| Cover | May 03, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | May 3, 2021 |
| Entity File Number | 001-34972 |
| Entity Registrant Name | Booz Allen Hamilton Holding Corporation |
| Entity Central Index Key | 0001443646 |
| Entity Tax Identification Number | 26-2634160 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 8283 Greensboro Drive |
| Entity Address, City or Town | McLean |
| Entity Address, State or Province | VA |
| Entity Address, Postal Zip Code | 22102 |
| City Area Code | 703 |
| Local Phone Number | 902-5000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Class A Common Stock |
| Trading Symbol | BAH |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
