Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024	Dec. 31, 2023
Cash flows from operating activities:
Net income attributable to common shareholders	$ (44,737)	$ 20,771
Net Income (Loss) Attributable to Nonredeemable Noncontrolling Interest	(1,654)	(701)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest, Total	(14,490)	(3,369)
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Amortization of bond premium and discount	(63)	(83)
Share-based compensation	2,349	(463)
Unearned premiums, net	2,327	668
Losses and loss expenses, net	(20,876)	6,941
Ceded premiums payable	28,356	20,928
Premium receivables	(18,813)	(15,916)
Amortization of Intangible Assets	8,763	1,139
Net investment gains (losses), including impairments	3	(1)
Other, net	(3,341)	(7,193)
Net Cash Provided by (Used in) Operating Activities, Total	(12,612)	7,071
Proceeds from Sale of Debt Securities, Available-for-Sale	0	(467)
Net Cash Provided by (Used in) Investing Activities [Abstract]
Proceeds from matured bonds	8,488	8,460
Purchases of bonds	(10,990)	(22,077)
Purchases of other investments	0	(474)
Change in short-term investments	25,972	14,435
Other, net	(2,131)	(149)
Net cash provided by (used in) investing activities from continuing operations	21,339	(272)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Tax payments related to shares withheld for share-based compensation plans	(1,606)	(682)
Proceeds from (Payments to) Noncontrolling Interests	(708)	(650)
Net cash provided by (used in) financing activities from continuing operations	(5,436)	(1,332)
Effect of foreign exchange on cash and cash equivalents - discontinued operations	1,094	0
Treasury Stock, Value, Acquired, Cost Method	(3,122)	0	$ 11,698	$ 4,510
Net Cash Provided by (Used in) Financing Activities	(5,436)	(1,332)
Net Cash Provided by (Used in) Investing Activities	21,339	(272)
Net Cash Provided by (Used in) Operating Activities	(12,612)	7,071
Corporate costs reallocated to continuing operations	2,763	3,944
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect, Disposal Group, Including Discontinued Operations	8,910	15,744
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Disposal Group, Including Discontinued Operations	74,987	270,927	66,077	255,183
Net Cash Provided by (Used in) Continuing Operations	4,385	5,467
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	51,660	24,690	$ 47,275	$ 19,223
Cash Provided by (Used in) Operating Activities, Discontinued Operations	43,904	10,446
Cash Provided by (Used in) Investing Activities, Discontinued Operations	13,150	50,960
Cash Provided by (Used in) Financing Activities, Discontinued Operations	(48,369)	(45,558)
Net Cash Provided by (Used in) Discontinued Operations	225	(104)
Effect of foreign exchange on cash and cash equivalents - discontinued operations	1,094	0
Depreciation, Depletion and Amortization	9,176	1,614
Net income attributable to common shareholders	(44,737)	20,771
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	$ (30,247)	$ 24,140