| Document and Entity Information | May 13, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K/A |
| Amendment Flag | true |
| Amendment Description | This Current Report on Form 8-K/A amends the Current Report on Form 8-K filed by Alphatec Holdings, Inc. (the “Company”) on May 18, 2021, as amended on July 23, 2021, to include the unaudited pro forma condensed combined statement of operations of the Company and EOS imaging S.A., a société anonyme organized and existing under the laws of France (“EOS”), for the six month period ended June 30, 2021. |
| Document Period End Date | May 13, 2021 |
| Entity Registrant Name | ALPHATEC HOLDINGS, INC. |
| Entity Central Index Key | 0001350653 |
| Entity Emerging Growth Company | false |
| Entity File Number | 000-52024 |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 20-2463898 |
| Entity Address, Address Line One | 1950 Camino Vida Roble |
| Entity Address, City or Town | Carlsbad |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 92008 |
| City Area Code | 760 |
| Local Phone Number | 431-9286 |
| 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 $.0001 per share |
| Trading Symbol | ATEC |
| Security Exchange Name | NASDAQ |
