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Investments - Summary of Amortized Cost and Estimated Fair Value of Available-for-Sale Investments, Excluding VIE Investments (Detail) - USD ($) $ in Thousands | Dec. 31, 2025 | Dec. 31, 2024
--- | --- | ---
Debt Securities, Available-for-sale [Line Items] |  |
Fixed income securities, amortized cost | $ 269,848 | $ 289,712
Gross Unrealized Gains | 1,205 | 260
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 2,316 | 5,351
Available-for-sale Securities | 122,295 | 157,020
Debt Securities, Available-for-sale, Allowance for Credit Loss | 0 | 0
Debt Securities, Available-for-Sale, Current | 268,737 | 284,621
Municipal Bonds [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Fixed income securities, amortized cost | 11,697 | 14,646
Gross Unrealized Gains | 121 | 7
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 228 | 570
Available-for-sale Securities | 11,590 | 14,083
Debt Securities, Available-for-sale, Allowance for Credit Loss | 0 | 0
Corporate Obligations [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Fixed income securities, amortized cost | 67,881 | 92,990
Gross Unrealized Gains | 634 | 107
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 1,942 | 3,905
Available-for-sale Securities | 66,573 | 89,192
Debt Securities, Available-for-sale, Allowance for Credit Loss | 0 | 0
U.S. Government Obligations [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Fixed income securities, amortized cost | 35,190 | 41,706
Gross Unrealized Gains | 365 | 98
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 131 | 809
Available-for-sale Securities | 35,424 | 40,995
Debt Securities, Available-for-sale, Allowance for Credit Loss | 0 | 0
Residential Mortgage-Backed Securities [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Fixed income securities, amortized cost | 1,604 | 2,475
Gross Unrealized Gains | 0 | 0
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 7 | 29
Available-for-sale Securities | 1,597 | 2,446
Debt Securities, Available-for-sale, Allowance for Credit Loss | 0 | 0
Collateralized Debt Obligations [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Fixed income securities, amortized cost | 1,963 | 3,131
Gross Unrealized Gains | 12 | 13
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 0 | 2
Available-for-sale Securities | 1,975 | 3,142
Debt Securities, Available-for-sale, Allowance for Credit Loss | 0 | 0
Asset-backed Securities [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Fixed income securities, amortized cost | 1,772 | 5,049
Gross Unrealized Gains | 23 | 14
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 0 | 2
Available-for-sale Securities | 1,795 | 5,061
Debt Securities, Available-for-sale, Allowance for Credit Loss | 0 | 0
Short-term Investments [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Fixed income securities, amortized cost | 146,434 | 127,588
Gross Unrealized Gains | 8 | 13
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 0 | 0
Available-for-sale Securities | 146,442 | 127,601
Debt Securities, Available-for-sale, Allowance for Credit Loss | 0 | 0
Commercial Mortgage Backed Securities [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Fixed income securities, amortized cost | 3,307 |
Gross Unrealized Gains | 42 | 8
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 8 | 34
Available-for-sale Securities | 3,341 | 2,101
Debt Securities, Available-for-sale, Allowance for Credit Loss | 0 | 0
Collateralized Mortgage Backed Securities [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Fixed income securities, amortized cost | 3,307 | 2,127
Long-Term Investments |  |
Debt Securities, Available-for-sale [Line Items] |  |
Gross Unrealized Gains | 1,197 | 247
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 2,316 | 5,351
Available-for-sale Securities | 122,295 | 157,020
Debt Securities, Available-for-sale, Allowance for Credit Loss | 0 | 0
Long-Term Investments | Fixed Income Investments And Other Investments [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Fixed income securities, amortized cost | $ 123,414 | $ 162,124

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