SECURITIES (Schedule of Securities) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Schedule of Securities [Line Items]
Securities—trading, Amortized Cost	$ 27,203	$ 27,203
Securities—trading	25,741	25,896
Available-for-sale Securities, Amortized Cost	1,535,775	1,648,421
Available-for-sale Securities, Gross Unrealized Gains	27,751	7,171
Available-for-sale Securities, Gross Unrealized Losses	(2,517)	(19,369)
Securities—available-for-sale	1,561,009	1,636,223
Held-to-maturity Securities, Amortized Cost	203,222	234,220
Held-to-maturity Securities, Gross Unrealized Gains	4,365	1,807
Held-to-maturity Securities, Gross Unrealized Losses	670	3,490
Securities—held-to-maturity	206,917	232,537
U.S. Government and agency obligations [Member]
Schedule of Securities [Line Items]
Available-for-sale Securities, Amortized Cost	125,597	151,012
Available-for-sale Securities, Gross Unrealized Gains	437	149
Available-for-sale Securities, Gross Unrealized Losses	(966)	(2,049)
Securities—available-for-sale	125,068	149,112
Held-to-maturity Securities, Amortized Cost	388	1,006
Held-to-maturity Securities, Gross Unrealized Gains	6	14
Held-to-maturity Securities, Gross Unrealized Losses	0	1
Securities—held-to-maturity	394	1,019
Municipal bonds [Member]
Schedule of Securities [Line Items]
Available-for-sale Securities, Amortized Cost	106,379	116,548
Available-for-sale Securities, Gross Unrealized Gains	4,549	1,806
Available-for-sale Securities, Gross Unrealized Losses	(18)	(532)
Securities—available-for-sale	110,910	117,822
Held-to-maturity Securities, Amortized Cost	148,580	176,663
Held-to-maturity Securities, Gross Unrealized Gains	3,538	1,727
Held-to-maturity Securities, Gross Unrealized Losses	629	2,578
Securities—held-to-maturity	151,489	175,812
Corporate bonds [Member]
Schedule of Securities [Line Items]
Securities—trading, Amortized Cost	27,203	27,203
Securities—trading	25,741	25,896
Available-for-sale Securities, Amortized Cost	4,557	3,556
Available-for-sale Securities, Gross Unrealized Gains	12	0
Available-for-sale Securities, Gross Unrealized Losses	(8)	(61)
Securities—available-for-sale	4,561	3,495
Held-to-maturity Securities, Amortized Cost	3,668	3,736
Held-to-maturity Securities, Gross Unrealized Gains	0	0
Held-to-maturity Securities, Gross Unrealized Losses	12	13
Securities—held-to-maturity	3,656	3,723
Mortgage-backed or related securities [Member]
Schedule of Securities [Line Items]
Available-for-sale Securities, Amortized Cost	1,291,166	1,355,258
Available-for-sale Securities, Gross Unrealized Gains	22,751	5,210
Available-for-sale Securities, Gross Unrealized Losses	(1,484)	(16,607)
Securities—available-for-sale	1,312,433	1,343,861
Held-to-maturity Securities, Amortized Cost	50,586	52,815
Held-to-maturity Securities, Gross Unrealized Gains	821	66
Held-to-maturity Securities, Gross Unrealized Losses	29	898
Securities—held-to-maturity	51,378	51,983
Asset-backed Securities [Member]
Schedule of Securities [Line Items]
Available-for-sale Securities, Amortized Cost	8,076	22,047
Available-for-sale Securities, Gross Unrealized Gains	2	6
Available-for-sale Securities, Gross Unrealized Losses	(41)	(120)
Securities—available-for-sale	$ 8,037	$ 21,933

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

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Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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-Publisher FASB
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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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Amount of accumulated unrecognized gain on investment in debt security measured at amortized cost (held-to-maturity).

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Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity).

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Amount, before other-than-temporary impairment (OTTI) accretion, of investment in debt securities measured at amortized cost (held-to-maturity).

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Fair value of investment in debt security measured at amortized cost (held-to-maturity).

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of investment in debt security measured at fair value with change in fair value recognized in net income (trading) and investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Cost of investments in debt and equity securities and other forms of securities that provide ownership interests classified as trading.

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