DERIVATIVES - Additional Information (Details) $ in Thousands	Sep. 30, 2020 USD ($) entity	Dec. 31, 2019 USD ($) entity
Derivative [Line Items]
Number of counterparties | entity	19	18
Derivative liabilities	$ 280,837	$ 112,616
Derivative, Notional Amount	10,664,670	7,586,618
Other Credit Derivatives [Member]
Derivative [Line Items]
Derivative, Notional Amount	153,000	37,800
Credit Risk Derivative Liabilities, at Fair Value		$ 900
Credit Risk Derivative Assets, at Fair Value	$ (1,100)
Foreign Exchange [Member]
Derivative [Line Items]
Number of counterparties | entity	6	6
Credit Risk Contract [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 235,000	$ 216,200
Credit Risk Derivative Liabilities, at Fair Value	400	200
Interest Rate Lock Commitments [Member]
Derivative [Line Items]
Derivative, Notional Amount	158,100	33,400
Accrued interest and other liabilities | Derivative
Derivative [Line Items]
Derivative liabilities	206,200	67,500
Derivative, Notional Amount	2,200,000	1,900,000
Accrued interest and other liabilities | Derivative | Foreign Exchange [Member]
Derivative [Line Items]
Derivative liabilities	700	18,300
Derivative, Notional Amount	$ 3,100,000	$ 1,900,000