Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Investments:
Fixed maturities	$ 445,669	$ 409,460
Equity securities	107,582	88,085
Limited partnerships	59,954	54,705
Short-term and other	4,201	3,675
Total Investments	617,406	555,925
Cash and cash equivalents	71,549	89,726
Accounts receivable--less allowance (2012, $538; 2011, $659)	83,400	74,094
Accrued investment income	4,387	4,337
Reinsurance recoverable	175,191	138,404
Prepaid reinsurance premiums	2,679	3,059
Deferred policy acquisition costs	3,091	4,578
Property and equipment--less accumulated depreciation (2012, $15,184; 2011, $13,486)	12,257	12,991
Other assets	9,818	11,707
Current federal income taxes recoverable	3,246	3,354
Deferred federal income taxes	0	7,119
Total Assets	983,024	905,294
Reserves:
Losses and loss expenses	455,454	421,556
Unearned premiums	37,273	39,919
Total Reserves	492,727	461,475
Reinsurance payable	32,798	28,330
Short-term borrowings	10,000	10,000
Depository liabilities	42,503	36,436
Accounts payable and other liabilities	49,706	49,992
Deferred federal income taxes	8,578	0
Total Liabilities	636,312	586,233
Shareholders' equity:
Additional paid-in capital	50,275	48,751
Unrealized net gains on investments	35,467	26,592
Foreign exchange adjustment	1,976	1,759
Retained earnings	258,358	241,325
Shareholders' equity	346,712	319,061
Total liabilities and shareholders' equity	983,024	905,294
Class A voting [Member]
Shareholders' equity:
Common stock	112	112
Class B non-voting [Member]
Shareholders' equity:
Common stock	$ 524	$ 522