Investment in Direct Financing Lease - Narrative (Details) - USD ($)	Sep. 30, 2015	Dec. 31, 2014
Capital Leases, Net Investment in Direct Financing Leases [Abstract]
Percentage of term exceeding useful life of one office tower	75.00%
Carrying amount of net investment in direct financing lease	$ 6,700,000	$ 12,500,000
Allowance for losses related to our direct financing lease	$ 0	$ 0

Represents the percentage of the term exceeding the useful life of one office tower.

No definition available.

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- Definition

The net investment in direct financing leases as of the balance sheet date consisting of: (a) minimum lease payments due on direct financing leases, (b) unguaranteed residual value, and (c) any unamortized initial direct costs; less: (i) executory costs, (ii) unearned income, and (iii) the accumulated allowance for uncollectible minimum lease payments.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 30

-Section 50

-Paragraph 4

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=25496975&loc=d3e45377-112738

+ Details

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Period Type:	instant

- References

No definition available.

+ Details

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- Definition

The estimate of contractual payments on direct financing leases that are probable of not being collected as of the balance sheet date.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 30

-Section 50

-Paragraph 4

-Subparagraph (a)(1)(ii)

-URI http://asc.fasb.org/extlink&oid=25496975&loc=d3e45377-112738

+ Details

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