Assets Held for Sale (Details) $ in Thousands	Mar. 31, 2021 USD ($) ft²	Dec. 31, 2020 USD ($) ft²
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets held for sale	$ 73,876	$ 73,876
Liabilities related to assets held for sale	$ 213
Disposal Group, Held-for-sale \| Pen Place \| Arlington, Virginia
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of real estate property \| ft²	2,082	2,082
Assets held for sale	$ 73,876	$ 73,876
Liabilities related to assets held for sale	$ 213

Amount classified as liabilities attributable to disposal group held for sale or disposed of.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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