Segment Reporting (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) segment	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Segment reporting
Number of reportable segments | segment	2
Total revenues	$ 1,410,308,000	$ 1,283,566,000	$ 1,383,212,000
Expenses:
Property operating expenses	1,174,151,000	1,109,070,000	1,091,812,000
Depreciation and amortization	284,083,000	239,280,000	271,131,000
General and administrative	26,131,000	26,435,000	34,087,000
Acquisition and certain other transaction related costs	10,853,000	2,605,000	17,506,000
Impairment of assets	18,380,000	0	(174,000)
Total expenses	1,513,598,000	1,377,390,000	1,414,362,000
Gain on sale of properties	1,205,000	321,862,000	492,272,000
Gains (losses) on equity securities, net	8,126,000	(25,660,000)	(42,232,000)
Interest and other income	15,536,000	15,929,000	20,635,000
Interest expense	(191,775,000)	(209,383,000)	(255,759,000)
Loss on modification or early extinguishment of debt	(2,468,000)	(30,043,000)	(2,410,000)
(Loss) income from continuing operations before income tax expense and equity in net (losses) earnings of investees	(272,666,000)	(21,119,000)	181,356,000
Income tax expense	(445,000)	(710,000)	(1,430,000)
Equity in net (losses) earnings of investees	(20,461,000)	6,055,000	0
Net (loss) income	(293,572,000)	(15,774,000)	179,926,000
Net income attributable to noncontrolling interest			(5,411,000)
Net (loss) income attributable to common shareholders	(293,572,000)	(15,774,000)	174,515,000
Total assets	5,446,136,000	6,002,093,000	6,623,514,000
Non-Segment
Segment reporting
Total revenues	37,870,000	38,350,000	40,992,000
Expenses:
Property operating expenses	1,096,000	671,000	0
Depreciation and amortization	9,952,000	11,343,000	11,455,000
General and administrative	26,131,000	26,435,000	34,087,000
Acquisition and certain other transaction related costs	10,853,000	2,605,000	17,506,000
Impairment of assets	0		0
Total expenses	48,032,000	41,054,000	63,048,000
Gain on sale of properties	0	0	0
Gains (losses) on equity securities, net	8,126,000	(25,660,000)	(42,232,000)
Interest and other income	13,955,000	11,602,000	1,081,000
Interest expense	(190,775,000)	(206,936,000)	(230,193,000)
Loss on modification or early extinguishment of debt	(2,468,000)	(30,059,000)	(2,410,000)
(Loss) income from continuing operations before income tax expense and equity in net (losses) earnings of investees	(181,324,000)	(253,757,000)	(295,810,000)
Income tax expense	(445,000)	(710,000)	(1,430,000)
Equity in net (losses) earnings of investees	0	0
Net (loss) income			(297,240,000)
Net income attributable to noncontrolling interest			0
Net (loss) income attributable to common shareholders	(181,769,000)	(254,467,000)	(297,240,000)
Total assets	444,736,000	887,064,000	1,345,043,000
Office Portfolio | Operating Segments
Segment reporting
Total revenues	220,530,000	222,390,000	367,597,000
Expenses:
Property operating expenses	97,964,000	94,299,000	127,313,000
Depreciation and amortization	98,205,000	76,007,000	127,632,000
General and administrative	0	0	0
Acquisition and certain other transaction related costs	0	0	0
Impairment of assets	14,034,000		0
Total expenses	210,203,000	170,306,000	254,945,000
Gain on sale of properties	(1,600,000)	321,040,000	492,072,000
Gains (losses) on equity securities, net	0	0	0
Interest and other income	0	0	0
Interest expense	(449,000)	(913,000)	(23,477,000)
Loss on modification or early extinguishment of debt	0	16,000	0
(Loss) income from continuing operations before income tax expense and equity in net (losses) earnings of investees	8,278,000	372,227,000	581,247,000
Income tax expense	0	0	0
Equity in net (losses) earnings of investees	(20,461,000)	6,055,000
Net (loss) income			581,247,000
Net income attributable to noncontrolling interest			(5,411,000)
Net (loss) income attributable to common shareholders	(12,183,000)	378,282,000	575,836,000
Total assets	1,866,422,000	1,967,244,000	2,995,819,000
SHOP | Operating Segments
Segment reporting
Total revenues	1,151,908,000	1,022,826,000	974,623,000
Expenses:
Property operating expenses	1,075,091,000	1,014,100,000	964,499,000
Depreciation and amortization	175,926,000	151,930,000	132,044,000
General and administrative	0	0	0
Acquisition and certain other transaction related costs	0	0	0
Impairment of assets	4,346,000		(174,000)
Total expenses	1,255,363,000	1,166,030,000	1,096,369,000
Gain on sale of properties	2,805,000	822,000	200,000
Gains (losses) on equity securities, net	0	0	0
Interest and other income	1,581,000	4,327,000	19,554,000
Interest expense	(551,000)	(1,534,000)	(2,089,000)
Loss on modification or early extinguishment of debt	0	0	0
(Loss) income from continuing operations before income tax expense and equity in net (losses) earnings of investees	(99,620,000)	(139,589,000)	(104,081,000)
Income tax expense	0	0	0
Equity in net (losses) earnings of investees	0	0
Net (loss) income			(104,081,000)
Net income attributable to noncontrolling interest			0
Net (loss) income attributable to common shareholders	(99,620,000)	(139,589,000)	(104,081,000)
Total assets	3,134,978,000	3,147,785,000	2,282,652,000
Rental income
Segment reporting
Total revenues	258,400,000	260,740,000	408,589,000
Rental income | Non-Segment
Segment reporting
Total revenues	37,870,000	38,350,000	40,992,000
Rental income | Office Portfolio | Operating Segments
Segment reporting
Total revenues	220,530,000	222,390,000	367,597,000
Rental income | SHOP | Operating Segments
Segment reporting
Total revenues	0	0	0
Residents fees and services
Segment reporting
Total revenues	1,151,908,000	1,022,826,000	974,623,000
Residents fees and services | Non-Segment
Segment reporting
Total revenues	0	0	0
Residents fees and services | Office Portfolio | Operating Segments
Segment reporting
Total revenues	0	0	0
Residents fees and services | SHOP | Operating Segments
Segment reporting
Total revenues	$ 1,151,908,000	$ 1,022,826,000	$ 974,623,000