SEGMENT AND GEOGRAPHIC INFORMATION (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
SEGMENT AND GEOGRAPHIC INFORMATION
Revenue									$ 471,063	$ 527,113	$ 518,920
Long-lived assets:	$ 187,328				$ 188,455				187,328	188,455	186,101
United States
SEGMENT AND GEOGRAPHIC INFORMATION
Long-lived assets:	155,664				155,428				155,664	155,428	151,770
Canada
SEGMENT AND GEOGRAPHIC INFORMATION
Long-lived assets:	28,765				30,412				28,765	30,412	31,843
Mexico and Other
SEGMENT AND GEOGRAPHIC INFORMATION
Long-lived assets:	2,899				2,615				2,899	2,615	2,488
Product
SEGMENT AND GEOGRAPHIC INFORMATION
Revenue	$ 127,866	$ 156,962	$ 79,796	$ 102,803	$ 134,663	$ 181,913	$ 106,021	$ 101,019	467,427	523,616	515,251
Product | United States
SEGMENT AND GEOGRAPHIC INFORMATION
Revenue									431,024	478,790	471,561
Product | Canada, Mexico, and Other
SEGMENT AND GEOGRAPHIC INFORMATION
Revenue									$ 36,403	$ 44,826	$ 43,690