XML 83 R57.htm IDEA: XBRL DOCUMENT v3.8.0.1
Discontinued Operations, Assets Held for Sale and Impairments Real Estate Assets (Details) - USD ($)
$ in Thousands
Dec. 31, 2017
Dec. 31, 2016
Real Estate Assets [Abstract]    
Investment Building and Building Improvements $ 4,642,832 $ 3,752,423
Land and Land Improvements 1,950,735 1,392,382
Real Estate Assets $ 6,593,567 $ 5,144,805