Real Estate Properties - Narrative (Details) $ in Thousands |
9 Months Ended | 12 Months Ended | |
---|---|---|---|
Sep. 30, 2017
USD ($)
ft²
building
|
Sep. 30, 2016
USD ($)
|
Dec. 31, 2016
USD ($)
ft²
property
building
|
|
Real Estate [Abstract] | |||
Real estate improvements | $ | $ 43,300 | $ 88,500 | |
Number of properties held for sale | property | 0 | ||
Disposed of by Sale | |||
Real Estate Properties [Line Items] | |||
Number of properties sold | property | 30 | ||
Number of buildings sold | building | 20 | 62 | |
Square footage (in sqft) | ft² | 5,099,423 | 8,000,000 | |
Gross sales price | $ | $ 755,675 | $ 1,300,000 |