REVENUE (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Service charges and fees on deposit accounts	$ 16,544	$ 20,482	$ 34,320	$ 38,484
Loan servicing income	379	1,338	1,342	3,067
Securities gains, net	2,006	3,580	3,664	5,155
Unrealized gain on equity securities, net	680	112	449	370
Net gains on sale of loans held for sale	7,857	4,343	12,517	7,519
Valuation adjustment on servicing rights	9	(364)	(1,556)	(953)
Income on bank owned life insurance	1,167	888	1,665	1,787
Other noninterest income	1,995	1,682	4,053	3,349
Total noninterest income out-of-scope of Topic 606	14,093	11,579	22,134	20,294
TOTAL NONINTEREST INCOME	30,637	32,061	56,454	58,778
Service charges and fees on deposit accounts
Disaggregation of Revenue [Line Items]
Service charges and fees on deposit accounts	3,476	3,186	6,913	6,163
Overdraft fees
Disaggregation of Revenue [Line Items]
Service charges and fees on deposit accounts	1,634	2,876	4,443	5,619
Customer service and other service fees
Disaggregation of Revenue [Line Items]
Service charges and fees on deposit accounts	35	84	94	166
Credit card fee income
Disaggregation of Revenue [Line Items]
Service charges and fees on deposit accounts	4,067	4,270	7,967	7,619
Debit card income
Disaggregation of Revenue [Line Items]
Service charges and fees on deposit accounts	1,760	4,213	3,576	7,856
Total service charges and fees
Disaggregation of Revenue [Line Items]
Service charges and fees on deposit accounts	10,972	14,629	22,993	27,423
Trust fees
Disaggregation of Revenue [Line Items]
Service charges and fees on deposit accounts	4,977	4,825	9,999	9,299
Brokerage and insurance commissions
Disaggregation of Revenue [Line Items]
Service charges and fees on deposit accounts	$ 595	$ 1,028	$ 1,328	$ 1,762