Document and Entity Information
6 Months Ended
Sep. 30, 2015
Oct. 26, 2015
Common stock, Class A
Oct. 26, 2015
Non-voting common stock, Class B
Oct. 26, 2015
Restricted common stock, Class C
Oct. 26, 2015
Special voting common stock, Class E
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 Sep. 30, 2015        
Amendment Flag false        
Document Fiscal Year Focus 2016        
Document Fiscal Period Focus Q2        
Current Fiscal Year End Date --03-31        
Entity Filer Category Large Accelerated Filer        
Entity Listings [Line Items]          
Entity Common Stock, Shares Outstanding   148,448,758 0 0 0