Consolidated Statements of Shareholders' Equity (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]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Total
Balances at Dec. 31, 2010	$ 24	$ 4	$ 28,950	$ 41,343	$ 1,108	$ (22,845)	$ 48,584
Purchase of treasury stock						(591)	(591)
Issuance of common shares for the exercise of stock options			940				940
Tax benefit from the exercise of options and vested restricted stock			407				407
Non-cash stock compensation expense			763				763
Dividends declared per common share				(5,912)			(5,912)
Other comprehensive income (loss), foreign currency translation adjustment					(201)		(201)
Net income				11,564			11,564
Balances at Dec. 31, 2011	24	4	31,060	46,995	907	(23,436)	55,554
Purchase of treasury stock						(5,168)	(5,168)
Issuance of common shares for the exercise of stock options	1		5,967				5,968
Tax benefit from the exercise of options and vested restricted stock			2,078				2,078
Non-cash stock compensation expense			388				388
Dividends declared per common share				(17,363)			(17,363)
Other comprehensive income (loss), foreign currency translation adjustment					217		217
Net income				15,068			15,068
Balances at Dec. 31, 2012	25	4	39,493	44,700	1,124	(28,604)	56,742
Purchase of treasury stock						(206)	(206)
Issuance of common shares for the exercise of stock options			990				990
Tax benefit from the exercise of options and vested restricted stock			755				755
Non-cash stock compensation expense			955				955
Fractional share cashed out			(1)				(1)
Dividends declared per common share				(2,142)			(2,142)
Other comprehensive income (loss), foreign currency translation adjustment					(822)		(822)
Net income				15,484			15,484
Balances at Dec. 31, 2013	$ 25	$ 4	$ 42,192	$ 58,042	$ 302	$ (28,810)	$ 71,755