USE OF DERIVATIVE FINANCIAL INSTRUMENTS, OFFSETTING DISCLOSURES AND CHANGES IN OTHER COMPREHENSIVE INCOME BY COMPONENT - Offsetting Assets (Details) - USD ($) $ in Thousands		Sep. 30, 2015	Dec. 31, 2014
Offsetting of derivative assets [Abstract]
Gross Amounts of Recognized Assets		$ 0	$ 1,657
Net Amounts of Assets Presented in the Balance Sheet		50,715	34,893
Cash Collateral Received		65,868	53,139
Offsetting Derivatives Assets [Member]
Offsetting of derivative assets [Abstract]
Gross Amounts of Recognized Assets		0	1,128
Gross Amounts Offset in the Balance Sheet		0	529
Net Amounts of Assets Presented in the Balance Sheet		0	1,657
Financial Instruments	[1]	0	(1,657)
Cash Collateral Received	[1]	0	0
Net Amount		0	0
Offsetting Derivatives Assets [Member] | Counterparties 1-4 [Member]
Offsetting of derivative assets [Abstract]
Gross Amounts of Recognized Assets		0
Gross Amounts Offset in the Balance Sheet		0
Net Amounts of Assets Presented in the Balance Sheet		0
Financial Instruments	[1]	0
Cash Collateral Received	[1]	0
Net Amount		$ 0
Offsetting Derivatives Assets [Member] | Counterparty 2 [Member]
Offsetting of derivative assets [Abstract]
Gross Amounts of Recognized Assets			0
Gross Amounts Offset in the Balance Sheet			95
Net Amounts of Assets Presented in the Balance Sheet			95
Financial Instruments	[1]		(95)
Cash Collateral Received	[1]		0
Net Amount			0
Offsetting Derivatives Assets [Member] | Counterparty 4 [Member]
Offsetting of derivative assets [Abstract]
Gross Amounts of Recognized Assets			1,128
Gross Amounts Offset in the Balance Sheet			434
Net Amounts of Assets Presented in the Balance Sheet			1,562
Financial Instruments	[1]		(1,562)
Cash Collateral Received	[1]		0
Net Amount			$ 0

[1] 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.