Statutory Accounting and Regulatory Requirements - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2026
Dividends to the Company	10.00%
Dividends paid	$ 62.7	$ 71.0	$ 56.0
Forecast [Member]
Dividends permissible to pay without seeking regulatory approval				$ 40.1

Cash outflow in the form of capital distributions and dividends to common shareholders, preferred shareholders and noncontrolling interests.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 15
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-15

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