Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
REVENUES:
Net premiums written	$ 1,571,183	$ 1,607,365	$ 4,782,272	$ 4,913,656
Change in net unearned premiums	10,317	(21,421)	(62,028)	(240,584)
Net premiums earned	1,581,500	1,585,944	4,720,244	4,673,072
Net investment income	142,479	145,668	426,601	404,850
Net realized investment gains	183,959	175,738	276,760	207,508
Other-than-temporary impairments	0	0	0	(18,114)
Insurance service fees	33,612	32,135	100,475	109,437
Revenues from non-insurance businesses	89,786	80,242	225,033	305,787
Other income	6	0	695	0
Total revenues	2,031,342	2,019,727	5,749,808	5,682,540
OPERATING COSTS AND EXPENSES:
Losses and loss expenses	1,081,174	965,856	3,025,475	2,852,339
Other operating costs and expenses	600,822	606,348	1,821,155	1,770,450
Expenses from non-insurance businesses	86,412	78,865	221,389	291,127
Interest expense	36,821	37,043	110,419	104,019
Total operating costs and expenses	1,805,229	1,688,112	5,178,438	5,017,935
Income before income taxes	226,113	331,615	571,370	664,605
Income tax expense	(63,295)	(110,952)	(174,305)	(214,789)
Net income before noncontrolling interests	162,818	220,663	397,065	449,816
Noncontrolling interests	(764)	(13)	(2,560)	(689)
Net income to common stockholders	$ 162,054	$ 220,650	$ 394,505	$ 449,127
NET INCOME PER SHARE:
Basic (in dollar per share)	$ 1.29	$ 1.80	$ 3.17	$ 3.66
Diluted (in dollar per share)	$ 1.26	$ 1.72	$ 3.05	$ 3.50