Real Estate - Portfolio (Summary Of Real Estate Subject To Operating Leases) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Property Subject to or Available for Operating Lease [Line Items]
Real estate dubject to operating leases, gross	$ 3,777,202	$ 3,425,565
Less accumulated depreciation and amortization	(317,858)	(269,472)
Real estate subject to operating leases before work in process	3,459,344	3,156,093
Real estate subject to operating leases, net	3,565,782	3,211,022
Land And Improvements [Member]
Property Subject to or Available for Operating Lease [Line Items]
Real estate subject to operating leases, gross	1,411,703	1,310,785
Buildings And Improvements [Member]
Property Subject to or Available for Operating Lease [Line Items]
Buildings and improvements	2,364,209	2,113,490
Leasehold Interests [Member]
Property Subject to or Available for Operating Lease [Line Items]
Leasehold interests	1,290	1,290
Work In Progress [Member]
Property Subject to or Available for Operating Lease [Line Items]
Work in progess	$ 106,438	$ 54,929

Aggregate carrying amounts as of the balance sheet date of investments in leasehold interests

No definition available.

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- Definition

Real Estate Subject To Operating Leases Before Work In Process

+ References

No definition available.

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- Definition

Real Estate Subject to Operating Leases, Gross

+ References

No definition available.

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- Definition

The current amount of expenditures for a real estate project that has not yet been completed.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.10)

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- Definition

Aggregate of the carrying amounts as of the balance sheet date of investments in building and building improvements.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.1(d))

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- Definition

Carrying amount as of the balance sheet date of real estate held for productive use. This excludes land held for sale.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section 45

-Paragraph 4

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=6361293&loc=d3e6812-107765

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.13)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

The amount of accumulated depreciation, by major property class, recorded on property subject to or available for lease as of the balance sheet date.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 13

-Paragraph 19

-Subparagraph a

-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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-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

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- Definition

Amount of real estate investment property, net of accumulated depreciation, which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; and (7) other real estate investments.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.1(d))

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