PREMISES AND EQUIPMENT- Additional information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Impaired Long Lived Assets Held And Used [Line Items]
Depreciation and amortization expense	$ 15,000	$ 16,400	$ 17,600
Gain from insurance proceeds	537	0	0
Insurance proceeds	7,673	0	$ 0
Hurricane [Member]
Impaired Long Lived Assets Held And Used [Line Items]
Gain from insurance proceeds	500
Insurance proceeds	6,800
Hurricane [Member] | Property Plant And Equipment [Member]
Impaired Long Lived Assets Held And Used [Line Items]
Tangible Asset Impairment Charges	1,300	$ 600
Insurance proceeds	$ 2,000