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Line of Credit Facility, Option for Additional Borrowing Capacity subject to customary conditions and limitations

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- Definition

Properties encumbered mortgage indebtedness carrying value, net

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No definition available.

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Amount of noncash expense included in interest expense to issue debt and obtain financing associated with the related debt instruments. Alternate captions include noncash interest expense.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

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-Section S99

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-Subparagraph (SX 210.5-03.8)

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-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 8

-Article 5

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-Name Regulation S-X (SX)

-Number 210

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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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No definition available.

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Amount of long-term debt before deduction of unamortized discount or premium. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, with initial maturities beyond one year or the normal operating cycle, if longer.

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-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 20

-Article 5

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-Section 03

-Paragraph 16

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Face (par) amount of debt instrument at time of issuance.

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-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 30

-Section 45

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

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-Subparagraph (SX 210.5-02.22(a)(1))

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Average fixed interest rate related to the group of interest rate derivatives.

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- Definition

The cash outflow for the extinguishment of long-term borrowing, with the highest claim on the assets of the entity in case of bankruptcy or liquidation, before its maturity.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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-Topic 230

-SubTopic 10

-Section 45

-Paragraph 15

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-Glossary Financing Activities

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Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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-Name Accounting Standards Codification

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The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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-Publisher FASB

-Name Accounting Standards Codification

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-Subparagraph (SX 210.5-02.19(b),22(b))

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Debt Obligations (Details Textuals) (USD $)	12 Months Ended
Debt Obligations (Details Textuals) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Debt obligations (Textuals)
Amortization of Financing Costs	$ 4,676,000	$ 6,208,000	$ 4,991,000
Early Repayment of Senior Debt	31,296,000
Gain (loss) on early extinguishment of debt	(2,119,000)	(22,002,000)	(2,776,000)
Unsecured Debt [Member]
Debt obligations (Textuals)
Long-term Debt, Gross	1,929,703,000	2,027,953,000
Secured Debt [Member]
Participating Mortgage Loans [Line Items]
Properties encumbered mortgage indebtedness carrying value, net	669,762,000	591,300,000
Debt obligations (Textuals)
Long-term Debt, Gross	669,762,000	443,942,000
Letter of Credit [Member] \| Unsecured Debt [Member]
Debt obligations (Textuals)
Letters of credit outstanding	1,300,000
New Revolving Credit Facility [Member] \| Unsecured Debt [Member]
Participating Mortgage Loans [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.50%
Debt obligations (Textuals)
Unused availability under the Credit Facility	598,700,000
Option for additional borrowings subject to customary conditions and limitations	200,000,000
Long-term Debt, Gross	0	69,000,000
Note 2023 [Member] \| Unsecured Debt [Member]
Debt obligations (Textuals)
Long-term Debt, Gross	250,000,000	250,000,000
$300.0M 5.750% Guaranteed Notes due 2012 [Member] \| Unsecured Debt [Member]
Debt obligations (Textuals)
Debt instrument, face amount	300,000,000
Debt Instrument, Interest Rate, Stated Percentage	5.75%
$250.0M 5.400% Guaranteed Notes due 2014 [Member] \| Unsecured Debt [Member]
Debt obligations (Textuals)
Debt instrument, face amount	250,000,000
Debt Instrument, Interest Rate, Stated Percentage	5.40%
Long-term Debt, Gross	218,549,000	238,379,000
$250.0M 7.500% Guaranteed Notes due 2015 [Member] \| Unsecured Debt [Member]
Debt obligations (Textuals)
Debt instrument, face amount	250,000,000
Debt Instrument, Interest Rate, Stated Percentage	7.50%
Long-term Debt, Gross	157,625,000	166,535,000
$250.0M 6.000% Guaranteed Notes due 2016 [Member] \| Unsecured Debt [Member]
Debt obligations (Textuals)
Debt instrument, face amount	250,000,000
Debt Instrument, Interest Rate, Stated Percentage	6.00%
Long-term Debt, Gross	149,919,000	150,429,000
$300.0M 5.700% Guaranteed Notes due 2017 [Member] \| Unsecured Debt [Member]
Debt obligations (Textuals)
Debt instrument, face amount	300,000,000
Debt Instrument, Interest Rate, Stated Percentage	5.70%
Long-term Debt, Gross	300,000,000	300,000,000
$325.0M 4.950% Guaranteed Notes due 2018 [Member] \| Unsecured Debt [Member]
Debt obligations (Textuals)
Debt instrument, face amount	325,000,000
Debt Instrument, Interest Rate, Stated Percentage	4.95%
Long-term Debt, Gross	325,000,000	325,000,000
Three Year Term Loan [Member] \| Unsecured Debt [Member]
Participating Mortgage Loans [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.75%
Debt obligations (Textuals)
Debt instrument, face amount	150,000,000
Derivative, Average Fixed Interest Rate	2.596%
Long-term Debt, Gross	150,000,000	150,000,000
Seven Year Term Loan [Member] \| Unsecured Debt [Member]
Participating Mortgage Loans [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.90%
Debt obligations (Textuals)
Debt instrument, face amount	200,000,000
Derivative, Average Fixed Interest Rate	3.623%
Long-term Debt, Gross	200,000,000	200,000,000
Note Nine [Member] \| Unsecured Debt [Member]
Debt obligations (Textuals)
Debt instrument, face amount	$ 250,000,000
Debt Instrument, Interest Rate, Stated Percentage	3.95%
Federal Funds Rate [Member] \| Bank Term Loan and the Credit Facility [Member]
Participating Mortgage Loans [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.50%