Fair Value Measurement - Summary of Fair Values and Gross Unrealized Losses of Available for Sale Securities (Detail) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Less than 12 months, Recorded Basis	$ 829	$ 16,364
Less than 12 months, Gross Unrealized Losses	(1)	(82)
12 months or longer, Recorded Basis	209,323	224,185
12 months or longer, Gross Unrealized Losses	(15,981)	(26,566)
Total, Recorded Basis	210,152	240,549
Total, Gross Unrealized Losses	(15,982)	(26,648)
Investments [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Less than 12 months, Recorded Basis		20
12 months or longer, Recorded Basis	55,738	60,065
12 months or longer, Gross Unrealized Losses	(4,003)	(6,409)
Total, Recorded Basis	55,738	60,085
Total, Gross Unrealized Losses	(4,003)	(6,409)
Restricted Investments [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Less than 12 months, Recorded Basis	829	16,344
Less than 12 months, Gross Unrealized Losses	(1)	(82)
12 months or longer, Recorded Basis	153,585	164,120
12 months or longer, Gross Unrealized Losses	(11,978)	(20,157)
Total, Recorded Basis	154,414	180,464
Total, Gross Unrealized Losses	(11,979)	(20,239)
Corporate Bonds [Member] | Investments [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Less than 12 months, Recorded Basis		20
12 months or longer, Recorded Basis	26,394	25,377
12 months or longer, Gross Unrealized Losses	(1,238)	(2,365)
Total, Recorded Basis	26,394	25,397
Total, Gross Unrealized Losses	(1,238)	(2,365)
Corporate Bonds [Member] | Restricted Investments [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Less than 12 months, Recorded Basis	100	11,142
Less than 12 months, Gross Unrealized Losses		(15)
12 months or longer, Recorded Basis	73,745	71,716
12 months or longer, Gross Unrealized Losses	(3,876)	(7,287)
Total, Recorded Basis	73,845	82,858
Total, Gross Unrealized Losses	(3,876)	(7,302)
U.S. Treasuries [Member] | Investments [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
12 months or longer, Recorded Basis	13,627	11,320
12 months or longer, Gross Unrealized Losses	(634)	(1,140)
Total, Recorded Basis	13,627	11,320
Total, Gross Unrealized Losses	(634)	(1,140)
U.S. Treasuries [Member] | Restricted Investments [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Less than 12 months, Recorded Basis	729	1,399
Less than 12 months, Gross Unrealized Losses	(1)	(29)
12 months or longer, Recorded Basis	47,313	46,656
12 months or longer, Gross Unrealized Losses	(3,766)	(6,319)
Total, Recorded Basis	48,042	48,055
Total, Gross Unrealized Losses	(3,767)	(6,348)
Mortgage-Backed Securities [Member] | Investments [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
12 months or longer, Recorded Basis	9,148	9,536
12 months or longer, Gross Unrealized Losses	(2,026)	(2,592)
Total, Recorded Basis	9,148	9,536
Total, Gross Unrealized Losses	(2,026)	(2,592)
Mortgage-Backed Securities [Member] | Restricted Investments [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Less than 12 months, Recorded Basis		3,360
Less than 12 months, Gross Unrealized Losses		(37)
12 months or longer, Recorded Basis	26,916	29,877
12 months or longer, Gross Unrealized Losses	(4,000)	(5,637)
Total, Recorded Basis	26,916	33,237
Total, Gross Unrealized Losses	(4,000)	(5,674)
U.S. Government Agency Securities [Member] | Investments [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
12 months or longer, Recorded Basis	5,267	12,531
12 months or longer, Gross Unrealized Losses	(42)	(203)
Total, Recorded Basis	5,267	12,531
Total, Gross Unrealized Losses	(42)	(203)
U.S. Government Agency Securities [Member] | Restricted Investments [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
12 months or longer, Recorded Basis	5,611	15,871
12 months or longer, Gross Unrealized Losses	(336)	(914)
Total, Recorded Basis	5,611	15,871
Total, Gross Unrealized Losses	(336)	(914)
Asset-Backed Securities [Member] | Investments [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
12 months or longer, Recorded Basis	1,302	1,301
12 months or longer, Gross Unrealized Losses	(63)	(109)
Total, Recorded Basis	1,302	1,301
Total, Gross Unrealized Losses	$ (63)	(109)
Asset-Backed Securities [Member] | Restricted Investments [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Less than 12 months, Recorded Basis		443
Less than 12 months, Gross Unrealized Losses		(1)
Total, Recorded Basis		443
Total, Gross Unrealized Losses		$ (1)