Document and Entity Information
9 Months Ended
Dec. 31, 2014
Jan. 23, 2015
Common stock, Class A
Jan. 23, 2015
Non-voting common stock, Class B
Jan. 23, 2015
Restricted common stock, Class C
Jan. 23, 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 Dec. 31, 2014        
Amendment Flag false        
Document Fiscal Year Focus 2015        
Document Fiscal Period Focus Q3        
Current Fiscal Year End Date --03-31        
Entity Filer Category Large Accelerated Filer        
Entity Listings [Line Items]          
Entity Common Stock, Shares Outstanding   147,908,527 0 0 1,851,590