v3.7.0.1
Document and Entity Information - shares
6 Months Ended
Jun. 30, 2017
Jul. 31, 2017
Document Information [Line Items]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Jun. 30, 2017  
Document Fiscal Year Focus 2017  
Document Fiscal Period Focus Q2  
Trading Symbol PHII  
Entity Registrant Name PHI INC  
Entity Central Index Key 0000350403  
Current Fiscal Year End Date --12-31  
Entity Filer Category Accelerated Filer  
Voting Common Stock [Member]    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   2,905,757
Non-Voting Common Stock [Member]    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   12,892,321