SCHEDULE II CONDENSED FINANCIAL INFORMATION OF REGISTRANT (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Investments other than subsidiaries:
Fixed maturities	$ 445,669				$ 409,460				$ 445,669	$ 409,460
Limited partnerships	59,954				54,705				59,954	54,705
Total Investments	617,406				555,925				617,406	555,925
Cash and cash equivalents	71,549				89,726				71,549	89,726	38,223
Accounts receivable	83,400				74,094				83,400	74,094
Other assets	9,818				11,707				9,818	11,707
Total Assets	983,024				905,294				983,024	905,294
Liabilities:
Total Liabilities	636,312				586,233				636,312	586,233
Shareholders' equity:
Additional paid-in capital	50,275				48,751				50,275	48,751
Unrealized net gains on investments	35,467				26,592				35,467	26,592
Retained earnings	258,358				241,325				258,358	241,325	284,346	292,543
Shareholders' equity	346,712				319,061				346,712	319,061	368,735	372,943
Total liabilities and shareholders' equity	983,024				905,294				983,024	905,294
Revenue:
Commissions and service fees									5,722	6,098	6,911
Net investment income	2,734	2,343	2,431	2,422	2,652	2,779	2,644	2,653	9,930	10,729	11,335
Net realized gains (losses) on investments									9,011	(17,803)	16,485
Total revenue									262,124	243,594	249,469
Expenses:
Other									77,430	73,328	68,704
Total expenses									215,518	288,883	214,656
Income before federal income taxes and equity in undistributed income of subsidiaries									46,606	(45,289)	34,813
Federal income tax (benefit)									14,687	(17,114)	9,798
Equity in undistributed income (loss) of subsidiaries									7,052	(21,890)	8,206
Net income (loss)	4,676	11,687	4,050	11,506	5,498	(12,971)	(5,504)	(15,198)	31,919	(28,175)	25,015
Condensed Statements of Cash Flows
Net cash provided by operating activities									55,794	54,284	49,483
Investing activities:
Distributions from limited partnerships									3,957	757	297
Net cash provided by (used in) investing activities									(59,302)	17,295	(62,993)
Financing activities:
Dividends paid to shareholders									(14,886)	(14,846)	(33,212)
Drawing on line of credit									0	0	8,000
Net cash used in financing activities									(14,886)	(19,846)	(28,212)
Increase (decrease) in cash and cash equivalents									(18,177)	51,503	(41,281)
Cash and cash equivalents at beginning of period				89,726				38,223	89,726	38,223	79,504
Cash and cash equivalents at end of period	71,549				89,726				71,549	89,726	38,223
Class A [Member]
Shareholders' equity:
Common stock	112				112				112	112
Class B [Member]
Shareholders' equity:
Common stock	524				522				524	522
Parent Company [Member]
Assets
Investment in subsidiaries	362,450				334,328				362,450	334,328
Due from affiliates	2,719				5,282				2,719	5,282
Investments other than subsidiaries:
Fixed maturities	11,073				11,353				11,073	11,353
Limited partnerships	255				291				255	291
Total Investments	11,328				11,644				11,328	11,644
Cash and cash equivalents	12,134				5,690				12,134	5,690	12,546
Accounts receivable	8,033				5,890				8,033	5,890
Other assets	7,225				7,694				7,225	7,694
Total Assets	403,889				370,528				403,889	370,528
Liabilities:
Premiums payable	29,652				26,367				29,652	26,367
Deposits from insureds	15,489				13,682				15,489	13,682
Notes payable to bank	10,000				10,000				10,000	10,000
Current payable federal income taxes	0				368				0	368
Other liabilities	2,036				1,050				2,036	1,050
Total Liabilities	57,177				51,467				57,177	51,467
Shareholders' equity:
Additional paid-in capital	50,275				48,751				50,275	48,751
Unrealized net gains on investments	35,467				26,592				35,467	26,592
Retained earnings	260,334				243,084				260,334	243,084
Shareholders' equity	346,712				319,061				346,712	319,061
Total liabilities and shareholders' equity	403,889				370,528				403,889	370,528
Revenue:
Commissions and service fees									20,753	20,974	21,913
Dividends from subsidiaries									14,000	14,000	15,000
Net investment income									48	100	135
Net realized gains (losses) on investments									(49)	67	(100)
Other									24	98	284
Total revenue									34,776	35,239	37,232
Expenses:
Salary and related items									15,410	12,281	12,869
Other									7,098	5,550	5,615
Total expenses									22,508	17,831	18,484
Income before federal income taxes and equity in undistributed income of subsidiaries									12,268	17,408	18,748
Federal income tax (benefit)									(629)	1,004	1,195
Net income (loss)									12,897	16,404	17,553
Equity in undistributed income (loss) of subsidiaries									19,022	(44,579)	7,462
Net income (loss)									31,919	(28,175)	25,015
Condensed Statements of Cash Flows
Net cash provided by operating activities									20,735	13,255	32,296
Investing activities:
Purchases of long-term investments									(8,944)	(10,025)	(10,889)
Sales or maturities of long-term investments									8,902	9,704	9,910
Decrease in notes receivable from employees									1,252	106	611
Distributions from limited partnerships									0	444	23
Net disposals (purchases) of property and equipment									(834)	(622)	413
Other									228	128	212
Net cash provided by (used in) investing activities									604	(265)	280
Financing activities:
Dividends paid to shareholders									(14,886)	(14,846)	(33,212)
Drawing on line of credit									0	0	8,000
Repayment on line of credit									0	(5,000)	(3,000)
Net cash used in financing activities									(14,886)	(19,846)	(28,212)
Increase (decrease) in cash and cash equivalents									6,453	(6,856)	4,364
Cash and cash equivalents at beginning of period				5,690				12,546	5,690	12,546	8,182
Cash and cash equivalents at end of period	12,134				5,690				12,134	5,690	12,546
Parent Company [Member] | Class A [Member]
Shareholders' equity:
Common stock	112				112				112	112
Parent Company [Member] | Class B [Member]
Shareholders' equity:
Common stock	$ 524				$ 522				$ 524	$ 522