Supplemental Disclosure of Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Supplemental Cash Flow Information [Abstract]
Interest paid			$ 223,929	$ 260,504
Income taxes paid, net of refunds			1,595	2,195
Net cash paid			140,044	263,950
Net cash paid			400	12,157
Prepaid expenses and other assets			23,323	(7,338)
Loss (gain) on sale of assets, net			1,383	(2,126)
(Gain) loss on lease termination	$ 4,938	$ 0	11,306	0
Goodwill	(505,783)		(505,783)		$ (705,476)
Asset impairment	368,551	19,111	390,816	26,638
Additions to property, plant and equipment and leasehold intangibles, net [Member]
Supplemental Cash Flow Information [Abstract]
Property, plant and equipment and leasehold intangibles, net			139,734	230,837
Accounts payable			310	33,113
Net cash paid			140,044	263,950
Acquisition of assets, net of related payables [Member]
Supplemental Cash Flow Information [Abstract]
Property, plant and equipment and leasehold intangibles, net			0	19,457
Other intangible assets, net			(400)	7,300
Net cash paid			400	12,157
Proceeds from sale of assets, net [Member]
Supplemental Cash Flow Information [Abstract]
Prepaid expenses and other assets			(14,387)	(1,036)
Assets held for sale			(20,952)	(218,343)
Property, plant and equipment and leasehold intangibles, net			(19,184)	0
Investments in unconsolidated ventures			(26,301)	0
Long-term debt			7,552	0
Capital and financing lease obligations	7,646	0	7,646	0
Refundable entrance fees and deferred revenue			30,771	0
Other liabilities			39	2,034
Loss (gain) on sale of assets, net			1,408	0
(Gain) loss on lease termination			(1,162)	(2,126)
Net cash received			(34,570)	(219,471)
Formation of Blackstone Joint Venture [Member]
Supplemental Cash Flow Information [Abstract]
Property, plant and equipment and leasehold intangibles, net			(768,897)	0
Prepaid expenses and other assets			(8,173)	0
Investments in unconsolidated ventures	66,816	0	66,816	0
Capital and financing lease obligations			879,959	0
Deferred liabilities			7,504	0
Other liabilities			1,998	0
Net cash paid			179,207	0
Assets designated as held for sale [Member]
Supplemental Cash Flow Information [Abstract]
Property, plant and equipment and leasehold intangibles, net			29,345	(261,639)
Prepaid expenses and other assets			199	(2,130)
Assets held for sale			(29,544)	280,604
Goodwill	$ 0	$ (28,568)	0	(28,568)
Asset impairment			0	11,733
Net			$ 0	$ 0