Schedule II - Condensed Statement of Income (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Condensed Financial Statements, Captions [Line Items]
Interest and dividends	$ 4,393	$ 4,752
Net realized investment gains	333	1,340
Changes in the estimated fair value of equity security investments	4,904	10,303
Other	623	678
Total Revenues	236,408	183,502
Personnel expenses	51,929	46,058
Office and technology expenses	9,951	9,254
Other expenses	12,856	12,055
Income before Income Taxes	49,661	39,823
(Benefit) Provision for Income Taxes	10,241	8,365
Net Income	$ 39,420	$ 31,458
Basic Earnings per Common Share	$ 20.84	$ 16.66
Weighted Average Shares Outstanding – Basic	1,892	1,888
Diluted Earnings per Common Share	$ 20.80	$ 16.59
Weighted Average Shares Outstanding – Diluted	1,896	1,896
Parent Company
Condensed Financial Statements, Captions [Line Items]
Interest and dividends	$ 768	$ 707
Net realized investment gains	(473)	37
Changes in the estimated fair value of equity security investments	265	797
Rental income	702	853
Other	392	882
Total Revenues	1,654	3,276
Personnel expenses	908	1,160
Office and technology expenses	360	375
Other expenses	1,003	1,024
Total Operating Expenses	2,271	2,559
Equity in Net Income of Affiliated Companies	39,685	30,804
Income before Income Taxes	39,068	31,521
(Benefit) Provision for Income Taxes	(352)	63
Net Income	$ 39,420	$ 31,458
Basic Earnings per Common Share	$ 20.84	$ 16.66
Weighted Average Shares Outstanding – Basic	1,892	1,888
Diluted Earnings per Common Share	$ 20.80	$ 16.59
Weighted Average Shares Outstanding – Diluted	1,896	1,896