Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 761	$ 137	$ 419
Change in net unrealized gains (losses) on:
Investments with no credit impairment, net of tax provision (benefit) of $14, $(121) and $(31)	141	(718)	(202)
Investments with credit impairment, net of tax provision (benefit) of $1, $(20) and $2	6	(86)	6
Change in net unrealized gains (losses) on investments	147	(804)	(196)
Change in instrument-specific credit risk on financial guaranty variable interest entities’ liabilities with recourse, net of tax provision (benefit)	3	(2)	(1)
Other, net of tax provision (benefit)	6	(9)	(1)
Other comprehensive income (loss)	156	(815)	(198)
Comprehensive income (loss)	917	(678)	221
Less: Comprehensive income (loss) attributable to noncontrolling interests	22	13	30
Comprehensive income (loss) attributable to Assured Guaranty Ltd.	$ 895	$ (691)	$ 191