CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Class A Common Stock	Class B Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock	Total
Balance at Dec. 31, 2018	$ 67	$ 9	$ 64,795	$ 156,689	$ (36,561)	$ 184,999
Balance, shares at Dec. 31, 2018	6,732	923
Net income				1,370		1,370
Dividends declared per common share				(1,784)		(1,784)
Compensation expense related to restricted stock awards			559			559
Purchase of shares held in treasury					(80)	(80)
401(k) plan contribution			(113)		375	262
Balance at Mar. 31, 2019	$ 67	$ 9	65,241	156,275	(36,266)	185,326
Balance, shares at Mar. 31, 2019	6,732	923
Balance at Dec. 31, 2019	$ 68	$ 9	66,811	162,822	(37,358)	192,352
Balance, shares at Dec. 31, 2019	6,771	954
Net income				1,680		1,680
Dividends declared per common share				(1,919)		(1,919)
Compensation expense related to restricted stock awards			569			569
Purchase of shares held in treasury					(20)	(20)
401(k) plan contribution			(131)		382	251
Balance at Mar. 31, 2020	$ 68	$ 9	$ 67,249	$ 162,583	$ (36,996)	$ 192,913
Balance, shares at Mar. 31, 2020	6,771	954