GOODWILL AND OTHER INTANGIBLES - Gross Amount and Accumulated Amortization of Other Intangible Assets (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Core Deposits [Member]
Finite Lived Intangible Assets [Line Items]
Gross amount	$ 51,664	$ 51,664
Accumulated amortization	(48,377)	(48,176)
Net carrying amount	$ 3,287	$ 3,488
Remaining amortization period	4 years 9 months 18 days	5 years 1 month 6 days
Customer Relationships [Member] | Credit Card [Member]
Finite Lived Intangible Assets [Line Items]
Gross amount	$ 24,465	$ 24,465
Accumulated amortization	(21,324)	(20,850)
Net carrying amount	$ 3,141	$ 3,615
Remaining amortization period	1 year 7 months 6 days	1 year 10 months 24 days
Customer Relationships [Member] | Insurance Customer Intangible [Member]
Finite Lived Intangible Assets [Line Items]
Gross amount	$ 1,067	$ 1,067
Accumulated amortization	(635)	(597)
Net carrying amount	$ 432	$ 470
Remaining amortization period	2 years 9 months 18 days	3 years