Rental Property - Deferred Leasing Intangibles - Income Statement Disclosures (Details) (USD $)	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Above and Below Market Leases
Deferred leasing intangibles
Net decrease to rental revenue related to above and below market lease amortization	$ 2,100,000	$ 1,500,000
Net Decrease to Rental Income Related to Above and Below Market Leases
Remainder of 2015	6,002,000
2016	5,606,000
2017	3,941,000
2018	2,699,000
2019	2,408,000
Other Intangible Lease Assets
Deferred leasing intangibles
Other intangible lease assets amortization expense	14,300,000	11,500,000
Estimated Net Amortization of In-Place Leases, Leasing Commissions and Tenant Relationships
Remainder of 2015	40,909,000
2016	46,997,000
2017	37,992,000
2018	29,114,000
2019	$ 20,604,000

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Represents amount of net decrease (increase) to rental revenue expected from leases in the remainder of the fiscal year following the latest fiscal year ended.

+ References

No definition available.

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- Definition

Represents amount of decrease (increase) to rental revenue expected rental revenue expected from leases during the fifth fiscal year following the latest fiscal year.

+ References

No definition available.

+ Details

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Represents amount of decrease (increase) to rental revenue expected from leases during the fourth fiscal year following the latest fiscal year.

+ References

No definition available.

+ Details

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- Definition

Represents amount of decrease (increase) to rental revenue expected from leases during the third fiscal year following the latest fiscal year.

+ References

No definition available.

+ Details

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Represents amount of decrease (increase) to rental revenue expected from leases during the second fiscal year following the latest fiscal year.

+ References

No definition available.

+ Details

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- Definition

Represents amount of increase (decrease) to rental revenues related to net amortization of above (below) market leases.

+ References

No definition available.

+ Details

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The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

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-Name Accounting Standards Codification

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized in the remainder of the fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

No definition available.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(3)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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