Segment Reporting - Income Statements (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Revenues:
Total revenues	$ 346,030	$ 310,733
Expenses:
Property operating expenses	286,080	268,742
Depreciation and amortization	64,800	57,259
General and administrative	5,873	7,285
Acquisition and certain other transaction related costs	93	928
Impairment of assets	5,925	0
Total expenses	362,771	334,214
Gain on sale of properties	1,233	327,794
Gains and losses on equity securities, net	8,126	(8,553)
Interest and other income	4,195	395
Interest expense	(47,780)	(57,131)
Loss on modification or early extinguishment of debt	(1,075)	(483)
Income (loss) before income tax benefit and equity in net losses of investees	(52,042)	238,541
Income tax benefit (expense)	31	(1,472)
Equity in net (losses) earnings of investees	(647)	3,354
Net (loss) income	(52,658)	240,423
Rental income
Revenues:
Total revenues	66,438	65,285
Residents fees and services
Revenues:
Total revenues	279,592	245,448
Operating Segments | Office Portfolio
Revenues:
Total revenues	57,022	54,997
Expenses:
Property operating expenses	23,515	23,447
Depreciation and amortization	20,035	18,390
General and administrative	0	0
Acquisition and certain other transaction related costs	0	0
Impairment of assets	2,308
Total expenses	45,858	41,837
Gain on sale of properties	0	327,542
Gains and losses on equity securities, net	0	0
Interest and other income	0	0
Interest expense	(109)	(365)
Loss on modification or early extinguishment of debt	0	0
Income (loss) before income tax benefit and equity in net losses of investees	11,055	340,337
Income tax benefit (expense)	0	0
Equity in net (losses) earnings of investees	(647)	3,354
Net (loss) income	10,408	343,691
Operating Segments | SHOP
Revenues:
Total revenues	279,592	245,448
Expenses:
Property operating expenses	262,329	245,295
Depreciation and amortization	42,152	35,983
General and administrative	0	0
Acquisition and certain other transaction related costs	0	0
Impairment of assets	3,617
Total expenses	308,098	281,278
Gain on sale of properties	1,233	252
Gains and losses on equity securities, net	0	0
Interest and other income	0	199
Interest expense	(271)	(494)
Loss on modification or early extinguishment of debt	0	0
Income (loss) before income tax benefit and equity in net losses of investees	(27,544)	(35,873)
Income tax benefit (expense)	0	0
Equity in net (losses) earnings of investees	0	0
Net (loss) income	(27,544)	(35,873)
Operating Segments | Rental income | Office Portfolio
Revenues:
Total revenues	57,022	54,997
Operating Segments | Rental income | SHOP
Revenues:
Total revenues	0	0
Operating Segments | Residents fees and services | Office Portfolio
Revenues:
Total revenues	0	0
Operating Segments | Residents fees and services | SHOP
Revenues:
Total revenues	279,592	245,448
Non-Segment
Revenues:
Total revenues	9,416	10,288
Expenses:
Property operating expenses	236	0
Depreciation and amortization	2,613	2,886
General and administrative	5,873	7,285
Acquisition and certain other transaction related costs	93	928
Impairment of assets	0
Total expenses	8,815	11,099
Gain on sale of properties	0	0
Gains and losses on equity securities, net	8,126	(8,553)
Interest and other income	4,195	196
Interest expense	(47,400)	(56,272)
Loss on modification or early extinguishment of debt	(1,075)	(483)
Income (loss) before income tax benefit and equity in net losses of investees	(35,553)	(65,923)
Income tax benefit (expense)	31	(1,472)
Equity in net (losses) earnings of investees	0	0
Net (loss) income	(35,522)	(67,395)
Non-Segment | Rental income
Revenues:
Total revenues	9,416	10,288
Non-Segment | Residents fees and services
Revenues:
Total revenues	$ 0	$ 0