ADVANCES FROM THE FEDERAL HOME LOAN BANK (FHLB) - Summary of Advances from FHLB (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Short Term Debt [Line Items]
Fixed-rate advances from FHLB, with a weighted-average interest rate of 2.31% (December 31, 2011 - 3.59%)	$ 670,000	$ 455,000
long term debt [member]
Short Term Debt [Line Items]
Fixed-rate advances from FHLB, with a weighted-average interest rate of 2.31% (December 31, 2011 - 3.59%)	500,000	455,000
short term debt [member]
Short Term Debt [Line Items]
Fixed-rate advances from FHLB, with a weighted-average interest rate of 2.31% (December 31, 2011 - 3.59%)	$ 170,000	$ 0