CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Flows from Operating Activities
Net income (loss)	$ (571,606)	$ (404,636)	$ (458,155)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Loss on extinguishment of debt, net	714	1,251	121
Depreciation and amortization, net	494,758	529,802	736,516
Goodwill and asset impairment	409,782	248,515	57,941
Equity in loss (earnings) of unconsolidated ventures	14,827	(1,660)	804
Distributions from unconsolidated ventures from cumulative share of net earnings	8,258	23,544	7,825
Amortization of deferred gain	(4,366)	(4,372)	(4,372)
Amortization of entrance fees	(2,901)	(4,195)	(3,204)
Proceeds from deferred entrance fee revenue	(5,712)	(13,980)	(11,113)
Deferred income tax (benefit) provision	(15,309)	3,248	(95,261)
Straight-line lease (income) expense	(14,313)	767	6,956
Change in fair value of derivatives	174	178	797
Gain on sale of assets, net	(19,273)	(7,218)	(1,270)
Loss on facility lease termination	14,276	0	0
Non-cash stock-based compensation expense	27,832	32,285	31,651
Non-cash interest expense on financing lease obligations	17,744	26,496	23,472
Amortization of (above) below market lease, net	(6,677)	(6,864)	(7,158)
Other	(8,819)	(9,137)	(4,098)
Changes in operating assets and liabilities:
Accounts receivable, net	12,747	1,581	5,608
Prepaid expenses and other assets, net	21,970	2,954	51,079
Accounts payable and accrued expenses	(4,527)	(83,248)	(60,564)
Tenant refundable fees and security deposits	(422)	(839)	(524)
Deferred revenue	(13,917)	3,300	(6,911)
Net cash provided by operating activities	366,664	365,732	292,366
Cash Flows from Investing Activities
Change in lease security deposits and lease acquisition deposits, net	(2,113)	(2,225)	10,866
Change in cash and escrow deposits — restricted	1,026	5,027	29,286
Purchase of marketable securities, net	(291,187)	0	0
Additions to property, plant and equipment and leasehold intangibles, net	(213,887)	(333,647)	(411,051)
Acquisition of assets, net of related payables and cash received	(5,196)	(12,157)	(191,216)
Investment in unconsolidated ventures	(199,017)	(13,377)	(69,297)
Distributions received from unconsolidated ventures	29,035	218,973	9,054
Proceeds from sale of assets, net	70,507	297,932	49,226
Property insurance proceeds	8,550	9,137	3,157
Other	975	7,162	998
Net cash (used in) provided by investing activities	(601,307)	176,825	(568,977)
Cash Flows from Financing Activities
Proceeds from debt	1,307,205	387,348	585,650
Repayment of debt and capital and financing lease obligations	(1,054,161)	(469,309)	(485,762)
Proceeds from line of credit	100,000	1,276,500	1,175,000
Repayment of line of credit	(100,000)	(1,586,500)	(965,000)
Purchase of treasury stock	0	(9,640)	0
Payment of financing costs, net of related payables	(5,574)	(2,938)	(32,622)
Proceeds from refundable entrance fees, net of refunds	(2,179)	(901)	(2,472)
Cash portion of loss on extinguishment of debt	0	0	(44)
Payment on lease termination	(552)	(9,250)	(17,000)
Payments of employee taxes for withheld shares	(5,889)	(1,640)	0
Other	2,043	2,141	2,807
Net cash provided by (used in) financing activities	240,893	(414,189)	260,557
Net increase (decrease) in cash and cash equivalents	6,250	128,368	(16,054)
Cash and cash equivalents at beginning of year	216,397	88,029	104,083
Cash and cash equivalents at end of year	$ 222,647	$ 216,397	$ 88,029