Investments - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2025 USD ($) Security	Dec. 31, 2024 USD ($)
Marketable Securities [Line Items]
Short-term investments		$ 9,300
Individual fixed maturity held in unrealized loss position | Security	144
Individual fixed maturity held in unrealized loss position longer than 12 months | Security	118
Number of fixed maturity securities, allowance for credit loss | Security	269
Fixed maturity securities, held-to-maturity, allowance for credit losses	$ 73,000	116,000
Debt Securities Available For Sale Allowance For Credit Loss	0	0
Held-to-Maturity Securities [Member]
Marketable Securities [Line Items]
Investments on deposit with regulatory agencies	23,600,000
Available-for-Sale Securities [Member]
Marketable Securities [Line Items]
Investments on deposit with regulatory agencies		2,100,000
Corporate Bonds [Member]
Marketable Securities [Line Items]
Short-term investments	14,200,000
Fixed maturity securities, held-to-maturity, allowance for credit losses	$ 50,000	86,000
Number of majority securities | Security	9
States and Political Subdivisions [Member]
Marketable Securities [Line Items]
Fixed maturity securities, held-to-maturity, allowance for credit losses	$ 23,000	$ 30,000
Number of majority securities | Security	259
Corporate Fixed Income Securities [Member] | Maximum [Member]
Marketable Securities [Line Items]
Investments maturity period using default rate	20 years