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, 2017	$ 516,426	$ 35	$ 568,780	$ (53,713)	$ 15	$ 204	$ 1,105
Balance (in shares) at Dec. 31, 2017		35,747,134
Issuance of stock - employee stock purchase plan	597		597
Issuance of stock - employee stock purchase plan (shares)		13,323
Issuance of stock - 401(k) plan	2,379		2,379
Issuance of stock - 401(k) plan (shares)		45,149
Issuance/(cancellation) of non-vested stock	0		0
Issuance/(cancellation) of non-vested stock (shares)		53,251
Exercise of stock options	125		125
Exercise of stock options (in shares)		2,612
Non-cash compensation	4,044		4,044
Surrendered Shares	(1,305)			(1,305)
Noncontrolling interest distribution	(28)						(28)
Net income	27,320					27,159	161
Balance, Stockholders Equity at Mar. 31, 2018	549,558	$ 35	575,925	(55,018)	15	27,363	1,238
Balance (in shares) at Mar. 31, 2018		35,861,469
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
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