Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Operating Activities
Net income	$ 17,888	$ 26,059
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	778	772
Net amortization of investments	4,559	3,623
Deferred income taxes	2,127	(4,317)
Net realized gains on investments	(760)	(2,284)
Share-based compensation	361	872
Changes in operating assets and liabilities:
Premiums receivable, net	(10,465)	8,346
Accrued interest receivable	(1,511)	(1,271)
Deferred policy acquisition costs and deferred charges	(2,896)	(815)
Other assets and federal income tax recoverable	(3,105)	4,388
Reserves for loss and loss adjustment expenses	45	6,664
Unearned premiums	14,681	(747)
Reinsurance balances	1,634	(15,011)
Amounts held for others and policyholder deposits	3,303	3,218
Accounts payable and other liabilities	3,133	(9,035)
Net cash provided by operating activities	29,772	20,462
Investing Activities
Purchases of investments held-to-maturity	(59,697)	(56,791)
Purchases of investments available-for-sale	(76,551)	(21,663)
Purchases of short-term investments	(64,623)	(62,047)
Proceeds from maturities of investments held-to-maturity	76,513	44,452
Proceeds from sales and maturities of investments available-for-sale	23,554	25,831
Proceeds from sales and maturities of short-term investments	96,961	52,514
Purchases of property and equipment	(683)	(2,302)
Net cash used in investing activities	(4,526)	(20,006)
Financing Activities
Proceeds from stock option exercises	1,993	1,335
Tax benefit from share-based payments	701	210
Treasury shares purchased	(9,656)	(10,373)
Redemption of subordinated debt security	(10,310)
Net cash used in financing activities	(17,272)	(8,828)
Change in cash and cash equivalents	7,974	(8,372)
Cash and cash equivalents at beginning of period	60,966	63,188
Cash and cash equivalents at end of period	$ 68,940	$ 54,816