GOODWILL, CORE DEPOSIT PREMIUM AND OTHER INTANGIBLE ASSETS (Estimated future amortization expense for amortizable intangible assets) (Details) $ in Thousands	Mar. 31, 2019 USD ($)
Future amortization expense for amortizable intangible assets [Line Items]
Nine months ending December 31, 2019	$ 8,023
Year ending December 31,
2020	10,028
2021	8,590
2022	6,937
2023	5,944
2024	4,740
Thereafter	8,330
Total	52,592
Core Deposit Intangibles
Future amortization expense for amortizable intangible assets [Line Items]
Nine months ending December 31, 2019	6,949
Year ending December 31,
2020	8,230
2021	7,036
2022	5,634
2023	4,933
2024	4,008
Thereafter	7,614
Total	44,404
Customer Relationship Intangibles
Future amortization expense for amortizable intangible assets [Line Items]
Nine months ending December 31, 2019	28
Year ending December 31,
2020	36
2021	35
2022	35
2023	34
2024	33
Thereafter	32
Total	233
Mortgage Servicing Rights
Future amortization expense for amortizable intangible assets [Line Items]
Nine months ending December 31, 2019	736
Year ending December 31,
2020	1,431
2021	1,226
2022	1,022
2023	818
2024	613
Thereafter	613
Total	6,459
Commercial Servicing Rights
Future amortization expense for amortizable intangible assets [Line Items]
Nine months ending December 31, 2019	310
Year ending December 31,
2020	331
2021	293
2022	246
2023	159
2024	86
Thereafter	71
Total	$ 1,496

Future amortization expense for amortizable intangible assetse [Line Items]

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

No definition available.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized in the remainder of the fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

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