CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS’ EQUITY (unaudited) - USD ($) $ in Thousands	Class B Preferred Stock	Common Stock	Additional Paid-in Capital	Retained Earnings	AOCI (Loss), Net	Total
Balance at Dec. 31, 2017	$ 3	$ 81	$ 211,145	$ 25,861	$ (206)	$ 236,884
Balance (in shares) at Dec. 31, 2017	272,636	8,196,310
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock, net of forfeiture			440			440
Restricted stock, net of forfeiture (in shares)		8,987
Issuance of common stock, net			(33)			(33)
Repurchase of shares for exercise of stock options and tax withholding for restricted stock vesting			(72)			(72)
Repurchase of shares for exercise of stock options and tax withholding for restricted stock vesting (in shares)		(63)
Employee and non-employee stock-based compensation			619			619
Net income				12,156		12,156
Other comprehensive income (loss)					(411)	(411)
Balance at Jun. 30, 2018	$ 3	$ 81	212,100	38,017	(617)	249,584
Balance (in shares) at Jun. 30, 2018	272,636	8,205,234
Balance at Mar. 31, 2018	$ 3	$ 81	211,333	32,152	(528)	243,041
Balance (in shares) at Mar. 31, 2018	272,636	8,194,925
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net issuance of shares for exercise of stock options and tax withholding for restricted stock vesting (in shares)		1,322
Restricted stock, net of forfeiture			440			440
Restricted stock, net of forfeiture (in shares)		8,987
Employee and non-employee stock-based compensation			327			327
Net income				5,865		5,865
Other comprehensive income (loss)					(89)	(89)
Balance at Jun. 30, 2018	$ 3	$ 81	212,100	38,017	(617)	249,584
Balance (in shares) at Jun. 30, 2018	272,636	8,205,234
Balance at Dec. 31, 2018	$ 3	$ 82	213,490	51,415	(473)	264,517
Balance (in shares) at Dec. 31, 2018	272,636	8,217,274
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock, net of forfeiture (in shares)		106,423
Repurchase of shares for exercise of stock options and tax withholding for restricted stock vesting			(88)			(88)
Repurchase of shares for exercise of stock options and tax withholding for restricted stock vesting (in shares)		(2,881)
Employee and non-employee stock-based compensation			1,478			1,478
Net income				14,588		14,588
Cumulative effect of adopting new accounting standard | ASU 2016-01				(68)	68
Cumulative effect of adopting new accounting standard | ASU 2014-09				(117)		(117)
Other comprehensive income (loss)					952	952
Balance at Jun. 30, 2019	$ 3	$ 82	214,880	65,818	547	281,330
Balance (in shares) at Jun. 30, 2019	272,636	8,320,816
Balance at Mar. 31, 2019	$ 3	$ 82	214,088	59,761	(147)	273,787
Balance (in shares) at Mar. 31, 2019	272,636	8,320,816
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Employee and non-employee stock-based compensation			792			792
Net income				6,057		6,057
Other comprehensive income (loss)					694	694
Balance at Jun. 30, 2019	$ 3	$ 82	$ 214,880	$ 65,818	$ 547	$ 281,330
Balance (in shares) at Jun. 30, 2019	272,636	8,320,816