Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Operating activities
Net income	$ 40,896	$ 29,449
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	594	687
Net amortization of investments	8,163	8,246
Deferred income taxes	291	(662)
Net realized (gains) losses on investments	(793)	2,558
Net realized losses on disposal of assets	1	1
Share-based compensation	744	380
Changes in operating assets and liabilities:
Premiums receivable, net	(22,871)	(24,184)
Accrued interest receivable	37	15
Deferred policy acquisition costs	(263)	(1,741)
Amounts held by others	1,016	(27,848)
Other assets	(756)	(1,818)
Reserves for loss and loss adjustment expenses	7,516	27,543
Unearned premiums	11,817	11,369
Reinsurance balances	(3,270)	(4,901)
Amounts held for others and policyholder deposits	4,700	2,295
Accounts payable and other liabilities	8,539	4,712
Net cash provided by operating activities	56,361	26,101
Investing activities
Purchases of investments held-to-maturity	(76,920)	(117,104)
Purchases of investments available-for-sale	(132,699)	(59,707)
Purchases of short-term investments	(12,132)	(4,440)
Proceeds from maturities of investments held-to-maturity	103,565	59,268
Proceeds from sales and maturities of investments available-for-sale	66,755	39,821
Proceeds from sales and maturities of short-term investments	2,507	31,055
Purchases of property and equipment	(850)	(553)
Net cash used in investing activities	(49,774)	(51,660)
Financing activities
Proceeds from stock option exercises	501	834
Tax benefit from share-based payments	546	1,071
Dividends to shareholders	(6,960)	(5,713)
Net cash used in financing activities	(5,913)	(3,808)
Change in cash and cash equivalents	674	(29,367)
Cash and cash equivalents at beginning of period	69,481	90,956
Cash and cash equivalents at end of period	$ 70,155	$ 61,589