USE OF DERIVATIVES, OFFSETTING DISCLOSURES AND CHANGES IN OTHER COMPREHENSIVE INCOME (LOSS) BY COMPONENT - Changes in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 912,889	$ 1,022,388	$ 1,073,733	$ 1,059,063
Other comprehensive income	(9,498)	(13,042)	35,855	46,765
Ending Balance	913,829	1,071,756	913,829	1,071,756
Unrealized Gains and Losses on Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(52,268)		(31,868)
Other comprehensive loss before reclassifications	2,113		(19,705)
Amounts reclassified from accumulated other comprehensive income (loss)	952		2,370
Other comprehensive income	3,065		(17,335)
Ending Balance	(49,203)		(49,203)
Unrealized Gains and Losses on Available-for-sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	111,020		45,267
Other comprehensive loss before reclassifications	(12,563)		(13,674)
Amounts reclassified from accumulated other comprehensive income (loss)	0		66,864
Other comprehensive income	(12,563)		53,190
Ending Balance	98,457		98,457
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	58,752	38,761	13,399	(21,046)
Other comprehensive loss before reclassifications	(10,450)		(33,379)
Amounts reclassified from accumulated other comprehensive income (loss)	952		69,234
Other comprehensive income	(9,498)		35,855
Ending Balance	$ 49,254	$ 25,719	$ 49,254	$ 25,719