LOAN PORTFOLIO - Breakdown Between Accrual and Nonaccrual Status of TDRs (Parenthetical) (Detail) - USD ($) $ in Thousands	Sep. 30, 2017		Jun. 30, 2017	Dec. 31, 2016		Sep. 30, 2016	Jun. 30, 2016	Dec. 31, 2015
Financing Receivable Modifications [Line Items]
Total TDR loans	$ 585,795		$ 568,543	$ 647,048		$ 656,318	$ 670,991	$ 661,591
Non Accrual [Member]
Financing Receivable Modifications [Line Items]
Total TDR loans	196,961	[1]		262,161	[2]
Performing Financing Receivable [Member] | Non Accrual [Member]
Financing Receivable Modifications [Line Items]
Total TDR loans	$ 82,800			$ 110,600

[1] Included in non-accrual loans are $82.8 million in loans that are performing under the terms of the restructuring agreement but are reported in nonaccrual status until the restructured loans meet the criteria of sustained payment performance under the revised terms for reinstatement to accrual status and are deemed fully collectible.

[2] Included in non-accrual loans are $110.6 million in loans that are performing under the terms of the restructuring agreement but are reported in non-accrual status until the restructured loans meet the criteria of sustained payment performance under the revised terms for reinstatement to accrual status and are deemed fully collectible.