Segment Reporting (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Revenues:
Total revenues	$ 442,467	$ 266,286
Expenses:
Property operating expenses	316,585	117,222
Depreciation and amortization	68,430	72,230
General and administrative	8,832	9,816
Acquisition and certain other transaction related costs	663	7,814
Impairment of assets	11,234	6,206
Total expenses	405,744	213,288
Gain (loss) on sale of properties	2,782	(122)
Dividend income	0	923
Gains and losses on equity securities, net	(9,943)	22,932
Interest and other income	138	114
Interest expense	(41,650)	(45,611)
Gain on lease termination	22,896	0
Loss on early extinguishment of debt	(246)	0
Income from continuing operations before income tax expense and equity in earnings of an investee	10,700	31,234
Income tax benefit (expense)	443	(134)
Equity in earnings of an investee	0	404
Net income	11,143	31,504
Comprehensive income attributable to noncontrolling interest	(1,408)	(1,422)
Net income attributable to common shareholders	9,735	30,082
Assets	6,703,723		$ 6,653,826
Rental income
Revenues:
Total revenues	110,498	158,241
Residents fees and services
Revenues:
Total revenues	331,969	108,045
Corporate, Non-Segment [Member]
Revenues:
Total revenues	11,728	15,707
Expenses:
Property operating expenses	0	0
Depreciation and amortization	3,225	5,176
General and administrative	8,832	9,816
Acquisition and certain other transaction related costs	663	7,814
Impairment of assets	0	0
Total expenses	12,720	22,806
Gain (loss) on sale of properties	0	0
Dividend income		923
Gains and losses on equity securities, net	(9,943)	22,932
Interest and other income	138	114
Interest expense	(35,034)	(38,587)
Gain on lease termination	22,896
Loss on early extinguishment of debt	0
Income from continuing operations before income tax expense and equity in earnings of an investee	(22,935)	(21,717)
Income tax benefit (expense)	443	(134)
Equity in earnings of an investee		404
Net income	(22,492)	(21,447)
Comprehensive income attributable to noncontrolling interest	0	0
Net income attributable to common shareholders	(22,492)	(21,447)
Assets	489,840		443,260
Corporate, Non-Segment [Member] | Rental income
Revenues:
Total revenues	11,728	15,707
Corporate, Non-Segment [Member] | Residents fees and services
Revenues:
Total revenues	0	0
Medical Office and Life Science Properties [Member]
Revenues:
Total revenues	98,770	103,221
Expenses:
Property operating expenses	32,706	32,177
Depreciation and amortization	32,163	36,101
General and administrative	0	0
Acquisition and certain other transaction related costs	0	0
Impairment of assets	6,218	0
Total expenses	71,087	68,278
Gain (loss) on sale of properties	2,782	(122)
Dividend income		0
Gains and losses on equity securities, net	0	0
Interest and other income	0	0
Interest expense	(6,052)	(6,030)
Gain on lease termination	0
Loss on early extinguishment of debt	(246)
Income from continuing operations before income tax expense and equity in earnings of an investee	24,167	28,791
Income tax benefit (expense)	0	0
Equity in earnings of an investee		0
Net income	24,167	28,791
Comprehensive income attributable to noncontrolling interest	(1,408)	(1,422)
Net income attributable to common shareholders	22,759	27,369
Assets	3,133,881		3,165,577
Medical Office and Life Science Properties [Member] | Rental income
Revenues:
Total revenues	98,770	103,221
Medical Office and Life Science Properties [Member] | Residents fees and services
Revenues:
Total revenues	0	0
Senior Housing Operating Portfolio [Member]
Revenues:
Total revenues	331,969	147,358
Expenses:
Property operating expenses	283,879	85,045
Depreciation and amortization	33,042	30,953
General and administrative	0	0
Acquisition and certain other transaction related costs	0	0
Impairment of assets	5,016	6,206
Total expenses	321,937	122,204
Gain (loss) on sale of properties	0	0
Dividend income		0
Gains and losses on equity securities, net	0	0
Interest and other income	0	0
Interest expense	(564)	(994)
Gain on lease termination	0
Loss on early extinguishment of debt	0
Income from continuing operations before income tax expense and equity in earnings of an investee	9,468	24,160
Income tax benefit (expense)	0	0
Equity in earnings of an investee		0
Net income	9,468	24,160
Comprehensive income attributable to noncontrolling interest	0	0
Net income attributable to common shareholders	9,468	24,160
Assets	3,080,002		$ 3,044,989
Senior Housing Operating Portfolio [Member] | Rental income
Revenues:
Total revenues	0	39,313
Senior Housing Operating Portfolio [Member] | Residents fees and services
Revenues:
Total revenues	$ 331,969	$ 108,045