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Reinsurance - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Effects of Reinsurance [Line Items]
Ceded losses and loss adjustment expenses	$ (6.3)	$ 27.6	$ 48.7
Minimum [Member]
Effects of Reinsurance [Line Items]
Unsecured reinsurance receivable percentage of shareholders' equity	3.00%

X

- Definition

Ceded losses and loss adjustment expenses.

+ References

No definition available.

+ Details

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Balance Type:	credit
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X

- Definition

Unsecured Reinsurance Receivables, Percentage of Shareholders Equity

+ References

No definition available.

+ Details

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X

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

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Namespace Prefix:
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Balance Type:
Period Type: