SEGMENT INFORMATION - Schedule of Segment Reporting Information by Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenue:
Revenue	$ 96,933	$ 87,646
Income (loss) from operations:
Total income from operations of reportable segments	3,559	966
Depreciation and amortization:
Depreciation and amortization	10,272	8,925
Operating Segments
Revenue:
Revenue	96,933	87,646
Income (loss) from operations:
Total income from operations of reportable segments	8,284	7,035
Operating Segments | Consumer Payments
Revenue:
Revenue	86,031	79,009
Income (loss) from operations:
Total income from operations of reportable segments	7,152	7,719
Depreciation and amortization:
Depreciation and amortization	8,583	7,808
Operating Segments | Commercial Payments
Revenue:
Revenue	6,368	6,658
Income (loss) from operations:
Total income from operations of reportable segments	764	(451)
Depreciation and amortization:
Depreciation and amortization	76	98
Operating Segments | Integrated Partners
Revenue:
Revenue	4,534	1,979
Income (loss) from operations:
Total income from operations of reportable segments	368	(233)
Depreciation and amortization:
Depreciation and amortization	1,311	691
Corporate
Income (loss) from operations:
Total income from operations of reportable segments	(4,725)	(6,069)
Depreciation and amortization:
Depreciation and amortization	$ 302	$ 328