Income Taxes (Reconciliation between the Company's federal income tax (expense) benefit at statutory rates and the recorded income tax (expense) benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income tax expense at statutory rates	$ (257)	$ (203)	$ (459)
Tax benefit from tax exempt income	53	63	131
Foreign taxes and credits	(1)	(1)	3
State income taxes	(14)	(13)	(7)
Net deferred tax asset remeasurement	0	6	(83)
Other tax expense	(4)	(3)	4
Income tax expense	$ (223)	$ (151)	$ (411)