Debt And Lines Of Credit , Table - Maturities and Amortization of debt and lines of credit (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012
Debt Instrument [Line Items]
Total Due	$ 1,293,555
2012	39,912
2013	59,675
2014	211,799
2015	38,161
2016	320,159
After 5 years	623,849
Lines of Credit [Member]
Debt Instrument [Line Items]
Total Due	5,984
2012	5,984
2013	0
2014	0
2015	0
2016	0
After 5 years	0
Mortgage maturities [Member]
Debt Instrument [Line Items]
Total Due	1,003,025
2012	13,961
2013	33,754
2014	185,774
2015	16,622
2016	299,706
After 5 years	453,208
Mortgage principal amortization [Member]
Debt Instrument [Line Items]
Total Due	152,113
2012	12,636
2013	17,932
2014	17,594
2015	16,883
2016	15,293
After 5 years	71,775
Aspen and Series B-3 Preferred OP Units [Member]
Debt Instrument [Line Items]
Total Due	48,822
2012	4,670
2013	4,145
2014	4,225
2015	0
2016	0
After 5 years	35,782
Secured borrowing [Member]
Debt Instrument [Line Items]
Total Due	83,611
2012	2,661
2013	3,844
2014	4,206
2015	4,656
2016	5,160
After 5 years	$ 63,084

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Including current and noncurrent portions, aggregate carrying amount of long-term borrowings as of the balance sheet date. May include notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, which had initial maturities beyond one year or beyond the normal operating cycle, if longer, and after deducting unamortized discount or premiums, if any.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22)

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-Name Accounting Standards Codification

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-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.16)

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 7

-Section 03

-Paragraph 16

Reference 4: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

-Topic 944

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-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16)

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- Definition

Amount of long-term debt maturities after year five following the date of the latest balance sheet presented in the financial statements, which may include maturities of long-term debt, sinking fund requirements, and other securities redeemable at fixed of determinable prices and dates.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 47

-Paragraph 10

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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Amount of long-term debt maturing within the next twelve months following the date of the latest balance sheet presented in the financial statements, which may include maturities of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates.

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Amount of long-term debt maturing in year five following the date of the latest balance sheet presented in the financial statements, which may include maturities of long-term debt, sinking fund requirements, and other securities redeemable at fixed of determinable prices and dates.

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Amount of long-term debt maturing in year four following the date of the latest balance sheet presented in the financial statements, which may include maturities of long-term debt, sinking fund requirements, and other securities redeemable at fixed of determinable prices and dates.

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Amount of long-term debt maturing in year three following the date of the latest balance sheet presented in the financial statements, which may include maturities of long-term debt, sinking fund requirements, and other securities redeemable at fixed of determinable prices and dates.

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