Income Taxes (Deferred Tax Assets And Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Deferred tax assets:
20% of net unearned premium	$ 68,586	$ 66,353
Discounting of loss reserves and salvage and subrogation recoverable for tax purposes	12,810	15,019
Write-down of impaired investments	1,714	1,723
Tax credit carryforward	40,309	37,557
Expense accruals	12,497	10,910
Other deferred tax assets	5,653	4,860
Total gross deferred tax assets	141,569	136,422
Deferred tax liabilities:
Deferred acquisition costs	(68,063)	(65,069)
Tax liability on net unrealized gain on securities carried at fair value	(33,964)	(48,483)
Tax depreciation in excess of book depreciation	(9,667)	(10,191)
Undistributed earnings of insurance subsidiaries	(4,024)	(4,499)
Tax amortization in excess of book amortization	(1,447)	(914)
Other deferred tax liabilities	(9,184)	(7,711)
Total gross deferred tax liabilities	(126,349)	(136,867)
Net deferred tax assets (liabilities)	$ 15,220	$ (445)