LOANS AND ALLOWANCE FOR LOAN LOSSES (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Oct. 16, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit card portfolio sold				$ 26,400,000
Net income from sale of credit card portfolio		$ 805,000
Nonaccrual loans	$ 9,973,000	11,936,000	$ 19,300,000
Nonaccrual interest lost	$ 452,000	487,000	795,000
Period for restructured loan to be considered default	90 days
Acquired performing loan portfolio	$ 6,307,060,000	5,671,462,000	5,345,996,000
Acquired Performing Loan Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired performing loan portfolio	1,100,000,000	1,400,000,000
Remaining discount on acquired loans	16,900,000	20,800,000
Purchased Impaired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired performing loan portfolio	59,292,000	73,737,000	$ 105,788,000
Purchased impaired loans (gross)	73,600,000	90,300,000
Unfunded Loan Commitments
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for unfunded commitments	$ 425,000	$ 300,000