Investments - Narrative (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Gross unrealized gain (loss) on available for sale securities	$ 13,800,000
Proceeds from available-for-sale debt securities	1,800,000	$ 23,600,000
Gross realized gains or losses from sales, calls and maturities of available-for-sale debt and equity securities	0	0
Amount payable for securities purchased	0	0
Amount receivable for securities sold	0	0
Gross unrealized gains	505,000		$ 505,000
Gross unrealized losses	492,000		535,000
Other than temporary impairments losses, investments	0	$ 0
Investments	1,400,000		1,400,000
Deposits held in trust accounts	8,100,000		8,200,000
Deposits, held in trust for collateral requirements	122,500,000		$ 123,500,000
Collateral of gross unearned premiums and gross loss reserves	121,700,000
Unearned premiums run off	$ 0