The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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.

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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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GOODWILL AND CORE DEPOSIT INTANGIBLES (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2018
Goodwill
Beginning of period	$ 85,291	$ 85,291
End of the period	85,291		$ 85,291
Core Deposit Intangibles
Beginning of period	8,503	9,975
Less amortization	(316)	(380)	(1,472)
End of period	8,187		9,975
Amortization of intangible assets	316	380	1,472
Expected future amortization expense
Total	8,503	9,975	$ 9,975	$ 8,187
Core deposit intangibles
Core Deposit Intangibles
Less amortization	(316)	(380)
End of period	8,187
Amortization of intangible assets	316	$ 380
Expected future amortization expense
2018				879
2019				1,080
2020				993
2021				905
2022				818
Thereafter				3,512
Total	$ 8,187			$ 8,187
Core deposit intangibles \| Minimum
Core Deposit Intangibles
Intangible asset useful life	6 years
Core deposit intangibles \| Maximum
Core Deposit Intangibles
Intangible asset useful life	19 years