) benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Current tax expense	$ (269)	$ (171)	$ (243)
Deferred tax benefit (expense)	46	20	(168)
Income tax expense	$ (223)	$ (151)	$ (411)