Condensed Consolidated Statements of Shareholders' Equity (Unaudited) - 9 months ended Sep. 30, 2018 - USD ($) $ in Thousands	Common Stock [Member] Common Class A [Member]	Common Stock [Member] Common Class B [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 169,568 shares of class A and 3,677 shares of class B treasury stock						(6,141)			(6,141)
Issuance of 380,958 class A common shares and 9,296 class B common shares for the exercise of stock options			5,429						5,429
Issuance of restricted common shares, net of forfeitures (3,496 class A shares)
Non-cash stock compensation expense			1,255						1,255
Settlement of 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 class B common shares in connection with Recapitalization (retirement of 4,328,552 class B common shares)		(4)	(17,112)	(186,944)		204,060
Dividends declared of $0.44 and $0.60 per A and B common share, respectively				(12,638)					(12,638)
Other comprehensive income, foreign currency translation adjustment					(418)				(418)
Net income				22,246			$ 17,622	$ 4,624	22,246
Balances at Sep. 30, 2018	30		156,384	(97,027)	(2,053)	(27,195)			30,139
Cumulative effect adjustment for adoption of ASC 606				$ 2,735					$ 2,735