Investment Securities (Schedule Of Investment Securities) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Schedule of Investments [Line Items]
Securities Available-for-Sale, Amortized Cost	$ 1,206,219	$ 1,222,143
Securities Available-for-Sale, Gross Unrealized Holdings Gains	15,160	9,609
Securities Available-for-Sale, Gross Unrealized Holding Losses	24,084	55,486
Securities Available-for-Sale, Total Fair value	1,197,295	1,176,266
Securities Held-to-Maturity, Amortized Cost	162,304	182,061
Securities Held-to-Maturity, Gross Unrecognized Holding Gains	3,738	5,383
Securities Held-to-Maturity, Gross Unrecognized Holding Losses	256	42
Securities Held-to-Maturity, Estimated Fair Value	165,786	187,402
Obligations Of U.S. Treasury And Other U.S. Government Sponsored Entities [Member]
Schedule of Investments [Line Items]
Securities Available-for-Sale, Amortized Cost	570,634	570,632
Securities Available-for-Sale, Gross Unrealized Holdings Gains
Securities Available-for-Sale, Gross Unrealized Holding Losses	18,698	45,496
Securities Available-for-Sale, Total Fair value	551,936	525,136
Obligations Of States And Political Subdivisions [Member]
Schedule of Investments [Line Items]
Securities Held-to-Maturity, Amortized Cost	85	240
Securities Held-to-Maturity, Gross Unrecognized Holding Gains		1
Securities Held-to-Maturity, Gross Unrecognized Holding Losses
Securities Held-to-Maturity, Estimated Fair Value	85	241
U.S. Government Sponsored Entities Asset-Backed Securities [Member]
Schedule of Investments [Line Items]
Securities Available-for-Sale, Amortized Cost	634,465	650,391
Securities Available-for-Sale, Gross Unrealized Holdings Gains	13,631	8,070
Securities Available-for-Sale, Gross Unrealized Holding Losses	5,386	9,990
Securities Available-for-Sale, Total Fair value	642,710	648,471
Securities Held-to-Maturity, Amortized Cost	162,219	181,821
Securities Held-to-Maturity, Gross Unrecognized Holding Gains	3,738	5,382
Securities Held-to-Maturity, Gross Unrecognized Holding Losses	256	42
Securities Held-to-Maturity, Estimated Fair Value	165,701	187,161
Other Equity Securities [Member]
Schedule of Investments [Line Items]
Securities Available-for-Sale, Amortized Cost	1,120	1,120
Securities Available-for-Sale, Gross Unrealized Holdings Gains	1,529	1,539
Securities Available-for-Sale, Gross Unrealized Holding Losses
Securities Available-for-Sale, Total Fair value	$ 2,649	$ 2,659