DERIVATIVES (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Derivative [Line Items]
Fair value of derivatives with credit risk contingent feature associated with credit ratings	$ 300,000		$ 300,000
Additional collateral required	0		0
Fair value of derivatives with credit risk contingent features	9,300,000		9,300,000		$ 7,800,000
Collateral posted	21,700,000		21,700,000		$ 8,600,000
Cash flow hedge loss to be reclassified within next twelve months			31,100,000
Net unrealized gain (loss) on cash flow hedge derivative financial instruments
Derivative [Line Items]
Net amount of change recognized in OCI for cash flow hedge derivatives	(38,994,000)	$ 4,483,000	116,619,000	$ 16,188,000
Amount reclassified from OCI into earnings for cash flow hedge derivatives	$ 292,000	$ 3,734,000	$ 332,000	$ 166,000