CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY Statement - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Treasury Stock	Accumulated Other Comprehensive Income	Retained Earnings	Noncontrolling Interests
Balance, Stockholders Equity at Dec. 31, 2018	$ 482,633	$ 36	$ 603,666	$ (241,685)	$ 15	$ 119,550	$ 1,051
Balance (in shares) at Dec. 31, 2018		36,252,280
Issuance of stock - employee stock purchase plan	782		782
Issuance of stock - employee stock purchase plan (shares)		7,856
Issuance of stock - 401(k) plan	2,295		2,295
Issuance of stock - 401(k) plan (shares)		19,591
Issuance/(cancellation) of non-vested stock	0	$ 0	0
Issuance/(cancellation) of non-vested stock (shares)		51,162
Exercise of stock options	356		356
Exercise of stock options (in shares)		6,854
Non-cash compensation	6,615		6,615
Surrendered Shares	(2,688)			(2,688)
Noncontrolling interest distribution	(366)						(366)
Net income	31,573					31,304	269
Balance, Stockholders Equity at Mar. 31, 2019	521,200	$ 36	613,714	(244,373)	15	150,854	954
Balance (in shares) at Mar. 31, 2019		36,337,743
Balance, Stockholders Equity at Dec. 31, 2019	641,513	$ 37	645,256	(251,241)	15	246,383	1,063
Balance (in shares) at Dec. 31, 2019		36,638,021
Issuance of stock - employee stock purchase plan	860		860
Issuance of stock - employee stock purchase plan (shares)		6,063
Issuance of stock - 401(k) plan	3,057		3,057
Issuance of stock - 401(k) plan (shares)		18,312
Issuance/(cancellation) of non-vested stock	0	$ 0	0
Issuance/(cancellation) of non-vested stock (shares)		55,423
Exercise of stock options	1,184		1,184
Exercise of stock options (in shares)		28,735
Non-cash compensation	5,909		5,909
Surrendered Shares	(4,050)			(4,050)
Noncontrolling interest distribution	(360)						(360)
Write-off of other comprehensive income	(15)				(15)
Net income	32,046					31,802	244
Balance, Stockholders Equity at Mar. 31, 2020	$ 680,144	$ 37	$ 656,266	$ (255,291)	$ 0	$ 278,185	$ 947
Balance (in shares) at Mar. 31, 2020		36,746,554