Real Estate Activities - Impairment of Assets (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2021	Jun. 30, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of real estate assets		$ 1,302	$ 0
Valley View Center
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of real estate assets	$ 1,300
Asset classified as held for sale transaction completion period	1 year