Reinsurance Reinsurance (Effects of Reinsurance on Earnings - Related Party) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Effects of Reinsurance [Line Items]
Reinsurance assumed	$ 10	$ 11	$ 11
Ceded Earned Premiums	(779)	(810)	(943)
Premiums	882	900	863
Assumed Insurance Commissions And Fees	72	95	96
Ceded Insurance Commissions and Fees	(540)	(556)	(628)
Insurance Commissions and Fees	3,580	3,835	3,898
Commissions Fees And Other Income Assumed	1	0	28
Other Income Ceded	22	24	47
Other Income	389	397	651
Policyholder Benefits and Claims Incurred, Assumed	36	32	31
Policyholder Benefits and Claims Incurred, Ceded	$ (1,807)	(1,651)	(1,623)
Affiliated Entity | Assumed Reinsurance
Effects of Reinsurance [Line Items]
Reinsurance assumed		6	11
Assumed Insurance Commissions And Fees		45	96
Commissions Fees And Other Income Assumed		0	27
Policyholder Benefits and Claims Incurred, Assumed		9	30
Affiliated Entity | Ceded Reinsurance [Member]
Effects of Reinsurance [Line Items]
Ceded Earned Premiums		(201)	(537)
Ceded Insurance Commissions and Fees		1	(14)
Other Income Ceded		18	44
Policyholder Benefits and Claims Incurred, Ceded		(178)	(420)
Affiliated Entity | Reinsurance
Effects of Reinsurance [Line Items]
Premiums		(195)	(526)
Insurance Commissions and Fees		46	82
Other Income		18	71
Policyholder Benefits and Claims Incurred, Assumed and Ceded		$ (169)	$ (390)