BUSINESS COMBINATIONS - Additional Information (Details) - USD ($) $ in Thousands		1 Months Ended	3 Months Ended								8 Months Ended	12 Months Ended
	Apr. 30, 2018	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Professional Fees												$ 700
Payments for (Proceeds from) Previous Acquisition		$ 8,400
Revenues			$ 612,316	$ 495,612	$ 532,577	$ 578,410	$ 799,927	$ 592,883	$ 617,396	$ 626,540
Net income (loss) attributable to parent			$ 77,041	$ (16,685)	$ (40,246)	$ (42,487)	$ 46,228	$ 44,615	$ (95,034)	$ (6,888)		(22,377)	$ (11,079)	$ 14,040
Cloud Savings [Member]
Business Acquisition [Line Items]
Percentage of outstanding shares acquired	80.00%
Financing obligation incurred in connection with acquisition of business	$ 8,604
Contingent consideration liability incurred in connection with acquisition of business	1,600										$ 1,589
Total acquisition price	$ 74,556											74,556
Revenues												12,900
Net income (loss) attributable to parent												$ 1,100
Merchant relationships | Cloud Savings [Member]
Business Acquisition [Line Items]
Intangible assets, useful life												6 years
Trade names | Cloud Savings [Member]
Business Acquisition [Line Items]
Intangible assets, useful life												8 years
Developed technology | Cloud Savings [Member]
Business Acquisition [Line Items]
Intangible assets, useful life												2 years
Other Intangible Assets | Cloud Savings [Member]
Business Acquisition [Line Items]
Intangible assets, useful life												1 year