GOODWILL, OTHER INTANGIBLE ASSETS AND MORTGAGE SERVICING RIGHTS (Mortgage Servicing Rights) (Details) - Mortgage Servicing Rights [Member] - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Morgage Servicing Rights at Amortized Value [Line Items]
Loans Serviced For Others		$ 2,130,000		$ 2,130,000		$ 2,050,000
Custodial Accounts		22,500		22,500		$ 10,300
Servicing Asset at Amortized Value, Balance [Roll Forward]
Balance, net of valuation allowance, beginning of the period		14,985	$ 14,276	15,249	$ 13,354
Additions—amounts capitalized		826	1,652	2,477	4,371
Amortization	[1]	(1,057)	(1,102)	(2,972)	(2,899)
Balance, net of valuation allowance, end of the period	[2]	14,754	$ 14,826	14,754	$ 14,826
Valuation allowance, end of period	[2]	$ 0		$ 0

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

[2] There was no valuation allowance as of September 30, 2017 and 2016.