Investment Securities (Held To Maturity Securities Age Of Unrealized Losses And Fair Value Of Related Securities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Schedule of Held-to-maturity Securities [Line Items]
Less than Twelve Months, Fair Value	$ 85,657	$ 428,684
Less than Twelve Months, Unrealized Losses	(1,087)	(7,720)
More than Twelve Months, Fair Value	63,222	84,288
More than Twelve Months, Unrealized Losses	(23,552)	(59,328)
Total, Fair Value	148,879	512,972
Total, Unrealized Losses	(24,639)	(67,048)
U.S. Treasury Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Less than Twelve Months, Fair Value		57,027
Less than Twelve Months, Unrealized Losses		(909)
Total, Fair Value		57,027
Total, Unrealized Losses		(909)
Obligations Of States And Political Subdivisions [Member]
Schedule of Held-to-maturity Securities [Line Items]
Less than Twelve Months, Fair Value	1,854	123,399
Less than Twelve Months, Unrealized Losses	(13)	(3,467)
More than Twelve Months, Fair Value	50	50
More than Twelve Months, Unrealized Losses	(1)
Total, Fair Value	1,904	123,449
Total, Unrealized Losses	(14)	(3,467)
Residential Mortgage-Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Less than Twelve Months, Fair Value	33,520	226,135
Less than Twelve Months, Unrealized Losses	(152)	(3,081)
Total, Fair Value	33,520	226,135
Total, Unrealized Losses	(152)	(3,081)
Trust Preferred Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Less than Twelve Months, Fair Value	35,527	14,152
Less than Twelve Months, Unrealized Losses	(730)	(250)
More than Twelve Months, Fair Value	55,612	75,477
More than Twelve Months, Unrealized Losses	(22,137)	(59,115)
Total, Fair Value	91,139	89,629
Total, Unrealized Losses	(22,867)	(59,365)
Corporate And Other Debt Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Less than Twelve Months, Fair Value	14,756	7,971
Less than Twelve Months, Unrealized Losses	(192)	(13)
More than Twelve Months, Fair Value	7,560	8,761
More than Twelve Months, Unrealized Losses	(1,414)	(213)
Total, Fair Value	22,316	16,732
Total, Unrealized Losses	$ (1,606)	$ (226)