Loss And Loss Adjustment Expense Reserves (Schedule Of Insurance Loss Recoverable) (Detail) - Insurance Loss Recoverable [Member] $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($)
Roll forward of Insurance Loss Recoverable [Line Items]
Gross Reserve beginning balance, Insurance loss recoverable	$ 1,694
Collections for Cases	(8)
Accretion of Recoveries	7
Changes in Discount Rates	157
Changes in Assumptions	(241)	[1]
Other	(2)	[2]
Gross Reserve ending balance, Insurance loss recoverable	$ 1,607

[1] Includes amounts related to paid claims and LAE that are expected to be recovered in the future.

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