Document And Entity Information	12 Months Ended
	Dec. 31, 2021
Document Information Line Items
Entity Registrant Name	APPGATE, INC.
Document Type	S-1/A
Amendment Flag	true
Amendment Description	AMENDMENT NO. 1
Entity Central Index Key	0001353538
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	20-3547231