Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Operating Activities
Net income	$ 9,561	$ 6,630
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	262	266
Net amortization of investments	2,517	1,332
Deferred income taxes	189	(1,273)
Net realized gains on investments	(1,791)	(103)
Share-based compensation	108	131
Changes in operating assets and liabilities:
Premiums receivable, net	(17,143)	(10,682)
Accrued interest receivable	(820)	(1,084)
Deferred policy acquisition costs and deferred charges	(1,365)	(1,016)
Other assets and federal income tax recoverable	1,244	892
Reserves for loss and loss adjustment expenses	10,745	(62)
Unearned premiums	11,230	7,688
Reinsurance balances	(4,502)	306
Amounts held for others and policyholder deposits	2,660	(150)
Accounts payable and other liabilities	5,184	(2,421)
Net cash provided by operating activities	18,079	454
Investing Activities
Purchases of investments held-to-maturity	(42,941)	(25,660)
Purchases of investments available-for-sale	(15,212)	(21,390)
Purchases of short-term investments	(15,215)	(24,500)
Proceeds from maturities of investments held-to-maturity	38,138	29,588
Proceeds from sales and maturities of investments available-for-sale	23,233	1,023
Proceeds from sales and maturities of short-term investments	12,247	33,091
Purchases of property and equipment	(90)	(48)
Net cash provided by/(used in) investing activities	160	(7,896)
Financing Activities
Proceeds from stock option exercises		1,156
Tax benefit from share-based payments		381
Treasury shares purchased		(2,859)
Net cash used in financing activities		(1,322)
Change in cash and cash equivalents	18,239	(8,764)
Cash and cash equivalents at beginning of period	45,536	60,966
Cash and cash equivalents at end of period	$ 63,775	$ 52,202