SECURITIES (Temporarily Impaired Available-For-Sale Securities With Continuous Unrealized Loss Positions) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Fair Value	$ 253,756	$ 1,004,003
12 Months or Longer, Fair Value	16,854	34,022
Total, Fair Value	270,610	1,038,025
Less Than 12 Months, Unrealized Losses	3,135	5,403
12 Months or Longer, Unrealized Losses	62	568
Total, Unrealized Losses	3,197	5,971
US Government Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Fair Value		762,568
Total, Fair Value		762,568
Less Than 12 Months, Unrealized Losses		2,447
Total, Unrealized Losses		2,447
U.S. Government Agency Issued Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Fair Value	11,480	34,238
12 Months or Longer, Fair Value	16,211
Total, Fair Value	27,691	34,238
Less Than 12 Months, Unrealized Losses	38	176
12 Months or Longer, Unrealized Losses	61
Total, Unrealized Losses	99	176
U.S. Government Agency Issued Commercial Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Fair Value	23,943	193,621
12 Months or Longer, Fair Value	643	31,166
Total, Fair Value	24,586	224,787
Less Than 12 Months, Unrealized Losses	81	2,710
12 Months or Longer, Unrealized Losses	1	555
Total, Unrealized Losses	82	3,265
Obligations Of States And Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Fair Value	9,171	13,576
12 Months or Longer, Fair Value		2,856
Total, Fair Value	9,171	16,432
Less Than 12 Months, Unrealized Losses	2,915	70
12 Months or Longer, Unrealized Losses		13
Total, Unrealized Losses	$ 2,915	$ 83