Investment in Office Properties and Parking Properties - Business Combination Pro Forma (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Business Combinations [Abstract]
Revenues	$ 109,534	$ 106,248	$ 218,373	$ 211,822
Net income (loss) attributable to common stockholders	$ (9,845)	$ (9,549)	$ 451	$ 437
Basic net income (loss) attributable to common stockholders per share	$ (0.10)	$ (0.14)	$ 0.00	$ 0.01
Diluted net income (loss) attributable to common stockholders per share	$ (0.10)	$ (0.14)	$ 0.00	$ 0.01

The pro forma basic net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(2)-(3)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

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The pro forma diluted net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

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The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

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The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

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