ADVANCES FROM THE FEDERAL HOME LOAN BANK (FHLB) - Summary of Advances from FHLB (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Short Term Debt [Line Items]
Fixed-rate advances from FHLB, with a weighted-average interest rate of 1.69% (December 31, 2012 - 2.26%)	$ 325,000us-gaap_FederalHomeLoanBankAdvances	$ 325,000us-gaap_FederalHomeLoanBankAdvances

Amount of Federal Home Loan Bank (FHLBank) advances to member financial institutions.

No definition available.

Name:	us-gaap_FederalHomeLoanBankAdvances
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant