BUSINESS SEGMENTS - Segment Reporting Information Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended			12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Restructuring expenses				$ 211	$ 1,435	$ 2,324
Goodwill and intangible asset impairment				20,100	42,990	2,205
Goodwill impairment charges				19,100	42,990	2,205
U.S.
Segment Reporting Information [Line Items]
Restructuring expenses					700	2,100
Goodwill and intangible asset impairment				20,100	33,200
Goodwill impairment charges	$ 19,100	$ 33,200		19,100	33,242
International
Segment Reporting Information [Line Items]
Restructuring expenses				200	700	200
Goodwill impairment charges			$ 9,700	$ 0	$ 9,748	$ 2,200