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Reinsurance - Narrative (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Dec. 31, 2023	Sep. 30, 2023	Dec. 31, 2022
Effects of Reinsurance [Line Items]
Reinsurance recoverable on loss reserves	$ 45,327	$ 33,302	$ 40,934	$ 28,240
Most New Insurance Written In 2025 And 2026
Effects of Reinsurance [Line Items]
Reinsurance, quota share reinsurance agreement, terms, quota share, percent	40.00%
Quota Share Reinsurance Transactions
Effects of Reinsurance [Line Items]
Ceding commission, percentage (as a percent)	20.00%
Reinsurance, quote share reinsurance agreement, annual loss ratio cap (as a percent)	300.00%
Reinsurance, quota reinsurance agreement, lifetime loss ratio cap (as a percent)	200.00%
Threshold for private mortgage insurer eligibility requirements for termination election (less than) (as a percent)	90.00%
Reinsurance recoverable on loss reserves	$ 45,300	$ 33,300
Credit Union QSR Transaction
Effects of Reinsurance [Line Items]
Threshold for private mortgage insurer eligibility requirements for termination election (less than) (as a percent)	80.00%
Reinsurance, quota share reinsurance agreement, terms, quota share, percent	65.00%
Home Re special purpose insurers
Effects of Reinsurance [Line Items]
Percent of total trust assets invested in cash or direct U.S. federal government obligations	99.50%

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Reinsurance, Quota Share Reinsurance Agreement, Terms, Threshold For Private Mortgage Insurer Eligibility Requirements For Termination Election

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Reinsurance Retention Policy, Percent Of Total Trust Assets Invested In Cash Or Direct U.S. Federal Government Obligations

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Amount, after valuation allowance, recoverable under reinsurance contracts for losses reported to the ceding insurer but not yet paid and amounts expected for incurred losses and settlement expenses, which have not yet been reported to the ceding insurer.

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