Document and Entity Information - shares
6 Months Ended
Jun. 30, 2019
Jul. 22, 2019
Document And Entity Information [Abstract]    
Entity Registrant Name Alphatec Holdings, Inc.  
Entity Central Index Key 0001350653  
Current Fiscal Year End Date --12-31  
Entity Filer Category Non-accelerated Filer  
Document Type 10-Q  
Trading Symbol ATEC  
Document Period End Date Jun. 30, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus (Q1,Q2,Q3,FY) Q2  
Entity Current Reporting Status Yes  
Amendment Flag false  
Entity Small Business true  
Entity Emerging Growth Company false  
Entity Common Stock, Shares Outstanding   47,656,697
Entity Shell Company false  
Entity File Number 000-52024  
Entity Tax Identification Number 202463898  
Entity Address, Address Line One 5818 El Camino Real  
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