Condensed Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues [Abstract]
Earned premiums	$ 1,294	$ 1,241	$ 2,554	$ 2,449
Investment income, net of expenses	154	151	304	300
Investment gains and losses, net	105	(11)	(86)	149
Fee revenues	4	4	8	9
Other revenues	1	1	2	2
Total revenues	1,558	1,386	2,782	2,909
Benefits and Expenses
Insurance losses and contract holders' benefits	883	854	1,737	1,707
Underwriting, acquisition and insurance expenses	395	387	798	764
Interest expense	13	13	26	26
Other operating expenses	3	4	7	8
Total benefits and expenses	1,294	1,258	2,568	2,505
Income Before Income Taxes	264	128	214	404
Provision (Benefit) for Income Taxes
Current	33	31	61	71
Deferred	14	(3)	(33)	32
Total provision for income taxes	47	28	28	103
Net Income	$ 217	$ 100	$ 186	$ 301
Per Common Share
Net income—basic	$ 1.33	$ 0.61	$ 1.13	$ 1.83
Net income—diluted	$ 1.32	$ 0.60	$ 1.12	$ 1.81