| Document and Entity Information | Aug. 04, 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 August 4, 2021 solely to correct the aggregate amount of convertible senior notes due 2026 being offered. The entire Item 8.01 disclosure, as corrected, appears below. |
| Document Period End Date | Aug. 4, 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 |
