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		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Weighted average common shares outstanding
Basic (in shares)	116,801	116,071	116,804	115,977
Dilutive effect of options and restricted stock units (in shares)	2,192	0	1,813	0
Diluted weighted average common shares outstanding (in shares)	118,993	116,071	118,617	115,977