Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
REVENUES:
Net premiums written	$ 1,564,251	$ 1,642,569	$ 3,211,089	$ 3,306,291
Change in net unearned premiums	4,452	(82,776)	(72,345)	(219,163)
Net premiums earned	1,568,703	1,559,793	3,138,744	3,087,128
Net investment income	135,264	129,049	284,123	259,182
Net realized investment gains	40,453	6,315	92,801	31,772
Other-than-temporary impairments	0	0	0	(18,114)
Insurance service fees	33,584	36,939	66,864	77,301
Revenues from non-insurance businesses	69,857	123,764	135,247	225,544
Other income	188	54	688	312
Total revenues	1,848,049	1,855,914	3,718,467	3,663,125
OPERATING COSTS AND EXPENSES:
Losses and loss expenses	964,698	964,162	1,944,302	1,886,483
Other operating costs and expenses	616,632	581,955	1,220,332	1,164,414
Expenses from non-insurance businesses	68,959	116,731	134,978	212,262
Interest expense	36,799	34,752	73,597	66,976
Total operating costs and expenses	1,687,088	1,697,600	3,373,209	3,330,135
Income before income taxes	160,961	158,314	345,258	332,990
Income tax expense	(51,388)	(49,408)	(111,011)	(103,837)
Net income before noncontrolling interests	109,573	108,906	234,247	229,153
Noncontrolling interests	(569)	61	(1,796)	(676)
Net income to common stockholders	$ 109,004	$ 108,967	$ 232,451	$ 228,477
NET INCOME PER SHARE:
Basic (in dollar per share)	$ 0.87	$ 0.89	$ 1.88	$ 1.86
Diluted (in dollar per share)	$ 0.85	$ 0.85	$ 1.81	$ 1.78