GOODWILL, OTHER INTANGIBLE ASSETS AND MORTGAGE SERVICING RIGHTS (Mortgage Servicing Rights) (Details) - USD ($) $ in Thousands		3 Months Ended				9 Months Ended
		Sep. 30, 2018		Sep. 30, 2017		Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Servicing Asset at Amortized Value, Balance [Roll Forward]
Servicing Asset at Amortized Cost, Additions, Acquisitions		$ 47		$ 0			$ 0
Servicing Asset at Amortized Cost, Additions						$ 92
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Morgage Servicing Rights at Amortized Value [Line Items]
Loans Serviced For Others		2,300,000				2,300,000		$ 2,190,000
Custodial Accounts		24,200				24,200		$ 10,200
Servicing Asset at Amortized Value, Balance [Roll Forward]
Balance, net of valuation allowance, beginning of the period		14,521		14,985		14,738	15,249
Additions—amounts capitalized		952		826		2,636	2,477
Amortization		(999)	[1]	(1,057)	[1]	(2,945)	(2,972)
Balance, net of valuation allowance, end of the period	[2]	14,521		$ 14,754		14,521	$ 14,754
Valuation allowance, end of period		$ 0				$ 0

[1] Amortization of mortgage servicing rights is recorded as a reduction of loan servicing income within mortgage banking operations and any unamortized balance is fully amortized if the loan repays in full.

[2] There was no valuation allowance as of September 30, 2018 and 2017.