Supplemental Disclosure of Cash Flow Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Supplemental Cash Flow Information [Abstract]
Interest paid			$ 155,389,000	$ 175,386,000
Income taxes paid, net of refunds			1,876,000	1,997,000
Additions to property, plant and equipment and leasehold intangibles, net			89,570,000	190,060,000
Acquisition of assets, net of related payables			400,000	12,157,000
Prepaid expenses and other assets			18,979,000	(16,845,000)
Loss (gain) on sale of assets, net			1,150,000	(2,551,000)
(Gain) loss on lease termination	$ 6,368,000	$ 0	6,368,000	0
Assets held for sale	91,013,000		91,013,000		$ 97,843,000
Goodwill	(710,783,000)		(710,783,000)		$ (705,476,000)
Asset impairment	1,559,000	4,152,000	22,265,000	7,527,000
Additions to property, plant and equipment and leasehold intangibles, net [Member]
Supplemental Cash Flow Information [Abstract]
Property, plant and equipment and leasehold intangibles, net			91,014,000	158,841,000
Accounts payable			(1,444,000)	31,219,000
Additions to property, plant and equipment and leasehold intangibles, net			89,570,000	190,060,000
Acquisition of assets, net of related payables [Member]
Supplemental Cash Flow Information [Abstract]
Property, plant and equipment and leasehold intangibles, net			0	19,457,000
Other intangible assets, net			(400,000)	7,300,000
Acquisition of assets, net of related payables			400,000	12,157,000
Proceeds from sale of assets, net [Member]
Supplemental Cash Flow Information [Abstract]
Prepaid expenses and other assets			(13,954,000)	(319,000)
Assets held for sale			(20,952,000)	(42,714,000)
Property, plant and equipment and leasehold intangibles, net			(11,598,000)	0
Investments in unconsolidated ventures			(26,301,000)	0
Long-term debt			7,552,000	0
Refundable entrance fees and deferred revenue			30,771,000	0
Other liabilities			39,000	0
Loss (gain) on sale of assets, net			1,150,000	(2,551,000)
(Gain) loss on lease termination			(1,162,000)	0
Net cash received			(34,455,000)	(45,584,000)
Formation of Blackstone Joint Venture [Member]
Supplemental Cash Flow Information [Abstract]
Property, plant and equipment and leasehold intangibles, net			(768,897,000)	0
Prepaid expenses and other assets			(8,173,000)	0
Investments in unconsolidated ventures	66,816,000	0	66,816,000	0
Capital and financing lease obligations			879,959,000	0
Deferred liabilities			7,504,000	0
Other liabilities			1,998,000	0
Formation of the Blackstone Venture			179,207,000	0
Assets designated as held for sale [Member]
Supplemental Cash Flow Information [Abstract]
Property, plant and equipment and leasehold intangibles, net			(14,016,000)	(261,639,000)
Prepaid expenses and other assets			(106,000)	(836,000)
Assets held for sale	14,122,000	288,659,000	14,122,000	288,659,000
Goodwill	$ 0	$ (28,568,000)	0	(28,568,000)
Asset impairment			0	2,384,000
Net			$ 0	$ 0