Investments - Summary of Amortized Cost and Estimated Fair Value of Available-for-Sale Investments, Excluding VIE Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Mar. 31, 2025	Dec. 31, 2024	Mar. 31, 2024
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Allowance for Credit Loss	$ 0	$ 0	$ 0	$ 0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	260	881
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss			792
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer		60,829	68,012
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		3,735	4,559
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	5,351	3,994	5,351
Fixed maturity securities, at fair value		263,179
Debt Securities, Available-for-sale, Amortized Cost	289,712	266,292
Debt Securities, Available-for-Sale, Current	284,621	263,179
Short-term Investments [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	13	6
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	0	0
Fixed maturity securities, at fair value	127,601	101,610
Debt Securities, Available-for-sale, Amortized Cost	127,588	101,604	127,588
Fixed Income Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	247	875
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	5,351	3,994
Fixed maturity securities, at fair value	157,020	161,569
Debt Securities, Available-for-sale, Amortized Cost	162,124	164,688
Fixed Income Securities [Member] | Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position		8,730	12,624
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	7	53
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months		2,070	6,042
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		35	112
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer		6,660	6,582
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		373	458
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	570	408	570
Fixed maturity securities, at fair value	14,083	14,305
Debt Securities, Available-for-sale, Amortized Cost	14,646	14,660
Fixed Income Securities [Member] | Corporate Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position		51,803	70,396
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	107	343
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months		9,782	23,784
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		135	269
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer		42,021	46,612
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		3,018	3,636
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	3,905	3,153	3,905
Fixed maturity securities, at fair value	89,192	89,169
Debt Securities, Available-for-sale, Amortized Cost	92,990	91,979
Fixed Income Securities [Member] | Foreign Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position		0	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months		0	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		0	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer		0	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		0	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax		0	0
Fixed Income Securities [Member] | US Government Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position		18,852	30,737
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	98	429
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months		6,704	15,919
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		46	344
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer		12,148	14,818
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		344	465
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	809	390	809
Fixed maturity securities, at fair value	40,995	44,860
Debt Securities, Available-for-sale, Amortized Cost	41,706	44,821
Fixed Income Securities [Member] | Residential Mortgage-Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position		1,899	2,446
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0	16
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months		1,899	2,446
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		18	29
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer		0	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		0	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	29	18	29
Fixed maturity securities, at fair value	2,446	3,445
Debt Securities, Available-for-sale, Amortized Cost	2,475	3,447
Fixed Income Securities [Member] | Collateralized Debt Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position		654	655
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	13	14
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months		654	655
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		1	2
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer		0	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		0	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	2	1	2
Fixed maturity securities, at fair value	3,142	2,954
Debt Securities, Available-for-sale, Amortized Cost	3,131	2,941
Fixed Income Securities [Member] | Asset-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position		848	1,428
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	14	16
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months		848	1,428
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		2	2
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer		0	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		0	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	2	2	2
Fixed maturity securities, at fair value	5,061	4,787
Debt Securities, Available-for-sale, Amortized Cost	5,049	4,773
Fixed Income Securities [Member] | Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position		750	738
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months		750	738
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		22	34
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer		0	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		0	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax		22	$ 34
Fixed maturity securities, at fair value		2,049
Debt Securities, Available-for-sale, Amortized Cost		2,067
Fixed Income Securities [Member] | Collateralized Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	8	4
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	34	22
Fixed maturity securities, at fair value	2,101	2,049
Debt Securities, Available-for-sale, Amortized Cost	$ 2,127	$ 2,067