Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenues:
Direct premiums	$ 637,426	$ 612,189	$ 1,265,124	$ 1,209,319
Ceded premiums	(406,043)	(406,683)	(805,811)	(802,017)
Net premiums	231,383	205,506	459,313	407,302
Commissions and fees	148,317	136,902	292,584	265,723
Investment income net of investment expenses	25,829	24,994	51,442	50,387
Interest expense on surplus note	(6,087)	(4,605)	(11,806)	(8,760)
Net investment income	19,742	20,389	39,636	41,627
Realized investment gains (losses), including other-than- temporary impairment losses	104	3,440	238	2,657
Other, net	14,150	12,757	27,089	24,284
Total revenues	413,696	378,994	818,860	741,593
Benefits and expenses:
Benefits and claims	99,512	88,984	201,897	179,961
Amortization of deferred policy acquisition costs	47,861	38,720	99,710	81,849
Sales commissions	75,440	70,146	149,144	136,789
Insurance expenses	36,920	32,906	74,541	66,035
Insurance commissions	5,157	4,472	10,057	8,619
Interest expense	7,143	7,178	14,270	14,350
Other operating expenses	45,274	44,708	98,011	91,898
Total benefits and expenses	317,307	287,114	647,630	579,501
Income before income taxes	96,389	91,880	171,230	162,092
Income taxes	33,282	32,554	56,054	57,590
Net income	$ 63,107	$ 59,326	$ 115,176	$ 104,502
Earnings per share:
Basic earnings per share	$ 1.36	$ 1.23	$ 2.48	$ 2.15
Diluted earnings per share	$ 1.36	$ 1.23	$ 2.47	$ 2.15
Weighted-average shares used in computing earnings per share:
Basic	45,984	47,658	46,142	48,104
Diluted	46,071	47,708	46,222	48,141
Supplemental disclosures:
Total impairment losses	$ (484)	$ (803)	$ (695)	$ (2,830)
Net impairment losses recognized in earnings	(484)	(803)	(695)	(2,830)
Other net realized investment gains	588	4,243	933	5,487
Realized investment gains (losses), including other-than- temporary impairment losses	$ 104	$ 3,440	$ 238	$ 2,657
Dividends declared per share	$ 0.19	$ 0.17	$ 0.38	$ 0.34