Property, Plant and Equipment and Leasehold Intangibles, Net (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property, plant and equipment and leasehold intangibles gross	$ 8,459,337		$ 8,459,337		$ 8,916,465
Accumulated depreciation and amortization	(3,052,207)		(3,052,207)		(3,064,320)
Property, plant and equipment and leasehold intangibles, net	5,407,130		5,407,130		5,852,145
Depreciation and amortization expense	110,400	$ 116,700	339,000	$ 361,200
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment and leasehold intangibles gross	461,734		461,734		449,295
Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment and leasehold intangibles gross	4,952,807		4,952,807		4,923,621
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment and leasehold intangibles gross	123,765		123,765		124,850
Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment and leasehold intangibles gross	1,037,947		1,037,947		1,006,889
Resident and Leasehold Operating Intangibles [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment and leasehold intangibles gross	522,851		522,851		594,748
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment and leasehold intangibles gross	47,325		47,325		74,678
Assets Under Capital and Financing Leases [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment and leasehold intangibles gross	$ 1,312,908		$ 1,312,908		$ 1,742,384