LOAN PORTFOLIO - Credit Risk Payment Activity (Parenthetical) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable Recorded Investment [Line Items]
Residential mortgage loans insured by FHA or guaranteed by the VA	$ 40,400,000	$ 37,000,000
Period of residential mortgage loan that are no longer accruing interest	1 year 6 months 0 days	1 year 6 months 0 days
Loans considered to be defaulted if borrower has failed to make payment for a period or more than the period	0 years 2 months 29 days	0 years 2 months 29 days
Loans Receivable Held For Sale Net	76,956,000	75,969,000
Total Adversely Classified [Member]
Financing Receivable Recorded Investment [Line Items]
Loans Held For Sale Commercial Real Estate	6,800,000	7,000,000
Commercial Mortgage Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans Held For Sale Commercial Real Estate	6,839,000	6,999,000
Commercial Construction [Member] | Total Adversely Classified [Member]
Financing Receivable Recorded Investment [Line Items]
Loans Receivable Held For Sale Net	39,100,000	39,100,000
Residential Construction [Member] | Total Adversely Classified [Member]
Financing Receivable Recorded Investment [Line Items]
Loans Receivable Held For Sale Net	900,000	900,000
Land Construction [Member] | Total Adversely Classified [Member]
Financing Receivable Recorded Investment [Line Items]
Loans Receivable Held For Sale Net	$ 7,800,000	$ 7,800,000