Consolidated Statements Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
REVENUES:
Net premiums written	$ 2,325,138	$ 1,879,316	$ 6,587,357	$ 5,464,980
Change in net unearned premiums	(244,120)	(130,395)	(684,759)	(347,727)
Net premiums earned	2,081,018	1,748,921	5,902,598	5,117,253
Net investment income	179,851	142,650	506,615	402,844
Net realized and unrealized gains (losses) on investments	17,187	(7,772)	89,407	(89,404)
Change in allowance for expected credit losses on investments	2,314	46,750	(11,003)	29,093
Net investment gains (losses)	19,501	38,978	78,404	(60,311)
Revenues from non-insurance businesses	120,374	87,495	316,927	256,966
Insurance service fees	21,467	21,635	69,531	67,256
Other income	2,072	140	3,163	2,446
Total revenues	2,424,283	2,039,819	6,877,238	5,786,454
OPERATING COSTS AND EXPENSES:
Losses and loss expenses	1,298,392	1,114,632	3,623,630	3,357,011
Other operating costs and expenses	643,045	593,969	1,907,020	1,753,142
Expenses from non-insurance businesses	115,465	85,036	308,453	256,032
Interest expense	35,100	39,768	109,846	114,874
Total operating costs and expenses	2,092,002	1,833,405	5,948,949	5,481,059
Income before income taxes	332,281	206,414	928,289	305,395
Income tax expense	(64,963)	(54,048)	(191,577)	(84,900)
Net income before noncontrolling interests	267,318	152,366	736,712	220,495
Noncontrolling interests	(6,021)	(688)	(8,652)	(1,975)
Net income to common stockholders	$ 261,297	$ 151,678	$ 728,060	$ 218,520
NET INCOME PER SHARE:
Basic (in dollar per share)	$ 1.41	$ 0.82	$ 3.93	$ 1.17
Diluted (in dollar per share)	$ 1.40	$ 0.81	$ 3.89	$ 1.15