REVENUE - Revenues from Contract with Customers (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Wire transfer and money order fees	$ 394,669	$ 308,850	$ 274,161
Discounts and promotions	(1,428)	(941)	(1,080)
Revenues	459,206	357,209	319,601
Wire transfer and money order fees, net
Disaggregation of Revenue [Line Items]
Revenues	393,241	307,909	273,081
Foreign exchange gain, net
Disaggregation of Revenue [Line Items]
Revenues	62,832	46,763	44,268
Other income
Disaggregation of Revenue [Line Items]
Revenues	$ 3,133	$ 2,537	$ 2,252