v3.7.0.1
Document and Entity Information - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2016
Mar. 09, 2017
Jun. 30, 2015
Document Information [Line Items]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Dec. 31, 2016    
Document Fiscal Year Focus 2016    
Document Fiscal Period Focus FY    
Trading Symbol GALT    
Entity Registrant Name GALECTIN THERAPEUTICS INC    
Entity Central Index Key 0001133416    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer No    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Filer Category Smaller Reporting Company    
Entity Common Stock, Shares Outstanding   34,064,787  
Entity Public Float     $ 35.6