Available-For-Sale And Held-To-Maturity Securities (Schedule Of Gross Unrealized Losses And The Estimated Fair Value By Length Of Time In A Loss Position) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2016 USD ($)
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available-for-sale Securities, Gross unrealized losses, Less than 12 months	$ (6,639)
Available-for-sale Securities, Estimated fair value, Less than 12 months	667,209
Available-for-sale Securities, Gross unrealized losses, 12 months or more	(3,612)
Available-for-sale Securities, Estimated fair value, 12 months or more	137,474
Available-for-sale Securities, Gross unrealized losses, Total	(10,251)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	804,683
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	(1,074)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	111,822
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	(1,195)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	68,450
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss, Total	(2,269)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value, Total	180,272
U.S. Government Agency Securities [Member]
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available-for-sale Securities, Gross unrealized losses, Less than 12 months	(1)
Available-for-sale Securities, Estimated fair value, Less than 12 months	226
Available-for-sale Securities, Gross unrealized losses, Total	(1)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	226
State And Municipal Securities [Member]
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available-for-sale Securities, Gross unrealized losses, 12 months or more	(1,148)
Available-for-sale Securities, Estimated fair value, 12 months or more	62,491
Available-for-sale Securities, Gross unrealized losses, Total	(1,148)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	62,491
Corporate Fixed Income Securities [Member]
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available-for-sale Securities, Gross unrealized losses, Less than 12 months	(8)
Available-for-sale Securities, Estimated fair value, Less than 12 months	1,493
Available-for-sale Securities, Gross unrealized losses, Total	(8)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	1,493
Asset-Backed Securities [Member]
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available-for-sale Securities, Gross unrealized losses, Less than 12 months	(4,896)
Available-for-sale Securities, Estimated fair value, Less than 12 months	452,928
Available-for-sale Securities, Gross unrealized losses, 12 months or more	(2,215)
Available-for-sale Securities, Estimated fair value, 12 months or more	64,717
Available-for-sale Securities, Gross unrealized losses, Total	(7,111)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	517,645
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	(1,074)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	111,822
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	(1,172)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	65,903
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss, Total	(2,246)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value, Total	177,725
Mortgage Backed Securities [Member] | Agency [Member]
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available-for-sale Securities, Gross unrealized losses, Less than 12 months	(1,734)
Available-for-sale Securities, Estimated fair value, Less than 12 months	212,562
Available-for-sale Securities, Gross unrealized losses, 12 months or more	(84)
Available-for-sale Securities, Estimated fair value, 12 months or more	8,185
Available-for-sale Securities, Gross unrealized losses, Total	(1,818)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	220,747
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	(8)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	1,789
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss, Total	(8)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value, Total	1,789
Mortgage Backed Securities [Member] | Non-Agency [Member]
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available-for-sale Securities, Gross unrealized losses, 12 months or more	(165)
Available-for-sale Securities, Estimated fair value, 12 months or more	2,081
Available-for-sale Securities, Gross unrealized losses, Total	(165)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	2,081
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	(15)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	758
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss, Total	(15)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value, Total	$ 758