Consolidated Statements Of Income (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues
Earned premiums	$ 4,243	$ 3,902	$ 3,522
Investment income, net of expenses	549	529	531
Realized investment gains, net	133	83	42
Fee revenues	12	8	6
Other revenues	8	9	10
Total revenues	4,945	4,531	4,111
Benefits and Expenses
Insurance losses and policyholder benefits	2,856	2,505	2,322
Underwriting, acquisition and insurance expenses	1,301	1,243	1,155
Interest expense	53	54	54
Other operating expenses	14	15	14
Total benefits and expenses	4,224	3,817	3,545
Income Before Income Taxes	721	714	566
Provision for Income Taxes
Current	159	178	119
Deferred	37	19	26
Total provision for income taxes	196	197	145
Net Income	$ 525	$ 517	$ 421
Per Common Share
Net income—basic (in usd per share)	$ 3.21	$ 3.16	$ 2.59
Net income—diluted (in usd per share)	$ 3.18	$ 3.12	$ 2.57