Assets Held for Sale or Contribution - Summary of Assets Held for Sale or Contribution (Detail) ft² in Thousands, $ in Thousands |
Sep. 30, 2017
USD ($)
ft²
Property
|
Dec. 31, 2016
USD ($)
ft²
Property
|
|---|---|---|
| Long Lived Assets Held For Sale [Line Items] | ||
| Total assets held for sale or contribution | $ 321,905 | $ 322,139 |
| Total liabilities associated with assets held for sale or contribution – included in Other Liabilities | $ 7,389 | $ 4,984 |
| Disposal Group Heldforsale Not Discontinued Operations | ||
| Long Lived Assets Held For Sale [Line Items] | ||
| Number of operating properties | Property | 26 | 13 |
| Square feet | ft² | 4,952 | 4,167 |