Document and Entity Information
6 Months Ended
Jun. 30, 2015
Aug. 01, 2015
Document and Entity Information    
Entity Registrant Name Hill International, Inc.  
Entity Central Index Key 0001287808  
Document Type 10-Q  
Document Period End Date Jun. 30, 2015  
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Entity Current Reporting Status Yes  
Entity Filer Category Accelerated Filer  
Entity Common Stock, Shares Outstanding   50,602,975
Document Fiscal Year Focus 2015  
Document Fiscal Period Focus Q2