BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Textuals) (Details) (USD $)	12 Months Ended					12 Months Ended
	Dec. 31, 2013 plan subsidiary	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Subsidiary, Banner Bank [Member] office	Dec. 31, 2013 Subsidiary, Islanders Bank [Member] location	Dec. 31, 2013 Minimum [Member] Core Deposit Intangibles [Member]	Dec. 31, 2013 Maximum [Member] Core Deposit Intangibles [Member]	Dec. 31, 2013 Loans Receivable [Member] Interest Rate Swap [Member] F&M Bank [Member]	Dec. 31, 2007 Loans Receivable [Member] Interest Rate Swap [Member] F&M Bank [Member]	Dec. 31, 2013 Other assets [Member] Interest Rate Swap [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Number of wholly-owned subsidiaries	2
Number of offices				85
Number of production offices				8
Number of locations					3
Federal home loan bank stock	$ 35,390,000	$ 36,705,000
Federal home loan bank stock, par value per share	$ 100
Proceeds from sale of FHLB stock	1,300,000
FHLB stock, dividend income	18,000	0	0
Intangible asset, useful life						3 years	8 years
Cash surrender value of insurance policies	61,900,000	59,900,000
Derivative Asset, Notional Amount								$ 13,000,000	$ 23,000,000	$ 129,000,000
ESOP, employee loan, percentage of employer's initial public offering	8.00%
Number of stock option plans	3