Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
REVENUES:
Net premiums written	$ 1,665,338	$ 1,646,838
Change in net unearned premiums	(97,930)	(76,796)
Net premiums earned	1,567,408	1,570,042
Net investment income	174,518	148,858
Net realized and unrealized gains on investments	48,464	52,348
Revenues from non-insurance businesses	70,171	65,390
Insurance service fees	30,675	33,280
Other income	11	500
Total revenues	1,891,247	1,870,418
OPERATING COSTS AND EXPENSES:
Losses and loss expenses	963,219	979,603
Other operating costs and expenses	610,439	603,700
Expenses from non-insurance businesses	69,543	66,019
Interest expense	37,056	36,799
Total operating costs and expenses	1,680,257	1,686,121
Income before income taxes	210,990	184,297
Income tax expense	(43,417)	(59,623)
Net income before noncontrolling interests	167,573	124,674
Noncontrolling interests	(1,177)	(1,227)
Net income to common stockholders	$ 166,396	$ 123,447
NET INCOME PER SHARE:
Basic (in dollar per share)	$ 1.32	$ 1.01
Diluted (in dollar per share)	$ 1.30	$ 0.96