v3.10.0.1
Document and Entity Information - shares
3 Months Ended
Jun. 30, 2018
Jul. 25, 2018
Document and Entity Information [Abstract]    
Entity Registrant Name Booz Allen Hamilton Holding Corp  
Entity Central Index Key 0001443646  
Document Type 10-Q  
Document Period End Date Jun. 30, 2018  
Amendment Flag false  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q1  
Current Fiscal Year End Date --03-31  
Entity Filer Category Large Accelerated Filer  
Common stock, Class A    
Entity Listings [Line Items]    
Entity Common Stock, Shares Outstanding   142,521,079
Non-voting common stock, Class B    
Entity Listings [Line Items]    
Entity Common Stock, Shares Outstanding   0
Restricted common stock, Class C    
Entity Listings [Line Items]    
Entity Common Stock, Shares Outstanding   0
Special voting common stock, Class E    
Entity Listings [Line Items]    
Entity Common Stock, Shares Outstanding   0