CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenues
Net premiums earned	$ 5,160,326	$ 4,709,850	$ 4,371,309
Net investment income	418,829	454,301	349,601
Other insurance related income (loss)	13,073	23,295	(8,089)
Net investment gains:
Allowance for expected credit losses	(11,421)	11	(323)
Impairment losses	(12,568)	(22)	(1,486)
Other realized and unrealized investment gains (losses)	(432,800)	134,290	130,942
Total net investment gains (losses)	(456,789)	134,279	129,133
Total revenues	5,135,439	5,321,725	4,841,954
Expenses
Net losses and loss expenses	3,242,410	3,008,783	3,281,252
Acquisition costs	1,022,017	921,834	929,517
General and administrative expenses	680,343	663,304	579,790
Foreign exchange losses (gains)	(157,945)	315	81,069
Interest expense and financing costs	63,146	62,302	75,049
Reorganization expenses	31,426	0	7,881
Amortization of value of business acquired	0	3,854	5,139
Amortization of intangible assets	10,917	12,424	11,390
Total expenses	4,892,314	4,672,816	4,971,087
Income (loss) before income taxes and interest in income (loss) of equity method investments	243,125	648,909	(129,133)
Income tax (expense) benefit	(22,037)	(62,384)	12,321
Interest in income (loss) of equity method investments	1,995	32,084	(3,612)
Net income (loss)	223,083	618,609	(120,424)
Preferred share dividends	30,250	30,250	30,250
Net income (loss) available (attributable) to common shareholders	$ 192,833	$ 588,359	$ (150,674)
Earnings (loss) per common share:
Earnings (loss) per common share (in dollars per share)	$ 2.27	$ 6.95	$ (1.79)
Earnings (loss) per diluted common share (in dollars per share)	$ 2.25	$ 6.90	$ (1.79)
Weighted average common shares outstanding (in shares)	84,864	84,707	84,262
Weighted average diluted common shares outstanding (in shares)	85,669	85,291	84,262