Schedule II - Condensed Financial Information of Registrant (Parent Company Only) (Cash Flows) (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2015
Sep. 30, 2015
Jun. 30, 2015
Mar. 31, 2015
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Cash flows from operating activities:                      
Net income (loss) $ 3,446 $ 6,698 $ 6,376 $ 5,343 $ 3,767 $ 3,463 $ 1,651 $ 4,548 $ 21,863 $ 13,429 $ 8,245
Adjustments to reconcile net income (loss) to cash provided by (used in) operating activities:                      
Depreciation and amortization expense                 3,516 3,224 4,300
Deferred income tax expense (benefit)                 (1,030) (393) (257)
Realized loss                 (2,503) (134) (10,540)
Change in current federal income tax (recoverable) payable                 (2,747) 249 (799)
Change in all other liabilities                 (1,420) 7,946 (6,551)
Change in all other assets                 (645) (628) 17,141
Net cash provided by operating activities                 52,936 33,684 68,338
Cash flows from investing activities:                      
Purchases of property and equipment, net                 (3,608) (546) (673)
Purchase of fixed maturity and equity securities                 (265,482) (188,749) (222,399)
Maturities and redemptions of investment securities                 169,409 146,777 214,738
Net cash used in investing activities                 (96,289) (42,242) (11,817)
Cash flows from financing activities:                      
Proceeds from exercise of employee stock options                 658 1,155  
Purchase of treasury shares                 (2,532) (1,805)  
Activity under revolving credit facility, net                 30,000 (1,473)  
Payment of debt issuance costs                 (96)    
Net cash provided by (used in) financing activities                 26,814 (2,123)  
(Decrease) Increase in cash and cash equivalents                 (16,539) (10,681) 56,521
Cash and cash equivalents at beginning of year       130,985       141,666 130,985 141,666 85,145
Cash and cash equivalents at end of year 114,446       130,985       114,446 130,985 141,666
Supplemental cash flow information:                      
Interest paid                 3,906 4,576 4,599
Income taxes (recovered) paid                 13,800 5,497 3,891
Parent Company [Member]                      
Cash flows from operating activities:                      
Net income (loss)                 21,863 13,429 8,245
Adjustments to reconcile net income (loss) to cash provided by (used in) operating activities:                      
Depreciation and amortization expense                 65 68 92
Deferred income tax expense (benefit)                 (195) 183 1,182
Undistributed share of (earnings) loss of subsidiaries                 (16,545) (8,394) (11,053)
Change in current federal income tax (recoverable) payable                 8 (3,290) (3,694)
Change in all other liabilities                 (7,039) 4,081 12,232
Change in all other assets                 147 (131) 63
Net cash provided by operating activities                 (1,696) 5,946 7,067
Cash flows from investing activities:                      
Purchases of property and equipment, net                 (159) (47) (116)
Capital contribution to subsidiaries                 (30,000)    
Net cash used in investing activities                 (30,159) (47) (116)
Cash flows from financing activities:                      
Proceeds from exercise of employee stock options                 658 1,155  
Purchase of treasury shares                 (2,532) (1,805)  
Activity under revolving credit facility, net                 30,000 (1,473)  
Payment of debt issuance costs                 (96)    
Net cash provided by (used in) financing activities                 28,030 (2,123)  
(Decrease) Increase in cash and cash equivalents                 (3,825) 3,776 6,951
Cash and cash equivalents at beginning of year       $ 11,839       $ 8,063 11,839 8,063 1,112
Cash and cash equivalents at end of year $ 8,014       $ 11,839       8,014 11,839 8,063
Supplemental cash flow information:                      
Interest paid                 3,906 4,576 4,599
Income taxes (recovered) paid                 $ (1,086) $ 1,481 $ 1,285