Property, Plant and Equipment and Leasehold Intangibles, Net - Property, Plant and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property, plant and equipment and leasehold intangibles gross	$ 8,916,465	$ 10,264,151
Accumulated depreciation and amortization	(3,064,320)	(2,884,846)
Property, plant and equipment and leasehold intangibles, net	5,852,145	7,379,305
Depreciation and amortization expense for plant and equipment and leasehold intangibles	479,400	514,200	$ 721,000
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment and leasehold intangibles gross	449,295	455,307
Buildings and improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment and leasehold intangibles gross	4,923,621	5,053,204
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment and leasehold intangibles gross	124,850	126,325
Furniture and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment and leasehold intangibles gross	1,006,889	974,516
Resident and leasehold operating intangibles
Property, Plant and Equipment [Line Items]
Property, plant and equipment and leasehold intangibles gross	594,748	705,000
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment and leasehold intangibles gross	74,678	69,803
Assets under capital and financing leases
Property, Plant and Equipment [Line Items]
Property, plant and equipment and leasehold intangibles gross	$ 1,742,384	$ 2,879,996