| Document and Entity Information | Sep. 19, 2023 |
| Document Information [Line Items] | |
| Document Type | 8-K |
| Document Period End Date | Sep. 19, 2023 |
| Entity Registrant Name | AB PRIVATE CREDIT INVESTORS CORPORATION |
| Entity Incorporation, State or Country Code | MD |
| Entity File Number | 814-01196 |
| Entity Tax Identification Number | 81-2491356 |
| Entity Address, Address Line One | 405 Colorado Street |
| Entity Address, Address Line Two | Suite 1500 |
| Entity Address, City or Town | Austin |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 78701 |
| City Area Code | 512 |
| Local Phone Number | 721-2900 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Amendment Flag | false |
| Entity Central Index Key | 0001634452 |
| Former Address [Member] | |
| Document Information [Line Items] | |
| Entity Address, Address Line One | 1345 Avenue of the Americas |
| Entity Address, Address Line Two | Suite 1500 |
| Entity Address, City or Town | New York |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 10105 |
