Income Taxes (Deferred Tax Assets And Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Income Taxes [Abstract]
Percentage of net unearned premium	20.00%
Net unearned premium	$ 61,039	$ 60,473
Capital loss carryforward	7,108	14,718
Discounting of loss reserves and salvage and subrogation recoverable for tax purposes	15,034	15,843
Write-down of impaired investments	4,638	5,389
Tax credit carryforward	20,060	16,679
Expense accruals	11,632	14,467
Other deferred tax assets	3,568	4,337
Total gross deferred tax assets	123,079	131,906
Deferred acquisition costs	(60,000)	(59,702)
Tax liability on net unrealized gain on securities carried at fair value	(31,997)	(18,808)
Tax depreciation in excess of book depreciation	(15,164)	(16,839)
Undistributed earnings of insurance subsidiaries	(3,962)	(4,447)
Accounting method transition adjustments	0	(112)
Tax amortization in excess of book amortization	(442)	(24)
Other deferred tax liabilities	(5,003)	(5,475)
Total gross deferred tax liabilities	(116,568)	(105,407)
Net deferred tax assets	$ 6,511	$ 26,499