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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities.

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Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, and capital lease obligations.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

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The number of derivative instruments of a particular derivative asset or group of derivative assets held by the entity.

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-Publisher FASB

-Name Accounting Standards Codification

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Fair value as of the balance sheet date of interest rate derivative assets, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as assets.

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Fair value as of the balance sheet date of interest rate derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as liabilities.

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The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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FAIR VALUE MEASUREMENTS - Recurring Basis (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Assets:
Available-for-sale securities	$ 20,512us-gaap_AvailableForSaleSecurities	$ 13,973us-gaap_AvailableForSaleSecurities
Interest rate cap		0
Liabilities:
Interest rate swaps	2,226	4,007
Net realized gains and losses on sale of available-for-sale securities	0	0	224
Fair value of mortgage and other indebtedness	4,947,026us-gaap_LongTermDebtFairValue	5,126,300us-gaap_LongTermDebtFairValue
Mortgage and other indebtedness	4,700,460us-gaap_DebtAndCapitalLeaseObligations	4,857,523us-gaap_DebtAndCapitalLeaseObligations
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets:
Available-for-sale securities	20,512	13,973
Interest rate cap		0
Liabilities:
Interest rate swaps	0	0
Significant Other Observable Inputs (Level 2) [Member]
Assets:
Available-for-sale securities	0	0
Interest rate cap		0
Liabilities:
Interest rate swaps	2,226	4,007
Significant Unobservable Inputs (Level 3) [Member]
Assets:
Available-for-sale securities	0	0
Interest rate cap		0
Liabilities:
Interest rate swaps	$ 0	$ 0
Fair Value, Measurements, Recurring [Member] \| Interest Rate Swap [Member]
Liabilities:
Number of instruments held	4	4
Fair Value, Measurements, Recurring [Member] \| Interest Rate Cap [Member]
Liabilities:
Number of instruments held		1