Property, Plant and Equipment and Leasehold Intangibles, Net - Property, Plant and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property, plant and equipment and leasehold intangibles gross	$ 8,322,802	$ 8,916,465
Accumulated depreciation and amortization	(3,047,375)	(3,064,320)
Property, plant and equipment and leasehold intangibles, net	5,275,427	5,852,145
Depreciation and amortization expense for plant and equipment and leasehold intangibles	444,300	479,400	$ 514,200
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment and leasehold intangibles gross	456,912	449,295
Buildings and improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment and leasehold intangibles gross	4,919,789	4,923,621
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment and leasehold intangibles gross	123,366	124,850
Furniture and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment and leasehold intangibles gross	1,036,113	1,006,889
Resident and leasehold operating intangibles
Property, Plant and Equipment [Line Items]
Property, plant and equipment and leasehold intangibles gross	477,827	594,748
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment and leasehold intangibles gross	57,636	74,678
Assets under capital and financing leases
Property, Plant and Equipment [Line Items]
Property, plant and equipment and leasehold intangibles gross	$ 1,251,159	$ 1,742,384