Comprehensive Income (Loss) (Components Of Accumulated Other Comprehensive Income (Loss), Net Of Tax, In The Consolidated Balance Sheets) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Comprehensive Income (Loss) [Abstract]
Beginning balance of URA (D) on securities	$ 369,438	$ 309,274
Current period change in URA (D) of investments - temporary	79,251	58,709
Current period change in URA (D) of investments - non-credit OTTI	890	1,455
Ending balance of URA (D) on securities	449,579	369,438
Beginning balance of foreign currency translation adjustments	(11,097)	(12,968)
Current period change in foreign currency translation adjustments	(15,969)	1,871
Ending balance of foreign currency translation adjustments	(27,066)	(11,097)
Beginning balance of pension	(26,083)	(24,268)
Current period change in pension	(29,452)	(1,815)
Ending balance of pension	(55,535)	(26,083)
Ending balance of accumulated other comprehensive income (loss)	$ 366,978	$ 332,258