SECURITIES (Securities with Continuous Loss Position) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Available-for-Sale:
Less than 12 Months, Fair Value	$ 518,373	$ 637,744
Less than 12 Months, Unrealized Losses	(7,283)	(5,270)
12 Months or More, Fair Value	68,099	89,748
12 Months or More, Unrealized Losses	(888)	(1,085)
Total Fair Value	586,472	727,492
Total Unrealized Losses	(8,171)	(6,355)
Held-to-Maturity:
Less Than 12 Months, Fair Value	108,094	63,038
Less Than 12 Months, Unrealized Losses	(1,822)	(511)
12 Months or More, Fair Value	204	509
12 Months or More, Unrealized Losses	(5)	(5)
Total Fair Value	108,298	63,547
Total Unrealized Losses	(1,827)	(516)
U.S. Government and agency obligations
Available-for-Sale:
Less than 12 Months, Fair Value	39,043	8,707
Less than 12 Months, Unrealized Losses	(442)	(97)
12 Months or More, Fair Value	1,012	10,489
12 Months or More, Unrealized Losses	(14)	(96)
Total Fair Value	40,055	19,196
Total Unrealized Losses	(456)	(193)
Held-to-Maturity:
Less Than 12 Months, Fair Value	1,047
Less Than 12 Months, Unrealized Losses	(18)
12 Months or More, Fair Value	0
12 Months or More, Unrealized Losses	0
Total Fair Value	1,047
Total Unrealized Losses	(18)
Municipal bonds
Available-for-Sale:
Less than 12 Months, Fair Value	60,765	69,848
Less than 12 Months, Unrealized Losses	(1,087)	(426)
12 Months or More, Fair Value	556	905
12 Months or More, Unrealized Losses	(2)	(6)
Total Fair Value	61,321	70,753
Total Unrealized Losses	(1,089)	(432)
Held-to-Maturity:
Less Than 12 Months, Fair Value	64,802	28,545
Less Than 12 Months, Unrealized Losses	(1,267)	(188)
12 Months or More, Fair Value	204	254
12 Months or More, Unrealized Losses	(5)	(3)
Total Fair Value	65,006	28,799
Total Unrealized Losses	(1,272)	(191)
Corporate bonds
Available-for-Sale:
Less than 12 Months, Fair Value	5,206	5,153
Less than 12 Months, Unrealized Losses	(49)	(12)
12 Months or More, Fair Value	0	0
12 Months or More, Unrealized Losses	0	0
Total Fair Value	5,206	5,153
Total Unrealized Losses	(49)	(12)
Mortgage-backed or related securities
Available-for-Sale:
Less than 12 Months, Fair Value	403,431	533,143
Less than 12 Months, Unrealized Losses	(5,604)	(4,380)
12 Months or More, Fair Value	47,467	68,562
12 Months or More, Unrealized Losses	(647)	(735)
Total Fair Value	450,898	601,705
Total Unrealized Losses	(6,251)	(5,115)
Held-to-Maturity:
Less Than 12 Months, Fair Value	42,245	34,493
Less Than 12 Months, Unrealized Losses	(537)	(323)
12 Months or More, Fair Value	0	255
12 Months or More, Unrealized Losses	0	(2)
Total Fair Value	42,245	34,748
Total Unrealized Losses	(537)	(325)
Asset-backed securities
Available-for-Sale:
Less than 12 Months, Fair Value	9,928	20,893
Less than 12 Months, Unrealized Losses	(101)	(355)
12 Months or More, Fair Value	19,064	9,792
12 Months or More, Unrealized Losses	(225)	(248)
Total Fair Value	28,992	30,685
Total Unrealized Losses	$ (326)	$ (603)