Supplemental Disclosure of Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Supplemental Cash Flow Information [Abstract]
Interest paid			$ 198,133	$ 223,929
Income taxes paid, net of refunds			1,542	1,595
Net cash paid			169,349	140,044
Prepaid expenses and other assets, net			21,874	23,323
(Gain) loss on sale of assets, net	$ (9,833)	$ 233	(76,586)	1,383
Loss on facility lease termination and modification, net	2,337	4,938	148,804	11,306
Net cash paid			12,548	552
Additions to property, plant and equipment and leasehold intangibles, net
Supplemental Cash Flow Information [Abstract]
Property, plant and equipment and leasehold intangibles, net			154,249	139,734
Trade accounts payable			15,100	310
Net cash paid			169,349	140,044
Acquisition of assets, net of related payables and cash received
Supplemental Cash Flow Information [Abstract]
Property, plant and equipment and leasehold intangibles, net			237,563	0
Other intangible assets, net			(4,345)	400
Capital and financing lease obligations			36,120	0
Other liabilities			2,433	0
Net cash paid			271,771	400
Proceeds from sale of assets, net
Supplemental Cash Flow Information [Abstract]
Prepaid expenses and other assets, net			(3,006)	(14,387)
Assets held for sale			(18,758)	(20,952)
Property, plant and equipment and leasehold intangibles, net			(91,778)	(19,184)
Investments in unconsolidated ventures			(58,179)	(26,301)
Long-term debt			0	7,552
Capital and financing lease obligations			93,514	7,646
Refundable entrance fees and deferred revenue			8,345	30,771
Other liabilities			2,690	39
(Gain) loss on sale of assets, net			(64,740)	1,408
Loss on facility lease termination and modification, net			0	1,162
Net cash received			(131,912)	(34,570)
Lease termination and modification, net
Supplemental Cash Flow Information [Abstract]
Prepaid expenses and other assets, net			(2,040)	0
Property, plant and equipment and leasehold intangibles, net			(81,320)	0
Capital and financing lease obligations			58,099	0
(Gain) loss on sale of assets, net			(5,761)	0
Loss on facility lease termination and modification, net			22,260	0
Deferred liabilities			67,950	0
Net cash paid			59,188	0
Formation of the Blackstone Venture
Supplemental Cash Flow Information [Abstract]
Prepaid expenses and other assets, net			0	(8,173)
Investments in unconsolidated ventures	$ 0	$ 66,816	0	66,816
Capital and financing lease obligations			0	879,959
Deferred liabilities			0	7,504
Other liabilities			0	1,998
Property, plant and equipment and leasehold intangibles, net			0	(768,897)
Net cash paid			0	179,207
Assets designated as held for sale
Supplemental Cash Flow Information [Abstract]
Prepaid expenses and other assets, net			281	(199)
Assets held for sale			(162,157)	29,544
Property, plant and equipment and leasehold intangibles, net			(161,876)	29,345
Net			0	0
Lease termination and modification, net
Supplemental Cash Flow Information [Abstract]
Prepaid expenses and other assets, net			4,783	0
Property, plant and equipment and leasehold intangibles, net			106,264	0
Capital and financing lease obligations			112,267	0
Other liabilities			625	0
(Gain) loss on sale of assets, net			(6,085)	0
Loss on facility lease termination and modification, net			126,544	0
Deferred liabilities			(122,304)	0
Net			$ 0	$ 0