Subsequent Events (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended						0 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Oct. 09, 2013 Subsequent event FSP Galleria North Corp.	Oct. 11, 2013 Cash distribution declared Subsequent event
Subsequent events
Cash dividend declared per share (in dollars per share)	$ 0.19	$ 0.19	$ 0.19	$ 0.19	$ 0.19	$ 0.19		$ 0.19
Advance paid to related party pursuant to a Sponsored REIT Loan							$ 1.2