FAIR VALUE ACCOUNTING AND MEASUREMENT (Non-recurring Basis) (Details) (USD $)	3 Months Ended			6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012	Jun. 30, 2013		Jun. 30, 2012	Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing Asset at Amortized Value, Valuation Allowance				$ 0		$ 0
Loans individually evaluated for impairment	62,488,000		59,145,000	62,488,000		59,145,000
Allowance for credit losses, write-downs	2,086,000		7,614,000	4,777,000		15,343,000
Impaired Financing Receivable, Related Allowance	6,973,000			6,973,000			8,338,000
Allowance individually evaluated for impairment	6,254,000		6,971,000	6,254,000		6,971,000
Loans collectively evaluated for impairment	3,227,713,000		3,153,112,000	3,227,713,000		3,153,112,000
Allowance collectively evaluated for impairment	70,599,000		73,250,000	70,599,000		73,250,000
Impaired Financing Receivable, with Related Allowance, Recorded Investment	77,834,000			77,834,000			91,852,000
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	83,039,000			83,039,000			98,232,000
Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Classifed loans	128,000,000			128,000,000
Allowance for credit losses, write-downs				3,000,000
Impairment of real estate owned	226,000		1,600,000
With Specific Allowance Reserve , Individually Evaluated for Impairment [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Financing Receivable, Related Allowance	6,254,000	[1]		6,254,000	[1]		5,725,000	[1]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	62,488,000	[1]		62,488,000	[1]		63,123,000	[1]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	64,843,000	[1]		64,843,000	[1]		66,012,000	[1]
Loans Without Specific Allowance Reserve, Collectively Evaluated for Impairment [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Financing Receivable, Related Allowance	719,000	[2]		719,000	[2]		2,613,000	[2]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	15,346,000	[2]		15,346,000	[2]		28,729,000	[2]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	18,196,000	[2]		18,196,000	[2]		32,220,000	[2]
Servicing Contracts for Third Parties [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Serviced For Others	1,037,000,000		780,000,000	1,037,000,000		780,000,000	918,000,000
Mortgage Servicing Rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing Asset at Amortized Value, Other Changes that Affect Balance, Amount	600,000		0	600,000		0
Custodial Accounts	$ 5,500,000		$ 4,200,000	$ 5,500,000		$ 4,200,000	$ 4,700,000

[1] Loans with a specific allowance reserve have been individually evaluated for impairment using either a discounted cash flow analysis or, for collateral dependent loans, current appraisals to establish realizable value. These analyses may identify a specific impairment amount needed or may conclude that no reserve is needed. Any specific impairment that is identified is included in the category’s Related Allowance column.

[2] Loans without a specific allowance reserve have not been individually evaluated for impairment, but have been included in pools of homogeneous loans for evaluation of related allowance reserves.