Unaudited Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Revenues
Net premiums earned	$ 2,325,775	$ 2,120,909	$ 4,446,408	$ 4,069,331
Net investment income	106,392	111,613	186,828	210,469
Net realized gains (losses)	(266,579)	202,907	(558,993)	345,368
Other underwriting income	2,970	5,529	8,867	11,639
Equity in net income (loss) of investment funds accounted for using the equity method	58,061	122,186	94,366	193,872
Other income (loss)	(11,777)	6,852	(20,802)	5,111
Total revenues	2,214,842	2,569,996	4,156,674	4,835,790
Expenses
Losses and loss adjustment expenses	1,102,656	1,159,831	2,103,491	2,362,931
Acquisition expenses	413,319	335,143	791,478	639,624
Other operating expenses	277,392	244,943	567,335	505,976
Corporate expenses	27,620	15,951	59,952	41,335
Amortization of intangible assets	27,207	15,286	54,374	29,688
Interest expense	32,795	35,700	65,503	74,046
Net foreign exchange (gains) losses	(87,775)	17,775	(91,620)	(2,288)
Total expenses	1,793,214	1,824,629	3,550,513	3,651,312
Income (loss) before income taxes and income (loss) from operating affiliates	421,628	745,367	606,161	1,184,478
Income tax expense	(22,323)	(51,179)	(33,942)	(90,039)
Income (loss) from operating affiliates	4,640	24,476	29,158	99,933
Net income (loss)	403,945	718,664	601,377	1,194,372
Net (income) loss attributable to noncontrolling interests	399	(43,178)	(1,233)	(80,730)
Net income (loss) available to Arch	404,344	675,486	600,144	1,113,642
Preferred dividends	(10,184)	(11,666)	(20,368)	(22,069)
Net income (loss) available to Arch common shareholders	$ 394,160	$ 663,820	$ 579,776	$ 1,091,573
Net income per common share and common share equivalent
Basic (per share)	$ 1.07	$ 1.67	$ 1.56	$ 2.73
Diluted (per share)	$ 1.04	$ 1.63	$ 1.52	$ 2.68
Weighted average common shares and common share equivalents outstanding
Basic (shares)	369,241,193	397,743,402	371,728,683	399,267,183
Diluted (shares)	377,952,988	406,485,994	380,905,512	407,687,680