Reinsurance (Earned Life Insurance Premiums On Ceded Business) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Direct Premiums Earned	$ 5,251	$ 5,052	$ 4,857
Ceded earned premiums	(230)	(230)	(224)
Life Insurance Segment
Direct Premiums Earned	320	300	290
Ceded earned premiums	(70)	(68)	(62)
Net earned premiums	250	232	228
Policyholder Benefits and Claims Incurred, Direct	328	319	303
Policyholder Benefits and Claims Incurred, Assumed	(61)	(67)	(57)
Policyholder Benefits and Claims Incurred, Ceded	$ 267	$ 252	$ 246