| Document and Entity Information | Oct. 06, 2020 |
| Cover [Abstract] | |
| Entity Registrant Name | NN INC |
| Amendment Flag | true |
| Entity Central Index Key | 0000918541 |
| Document Type | 8-K/A |
| Document Period End Date | Oct. 6, 2020 |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 000-23486 |
| Entity Tax Identification Number | 62-1096725 |
| Entity Address, Address Line One | 6210 Ardrey Kell Road |
| Entity Address, City or Town | Charlotte |
| Entity Address, State or Province | NC |
| Entity Address, Postal Zip Code | 28277 |
| City Area Code | (980) |
| Local Phone Number | 264-4300 |
| Security 12b Title | Common Stock, par value $0.01 |
| Trading Symbol | NNBR |
| Security Exchange Name | NASDAQ |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Amendment Description | This Amendment corrects certain typographical errors as well as errors in the calculation of certain Life Sciences Business Adjustments appearing in the unaudited pro forma condensed consolidated balance sheet of NN, Inc. (“NN”) as of June 30, 2020 and the unaudited pro forma condensed consolidated statements of operations of NN for the years ended December 31, 2017, December 31, 2018 and December 31, 2019 and the six months ended June 30, 2020, which were filed as Exhibit 99.2 to the Form 8-K filed with the Securities and Exchange Commission on October 8, 2020. |
