Discontinued Operations and Assets Held for Sale (Aggregate Balance Sheet of Properties Held for Sale Included in Discontinued Operations) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($) buildings	Dec. 31, 2020 USD ($)
Discontinued Operations
Continuing Operations, Number of In-service Properties Held for Sale | buildings	3
Land and Land Improvements Held-for-Sale	$ (67,818)
Buildings and Tenant Improvements Held-for-Sale	(102,867)
Accumulated Depreciation of Assets Held-for-Sale	36,785
Total assets held-for-sale	144,651	$ 67,946
Total liabilities held-for-sale	6,278	7,740
Continuing Operations [Member]
Discontinued Operations
Land and Land Improvements Held-for-Sale	67,818	27,954
Buildings and Tenant Improvements Held-for-Sale	102,867	44,800
Accumulated Depreciation of Assets Held-for-Sale	(36,785)	(5,976)
Lease Related Assets, Held for Sale	5,392	936
Other assets	5,359	232
Total assets held-for-sale	144,651	67,946
Accrued Expenses Held-for-Sale	43	660
Other Liabilities Held-for-Sale	6,235	7,080
Total liabilities held-for-sale	$ 6,278	$ 7,740