BUSINESS COMBINATIONS - Schedule of Unaudited Pro forma Combined Information (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Business Combinations [Abstract]
Revenues	$ 202,910	$ 208,234	$ 577,994	$ 591,212
Operating income	20,660	19,351	45,342	42,266
Net income	$ 15,119	$ 12,813	$ 28,216	$ 24,532
Weighted average common shares outstanding, basic	48,370	47,690	48,241	47,029
Basic earnings per common share (in dollars per share)	$ 0.31	$ 0.27	$ 0.58	$ 0.52
Weighted average common shares outstanding, diluted	48,619	48,361	48,481	47,660
Diluted earnings per common share (in dollars per share)	$ 0.31	$ 0.26	$ 0.58	$ 0.51