Quarterly report pursuant to Section 13 or 15(d)

Licenses Acquired - Additional Information (Detail)

v2.4.1.9
Licenses Acquired - Additional Information (Detail) (USD $)
 3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Research and Development Arrangement, Contract to Perform for Others [Line Items]    
Payments to Acquire Intangible Assets $ 1,250,000us-gaap_PaymentsToAcquireIntangibleAssets $ 0us-gaap_PaymentsToAcquireIntangibleAssets
Research And Development In Process 7,439,000us-gaap_ResearchAndDevelopmentInProcess 0us-gaap_ResearchAndDevelopmentInProcess
Mustang Bio, Inc [Member]    
Research and Development Arrangement, Contract to Perform for Others [Line Items]    
Payments to Acquire Intangible Assets 2,000,000us-gaap_PaymentsToAcquireIntangibleAssets
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= fbio_MustangBioIncMember 		 
Stock Issued, Value, Issued for Noncash Consideration 260,000us-gaap_StockIssuedDuringPeriodValueIssuedForNoncashConsiderations
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= fbio_MustangBioIncMember 		 
Coronado SO Co, Inc [Member]    
Research and Development Arrangement, Contract to Perform for Others [Line Items]    
Payments to Acquire Intangible Assets 929,000us-gaap_PaymentsToAcquireIntangibleAssets
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= fbio_CoronadoSoCoIncMember 		 
Stock Issued, Value, Issued for Noncash Consideration 250,000us-gaap_StockIssuedDuringPeriodValueIssuedForNoncashConsiderations
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= fbio_CoronadoSoCoIncMember 		 
Research And Development In Process $ 1,179,000us-gaap_ResearchAndDevelopmentInProcess
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= fbio_CoronadoSoCoIncMember 		[1]  
[1] Coronado SO: $929,000 in cash and $250,000 of Coronado SO shares issued in connection with acquiring the license.