CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities:
Net income	$ 99,410	$ 106,484	$ 72,988
Adjustments to reconcile net income to net cash provided by operating activities:
Bad debt expense	406	611	431
Depreciation and amortization	3,242	2,033	1,194
Amortization of share-based compensation	10,288	17,386	12,342
Amortization of original issue discount on debt	149	521	840
Accretion of deferred credit	(149)	(521)	(840)
Book overdraft increase (decrease)		(5,924)	(9,023)
Net realized (gains) losses on investments	(2,294)	(1,060)	(5,627)
Amortization of premium/accretion of discount, net	3,481	1,831	2,116
Deferred income taxes	4,724	(693)	1,118
Excess tax (benefits) shortfall from share-based compensation	1,154	(5,310)	(7,006)
Other	31	42	19
Net change in assets and liabilities relating to operating activities:
Restricted cash and cash equivalents			(35)
Prepaid reinsurance premiums	(9,712)	75,832	50,709
Reinsurance recoverable	22,747	32,334	52,660
Reinsurance receivable, net	167	7,115	(7,265)
Premiums receivable, net	(3,249)	(385)	(4,911)
Accrued investment income	(1,514)	(298)	(230)
Other receivables	1,087	(1,783)	12
Income taxes recoverable	1,004	255	2,477
Deferred policy acquisition costs, net	(4,893)	(34,359)	(9,761)
Other assets	(320)	(750)	(740)
Unpaid losses and loss adjustment expenses	(40,346)	(35,513)	(24,869)
Unearned premiums	33,390	46,618	12,260
Accounts payable	2,809	(3,743)	680
Reinsurance payable, net	7,306	7,519	(20,166)
Income taxes payable		3,510	6,239
Other liabilities and accrued expenses	(505)	625	2,774
Advance premium	(7,017)	6,894	(5,040)
Net cash provided by (used in) operating activities	121,396	219,271	123,346
Cash flows from investing activities:
Proceeds from sale of property and equipment	36	86	84
Purchases of property and equipment	(8,223)	(11,869)	(9,267)
Payments to acquire a business		(1,000)
Purchases of equity securities	(66,688)	(65,038)	(116,541)
Purchases of fixed maturities	(320,131)	(178,198)	(106,885)
Purchases of short-term investments		(87,538)	(50,000)
Purchases of investment real estate, net	(5,496)	(6,220)
Proceeds from sales of equity securities	60,558	41,456	163,981
Proceeds from sales of fixed maturities	86,018	38,379	17,153
Proceeds from sales of short-term investments		12,500
Maturities of fixed maturities	54,615	74,390	24,287
Maturities of short-term investments	25,000	100,000
Net cash provided by (used in) investing activities	(174,311)	(83,052)	(77,188)
Cash flows from financing activities:
Preferred stock dividend	(10)	(10)	(13)
Common stock dividend	(24,192)	(22,287)	(19,240)
Issuance of common stock	119	511	73
Purchase of treasury stock	(8,510)	(18,649)	(29,736)
Sale of treasury stock	2,965
Purchase of preferred stock		(256)
Proceeds received from issuance of contingently redeemable common stock			19,000
Payments related to tax withholding for share-based compensation	(5,451)	(12,141)	(17,655)
Excess tax benefits (shortfall) from share-based compensation	(1,154)	5,310	7,006
Repayment of debt	(2,136)	(8,470)	(7,471)
Borrowings under promissory note		1,390
Net cash provided by (used in) financing activities	(38,369)	(54,602)	(48,036)
Net increase (decrease) in cash and cash equivalents	(91,284)	81,617	(1,878)
Cash and cash equivalents at beginning of period	197,014	115,397	117,275
Cash and cash equivalents at end of period	105,730	197,014	115,397
Supplemental cash and non-cash flow disclosures:
Interest paid	421	963	1,486
Income taxes paid	63,378	$ 65,383	$ 44,769
Income tax refund	$ 5,633