FAIR VALUE DISCLOSURES OF FINANCIAL ASSETS AND LIABILITIES - Schedule of Financial Instruments Carried at Fair Value (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	$ 907,818	$ 837,499
Total assets measured at fair value on a recurring basis	909,603	838,869
Other real estate owned	2,567	2,503
Loans held for sale	15,937	31,055
Total assets measured at fair value on a nonrecurring basis	107,404	107,995
Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Other liabilities	4,335	3,225
Fair Value, Measurements, Nonrecurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Other real estate owned	2,567	2,503
Loans held for sale	15,937	31,055
Impaired loans, net	56,154	57,089
GSE | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale		0
CMO
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	269,236	246,539
CMO | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	269,236	246,539
FNMA MBS
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	509,000	473,987
FNMA MBS | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	509,000	473,987
FHLMC MBS
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	97,299	87,875
FHLMC MBS | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	97,299	87,875
GNMA MBS
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	32,283	29,098
GNMA MBS | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	32,283	29,098
Other investments | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	617	623
Other investments | Fair Value, Measurements, Nonrecurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total assets measured at fair value on a nonrecurring basis	32,746	17,348
Other Assets | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	1,168	747
Quoted Prices in Active Markets for Identical Asset (Level 1)
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total assets measured at fair value on a recurring basis	617	623
Total assets measured at fair value on a nonrecurring basis	0	0
Quoted Prices in Active Markets for Identical Asset (Level 1) | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Other liabilities	0	0
Quoted Prices in Active Markets for Identical Asset (Level 1) | Fair Value, Measurements, Nonrecurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Other real estate owned	0	0
Loans held for sale	0	0
Impaired loans, net	0	0
Quoted Prices in Active Markets for Identical Asset (Level 1) | GSE | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale		0
Quoted Prices in Active Markets for Identical Asset (Level 1) | CMO | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	0	0
Quoted Prices in Active Markets for Identical Asset (Level 1) | FNMA MBS | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	0	0
Quoted Prices in Active Markets for Identical Asset (Level 1) | FHLMC MBS | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	0	0
Quoted Prices in Active Markets for Identical Asset (Level 1) | GNMA MBS | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	0	0
Quoted Prices in Active Markets for Identical Asset (Level 1) | Other investments | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	617	623
Quoted Prices in Active Markets for Identical Asset (Level 1) | Other investments | Fair Value, Measurements, Nonrecurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total assets measured at fair value on a nonrecurring basis	0	0
Quoted Prices in Active Markets for Identical Asset (Level 1) | Other Assets | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	0	0
Significant Other Observable Inputs (Level 2)
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total assets measured at fair value on a recurring basis	908,986	838,246
Total assets measured at fair value on a nonrecurring basis	15,937	31,055
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Other liabilities	4,335	3,225
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Nonrecurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Other real estate owned	0	0
Loans held for sale	15,937	31,055
Impaired loans, net	0	0
Significant Other Observable Inputs (Level 2) | GSE | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale		0
Significant Other Observable Inputs (Level 2) | CMO | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	269,236	246,539
Significant Other Observable Inputs (Level 2) | FNMA MBS | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	509,000	473,987
Significant Other Observable Inputs (Level 2) | FHLMC MBS | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	97,299	87,875
Significant Other Observable Inputs (Level 2) | GNMA MBS | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	32,283	29,098
Significant Other Observable Inputs (Level 2) | Other investments | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	0	0
Significant Other Observable Inputs (Level 2) | Other investments | Fair Value, Measurements, Nonrecurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total assets measured at fair value on a nonrecurring basis	0	0
Significant Other Observable Inputs (Level 2) | Other Assets | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	1,168	747
Significant Unobservable Inputs (Level 3)
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total assets measured at fair value on a recurring basis	0	0
Total assets measured at fair value on a nonrecurring basis	91,467	76,940
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Other liabilities	0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Nonrecurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Other real estate owned	2,567	2,503
Loans held for sale	0	0
Impaired loans, net	56,154	57,089
Significant Unobservable Inputs (Level 3) | GSE | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale		0
Significant Unobservable Inputs (Level 3) | CMO | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	0	0
Significant Unobservable Inputs (Level 3) | FNMA MBS | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	0	0
Significant Unobservable Inputs (Level 3) | FHLMC MBS | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	0	0
Significant Unobservable Inputs (Level 3) | GNMA MBS | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	0	0
Significant Unobservable Inputs (Level 3) | Other investments | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	0	0
Significant Unobservable Inputs (Level 3) | Other investments | Fair Value, Measurements, Nonrecurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total assets measured at fair value on a nonrecurring basis	32,746	17,348
Significant Unobservable Inputs (Level 3) | Other Assets | Fair Value, Measurements, Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investment securities available for sale	$ 0	$ 0