Investment Securities (Schedule Of Fair Value And Unrealized Losses Of Securities) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Investment Holdings [Line Items]
Available-for-sale Securities, Less than 12 Months, Fair Value	$ 372,520	$ 231,677
Available-for-sale Securities, Less than 12 Months, Unrealized Losses	1,676	1,362
Available-for-sale Securities, 12 Months or Longer, Fair Value	366,386	503,646
Available-for-sale Securities, 12 Months or Longer, Unrealized Losses	6,273	10,539
Available-for-sale Securities, Fair Value	738,906	735,323
Available-for-sale Securities, Unrealized Losses	7,949	11,901
Held-to-maturity Securities, Less than 12 Months, Fair Value	38	224
Held-to-maturity Securities, Less than 12 Months, Unrealized Losses	2	15
Held-to-maturity Securities, 12 Months or Longer, Fair Value	0	0
Held-to-maturity Securities, 12 Months or Longer, Unrealized Losses	0	0
Held-to-maturity Securities, Fair Value	38	224
Held-to-maturity Securities, Unrealized Losses	2	15
Obligations Of States And Political Subdivisions [Member]
Investment Holdings [Line Items]
Available-for-sale Securities, Less than 12 Months, Fair Value	4,169	11,100
Available-for-sale Securities, Less than 12 Months, Unrealized Losses	434	547
Available-for-sale Securities, 12 Months or Longer, Fair Value	6,176	8,550
Available-for-sale Securities, 12 Months or Longer, Unrealized Losses	106	294
Available-for-sale Securities, Fair Value	10,345	19,650
Available-for-sale Securities, Unrealized Losses	540	841
Residential Mortgage-Backed Securities And Collateralized Mortgage Obligations [Member]
Investment Holdings [Line Items]
Available-for-sale Securities, Less than 12 Months, Fair Value	368,351	220,577
Available-for-sale Securities, Less than 12 Months, Unrealized Losses	1,242	815
Available-for-sale Securities, 12 Months or Longer, Fair Value	360,210	495,096
Available-for-sale Securities, 12 Months or Longer, Unrealized Losses	6,167	10,245
Available-for-sale Securities, Fair Value	728,561	715,673
Available-for-sale Securities, Unrealized Losses	7,409	11,060
Held-to-maturity Securities, Less than 12 Months, Fair Value	38	224
Held-to-maturity Securities, Less than 12 Months, Unrealized Losses	2	15
Held-to-maturity Securities, 12 Months or Longer, Fair Value	0	0
Held-to-maturity Securities, 12 Months or Longer, Unrealized Losses	0	0
Held-to-maturity Securities, Fair Value	38	224
Held-to-maturity Securities, Unrealized Losses	$ 2	$ 15

Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for twelve months or longer.

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