LOAN PORTFOLIO - Loans Held for Investment on Which Accrual of Interest Income had been Discontinued (Parenthetical) (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013	May 30, 2012
Accounts Notes And Loans Receivable [Line Items]
Purchased credit impaired loans, fair value			$ 15,700,000
Loans held for sale	80,014,000	75,969,000
Non Accrual [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for sale	$ 54,600,000	$ 54,800,000