CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Revenues
Net premiums earned	$ 5,306,235	$ 5,083,781	$ 5,160,326
Net investment income	759,229	611,742	418,829
Other insurance related income	30,721	22,495	13,073
Net investment gains (losses):
Increase in allowance for expected credit losses	(10,338)	(5,246)	(11,421)
Impairment losses	(408)	(12,757)	(12,568)
Other realized and unrealized investment gains (losses)	(127,788)	(56,627)	(432,800)
Total net investment gains (losses)	(138,534)	(74,630)	(456,789)
Total revenues	5,957,651	5,643,388	5,135,439
Expenses
Net losses and loss expenses	3,158,487	3,393,102	3,242,410
Acquisition costs	1,070,551	1,000,945	1,022,017
General and administrative expenses	666,202	684,446	680,343
Foreign exchange losses (gains)	(50,822)	58,115	(157,945)
Interest expense and financing costs	67,766	68,421	63,146
Reorganization expenses	26,312	28,997	31,426
Amortization of intangible assets	10,917	10,917	10,917
Total expenses	4,949,413	5,244,943	4,892,314
Income before income taxes and interest in income of equity method investments	1,008,238	398,445	243,125
Income tax (expense) benefit	55,595	(26,316)	(22,037)
Interest in income of equity method investments	17,953	4,163	1,995
Net income	1,081,786	376,292	223,083
Preferred share dividends	30,250	30,250	30,250
Net income available to common shareholders	$ 1,051,536	$ 346,042	$ 192,833
Earnings per common share:
Earnings per common share (in dollars per share)	$ 12.49	$ 4.06	$ 2.27
Earnings per diluted common share (in dollars per share)	$ 12.35	$ 4.02	$ 2.25
Weighted average common shares outstanding (in shares)	84,165	85,142	84,864
Weighted average diluted common shares outstanding (in shares)	85,176	86,012	85,669