Series A Preferred Shares (Details) $ / shares in Units, $ in Thousands				12 Months Ended
	Oct. 01, 2029	Nov. 11, 2024 USD ($) $ / shares	Mar. 01, 2022 USD ($) $ / shares	Dec. 31, 2025 USD ($) d $ / shares shares	Dec. 31, 2024 USD ($) $ / shares shares	Dec. 31, 2023 USD ($)
Temporary Equity [Line Items]
Number of shares issued during period (in shares) \| shares				112,500	112,500
Dividends on Series A preferred shares				$ 7,876	$ 10,143	$ 10,500
Conversion of shares					37,500
Deemed dividend					25,717
Carrying value				133,115	133,115
Common stock
Temporary Equity [Line Items]
Conversion of shares					1
Retained Earnings
Temporary Equity [Line Items]
Dividends on Series A preferred shares				$ 7,876	10,143	10,500
Conversion of shares					(1,289)
Deemed dividend					$ 25,717
Private Placement
Temporary Equity [Line Items]
Sale of stock, consideration received on transaction		$ 12,500
Per share price (in dollars per share) \| $ / shares		$ 6.40
Convertible Preferred Stock
Temporary Equity [Line Items]
Number of shares issued during period (in shares) \| shares				112,500	112,500
Preferred stock, dividend rate, percentage				7.00%
Series A convertible preferred shares (in dollars per share) \| $ / shares				$ 0.00125	$ 0.00125
Liquidation preference (in dollars per share) \| $ / shares				$ 1,000
Dividends on Series A preferred shares				$ 7,900	$ 10,100	$ 10,500
Convertible preferred stock, shares issued upon conversion \| shares				13,521,634
Preferred stock, convertible, conversion price (in dollars per share) \| $ / shares		$ 6.40		$ 8.32
Percentage of then-applicable conversion price threshold				200.00%
Number of trading days \| d				20
Preferred stock, discount rate, percentage				3.50%
Number of trading days immediately preceding Mandatory Conversion \| d				5
Preferred stock, value		$ 133,100		$ 133,100
Voting equity percentage				9.90%
Conversion of shares		37,500
Carrying value		144,900
Convertible Preferred Stock \| Forecast
Temporary Equity [Line Items]
Preferred stock, dividend rate, percentage	8.00%
Preferred stock, dividend term	5 years
Preferred stock, dividend payment rate, variable spread	5.20%
Convertible Preferred Stock \| AM Best, Below A- Rating
Temporary Equity [Line Items]
Voting equity percentage				19.90%
Convertible Preferred Stock \| Common stock
Temporary Equity [Line Items]
Common stock, covenant, threshold, cash paid (in dollars per share) \| $ / shares				$ 0.05
Cash dividend declared (in dollars per share) \| $ / shares				$ 0.10
Convertible Preferred Stock \| Retained Earnings
Temporary Equity [Line Items]
Deemed dividend		$ 25,700
Convertible Preferred Stock \| Private Placement
Temporary Equity [Line Items]
Sale of stock, consideration received on transaction			$ 150,000
Per share price (in dollars per share) \| $ / shares			$ 1,000

James River Group Holdings, Inc. 10-K