Investments - ProAssurance's Equity Method Investments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2021
Schedule of Equity Method Investments [Line Items]
Total assets	$ 5,574,273	$ 5,631,925
Total liabilities	4,372,524	4,519,945
Total partners' capital	1,201,749	1,111,980	$ 1,104,018			$ 1,428,387
Net investment income (loss)	144,538	128,419	95,972
Total net investment gains (losses)	1,903	13,828	(33,157)
Net gain (loss) attributable to ProAssurance	52,744	(38,604)	(402)
Significant Equity Method Investees
Schedule of Equity Method Investments [Line Items]
Total assets				$ 316,699	$ 228,725
Total liabilities				14,830	80
Total partners' capital				$ 301,869	$ 228,645
Net investment income (loss)	74,769	(4,846)	(5,814)
Net investment gains (losses)	0	(475)	3,025
Net change in unrealized appreciation (depreciation)	27,152	20,976	8,171
Total net investment gains (losses)	101,921	15,655	5,382
Net gain (loss) attributable to ProAssurance	$ 6,348	$ (4,517)	$ 377