Land, Buildings and Improvements and Assets Held for Sale - Summary of Assets Held for Sale (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Real Estate Properties
Assets held for sale, net	$ 5,682	$ 18,590
In-place lease intangible assets and other, net
Real Estate Properties
Assets held for sale, net	0	12,754
Above-market rent intangible assets
Real Estate Properties
Assets held for sale, net	0	518
Land, buildings and improvements
Real Estate Properties
Assets held for sale, net	8,334	14,051
Accumulated depreciation and amortization
Real Estate Properties
Assets held for sale, net	$ 2,652	$ 8,733