SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Reconciliations of Basic and Diluted Distributed and Undistributed Earnings (Loss) Per Common Share (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Weighted average common shares outstanding
Basic (in shares)	117,008	116,155	116,872	116,036
Dilutive effect of options and restricted stock units (in shares)	2,189	0	1,916	0
Diluted weighted average common shares outstanding (in shares)	119,197	116,155	118,788	116,036