Consolidated Statement of Earnings - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues:
Property and casualty insurance net earned premiums	$ 4,865	$ 4,579	$ 4,328
Life, accident and health net earned premiums	24	22	24
Net investment income	2,094	1,831	1,696
Realized gains (losses) on:
Securities	(266)	5	19
Subsidiaries	0	0	2
Income (loss) of managed investment entities:
Investment income	255	210	190
Gain (loss) on change in fair value of assets/liabilities	(21)	12	15
Other income	199	206	224
Total revenues	7,150	6,865	6,498
Costs and Expenses:
Property and casualty insurance: Losses and loss adjustment expenses	3,003	2,955	2,762
Property and casualty insurance: Commissions and other underwriting expenses	1,583	1,407	1,349
Annuity benefits	998	892	800
Life, accident and health benefits	40	26	33
Annuity and supplemental insurance acquisition expenses	261	173	186
Interest charges on borrowed money	62	85	77
Expenses of managed investment entities	211	181	151
Other expenses	353	422	353
Total costs and expenses	6,511	6,141	5,711
Earnings before income taxes	639	724	787
Provision for income taxes	122	247	119
Net earnings, including noncontrolling interests	517	477	668
Less: Net earnings (losses) attributable to noncontrolling interests	(13)	2	19
Net Earnings Attributable to Shareholders	$ 530	$ 475	$ 649
Earnings Attributable to Shareholders per Common Share:
Basic (USD per share)	$ 5.95	$ 5.40	$ 7.47
Diluted (USD per share)	$ 5.85	$ 5.28	$ 7.33
Average number of Common Shares:
Basic (shares)	89.0	87.8	86.9
Diluted (shares)	90.6	89.8	88.5
Supplemental disclosure of Realized gains (losses) on securities:
Realized gains (losses) before impairments	$ (247)	$ 78	$ 135
Losses on securities with impairment	(19)	(74)	(115)
Non-credit portion recognized in other comprehensive income (loss)	0	1	(1)
Impairment charges recognized in earnings	(19)	(73)	(116)
Total realized gains (losses) on securities	$ (266)	$ 5	$ 19