Cover Page - shares	9 Months Ended
	Sep. 30, 2023	Oct. 26, 2023
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Entity Central Index Key	0000814585
Current Fiscal Year End Date	--12-31
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Sep. 30, 2023
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Trading Symbol	MBI
Entity Registrant Name	MBIA INC.
Entity Filer Category	Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		51,139,497
Title of 12(b) Security	Common Stock
Security Exchange Name	NYSE
Entity File Number	1-9583
Entity Tax Identification Number	06-1185706
Entity Address, Address Line One	1 Manhattanville Road, Suite 301
Entity Address, City or Town	Purchase
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10577
Entity Incorporation, State or Country Code	CT
City Area Code	914
Local Phone Number	273-4545