USE OF DERIVATIVES, OFFSETTING DISCLOSURES AND CHANGES IN OTHER COMPREHENSIVE INCOME BY COMPONENT- Offsetting Liabilities (Details) - USD ($) $ in Thousands		Mar. 31, 2016	Dec. 31, 2015
Offsetting of financial liabilities and derivative liabilities [Abstract]
Gross Amounts of Recognized Liabilities		$ 46,309	$ 26,061
Offsetting Financial Liabilities and Derivative Liabilities [Member]
Offsetting of financial liabilities and derivative liabilities [Abstract]
Gross Amounts of Recognized Liabilities	[1]	11,936,721	10,124,887
Gross Amounts Offset in the Balance Sheet		338	2,962
Net Amounts of Liabilities Presented in the Balance Sheet	[2]	11,937,059	10,127,849
Financial Instruments	[3]	(11,880,818)	(10,098,566)
Cash Collateral Pledged	[3]	(55,994)	(29,283)
Net Amount		247	0
Offsetting Financial Liabilities and Derivative Liabilities [Member] | Counterparty 1 [Member]
Offsetting of financial liabilities and derivative liabilities [Abstract]
Gross Amounts of Recognized Liabilities	[1]	36,041	26,311
Gross Amounts Offset in the Balance Sheet		0	0
Net Amounts of Liabilities Presented in the Balance Sheet	[2]	36,041	26,311
Financial Instruments	[3]	0	0
Cash Collateral Pledged	[3]	(36,041)	(26,311)
Net Amount		0	0
Offsetting Financial Liabilities and Derivative Liabilities [Member] | Counterparty 2 [Member]
Offsetting of financial liabilities and derivative liabilities [Abstract]
Gross Amounts of Recognized Liabilities	[1]	747	776
Gross Amounts Offset in the Balance Sheet		0	23
Net Amounts of Liabilities Presented in the Balance Sheet	[2]	747	799
Financial Instruments	[3]	0	(23)
Cash Collateral Pledged	[3]	(500)	(776)
Net Amount		247	0
Offsetting Financial Liabilities and Derivative Liabilities [Member] | Counterparty 4 [Member]
Offsetting of financial liabilities and derivative liabilities [Abstract]
Gross Amounts of Recognized Liabilities	[1]	19,917	6,954
Gross Amounts Offset in the Balance Sheet		338	2,939
Net Amounts of Liabilities Presented in the Balance Sheet	[2]	20,255	9,893
Financial Instruments	[3]	(802)	(7,697)
Cash Collateral Pledged	[3]	(19,453)	(2,196)
Net Amount		0	0
Offsetting Financial Liabilities and Derivative Liabilities [Member] | Derivative Counterparties [Member]
Offsetting of financial liabilities and derivative liabilities [Abstract]
Gross Amounts of Recognized Liabilities	[1]	56,705	34,041
Gross Amounts Offset in the Balance Sheet		338	2,962
Net Amounts of Liabilities Presented in the Balance Sheet	[2]	57,043	37,003
Financial Instruments	[3]	(802)	(7,720)
Cash Collateral Pledged	[3]	(55,994)	(29,283)
Net Amount		247	0
Borrowings under Repurchase Arrangements [Member] | Offsetting Financial Liabilities and Derivative Liabilities [Member]
Offsetting of financial liabilities and derivative liabilities [Abstract]
Gross Amounts of Recognized Liabilities	[1]	11,880,016	10,090,846
Gross Amounts Offset in the Balance Sheet		0	0
Net Amounts of Liabilities Presented in the Balance Sheet	[2]	11,880,016	10,090,846
Financial Instruments	[3]	(11,880,016)	(10,090,846)
Cash Collateral Pledged	[3]	0	0
Net Amount		$ 0	$ 0

[1] Amounts include accrued interest of $10.7 million and $10.9 million on interest rate swap agreements and $8.2 million and $9.3 million on borrowings under repurchase arrangements, included in " Accounts payable and accrued expenses " on the face of the Balance Sheets as of March 31, 2016 and December 31, 2015, respectively.

[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.

[3] Amounts presented are limited to recognized assets and collateral pledged 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.