RECONCILIATION OF STOCKHOLDERS' EQUITY (DEFICIT) AND NON-CONTROLLING INTEREST - Equity Reconciliation (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Feb. 28, 2019	Aug. 31, 2018
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ (120,689,000)
Net loss	(5,869,000)	$ (6,446,000)
Ending balance	(126,220,000)
Warrants and rights, number of shares allowed to purchase (in shares)			420,000
Class of warrant or right, number of securities called by each warrant or right (in shares)				0.192
Net income (loss) attributable to noncontrolling interest	$ 0	$ 0
Preferred Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)	0	0
Beginning balance	$ 0	$ 0
Ending balance (in shares)	0	0
Ending balance	$ 0	$ 0
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)	67,061,000	67,038,000
Beginning balance	$ 68,000	$ 67,000
Warrant redemptions (in shares)		420,000
Ending balance (in shares)	67,061,000	67,458,000
Ending balance	$ 68,000	$ 67,000
Conversion of MI Acquisitions shares		$ 1,000,000
Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)	451,000	0
Beginning balance	$ (2,388,000)	$ 0
Ending balance (in shares)	451,000	0
Ending balance	$ (2,388,000)	$ 0
Additional Paid-In Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	3,651,000	0
Stock-based compensation	338,000	1,160,000
Ending balance	3,989,000	1,160,000
Accumulated (Deficit)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(127,674,000)	(94,085,000)
Net loss	(5,869,000)	(6,446,000)
Ending balance	(133,543,000)	(100,531,000)
Total Priority Technology Holdings, Inc. Stockholders' (Deficit)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(126,343,000)	(94,018,000)
Stock-based compensation	338,000	1,160,000
Net loss	(5,869,000)	(6,446,000)
Issuance of non-controlling interest (c)		0
Ending balance	(131,874,000)	(99,304,000)
Non-Controlling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	5,654,000	0
Issuance of non-controlling interest (c)		5,654,000
Ending balance	$ 5,654,000	$ 5,654,000
MI Acquisitions Warrants, Public
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Class of warrant or right, outstanding (in shares)				5,310,109
MI Acquisitions Warrants, Private
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Warrants and rights, number of shares allowed to purchase (in shares)				421,107