Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Operating activities
Net income	$ 13,524	$ 24,257
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	266	290
Net amortization of investments	3,769	4,095
Deferred income taxes	(13)	349
Net realized (gains) losses on investments	181	(248)
Net realized losses on disposal of assets	2	1
Share-based compensation	416	231
Changes in operating assets and liabilities:
Premiums receivable, net	(8,271)	(11,821)
Accrued interest receivable	(547)	(804)
Deferred policy acquisition costs	(566)	190
Amounts held by others		1,017
Other assets	(1,148)	(274)
Reserves for loss and loss adjustment expenses	6,720	4,145
Unearned premiums	1,775	1,870
Reinsurance balances	741	(1,306)
Amounts held for others and policyholder deposits	414	1,727
Accounts payable and other liabilities	6,531	6,615
Net cash provided by operating activities	23,794	30,334
Investing activities
Purchases of investments held-to-maturity	(53,640)	(39,852)
Purchases of investments available-for-sale	(34,081)	(65,963)
Purchases of short-term investments	(4,907)	(5,576)
Proceeds from maturities of investments held-to-maturity	19,752	57,603
Proceeds from sales and maturities of investments available-for-sale	29,851	34,448
Proceeds from sales and maturities of short-term investments	1,630	1,508
Proceeds from redemption of other invested assets	2,000
Purchases of property and equipment	(73)	(98)
Net cash used in investing activities	(39,468)	(17,930)
Financing activities
Proceeds from stock option exercises		454
Tax benefit from share-based payments		435
Dividends to shareholders	(3,909)	(3,484)
Net cash used in financing activities	(3,909)	(2,595)
Change in cash and cash equivalents	(19,583)	9,809
Cash and cash equivalents at beginning of period	58,936	69,481
Cash and cash equivalents at end of period	$ 39,353	$ 79,290