| Document and Entity Information | Mar. 15, 2022 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001588972 |
| Current Fiscal Year End Date | --12-31 |
| Document Type | 8-K |
| Document Period End Date | Mar. 15, 2022 |
| Entity Registrant Name | Recro Pharma, Inc. |
| Entity Incorporation State Country Code | PA |
| Entity File Number | 001-36329 |
| Entity Tax Identification Number | 26-1523233 |
| Entity Address, Address Line One | 1 E. Uwchlan Ave |
| Entity Address, Address Line Two | Suite 112 |
| Entity Address, City or Town | Exton |
| Entity Address, State or Province | PA |
| Entity Address, Postal Zip Code | 19341 |
| City Area Code | 770 |
| Local Phone Number | 534-8239 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common stock, par value $0.01 |
| Trading Symbol | REPH |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
