REVENUE (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Service charges and fees on deposit accounts	$ 17,755	$ 18,287	$ 52,075	$ 56,771
Loan servicing income	638	821	1,980	3,888
Securities gains, net	1,300	2,013	4,964	7,168
Unrealized gain on equity securities, net	155	144	604	514
Net gains on sale of loans held for sale	8,894	4,673	21,411	12,192
Valuation adjustment on servicing rights	(120)	(626)	(1,676)	(1,579)
Income on bank owned life insurance	868	881	2,533	2,668
Other noninterest income	1,726	3,207	5,779	6,556
Total noninterest income out-of-scope of Topic 606	13,461	11,113	35,595	31,407
TOTAL NONINTEREST INCOME	31,216	29,400	87,670	88,178
Service charges and fees on deposit accounts
Disaggregation of Revenue [Line Items]
Service charges and fees on deposit accounts	3,710	3,221	10,623	9,383
Overdraft fees
Disaggregation of Revenue [Line Items]
Service charges and fees on deposit accounts	2,184	2,917	6,627	8,537
Customer service and other service fees
Disaggregation of Revenue [Line Items]
Service charges and fees on deposit accounts	39	104	133	270
Credit card fee income
Disaggregation of Revenue [Line Items]
Service charges and fees on deposit accounts	3,894	3,936	11,861	11,555
Debit card income
Disaggregation of Revenue [Line Items]
Service charges and fees on deposit accounts	1,922	2,188	5,498	10,044
Total service charges and fees
Disaggregation of Revenue [Line Items]
Service charges and fees on deposit accounts	11,749	12,366	34,742	39,789
Trust fees
Disaggregation of Revenue [Line Items]
Service charges and fees on deposit accounts	5,357	4,959	15,356	14,258
Brokerage and insurance commissions
Disaggregation of Revenue [Line Items]
Service charges and fees on deposit accounts	$ 649	$ 962	$ 1,977	$ 2,724