Consolidated Statements Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
REVENUES:
Net premiums written	$ 1,879,316	$ 1,749,906	$ 5,464,980	$ 5,202,971
Change in net unearned premiums	(130,395)	(73,096)	(347,727)	(286,464)
Net premiums earned	1,748,921	1,676,810	5,117,253	4,916,507
Net investment income	142,650	161,692	402,844	508,279
Net realized and unrealized (losses) gains on investments	(7,772)	1,465	(89,404)	143,691
Change in allowance for expected credit losses on investments	46,750	0	29,093	0
Net investment gains (losses)	38,978	1,465	(60,311)	143,691
Revenues from non-insurance businesses	87,495	101,880	256,966	283,005
Insurance service fees	21,635	23,681	67,256	71,440
Other income	140	188	2,446	3,200
Total revenues	2,039,819	1,965,716	5,786,454	5,926,122
OPERATING COSTS AND EXPENSES:
Losses and loss expenses	1,114,632	1,041,471	3,357,011	3,058,950
Other operating costs and expenses	593,969	581,045	1,753,142	1,760,961
Expenses from non-insurance businesses	85,036	101,743	256,032	280,141
Interest expense	39,768	38,475	114,874	119,913
Total operating costs and expenses	1,833,405	1,762,734	5,481,059	5,219,965
Income before income taxes	206,414	202,982	305,395	706,157
Income tax expense	(54,048)	(37,831)	(84,900)	(141,965)
Net income before noncontrolling interests	152,366	165,151	220,495	564,192
Noncontrolling interests	(688)	57	(1,975)	(1,554)
Net income to common stockholders	$ 151,678	$ 165,208	$ 218,520	$ 562,638
NET INCOME PER SHARE:
Basic (in dollar per share)	$ 0.82	$ 0.87	$ 1.17	$ 2.95
Diluted (in dollar per share)	$ 0.81	$ 0.85	$ 1.15	$ 2.91