Investments (Summary Of Changes In Net Unrealized Appreciation (Depreciation) For The Company's Investments) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Increase (Decrease) During The Period Between The Market Value And Cost Of Investments Carried At Market Value, And Deferred Taxes Thereon:
Change in unrealized appreciation (depreciation), pre-tax	$ 28,149	$ 11,988	$ 38,780	$ 49,693
Deferred tax benefit (expense)	(9,879)	(4,243)	(13,624)	(17,438)
Deferred tax benefit (expense), other-than-temporary impairment	27	48	51	46
Change in unrealized appreciation (depreciation), net of deferred taxes, included in stockholder's equity	18,297	7,793	25,207	32,301
Fixed Maturity Securities [Member]
Increase (Decrease) During The Period Between The Market Value And Cost Of Investments Carried At Market Value, And Deferred Taxes Thereon:
Change in unrealized appreciation (depreciation), pre-tax	28,226	11,911	38,923	51,341
Fixed Maturity Securities, Other-Than-Temporary Impairment [Member]
Increase (Decrease) During The Period Between The Market Value And Cost Of Investments Carried At Market Value, And Deferred Taxes Thereon:
Change in unrealized appreciation (depreciation), pre-tax	(77)	(137)	(146)	(132)
Equity Securities [Member]
Increase (Decrease) During The Period Between The Market Value And Cost Of Investments Carried At Market Value, And Deferred Taxes Thereon:
Change in unrealized appreciation (depreciation), pre-tax		(1)	3	(1)
Other Invested Assets [Member]
Increase (Decrease) During The Period Between The Market Value And Cost Of Investments Carried At Market Value, And Deferred Taxes Thereon:
Change in unrealized appreciation (depreciation), pre-tax		$ 215		$ (1,515)