Condensed Consolidated Statements of Income - Unaudited - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues:
Direct premiums	$ 717,088	$ 687,262	$ 1,419,725	$ 1,364,548
Ceded premiums	(402,549)	(400,588)	(789,374)	(790,383)
Net premiums	314,539	286,674	630,351	574,165
Commissions and fees	171,788	178,468	361,857	345,783
Investment income net of investment expenses	36,784	36,637	65,676	71,424
Interest expense on surplus note	(14,074)	(11,769)	(27,546)	(22,444)
Net investment income	22,710	24,868	38,130	48,980
Realized investment gains (losses)	1,742	1,067	(8,288)	3,914
Other, net	15,036	13,825	28,701	27,048
Revenues	525,815	504,902	1,050,751	999,890
Benefits and expenses:
Benefits and claims	139,646	115,068	274,459	237,352
Amortization of deferred policy acquisition costs	53,177	58,762	123,488	123,390
Sales commissions	85,492	90,099	182,099	173,898
Insurance expenses	43,753	44,570	92,463	87,972
Insurance commissions	6,333	5,829	13,177	11,447
Interest expense	7,200	7,201	14,392	14,381
Other operating expenses	56,152	55,913	122,066	121,622
Total benefits and expenses	391,753	377,442	822,144	770,062
Income before income taxes	134,062	127,460	228,607	229,828
Income taxes	32,552	30,014	54,628	53,217
Net income	$ 101,510	$ 97,446	$ 173,979	$ 176,611
Earnings per share:
Basic earnings per share	$ 2.52	$ 2.28	$ 4.26	$ 4.12
Diluted earnings per share	$ 2.51	$ 2.28	$ 4.25	$ 4.11
Weighted-average shares used in computing earnings per share:
Basic	40,132	42,483	40,632	42,653
Diluted	40,246	42,619	40,743	42,780
Supplemental disclosures:
Total impairment losses	$ (545)	$ (161)	$ (4,246)	$ (161)
Net impairment losses recognized in earnings	(545)	(161)	(4,246)	(161)
Other net realized investment gains	740	251	1,083	197
Net gains (losses) recognized on equity securities	1,547	977	(5,125)	3,878
Net realized investment gains (losses)	$ 1,742	$ 1,067	$ (8,288)	$ 3,914