Schedule II. Condensed Financial Information of Registrant - Condensed Balance Sheets (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Assets
Fixed maturity securities available for sale, at fair value (amortized cost $338,593, allowance for credit losses of $0 in 2022and amortized cost $324,597, allowance for credit losses of $0 in 2021)	$ 321,121	$ 341,769
Equity securities, at fair value(cost $50,185 and $44,175 in 2022 and 2021, respectively)	62,058	64,140
Short-term investments	14,120	57,431
Total investments	888,987	1,012,571
Cash and cash equivalents	61,469	70,722
Deferred income taxes	22,794	14,384
Property and equipment, net	7,225	6,459
Federal income tax recoverable	1,453	6,414
Other assets	14,132	11,374
Total assets	1,269,279	1,402,724
Liabilities:
Accounts payable and other liabilities	38,058	37,883
Total liabilities	951,847	1,003,401
Shareholders' equity (net of Treasury stock of $34,759 and $22,370 at December 31, 2022 and 2021, respectively)	317,432	399,323	$ 438,816	$ 430,215
Total liabilities and shareholders’ equity	1,269,279	1,402,724
Parent Company [Member]
Assets
Fixed maturity securities available for sale, at fair value (amortized cost $338,593, allowance for credit losses of $0 in 2022and amortized cost $324,597, allowance for credit losses of $0 in 2021)	19,470	19,605
Equity securities, at fair value(cost $50,185 and $44,175 in 2022 and 2021, respectively)	13,602	14,092
Short-term investments	10,145	55,559
Investment in subsidiaries	239,664	290,077
Total investments	282,881	379,333
Cash and cash equivalents	31,911	18,825
Deferred income taxes	982	1,148
Notes receivable from subsidiaries	1,855	2,275
Property and equipment, net	2,736	2,003
Federal income tax recoverable	543	857
Other assets	1,752	1,295
Total assets	322,660	405,736
Liabilities:
Accounts payable and other liabilities	5,228	6,413
Total liabilities	5,228	6,413
Shareholders' equity (net of Treasury stock of $34,759 and $22,370 at December 31, 2022 and 2021, respectively)	317,432	399,323
Total liabilities and shareholders’ equity	$ 322,660	$ 405,736