General - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Potentially dilutive securities (in shares)	0
Dividends declared and paid (in dollars per share)	$ 0.3175	$ 0.3175
Deferred policy acquisition cost amortization	$ 228,720,000	$ 196,040,000
Advertising expenses	5,500,000	3,300,000
Ceded premiums earned	106,700,000	31,100,000
Losses and loss adjustment expenses, ceded	1,292,500,000	(800,000)
Revenue from contract with customer	7,000,000.0	5,700,000
Cost of goods and services sold	3,600,000	3,200,000
Contract with customer, asset	0		$ 0
Contract with customer, liability	0		0
Revenue, remaining performance obligation	0		$ 0
Accrued interest receivable considered uncollectible or written off	0	$ 0
Reinsurance Contract [Axis]: Catastrophe Participation Reinsurance Contract (the "Contract")
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Reinsurance reimbursable amount	$ 30,000,000
Reinsurance retention policy, threshold loss ratio	73.50%
Reinsurance Contract [Axis]: Catastrophe Reinsurance Treaty (the "Treaty")
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Reinsurance retention policy, excess retention, amount reinsured	$ 1,290,000,000
Reinsurance policy, amount retained	150,000,000
Reinsurance Contract [Axis]: Property Quota Share Reinsurance Contract ("Quota Share")
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Assumed premium written	11,000,000
Assumed maximum possible loss	32,000,000
Folsom, California Office Building | Disposal Group, Held-for-sale, Not Discontinued Operations
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Fixed asset classified as held for sale	10,000,000.0
Rancho Cucamonga, California Parcel Of Land | Disposal Group, Held-for-sale, Not Discontinued Operations
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Fixed asset classified as held for sale	$ 1,700,000