SECURITIES (Securities with Continuous Loss Position) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Schedule of Held-to-maturity Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 646,930	$ 518,373
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(6,256)	(7,283)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	60,419	68,099
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(834)	(888)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	707,349	586,472
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(7,090)	(8,171)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	87,607	108,094
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	1,669	1,822
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	203	204
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(4)	(5)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	87,810	108,298
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss	1,673	1,827
U.S. Government and agency obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	38,922	39,043
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(398)	(442)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	821	1,012
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(9)	(14)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	39,743	40,055
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(407)	(456)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	1,044	1,047
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	11	18
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	0	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	1,044	1,047
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss	11	18
Municipal bonds [Member]
Schedule of Held-to-maturity Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	51,717	60,765
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(790)	(1,087)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	301	556
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(1)	(2)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	52,018	61,321
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(791)	(1,089)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	48,692	64,802
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	1,169	1,267
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	203	204
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(4)	(5)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	48,895	65,006
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss	1,173	1,272
Corporate bonds [Member]
Schedule of Held-to-maturity Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	0	5,206
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	(49)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	5,076	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(47)	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	5,076	5,206
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(47)	(49)
Mortgage-backed or related securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	546,336	403,431
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(4,996)	(5,604)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	54,221	47,467
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(777)	(647)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	600,557	450,898
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(5,773)	(6,251)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	37,871	42,245
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	489	537
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	0	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	37,871	42,245
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss	489	537
Asset-backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	9,955	9,928
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(72)	(101)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	0	19,064
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	(225)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	9,955	28,992
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ (72)	$ (326)