Assets classified as held for sale (Details) $ in Thousands	Sep. 30, 2021 USD ($) ft²	Dec. 31, 2020 USD ($)
Discontinued Operations and Disposal Groups [Abstract]
Assets held for sale - area of real estate \| ft²	413,151
Net assets held for sale [Abstract]
Total assets	$ 28,174	$ 117,879
Total liabilities	(1,085)	(33,081)
Total accumulated other comprehensive loss	(1,276)	(841)
Net assets classified as held for sale	$ 25,813	$ 83,957

Disposal Group, Including Assets Held for Sale Not Qualifying as Discontinued Operations, Accumulated Other Comprehensive Income (Loss)

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