Investments (Schedule Of Sources Of Net Investment Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net Investment Income [Line Items]
Gross investment income	$ 3,643	$ 3,551	$ 3,598
Investment expenses	(187)	(176)	(172)
Net investment income	3,456	3,375	3,426
The Chubb Corporation [Member]
Net Investment Income [Line Items]
Amortization of Debt Issuance Costs and Discounts	(84)	(116)	(161)
Fixed Maturities [Member]
Net Investment Income [Line Items]
Gross investment income	3,300	3,321	3,385
Short-term investments
Net Investment Income [Line Items]
Gross investment income	35	48	84
Other interest income [Member]
Net Investment Income [Line Items]
Gross investment income	11	19	25
Equity securities
Net Investment Income [Line Items]
Gross investment income	150	81	26
Other Investments [Member]
Net Investment Income [Line Items]
Gross investment income	$ 147	$ 82	$ 78