Supplemental Disclosure of Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Supplemental Cash Flow Information [Abstract]
Interest paid			$ 157,688	$ 185,722
Income taxes paid, net of refunds			4,236	1,909
Net cash paid			140,690	206,385
Operating lease right-of-use assets	$ 3,300		75,600
Loss (gain) on debt modification and extinguishment, net	(7,917)	$ (2,455)	11,107	(5,194)
Investments in unconsolidated ventures			(1,809)	(4,294)
Loss (gain) on sale of assets, net	2,209	579	374,019	2,723
Prepaid expenses and other assets, net			27,504	50,387
Loss (gain) on facility lease termination and modification, net	$ 0	$ 0	0	2,006
Additions to property, plant and equipment and leasehold improvements
Supplemental Cash Flow Information [Abstract]
Net cash paid			140,690	206,385
Trade accounts payable			7,849	(4,522)
Acquisition of communities from Healthpeak
Supplemental Cash Flow Information [Abstract]
Property, plant and equipment and leasehold intangibles, net			286,734	0
Operating lease right-of-use assets			(63,285)	0
Financing lease obligations			129,196	0
Operating lease obligations			74,335	0
Loss (gain) on debt modification and extinguishment, net			(19,731)	0
Net cash paid			407,249	0
Ventas master lease and debt modification
Supplemental Cash Flow Information [Abstract]
Property, plant and equipment and leasehold intangibles, net			(66,444)	0
Operating lease right-of-use assets			(153,213)	0
Financing lease obligations			7,077	0
Operating lease obligations			362,944	0
Net cash paid			119,180	0
Other assets, net			(42,354)	0
Long-term debt			34,053	0
Additional paid-in-capital			(22,883)	0
Acquisition of assets, net of related payables and cash received
Supplemental Cash Flow Information [Abstract]
Property, plant and equipment and leasehold intangibles, net			684	0
Financing lease obligations			64,260	0
Net cash paid			64,944	453
Other intangible assets, net			0	453
Proceeds from sale of CCRC Venture, net:
Supplemental Cash Flow Information [Abstract]
Investments in unconsolidated ventures			(14,848)	0
Current portion of long-term debt			34,706	0
Other liabilities			60,748	0
Loss (gain) on sale of assets, net			(369,831)	0
Net cash received			(289,225)	0
Proceeds from sale of assets, net
Supplemental Cash Flow Information [Abstract]
Property, plant and equipment and leasehold intangibles, net			(938)	(647)
Investments in unconsolidated ventures			0	(156)
Other liabilities			(1,086)	(2,724)
Loss (gain) on sale of assets, net			(4,188)	(2,723)
Prepaid expenses and other assets, net			(1,318)	(5,298)
Assets held for sale			(34,348)	(41,882)
Net cash received			(41,878)	(53,430)
Assets designated as held for sale
Supplemental Cash Flow Information [Abstract]
Property, plant and equipment and leasehold intangibles, net			0	(9,164)
Prepaid expenses and other assets, net			0	(5)
Assets held for sale			0	9,169
Net			0	0
Healthpeak master lease modification:
Supplemental Cash Flow Information [Abstract]
Property, plant and equipment and leasehold intangibles, net			(57,462)	0
Operating lease right-of-use assets			88,044	0
Financing lease obligations			70,874	0
Operating lease obligations			(101,456)	0
Net			0	0
Noncash lease termination and modification, net
Supplemental Cash Flow Information [Abstract]
Property, plant and equipment and leasehold intangibles, net			13,498	(1,666)
Operating lease right-of-use assets			7,291	(8,644)
Financing lease obligations			(15,483)	0
Operating lease obligations			(5,199)	9,289
Other liabilities			(107)	(337)
Prepaid expenses and other assets, net			0	(648)
Loss (gain) on facility lease termination and modification, net			0	2,006
Net			0	0
Non-development | Additions to property, plant and equipment and leasehold improvements
Supplemental Cash Flow Information [Abstract]
Net cash paid			104,949	180,187
Development | Additions to property, plant and equipment and leasehold improvements
Supplemental Cash Flow Information [Abstract]
Net cash paid			9,913	18,677
Non-development - reimbursable | Additions to property, plant and equipment and leasehold improvements
Supplemental Cash Flow Information [Abstract]
Net cash paid			$ 17,979	$ 12,043