Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2024	Oct. 24, 2024
Cover [Abstract]
Entity Registrant Name	ALPHATEC HOLDINGS, INC.
Entity Central Index Key	0001350653
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Trading Symbol	ATEC
Document Period End Date	Sep. 30, 2024
Document Fiscal Year Focus	2024
Document Fiscal Period Focus (Q1,Q2,Q3,FY)	Q3
Entity Current Reporting Status	Yes
Amendment Flag	false
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		141,767,870
Entity Shell Company	false
Entity File Number	000-52024
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
Document Quarterly Report	true
Document Transition Report	false
Entity Incorporation, State or Country Code	DE
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common stock, par value $0.0001 per share
Security Exchange Name	NASDAQ