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, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Business Combinations [Abstract]
Revenues	$ 204,293	$ 196,686	$ 579,390	$ 561,912
Operating income	19,369	31,505	42,321	53,051
Net income	$ 12,905	$ 23,794	$ 24,810	$ 24,745
Weighted average common shares outstanding, basic	47,690	42,779	47,029	42,605
Basic earnings per common share (in dollars per share)	$ 0.27	$ 0.56	$ 0.53	$ 0.58
Weighted average common shares outstanding, diluted	48,361	44,175	47,660	43,938
Diluted earnings per common share (in dollars per share)	$ 0.27	$ 0.54	$ 0.52	$ 0.56