Schedule II: Valuation and Qualifying Accounts (Details) - Allowance Accounts - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Continuing Operations
Movement in Valuation Allowances and Reserves
Balance at Beginning of Year	$ 387	$ 624	$ 142,940
Additions
Amounts Charged Against Operations, net	76	(146)	3,366
Acquired Properties	3,531	387	0
Deductions
Uncollectible Accounts Written-off	0	0	(1,887)
Dispositions	0	0	(143,795)
Balance at End of Year	3,994	387	624
Discontinued Operations
Movement in Valuation Allowances and Reserves
Balance at Beginning of Year	4,178	27,173	26,434
Additions
Amounts Charged Against Operations, net	1,026	1,695	739
Acquired Properties	175	928	0
Deductions
Uncollectible Accounts Written-off	0	0	0
Dispositions	494	(700)	0
Balance at End of Year	$ 5,873	4,178	27,173
ASU 2016-02 | Continuing Operations
Movement in Valuation Allowances and Reserves
Balance at Beginning of Year		146
Deductions
Balance at End of Year			146
ASU 2016-02 | Discontinued Operations
Movement in Valuation Allowances and Reserves
Balance at Beginning of Year		$ 2,255
Deductions
Balance at End of Year			$ 2,255