Commitments and Contingencies (Schedule of Lease Commitments) (Details) $ in Thousands	Mar. 31, 2021 USD ($)
Maximum Commitment For All Active Development Projects	$ 28,395
Development in Process	(23,445)
Remaining Unfunded Development Commitment	4,950
Capital Improvement Commitment [Member]
Maximum Commitment For All Active Development Projects	1,650
Development in Process	(391)
Remaining Unfunded Development Commitment	1,259
Capital Improvement Commitment [Member] | Woodland Village [Member]
Maximum Commitment For All Active Development Projects	7,515
Development in Process	(7,425)
Remaining Unfunded Development Commitment	90
Capital Improvement Commitment [Member] | Senior Living Communities [Member]
Maximum Commitment For All Active Development Projects	9,930
Development in Process	(9,930)
Remaining Unfunded Development Commitment	0
Capital Improvement Commitment [Member] | Wingate Healthcare [Member]
Maximum Commitment For All Active Development Projects	1,900
Development in Process	(1,800)
Remaining Unfunded Development Commitment	100
Capital Improvement Commitment [Member] | Discovery Senior Living [Member]
Maximum Commitment For All Active Development Projects	900
Development in Process	(899)
Remaining Unfunded Development Commitment	1
Capital Improvement Commitment [Member] | Watermark Retirement [Member]
Maximum Commitment For All Active Development Projects	6,500
Development in Process	(3,000)
Remaining Unfunded Development Commitment	$ 3,500