v3.7.0.1
Document and Entity Information - USD ($)
12 Months Ended
Mar. 31, 2017
May 18, 2017
Sep. 30, 2016
Entity Information [Line Items]      
Entity Registrant Name Booz Allen Hamilton Holding Corp    
Entity Central Index Key 0001443646    
Document Type 10-K    
Document Period End Date Mar. 31, 2017    
Amendment Flag false    
Document Fiscal Year Focus 2017    
Document Fiscal Period Focus FY    
Current Fiscal Year End Date --03-31    
Entity Filer Category Large Accelerated Filer    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Public Float     $ 4,574,607,371
Common stock, Class A      
Entity Information [Line Items]      
Entity Common Stock, Shares Outstanding   147,920,835  
Non-voting common stock, Class B      
Entity Information [Line Items]      
Entity Common Stock, Shares Outstanding   0  
Restricted common stock, Class C      
Entity Information [Line Items]      
Entity Common Stock, Shares Outstanding   0  
Special voting common stock, Class E      
Entity Information [Line Items]      
Entity Common Stock, Shares Outstanding   0