FAIR VALUE - Impairment of Valuation Adjustments were Recorded for Assets Recognized at Fair Value (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Mortgage servicing rights	$ 22,838		$ 21,987		$ 17,524		$ 15,226
Fair Value Inputs Level 1 [Member] | Fair Value Measurements Nonrecurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Loans receivable	0	[1]	0	[2]	0	[3]
Other Real Estate Owned	0	[4]	0	[5]	0	[6]
Mortgage servicing rights	0	[7]	0	[8]	0	[9]
Loans held for sale	0	[10]	0	[11]	0	[12]
Fair Value Inputs Level 2 [Member] | Fair Value Measurements Nonrecurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Loans receivable	0	[1]	0	[2]	0	[3]
Other Real Estate Owned	0	[4]	0	[5]	0	[6]
Mortgage servicing rights	0	[7]	0	[8]	0	[9]
Loans held for sale	0	[10]	0	[11]	0	[12]
Fair Value Inputs Level 3 [Member] | Fair Value Measurements Nonrecurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Loans receivable	446,816	[1]	465,191	[2]	757,152	[3]
Other Real Estate Owned	124,003	[4]	160,193	[5]	185,764	[6]
Mortgage servicing rights	22,838	[7]	21,987	[8]	17,524	[9]
Loans held for sale	54,641	[10]	54,801	[11]	2,641	[12]
Fair Value Inputs Level 3 [Member] | Fair Value Measurements Nonrecurring [Member] | Loans Receivable [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets Fair Value Adjustment	(43,318)	[1]	(13,928)	[2]	(110,457)	[3]
Fair Value Inputs Level 3 [Member] | Fair Value Measurements Nonrecurring [Member] | Other Real Estate Owned [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets Fair Value Adjustment	(9,656)	[4]	(25,698)	[5]	(8,851)	[6]
Fair Value Inputs Level 3 [Member] | Fair Value Measurements Nonrecurring [Member] | Mortgage Servicing Rights [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets Fair Value Adjustment	(228)	[7]	460	[8]	(394)	[9]
Fair Value Inputs Level 3 [Member] | Fair Value Measurements Nonrecurring [Member] | Loans Held For Sale [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets Fair Value Adjustment	$ 0	[10]	$ (338)	[11]	$ (2,168)	[12]

[1]   Mainly impaired commercial and construction loans. The impairment was generally measured based on the fair value of the   collateral. The fair values were derived from external appraisals that take into consideration prices in observed transactions   involving similar assets in similar locations but adjusted for specific characteristics and assumptions of the collateral   (e.g., absorption rates), which are not market observable.

[2]  Mainly impaired commercial and construction loans. The impairment was generally measured based on the fair value of the  collateral. The fair values were derived from external appraisals that take into consideration prices in observed transactions  involving similar assets in similar locations but adjusted for specific characteristics and assumptions of the collateral (e.g.,   absorption rates), which are not market observable.

[3]  Mainly impaired commercial and construction loans. The impairment was generally measured based on the fair value of the  collateral. The fair values were derived from external appraisals that take into consideration prices in observed transactions involving similar assets in similar locations but adjusted for specific characteristics and assumptions of the collateral (e.g.,  absorption rates), which are not market observable.

[4]   The fair value was derived from appraisals that take into consideration prices in observed transactions involving similar   assets in similar locations but adjusted for specific characteristics and assumptions of the properties (e.g., absorption   rates and net operating income of income producing properties), which are not market observable. Losses   were related to market valuation adjustments after the transfer of the loans to the OREO portfolio.

[5]  The fair value was derived from appraisals that take into consideration prices in observed transactions involving similar assets in  similar locations but adjusted for specific characteristics and assumptions of the properties (e.g., absorption rates and net operating  income of income producing properties), which are not market observable. Losses were related to market valuation adjustments   after the transfer of the loans to the OREO portfolio.

[6]  The fair value was derived from appraisals that take into consideration prices in observed transactions involving similar assets in similar locations but adjusted for specific characteristics and assumptions of the properties (e.g., absorption rates and net operating income of income producing properties), which are not market observable. Losses were related to market valuation adjustments  after the transfer of the loans to the OREO portfolio.

[7]   Fair value adjustments to mortgage servicing rights were mainly due to assumptions associated with mortgage   prepayment rates. The Corporation carries its mortgage servicing rights at the lower of cost or market, measured at   fair value on a non-recurring basis. Assumptions for the value of mortgage servicing rights include: Prepayment rate   9.74%, Discount rate 10.60%.

[8]  Fair value adjustments to the mortgage servicing rights were mainly due to assumptions associated with mortgage prepayments  rates. The Corporation carries its mortgage servicing rights at the lower of cost or market, measured at fair value on a non- recurring basis. Assumptions for the value of mortgage servicing rights include: Prepayment rate 8.90%, Discount rate 10.60%.

[9]  Fair value adjustments to the mortgage servicing rights were mainly due to assumptions associated with mortgage prepayments rates. The Corporation carries its mortgage servicing rights at the lower of cost or market, measured at fair value on a non-recurring basis. Assumptions for the value of mortgage servicing rights include: Prepayment rate 11.15%, Discount rate 12.08%.

[10]   The value of these loans was derived from external appraisals, adjusted for specific characteristics of the loans, and for    loans with signed sale agreements, the value was determined based on the sales price on such agreements.

[11]  The value of these loans was derived from external appraisals, adjusted for specific characteristics of the loans, and for loans  with signed sale agreements, the value was determined based on the sales price on such agreements.

[12]  Relates to $5.2 million Commercial and Industrial and Commercial Mortgage Loans transferred to held for sale during the fourth quarter of 2012, which were recorded at a value of $2.6 million.