Insurance In Force (Summary Of Company's Reinsurance Agreements For U.S. Public Finance And Structured Finance And International Insurance Operations) (Detail) - USD ($) $ in Millions		Dec. 31, 2023	Dec. 31, 2022
Ceded Par Outstanding		$ 782	$ 897
Letters of Credit/Trust Accounts		19
Reinsurance Recoverable/ (Payable) Net	[1]	12
Assured Guaranty Corp [Member]
Ceded Par Outstanding		328
Letters of Credit/Trust Accounts		0
Reinsurance Recoverable/ (Payable) Net	[1]	2
Assured Guaranty Re Ltd [Member]
Ceded Par Outstanding	[2]	405
Letters of Credit/Trust Accounts	[2]	19
Reinsurance Recoverable/ (Payable) Net	[1],[2]	10
Others [Member]
Ceded Par Outstanding	[2]	49
Letters of Credit/Trust Accounts	[2]	0
Reinsurance Recoverable/ (Payable) Net	[1],[2]	$ 0

[1] Total reinsurance recoverable/(payable) is primarily related to recoverables on paid and unpaid losses net of paid and unpaid salvage due to reinsurers

[2] Represents a withdrawal of ratings.