Annual report pursuant to Section 13 and 15(d)

Discontinued Operations (Narrative) (Details)

v3.3.1.900
Discontinued Operations (Narrative) (Details)
$ in Thousands
12 Months Ended
Dec. 31, 2015
USD ($)
ft²
item
Dec. 31, 2014
USD ($)
ft²
property
Dec. 31, 2013
USD ($)
ft²
property
item
Discontinued Operations [Abstract]      
Number of properties sold 6 16 24
Area of property sold (in square feet) | ft² 690,315 2,610,931 3,000,000
Number of land parcels sold | item     3
Sales proceeds | $ $ 148,256 $ 319,239 $ 390,600