Consolidated Statements of Stockholders' Equity (USD $) In Thousands	Total	Common Class A [Member]	Common Class B [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]
Balance at Dec. 31, 2010	$ 80,078	$ 64	$ 8	$ 50,279	$ 58,200	$ (28,473)
Balance, shares at Dec. 31, 2010		6,358	798
Net income	12,631				12,631
Conversion of shares from Class B to Class A	0	1	(1)
Compensation expense related to restricted stock awards	187			187
Share-based compensation cost	196			196
Purchase of shares held in treasury	(117)					(117)
Balance at Dec. 31, 2011	92,975	64	8	50,662	70,831	(28,590)
Balance, shares at Dec. 31, 2011		6,359	797
Net income	17,925				17,925
Compensation expense related to restricted stock awards	110			110
Share-based compensation cost	22			22
Purchase of shares held in treasury	(80)					(80)
Net proceeds from exercised options	267			267
Net proceeds from exercised options (in shares)		10
Dividends declared per common share	(7,010)				(7,010)
Balance at Dec. 31, 2012	104,209	64	8	51,061	81,746	(28,670)
Balance, shares at Dec. 31, 2012		6,369	797
Net income	15,273				15,273
Conversion of shares from Class B to Class A	0	1	(1)
Compensation expense related to restricted stock awards	135			135
Purchase of shares held in treasury	(95)					(95)
Net proceeds from exercised options	275			275
Net proceeds from exercised options (in shares)		9
Dividends declared per common share	(10,326)				(10,326)
Issuance of restricted stock	0
Issuance of restricted stock (in shares)		30	20
401(k) plan contribution	230			(15)		245
Balance at Dec. 31, 2013	$ 109,701	$ 64	$ 8	$ 51,456	$ 86,693	$ (28,520)
Balance, shares at Dec. 31, 2013		6,409	816