Assets Held for Sale or Contribution - Summary of Assets Held for Sale or Contribution (Detail) ft² in Thousands, $ in Thousands	Mar. 31, 2021 USD ($) ft² Property	Dec. 31, 2020 USD ($) ft² Property
Long Lived Assets Held For Sale [Line Items]
Total assets held for sale or contribution	$ 1,055,751	$ 1,070,724
Total liabilities associated with assets held for sale or contribution – included in Other Liabilities	$ 21,828	$ 16,214
Disposal Group Held for Sale Not Discontinued Operations [Member]
Long Lived Assets Held For Sale [Line Items]
Number of operating properties | Property	80	66
Square feet | ft²	13,756	12,923