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		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 843,624	$ 1,064,878	$ 1,073,733	$ 1,059,063
Other comprehensive income	65,030	35,453	45,353	59,807
Ending Balance	912,889	1,022,388	912,889	1,022,388
Unrealized Gains and Losses on Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(52,639)		(31,868)
Other comprehensive loss (income) before reclassifications	(567)		(21,818)
Amounts reclassified from accumulated other comprehensive income	938		1,418
Other comprehensive income	371		(20,400)
Ending Balance	(52,268)		(52,268)
Unrealized Gains and Losses on Available-for-sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	46,361		45,267
Other comprehensive loss (income) before reclassifications	64,659		(1,111)
Amounts reclassified from accumulated other comprehensive income	0		66,864
Other comprehensive income	64,659		65,753
Ending Balance	111,020		111,020
Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(6,278)	3,308	13,399	(21,046)
Other comprehensive loss (income) before reclassifications	64,092		(22,929)
Amounts reclassified from accumulated other comprehensive income	938		68,282
Other comprehensive income	65,030		45,353
Ending Balance	$ 58,752	$ 38,761	$ 58,752	$ 38,761