Real Estate Assets Real estate assets owned (Details)	Dec. 31, 2021 ft²	Dec. 31, 2021 lease	Dec. 31, 2021	Dec. 31, 2021 number_of_properties	Dec. 31, 2021 unit	Dec. 31, 2020 ft²	Dec. 31, 2020	Dec. 31, 2020 number_of_properties	Dec. 31, 2020 unit
Business Combination Segment Allocation [Line Items]
Number of Real Estate Properties		109	10	1			14	2
Number of units in real estate property | unit					1,278				1,293
Area of Real Estate Property, Excluded from Floor Retail Space	0					35,000
Residential Properties
Business Combination Segment Allocation [Line Items]
Number of Real Estate Properties			41				37
Number of units in real estate property			12,052				11,143
New Market Properties [Member]
Business Combination Segment Allocation [Line Items]
Number of Real Estate Properties			54				54
Area of Real Estate Property	6,210,778					6,208,278
Preferred Office Properties [Member]
Business Combination Segment Allocation [Line Items]
Number of Real Estate Properties			2				9
Area of Real Estate Property, Excluded from Floor Retail Space	1,072,000					3,169,000
Lenox Portfolio [Member]
Business Combination Segment Allocation [Line Items]
Net Rentable Area	47,600