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 (loss)	$ 6,526	$ 21,863	$ 13,429
Adjustments to reconcile net income (loss) to cash provided by operating activities:
Depreciation and amortization expense	3,894	3,516	3,224
Deferred federal income taxes	405	(1,030)	(393)
Net realized gains	369	(2,503)	(134)
Share-based payments expense	(118)	383	222
Change in ceded unearned premiums	(16,388)	(11,718)	(8,388)
Change in premiums receivable	(6,339)	(12,373)	154
Change in accounts receivable	(264)	1,136	(759)
Change in deferred policy acquisition costs	1,173	380	1,840
Change in unpaid losses and loss adjustment expenses	30,689	35,743	32,495
Change in unearned premiums	24,847	19,581	11,523
Change in reinsurance recoverable	(33,534)	(4,568)	(32,901)
Change in reinsurance balances payable	12,747	7,338	5,805
Change in current federal income tax (recoverable)/payable	(2,172)	(2,747)	249
Change in all other liabilities	3,586	(1,368)	7,998
Change in all other assets	5,433	(697)	(680)
Net cash provided by operating activities	30,854	52,936	33,684
Cash flows from investing activities:
Purchases of property and equipment, net	(4,340)	(3,608)	(546)
Net transfers from restricted cash	1,195	3,392	276
Purchases of investment securities	(241,374)	(265,482)	(188,749)
Maturities, sales and redemptions of investment securities	186,286	169,409	146,777
Net cash used in investing activities	(58,233)	(96,289)	(42,242)
Cash flows from financing activities:
Activity under revolving credit facility, net		30,000	(1,473)
Payment of debt issuance costs		(96)
Payment of contingent consideration	(1,784)	(1,216)
Proceeds from exercise of employee stock options	466	658	1,155
Purchase of treasury shares	(6,117)	(2,532)	(1,805)
Net cash provided by (used in) financing activities	(7,435)	26,814	(2,123)
Decrease in cash and cash equivalents	(34,814)	(16,539)	(10,681)
Cash and cash equivalents at beginning of year	114,446	130,985	141,666
Cash and cash equivalents at end of year	79,632	114,446	130,985
Supplemental cash flow information:
Interest paid	4,287	3,906	4,576
Income taxes paid	3,718	13,800	5,497
Supplemental schedule of non-cash activities:
Change in receivable for securities related to investment disposals that settled after the balance sheet date	7,377	(9,492)	388
Change in payable for securities related to investment purchases that settled after the balance sheet date	$ 13,118	$ (224)	$ 1,115