| Document and Entity Information | Jan. 12, 2023 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001572694 |
| Document Type | 8-K |
| Document Period End Date | Jan. 12, 2023 |
| Entity Registrant Name | GOLDMAN SACHS BDC, INC. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 814-00998 |
| Entity Tax Identification Number | 46-2176593 |
| Entity Address, Address Line One | 200 West Street |
| Entity Address, City or Town | New York |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 10282 |
| City Area Code | (212) |
| Local Phone Number | 902-0300 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, par value $0.001 per share |
| Trading Symbol | GSBD |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
