FAIR VALUE MEASUREMENTS (Details 4) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Quantitative information about the significant unobservable inputs within Level 3
Other real estate owned	$ 2,513,000	$ 1,929,000
Non-recurring
Quantitative information about the significant unobservable inputs within Level 3
Liabilities measured at fair value	0
Non-recurring | Total losses
Quantitative information about the significant unobservable inputs within Level 3
Impaired loans	(760,000)
Capitalized mortgage servicing rights	324,000
Other real estate owned	115,000
Total	(321,000)
Level 3 Inputs | Recurring
Quantitative information about the significant unobservable inputs within Level 3
Assets measured on recurring basis	19,243,000	23,151,000
Level 3 Inputs | Recurring | Pricing Model
Quantitative information about the significant unobservable inputs within Level 3
Origination Costs	2,500,000	2,500,000
Level 3 Inputs | Recurring | Trading Account Security | Discounted Cash Flow
Quantitative information about the significant unobservable inputs within Level 3
Assets measured on recurring basis	16,485,000	16,893,000
Discount Rate (as percent)	2.46%	2.08%
Level 3 Inputs | Recurring | Interest rate lock commitments | Historical Trend
Quantitative information about the significant unobservable inputs within Level 3
Assets measured on recurring basis	2,758,000	6,258,000
Closing Ratio (as percent)	91.98%	93.04%
Level 3 Inputs | Non-recurring
Quantitative information about the significant unobservable inputs within Level 3
Impaired loans	6,864,000	6,104,000
Capitalized mortgage servicing rights	3,617,000	3,198,000
Other real estate owned	2,513,000	1,929,000
Total	12,994,000	11,231,000
Level 3 Inputs | Non-recurring | Minimum | Impaired loans | Fair value of collateral
Quantitative information about the significant unobservable inputs within Level 3
Loss severity (as percent)	9.18%	5.24%
Appraised value	130.0	15.7
Level 3 Inputs | Non-recurring | Minimum | Capitalized mortgage servicing rights | Discounted Cash Flow
Quantitative information about the significant unobservable inputs within Level 3
Discount Rate (as percent)	11.00%	11.00%
Constant prepayment rate (CPR) (as percent)	11.49%	13.25%
Level 3 Inputs | Non-recurring | Minimum | Other real estate owned | Fair value of collateral
Quantitative information about the significant unobservable inputs within Level 3
Appraised value	0.0	0.0
Level 3 Inputs | Non-recurring | Maximum | Impaired loans | Fair value of collateral
Quantitative information about the significant unobservable inputs within Level 3
Loss severity (as percent)	50.00%	100.00%
Appraised value	1,950.0	1,584.0
Level 3 Inputs | Non-recurring | Maximum | Capitalized mortgage servicing rights | Discounted Cash Flow
Quantitative information about the significant unobservable inputs within Level 3
Discount Rate (as percent)	15.50%	15.50%
Constant prepayment rate (CPR) (as percent)	20.42%	26.02%
Level 3 Inputs | Non-recurring | Maximum | Other real estate owned | Fair value of collateral
Quantitative information about the significant unobservable inputs within Level 3
Appraised value	1,000.0	1,000.0
Level 3 Inputs | Non-recurring | Weighted Average | Impaired loans | Fair value of collateral
Quantitative information about the significant unobservable inputs within Level 3
Loss severity (as percent)	25.57%	42.79%
Appraised value	887.0	863.8
Level 3 Inputs | Non-recurring | Weighted Average | Capitalized mortgage servicing rights | Discounted Cash Flow
Quantitative information about the significant unobservable inputs within Level 3
Discount Rate (as percent)	11.23%	11.14%
Constant prepayment rate (CPR) (as percent)	15.09%	18.41%
Level 3 Inputs | Non-recurring | Weighted Average | Other real estate owned | Fair value of collateral
Quantitative information about the significant unobservable inputs within Level 3
Appraised value	$ 414.1	$ 457.1