SECURITIES - Held to Maturity Investment Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Amortized Cost, Held to maturity:
Within one year	$ 8,827
One to five years	28,070
Five to ten years	23,752
Beyond ten years	72,989
Total	133,638	$ 160,163
Estimated Fair Value, Held to maturity:
Within one year	8,838
One to five years	28,593
Five to ten years	24,063
Beyond ten years	73,533
Estimated Fair Value	135,027	156,792
State and municipal obligations
Amortized Cost, Held to maturity:
Within one year	8,827
One to five years	22,902
Five to ten years	9,129
Beyond ten years	150
Total	41,008	53,540
Estimated Fair Value, Held to maturity:
Within one year	8,838
One to five years	23,382
Five to ten years	9,444
Beyond ten years	153
Estimated Fair Value	41,817	53,554
U.S. GSE residential mortgage-backed securities
Amortized Cost, Held to maturity:
Within one year	0
One to five years	0
Five to ten years	5,947
Beyond ten years	2,195
Total	8,142	9,688
Estimated Fair Value, Held to maturity:
Within one year	0
One to five years	0
Five to ten years	5,919
Beyond ten years	2,174
Estimated Fair Value	8,093	9,352
U.S. GSE residential collateralized mortgage obligations
Amortized Cost, Held to maturity:
Within one year	0
One to five years	0
Five to ten years	3,871
Beyond ten years	36,065
Total	39,936	48,244
Estimated Fair Value, Held to maturity:
Within one year	0
One to five years	0
Five to ten years	3,865
Beyond ten years	36,633
Estimated Fair Value	40,498	47,277
U.S. GSE commercial mortgage-backed securities
Amortized Cost, Held to maturity:
Within one year	0
One to five years	4,776
Five to ten years	4,805
Beyond ten years	7,634
Total	17,215	19,098
Estimated Fair Value, Held to maturity:
Within one year	0
One to five years	4,824
Five to ten years	4,835
Beyond ten years	7,576
Estimated Fair Value	17,235	18,482
U.S. GSE commercial collateralized mortgage obligations
Amortized Cost, Held to maturity:
Within one year	0
One to five years	392
Five to ten years	0
Beyond ten years	26,945
Total	27,337	29,593
Estimated Fair Value, Held to maturity:
Within one year	0
One to five years	387
Five to ten years	0
Beyond ten years	26,997
Estimated Fair Value	$ 27,384	$ 28,127

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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118954083&loc=d3e26610-111562

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27232-111563

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Fair value of investment in debt security measured at amortized cost (held-to-maturity), with single maturity date and allocated without single maturity date, maturing in next rolling fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27232-111563

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