CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Accumulated Deficit [Member]	Stockholders' Equity [Member]	Noncontrolling Interest [Member]
Balances at beginning of period at Dec. 31, 2013	$ 1,020,937	$ 1,277	$ 2,025,471	$ (46,800)	$ (959,011)	$ 1,020,937	$ 0
Balances at beginning of period - shares (in share) at Dec. 31, 2013		127,727,000
Compensation expense related to restricted stock grants	28,299	$ 0	28,299	0	0	28,299	0
Establishment of noncontrolling interest in Emeritus acquisition	953	0	0	0	0	0	953
Net income (loss)	(149,426)	0	0	0	(148,990)	(148,990)	(436)
Common stock issued in connection with Emeritus acquisition	$ 1,648,782	$ 476	1,648,306	0	0	1,648,782	0
Stock Issued During Period, Shares, Acquisitions	47,584,000	47,584,000
Stock Issued During Period, Value, New Issues	$ 330,386	$ 103	330,283	0	0	330,386	0
Stock Issued During Period, Shares, New Issues	10,299,000
Issuance of common stock under Associate Stock Purchase Plan	$ 2,004	$ 0	2,004	0	0	2,004	0
Issuance of common stock under Associate Stock Purchase Plan - shares (in shares)		64,000
Restricted stock, net	$ 0	$ 14	(14)	0	0	0	0
Restricted stock, net - shares (in shares)	1,364,000
Other	$ 306	$ 0	306	0	0	306	0
Stockholders' Equity, Other Shares		0
Balances at end of period at Dec. 31, 2014	$ 2,882,241	$ 1,870	4,034,655	(46,800)	(1,108,001)	2,881,724	517
Balances at end of period - shares (in shares) at Dec. 31, 2014	187,038,000
Compensation expense related to restricted stock grants	$ 31,651	0	31,651	0	0	31,651	0
Net income (loss)	(458,155)	0	0	0	(457,477)	(457,477)	(678)
Issuance of common stock under Associate Stock Purchase Plan	2,870	$ 1	2,869	0	0	2,870	0
Issuance of common stock under Associate Stock Purchase Plan - shares (in shares)		122,000
Restricted stock, net	0	$ 12	(12)	0	0	0	0
Restricted stock, net - shares (in shares)		1,179,000
Other	120	$ 0	120	0	0	120	0
Stockholders' Equity, Other Shares		0
Balances at end of period at Dec. 31, 2015	$ 2,458,727	$ 1,883	4,069,283	(46,800)	(1,565,478)	2,458,888	(161)
Balances at end of period - shares (in shares) at Dec. 31, 2015	188,338,790	188,339,000
Compensation expense related to restricted stock grants	$ 32,285	$ 0	32,285	0	0	32,285	0
Net income (loss)	$ (404,636)	0	0	0	(404,397)	(404,397)	(239)
Stock Issued During Period, Shares, New Issues	10,298,506
Issuance of common stock under Associate Stock Purchase Plan	$ 2,349	$ 2	2,347	0	0	2,349	0
Issuance of common stock under Associate Stock Purchase Plan - shares (in shares)		172,000
Restricted stock, net	0	$ 24	(24)	0	0	0	0
Restricted stock, net - shares (in shares)		2,396,000
Purchase of treasury stock	$ (9,640)	$ (8)	8	(9,640)	0	(9,640)	0
Purchase of treasury stock (in shares)	750,000	(750,000)
Other	$ (1,353)	$ (1)	(1,502)	0	0	(1,503)	150
Stockholders' Equity, Other Shares		(111,000)
Balances at end of period at Dec. 31, 2016	$ 2,077,732	$ 1,900	$ 4,102,397	$ (56,440)	$ (1,969,875)	$ 2,077,982	$ (250)
Balances at end of period - shares (in shares) at Dec. 31, 2016	190,045,681	190,046,000