CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Class A Common Stock	Class B Common Stock	Additional paid-in Capital	Retained Earnings
Balance at Dec. 31, 2017	$ 136,585	$ 24	$ 100	$ 55,612	$ 80,849
Net income	3,726				3,726
Cash dividends	(621)				(621)
Balance at Mar. 31, 2018	139,690	24	100	55,612	83,954
Balance at Dec. 31, 2017	136,585	24	100	55,612	80,849
Net income	12,655
Balance at Sep. 30, 2018	147,514	124		55,751	91,639
Balance at Mar. 31, 2018	139,690	24	100	55,612	83,954
Net income	4,997				4,997
Issuance of common stock	139			139
Cash dividends	(622)				(622)
Balance at Jun. 30, 2018	144,204	24	100	55,751	88,329
Net income	3,931				3,931
Share conversion		100	$ (100)
Cash dividends	(621)				(621)
Balance at Sep. 30, 2018	147,514	124		55,751	91,639
Balance at Dec. 31, 2018	149,562	124		55,751	93,687
Net income	3,986				3,986
Cash dividends	(870)				(870)
Balance at Mar. 31, 2019	152,678	124		55,751	96,803
Balance at Dec. 31, 2018	149,562	124		55,751	93,687
Net income	12,768
Balance at Sep. 30, 2019	159,835	124		55,869	103,842
Balance at Mar. 31, 2019	152,678	124		55,751	96,803
Net income	4,895				4,895
Issuance of common stock	118			118
Cash dividends	(872)				(872)
Balance at Jun. 30, 2019	156,819	124		55,869	100,826
Net income	3,887				3,887
Cash dividends	(871)				(871)
Balance at Sep. 30, 2019	$ 159,835	$ 124		$ 55,869	$ 103,842