DISCLOSURE OF SUPPLEMENTAL CASH FLOW INFORMATION (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income taxes and interest paid:
Income taxes paid, net of receipts	$ 1,951	$ 7,774	$ 14,777
Interest paid	25,771	28,433	17,204
Non-cash investing and financing activities:
Adjustments to closure/post-closure retirement asset	732	5,422	(221)
Capital expenditures in accounts payable	7,702	4,712	2,882
Acquisition of equipment with financing arrangements		6,197	2,481
Restricted stock issued from treasury shares	$ 5,654	$ 2,491	514
NRC
Non-cash investing and financing activities:
Fair value of equity issued for acquisition of NRC			$ 626,460