Income Taxes (Components Of Deferred Tax Assets And Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Unearned premiums	$ 131	$ 119
Loss and loss expense reserves	92	81
Net operating loss on international earnings	34	26
Deferred international earnings	31	45
Other	50	41
Deferred tax assets before valuation allowance	338	312
Valuation allowance for international operations	53	56
Deferred tax assets net of valuation allowance	285	256
Deferred tax liabilities:
Investment gains and other, net	1,684	1,240
Deferred acquisition costs	155	143
Life policy reserves	116	121
Investments	38	13
Other	36	38
Total gross deferred tax liabilities	2,029	1,555
Net deferred income tax liability	$ 1,744	$ 1,299