EARNINGS PER SHARE (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Numerator:
Net income	$ 15,117	$ 12,386	$ 28,189	$ 22,587
Denominators:
Shares to be issued - acquisition	0	36,000	0	36,000
Unvested restricted stock (in shares)	(2,000)	(9,000)	(2,000)	(9,000)
Effect of weighted average shares outstanding (in shares)	0	(117,000)	(129,000)	(778,000)
Weighted average common shares outstanding, basic	48,370,000	47,690,000	48,241,000	47,029,000
Impact of potentially dilutive securities:
Dilutive effect of stock options and other stock awards (in shares)	249,000	671,000	240,000	631,000
Weighted average common shares outstanding, diluted	48,619,000	48,361,000	48,481,000	47,660,000
Anti-dilutive potentially issuable shares	0	2,000	1,000	2,000
Class A Common Stock
Denominators:
Common stock, shares outstanding	47,384,000	46,792,000	47,384,000	46,792,000	46,803,000
Class B Common Stock
Denominators:
Common stock, shares outstanding	988,000	988,000	988,000	988,000	988,000