Loss And Loss Adjustment Expense Reserves (Schedule Of Insurance Loss Recoverable) (Detail) - Insurance Loss Recoverable [Member] $ in Millions	9 Months Ended
	Sep. 30, 2021 USD ($)
Roll forward of Insurance Loss Recoverable [Line Items]
Gross Reserve beginning balance, Insurance loss recoverable	$ 1,677
Collections for Cases	(74)
Accretion of Recoveries	12
Changes in Discount Rates	5
Changes in Assumptions	(80)	[1]
Other	(3)	[2]
Gross Reserve ending balance, Insurance loss recoverable	$ 1,537

[1] Includes amounts related to paid claims.

[2] Primarily changes in amount and timing of collections and LAE.