FAIR VALUE ACCOUNTING AND MEASUREMENT (Non-recurring Basis) (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans individually evaluated for impairment	$ 53,009,000	$ 72,632,000
Write-downs on loans individually evaluated for impairment	1,528,000	2,691,000
Allowance on loans individually evaluated for impairment	4,693,000	7,531,000
Loans collectively evaluated for impairment	3,469,903,000	3,167,689,000
Allowance on loans collectively evaluated for impairment	69,678,000	68,865,000
Impaired Financing Receivable, with Related Allowance, Recorded Investment	63,035,000		72,196,000
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	68,159,000		78,371,000
Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Classifed loans	81,000,000
Impaired loans	63,035,000
Loans individually evaluated for impairment	53,009,000
Loans individually evaluated for impairment, original carrying value	56,324,000
Write-downs on loans individually evaluated for impairment	3,000,000
Allowance on loans individually evaluated for impairment	4,693,000
Loans collectively evaluated for impairment	10,026,000
Allowance on loans collectively evaluated for impairment	230,000
Impairment of real estate owned	37,000	73,000
Mortgage Servicing Rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Serviced For Others	1,146,000,000	984,000,000	1,116,000,000
Custodial Accounts	$ 3,000,000	$ 2,800,000	$ 5,400,000