LOAN PORTFOLIO - Loans Held for Investment on Which Accrual of Interest Income had been Discontinued (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Accounts Notes And Loans Receivable [Line Items]
Loans held for sale	$ 81,723	$ 76,956
Non Accrual [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for sale	$ 54,600	$ 54,600