Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Operating Activities
Net income	$ 8,851	$ 9,561
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	322	262
Net amortization of investments	2,928	2,517
Deferred income taxes	(885)	189
Net realized gains on investments	(24)	(1,791)
Share-based compensation	290	108
Changes in operating assets and liabilities:
Premiums receivable, net	(25,197)	(17,143)
Accrued interest receivable	87	(820)
Deferred policy acquisition costs	(1,619)	(1,097)
Other assets and federal income tax recoverable	(860)	1,244
Reserves for loss and loss adjustment expenses	7,538	10,745
Unearned premiums	14,932	11,230
Reinsurance balances	2,675	(4,502)
Amounts held for others and policyholder deposits	3,124	2,660
Accounts payable and other liabilities	9,615	4,916
Net cash provided by operating activities	21,777	18,079
Investing Activities
Purchases of investments held-to-maturity	(26,454)	(42,941)
Purchases of investments available-for-sale	(43,263)	(15,212)
Purchases of short-term investments	(47,603)	(15,215)
Proceeds from maturities of investments held-to-maturity	34,411	38,138
Proceeds from sales and maturities of investments available-for-sale	2,528	23,233
Proceeds from sales and maturities of short-term investments	41,338	12,247
Purchases of property and equipment	(144)	(90)
Net cash provided by/(used in) investing activities	(39,187)	160
Financing Activities
Proceeds from stock option exercises	855
Tax benefit from share-based payments	642
Dividends to stockholders	(1,469)
Net cash provided by financing activities	28
Change in cash and cash equivalents	(17,382)	18,239
Cash and cash equivalents at beginning of period	92,676	45,536
Cash and cash equivalents at end of period	$ 75,294	$ 63,775