Other Matters (Details) (USD $) Share data in Millions, except Per Share data, unless otherwise specified	0 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended	0 Months Ended		1 Months Ended
	Apr. 25, 2013	Sep. 30, 2013 sqft	Sep. 30, 2012	Sep. 30, 2013 sqft	Sep. 30, 2012	Dec. 31, 2012	Mar. 25, 2013 Public offering	Mar. 25, 2013 Pursuant to the exercise of the underwriter	Jul. 31, 2013 Facility Closing	Sep. 30, 2013 Mesa Corporate Center sqft
Subsidiary, Sale of Stock [Line Items]
Shares issued in transaction (in shares)							11.00	1.65
Public offering price per share (in dollars per share)							$ 17.25
Net proceeds on Transaction							$ 209,000,000
Series D Cumulative Redeemable preferred stock interest rate (in percent)				8.00%		8.00%
Expected charge related to the redemption of preferred stock	6,600,000
Expected closure costs to be incurred in Q3 of 2013									3,600,000
Non-cash impairment loss on real estate		$ 5,600,000	$ 0	$ 5,600,000	$ 0
Area of real estate property (in square feet)		640,000		640,000						106,000