Discontinued Operations (Details Textuals) (Details) (USD $)	3 Months Ended		6 Months Ended		0 Months Ended	12 Months Ended		3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Apr. 07, 2014 Princeton Pike Corporate Center [Member]	Feb. 25, 2014 Princeton Pike Corporate Center [Member]	Feb. 25, 2013 Princeton Pike Corporate Center [Member]	Jun. 30, 2013 Discontinued Operations [Member]	Jun. 30, 2013 Discontinued Operations [Member]	Dec. 31, 2013 Discontinued Operations [Member] Properties
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Business Acquisition, Transaction Costs							$ 2,000,000
Net gain on disposition of discontinued operations	$ 903,000	$ (2,259,000)	$ 903,000	$ 3,045,000	$ 900,000	$ 5,300,000		$ (2,259,000)	$ 3,045,000
Number of properties sold										14