Investment Securities (Gains And Losses, Including OTTI, Recognized In Statement Of Income) (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
Investments [Abstract]
Investment securities, Held-to-maturity, Gross gains	$ 22	$ 85	$ 120	$ 202
Investment securities Held-to-maturity, Gross losses	657	769	998	769
Investment securities, Available-for-sale, Gross gains	3,026	12,950	14,955	20,532
Investment securities, Available-for-sale, Gross losses	2,081	12,565	25,045	30,982
Other noninterest-bearing investments, Nonmarketable equity securities, Gross gains	3,230	5,482	22,951	6,550
Other noninterest-bearing investments, Nonmarketable equity securities, Gross losses	547	193	11,016	2,000
Total investment securities and other noninterest-bearing investments, Gross gains	6,278	18,517	38,026	27,284
Total investment securities and other noninterest-bearing investments, Gross losses	3,285	13,527	37,059	33,751
Net losses	2,993	4,990	967	(6,467)
Net impairment losses on investment securities	(2,736)	(13,334)	(20,253)	(21,597)
Equity securities gains (losses)	2,683	5,289	11,935	4,550
Fixed income securities gains (losses), net	$ 3,046	$ 13,035	$ 9,285	$ 10,580