DEPOSITS - Components of Interest Expense on Deposits (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Deposits [Abstract]
Interest expense on deposits	$ 18,921	$ 16,667	$ 36,226	$ 33,274
Accretion Of Premium From Acquisitions	(2)	(2)	(4)	(5)
Amortization of broker placement fees	184	309	373	676
Interest expense on deposits	$ 19,103	$ 16,974	$ 36,595	$ 33,945

Aggregate amount of interest expense on all deposits.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.6)
-URI http://asc.fasb.org/extlink&oid=114873765&loc=SL114874048-224260

Name:	us-gaap_InterestExpenseDeposits
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration