| Cover Page | May 07, 2020 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | May 11, 2021 |
| Entity Registrant Name | NATURAL GAS SERVICES GROUP, INC. |
| Entity Incorporation, State or Country Code | CO |
| Entity File Number | 1-31398 |
| Entity Tax Identification Number | 75-2811855 |
| Entity Address, Address Line One | 404 Veterans Airpark Lane, Suite 300 |
| Entity Address, City or Town | Midland |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 79705 |
| City Area Code | 432 |
| Local Phone Number | 262-2700 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, Par Value $0.01 |
| Trading Symbol | NGS |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
| Amendment Flag | false |
| Entity Central Index Key | 0001084991 |
