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Document and Entity Information - USD ($)
12 Months Ended
Dec. 31, 2015
Feb. 25, 2016
Jun. 30, 2015
Document Documentand Entity Information [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Dec. 31, 2015    
Document Fiscal Year Focus 2015    
Document Fiscal Period Focus FY    
Trading Symbol MBI    
Entity Registrant Name MBIA INC    
Entity Central Index Key 0000814585    
Current Fiscal Year End Date --12-31    
Entity Filer Category Large Accelerated Filer    
Entity Common Stock, Shares Outstanding   136,600,851  
Entity Well-Known Seasoned Issuer Yes    
Entity Public Float     $ 880,396,155
Entity Current Reporting Status Yes    
Entity Voluntary Filers No