USE OF DERIVATIVES, OFFSETTING DISCLOSURES AND CHANGES IN OTHER COMPREHENSIVE INCOME BY COMPONENT - Components of Income Statement and Other Comprehensive Income (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income statement-related [Abstract]
Amount of gain (loss) reclassified from Accumulated other comprehensive income		$ (11,162)	$ (3,213)	$ (25,776)	$ (2,207)
Other comprehensive income (loss)-related [Abstract]
Amount of gain recognized in Other comprehensive income		7,580	1,827	46,385	3,541
Interest Expense [Member]
Income statement-related [Abstract]
Decrease (increase) in interest expense and increase(decrease) in Net income as a result of the use of Derivatives		11,162	4,354	25,776	1,847
Interest Expense [Member] | Secured Borrowings [Member]
Income statement-related [Abstract]
Amount of gain (loss) reclassified from Accumulated other comprehensive income		11,585	3,912	27,277	4,412
Amount of loss recognized in income			1,141		(360)
Decrease (increase) in interest expense and increase(decrease) in Net income as a result of the use of Derivatives	[1]	11,585	5,053	27,277	4,052
Interest Expense [Member] | Unsecured Borrowings [Member]
Income statement-related [Abstract]
Amount of gain (loss) reclassified from Accumulated other comprehensive income	[2]	$ (423)	$ (699)	$ (1,501)	$ (2,205)

[1] Included in “Interest expense: Secured borrowings” on the face of the Statements of Income.

[2] Included in “Interest expense: Unsecured borrowings” on the face of the Statements of Income