Schedule II - Condensed Statement of Income (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Condensed Financial Statements, Captions [Line Items]
Interest and dividends	$ 4,752	$ 4,619	$ 4,445
Net realized investment gains (losses)	1,340	(110)	1,041
Changes in the estimated fair value of equity security investments	10,303	(4,130)	0
Other	678	470	460
Total Revenues	183,502	156,259	161,627
Personnel expenses	46,058	43,552	39,937
Office and technology expenses	9,254	8,813	8,172
Other expenses	12,055	11,382	11,293
Income before Income Taxes	39,823	27,069	30,271
Provision (Benefit) for Income Taxes	8,365	5,210	4,570
Net Income	31,458	21,859	25,701
Net Loss Attributable to Noncontrolling Interests	0	(33)	(6)
Net Income Attributable to the Company	$ 31,458	$ 21,892	$ 25,707
Basic Earnings per Common Share	$ 16.66	$ 11.60	$ 13.63
Weighted Average Shares Outstanding – Basic	1,888	1,887	1,886
Diluted Earnings per Common Share	$ 16.59	$ 11.54	$ 13.56
Weighted Average Shares Outstanding – Diluted	1,896	1,897	1,896
Parent Company
Condensed Financial Statements, Captions [Line Items]
Interest and dividends	$ 707	$ 668	$ 502
Net realized investment gains (losses)	37	27	36
Changes in the estimated fair value of equity security investments	797	(384)	0
Rental income	853	842	813
Other	882	930	220
Total Revenues	3,276	2,083	1,571
Personnel expenses	1,160	1,085	1,004
Office and technology expenses	375	355	349
Other expenses	1,024	892	763
Total Operating Expenses	2,559	2,332	2,116
Equity in Net Income of Affiliated Companies	30,804	22,014	25,634
Income before Income Taxes	31,521	21,765	25,089
Provision (Benefit) for Income Taxes	63	(94)	(612)
Net Income	31,458	21,859	25,701
Net Loss Attributable to Noncontrolling Interests	0	(33)	(6)
Net Income Attributable to the Company	$ 31,458	$ 21,892	$ 25,707
Basic Earnings per Common Share	$ 16.66	$ 11.60	$ 13.63
Weighted Average Shares Outstanding – Basic	1,888	1,887	1,886
Diluted Earnings per Common Share	$ 16.59	$ 11.54	$ 13.56
Weighted Average Shares Outstanding – Diluted	1,896	1,897	1,896