USE OF DERIVATIVE FINANCIAL INSTRUMENTS, OFFSETTING DISCLOSURES AND CHANGES IN OTHER COMPREHENSIVE INCOME BY COMPONENT - Balance Sheet and Income Statement Location (Detail) (USD $) In Thousands, unless otherwise specified			3 Months Ended		9 Months Ended		3 Months Ended				9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013 Other Comprehensive Income (Loss) [Member]	Sep. 30, 2012 Other Comprehensive Income (Loss) [Member]	Sep. 30, 2013 Other Comprehensive Income (Loss) [Member]	Sep. 30, 2012 Other Comprehensive Income (Loss) [Member]	Sep. 30, 2013 Interest Expense [Member]		Sep. 30, 2012 Interest Expense [Member]		Sep. 30, 2013 Interest Expense [Member]		Sep. 30, 2012 Interest Expense [Member]		Sep. 30, 2013 Other Assets [Member]		Dec. 31, 2012 Other Assets [Member]		Sep. 30, 2013 Accounts Payable and Accrued Liabilities [Member]		Dec. 31, 2012 Accounts Payable and Accrued Liabilities [Member]		Sep. 30, 2013 Borrowings Under Repurchase Arrangements [Member] Other Assets [Member]		Dec. 31, 2012 Borrowings Under Repurchase Arrangements [Member] Other Assets [Member]		Sep. 30, 2013 Unsecured Borrowings [Member] Other Assets [Member]		Dec. 31, 2012 Unsecured Borrowings [Member] Other Assets [Member]
Balance sheet-related [Abstract]
Interest rate swap agreements at fair value	$ 1,558	$ 169													$ 1,558	[1]	$ 169	[1]
Borrowings under repurchase arrangements																							(10,858)	[1]	(18,671)	[1]	(567)	[1]	(14,197)	[1]
Related net interest payable																			(6,356)	[2]	(7,788)	[2]
Interest rate swap agreements at fair value, net assets (liability)	(16,223)	(40,487)
Income statement-related [Abstract]
Amount of loss reclassified from Accumulated other comprehensive income related to the effective portion of active positions							(3,698)		(4,835)		(13,548)		(14,630)
Amount of gain (loss) recognized (ineffective portion)							(23)		211		73		(96)
Increase in interest expense and decrease in Net income as a result of the use of Derivatives							(3,721)	[3]	(4,624)	[3]	(13,475)	[3]	(14,726)	[3]
Other comprehensive income related [Abstract]
Amount of gain (loss recognized in Other comprehensive income (loss) (effective portion)			$ (10,867)	$ (8,454)	$ 9,136	$ (25,539)

[1] The fair value of Derivatives with realized and unrealized gains are aggregated and recorded as an asset on the face of the Balance Sheet separately from the fair value of Derivatives with realized and unrealized losses that are recorded as a liability. The amount of unrealized losses at September 30, 2013 scheduled to be recognized in the Statement of Income over the next twelve months primarily in the form of fixed-rate swap payments in excess of current market rates totaled $13.4 million.

[2] Included in “Accounts payable and accrued expenses” on the face of the Balance Sheet.

[3] Included in “Interest expense: Repurchase arrangements and similar borrowings” on the face of the Statement of Income.