Condensed Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Common Stock [Member] Common Class A [Member]	Common Stock [Member] Common Class B [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Treasury Stock [Member]	Common Class A [Member]	Common Class B [Member]	Total
Balances at Dec. 31, 2017	$ 26	$ 4		$ 51,025	$ 77,574	$ (1,635)	$ (36,953)			$ 90,041
Purchase of shares							(1,272)			(1,272)
Issuance of common shares for the exercise of stock options				737						737
Issuance of restricted common shares, net of (forfeitures)
Non-cash stock compensation expense				454						454
Dividends declared					(4,223)					(4,223)
Other comprehensive income, foreign currency translation adjustment						(414)				(414)
Net income					7,306					7,306
Cumulative effect adjustment for adoption of ASC 606, net of income tax					2,735					2,735
Balances at Mar. 31, 2018	26	4		52,216	83,392	(2,049)	(38,225)			95,364
Balances at Dec. 31, 2017	26	4		51,025	77,574	(1,635)	(36,953)			90,041
Other comprehensive income, foreign currency translation adjustment										(418)
Net income								$ 17,622	$ 4,624	22,246
Balances at Sep. 30, 2018	30			156,384	(97,027)	(2,053)	(27,195)			30,139
Balances at Mar. 31, 2018	26	4		52,216	83,392	(2,049)	(38,225)			95,364
Purchase of shares							(4,358)			(4,358)
Issuance of common shares for the exercise of stock options				4,182						4,182
Non-cash stock compensation expense				541						541
Dividends declared					(4,206)					(4,206)
Other comprehensive income, foreign currency translation adjustment						(284)				(284)
Net income					7,948					7,948
Settlement of class B restricted common shares and stock options in connection with Recapitalization for cash of $3,271 and 90,369 class A common shares				(2,548)			(723)			(3,271)
Settlement of class B common shares in connection with Recapitalization (3,527,246 class B common shares exchanged for $69,099 cash and 3,527,246 class A common shares)	4			118,335			(187,438)			(69,099)
Retirement of 4,328,552 class B common shares in connection with Recapitalization		(4)		(17,112)	(186,944)		204,060
Balances at Jun. 30, 2018	30			155,614	(99,810)	(2,333)	(26,684)			26,817
Purchase of shares							(511)			(511)
Issuance of common shares for the exercise of stock options				510						510
Non-cash stock compensation expense				260						260
Dividends declared					(4,209)					(4,209)
Other comprehensive income, foreign currency translation adjustment						280				280
Net income					6,992			$ 6,992		6,992
Balances at Sep. 30, 2018	$ 30			156,384	(97,027)	(2,053)	(27,195)			30,139
Balances at Dec. 31, 2018			$ 30	157,312	(106,339)	(2,916)	(29,004)			19,083
Purchase of shares							(1,116)			(1,116)
Issuance of common shares for the exercise of stock options				633						633
Issuance of restricted common shares, net of (forfeitures)
Non-cash stock compensation expense				302						302
Dividends declared					(4,724)					(4,724)
Other comprehensive income, foreign currency translation adjustment						365				365
Net income					8,196					8,196
Balances at Mar. 31, 2019			30	158,247	(102,867)	(2,551)	(30,120)			22,739
Balances at Dec. 31, 2018			30	157,312	(106,339)	(2,916)	(29,004)			19,083
Other comprehensive income, foreign currency translation adjustment										474
Net income										23,708
Balances at Sep. 30, 2019			30	160,524	(96,817)	(2,442)	(32,320)			28,975
Balances at Mar. 31, 2019			30	158,247	(102,867)	(2,551)	(30,120)			22,739
Purchase of shares							(137)			(137)
Issuance of common shares for the exercise of stock options				137						137
Non-cash stock compensation expense				307						307
Dividends declared					(4,727)					(4,727)
Other comprehensive income, foreign currency translation adjustment						255				255
Net income					7,393					7,393
Balances at Jun. 30, 2019			30	158,691	(100,201)	(2,296)	(30,257)			25,967
Purchase of shares							(2,063)			(2,063)
Issuance of common shares for the exercise of stock options				1,525						1,525
Non-cash stock compensation expense				308						308
Dividends declared					(4,735)					(4,735)
Other comprehensive income, foreign currency translation adjustment						(146)				(146)
Net income					8,119					8,119
Balances at Sep. 30, 2019			$ 30	$ 160,524	$ (96,817)	$ (2,442)	$ (32,320)			$ 28,975