SECURITIES (Schedule of Securities) (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Schedule of Securities [Line Items]
Securities—trading, Amortized Cost	$ 27,303	$ 27,246
Securities—trading	25,640	22,318
Available-for-sale Securities, Amortized Cost	1,429,925	926,112
Available-for-sale Securities, Gross Unrealized Gains	431	1,936
Available-for-sale Securities, Gross Unrealized Losses	(30,044)	(8,563)
Securities—available-for-sale	1,400,312	919,485
Held-to-maturity Securities, Amortized Cost	263,176	260,271
Held-to-maturity Securities, Gross Unrealized Gains	2,133	3,687
Held-to-maturity Securities, Gross Unrealized Losses	4,991	1,770
Securities—held-to-maturity	260,318	262,188
U.S. Government and agency obligations [Member]
Schedule of Securities [Line Items]
Available-for-sale Securities, Amortized Cost	143,733	72,829
Available-for-sale Securities, Gross Unrealized Gains	12	68
Available-for-sale Securities, Gross Unrealized Losses	(2,720)	(431)
Securities—available-for-sale	141,025	72,466
Held-to-maturity Securities, Amortized Cost	1,152	1,024
Held-to-maturity Securities, Gross Unrealized Gains	28	29
Held-to-maturity Securities, Gross Unrealized Losses	3	0
Securities—held-to-maturity	1,177	1,053
Municipal bonds [Member]
Schedule of Securities [Line Items]
Securities—trading, Amortized Cost	100	100
Securities—trading	100	100
Available-for-sale Securities, Amortized Cost	65,563	68,513
Available-for-sale Securities, Gross Unrealized Gains	242	665
Available-for-sale Securities, Gross Unrealized Losses	(761)	(445)
Securities—available-for-sale	65,044	68,733
Held-to-maturity Securities, Amortized Cost	194,431	189,860
Held-to-maturity Securities, Gross Unrealized Gains	2,105	3,385
Held-to-maturity Securities, Gross Unrealized Losses	3,115	1,252
Securities—held-to-maturity	193,421	191,993
Corporate bonds [Member]
Schedule of Securities [Line Items]
Securities—trading, Amortized Cost	27,203	27,132
Securities—trading	25,540	22,058
Available-for-sale Securities, Amortized Cost	5,053	5,431
Available-for-sale Securities, Gross Unrealized Gains	5	6
Available-for-sale Securities, Gross Unrealized Losses	(20)	(44)
Securities—available-for-sale	5,038	5,393
Held-to-maturity Securities, Amortized Cost	3,805	3,978
Held-to-maturity Securities, Gross Unrealized Gains	0	7
Held-to-maturity Securities, Gross Unrealized Losses	10	0
Securities—held-to-maturity	3,795	3,985
Mortgage-backed or related securities [Member]
Schedule of Securities [Line Items]
Available-for-sale Securities, Amortized Cost	1,188,772	745,956
Available-for-sale Securities, Gross Unrealized Gains	51	1,003
Available-for-sale Securities, Gross Unrealized Losses	(26,403)	(7,402)
Securities—available-for-sale	1,162,420	739,557
Held-to-maturity Securities, Amortized Cost	63,788	65,409
Held-to-maturity Securities, Gross Unrealized Gains	0	266
Held-to-maturity Securities, Gross Unrealized Losses	1,863	518
Securities—held-to-maturity	61,925	65,157
Asset-backed Securities [Member]
Schedule of Securities [Line Items]
Available-for-sale Securities, Amortized Cost	26,804	27,667
Available-for-sale Securities, Gross Unrealized Gains	121	184
Available-for-sale Securities, Gross Unrealized Losses	(140)	(93)
Securities—available-for-sale	$ 26,785	27,758
Equity Securities [Member]
Schedule of Securities [Line Items]
Securities—trading, Amortized Cost		14
Securities—trading		160
Available-for-sale Securities, Amortized Cost		5,716
Available-for-sale Securities, Gross Unrealized Gains		10
Available-for-sale Securities, Gross Unrealized Losses		(148)
Securities—available-for-sale		$ 5,578

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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