GOODWILL AND INTANGIBLE ASSETS - Definite Lived Intangibles (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Intangible assets with definite lives
Cost	$ 202,800	$ 225,400
Accumulated Amortization	(127,179)	(107,040)
Net	75,621	118,360
Technology
Intangible assets with definite lives
Cost	87,700	87,700
Accumulated Amortization	(69,369)	(48,166)
Net	$ 18,331	$ 39,534
Technology | Weighted Average Amortization Life
Intangible assets with definite lives
Weighted Average Amortization Life	4 years 3 months 18 days	4 years 3 months 18 days
Customer lists
Intangible assets with definite lives
Cost	$ 77,300	$ 77,300
Accumulated Amortization	(24,668)	(18,560)
Net	$ 52,632	$ 58,740
Customer lists | Weighted Average Amortization Life
Intangible assets with definite lives
Weighted Average Amortization Life	13 years 2 months 12 days	13 years 2 months 12 days
Trademarks and tradenames
Intangible assets with definite lives
Cost	$ 11,700	$ 17,200
Accumulated Amortization	(7,767)	(9,947)
Net	$ 3,933	$ 7,253
Trademarks and tradenames | Weighted Average Amortization Life
Intangible assets with definite lives
Weighted Average Amortization Life	4 years 10 months 24 days	4 years 10 months 24 days
Website content
Intangible assets with definite lives
Cost	$ 26,100	$ 43,200
Accumulated Amortization	(25,375)	(30,367)
Net	$ 725	$ 12,833
Website content | Weighted Average Amortization Life
Intangible assets with definite lives
Weighted Average Amortization Life	3 years	3 years