USE OF DERIVATIVES, OFFSETTING DISCLOSURES AND CHANGES IN OTHER COMPREHENSIVE INCOME BY COMPONENT - Schedule of Offsetting of Derivative Assets (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Offsetting of derivative assets [Abstract]
Interest rate swap agreements at fair value			$ 24,709
Net Amounts of Assets Presented in the Balance Sheet		$ 24,256	11,697
Offsetting Derivatives Assets [Member] | Counterparty 4 [Member]
Offsetting of derivative assets [Abstract]
Interest rate swap agreements at fair value	[1]	30,676	18,100
Gross Amounts Offset in the Balance Sheet	[1]	(30,676)	6,609
Net Amounts of Assets Presented in the Balance Sheet		0	24,709
Financial Instruments	[2]	0	(11,681)
Cash Collateral Received	[2]	0	0
Net Amount		$ 0	$ 13,028

[1] Included in gross amounts of recognized assets at December 31, 2017 is the fair value of exchange-traded swap agreements, calculated including accrued interest. Included in gross amounts offset in the balance sheet are variation margin amounts associated with these swaps at December 31, 2017

[2] Amounts presented are limited to recognized liabilities and cash collateral received associated with the indicated counterparty sufficient to reduce the related Net Amount to zero in accordance with ASU No. 2011-11, as amended by ASU No. 2013-01