EARNINGS PER SHARE - Summary of Basic Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share [Abstract]
Net income from continuing operations	$ (42,039)			$ 12,881	$ 21,080	$ 36,013	$ 88,213	$ 69,974
Net income from discontinued operations, net of tax	0			0	$ 993	$ 292	0	1,285
Net (loss) income	$ (42,039)	$ 104,517	$ 25,735	$ 12,881			$ 88,213	$ 71,259
Weight average common shares - basic (in shares)	41,220			40,885			41,459	40,838
Dilutive effect of stock options and restricted stock units (in shares)	0			890			1,963	822
Weighted average common shares - diluted (in shares)	41,220			41,775			43,422	41,660
Basic earnings per share:
Continuing operations (in usd per share)	$ (1.02)			$ 0.32			$ 2.13	$ 1.71
Discontinued operations (in usd per share)	0			0			0	0.03
Basic (loss) earnings per share (in usd per share)	(1.02)			0.32			2.13	1.74
Diluted earnings per share:
Continuing operations (in usd per share)	(1.02)			0.31			2.03	1.68
Discontinued operations (in usd per share)	0			0			0	0.03
Diluted (loss) earnings per share (in usd per share)	$ (1.02)			$ 0.31			$ 2.03	$ 1.71