CONDENSED CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total	Total Stockholders’ Equity	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Cumulative Dividends in Excess of Earnings	Noncontrolling Interests
Beginning balance at Dec. 31, 2017	$ 3,363,448	$ 3,278,782	$ 2,049	$ 4,508,528	$ 274	$ (1,232,069)	$ 84,666
Beginning balance (in shares) at Dec. 31, 2017			204,892,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based award transactions, net	3,507	3,507	$ 3	3,504
Share-based award transactions, net (in shares)			289,000
Repurchase and cancellation of common stock	(2,709)	(2,709)	$ (1)	(2,708)
Repurchase and cancellation of common stock (in shares)			(92,000)
Redemption of noncontrolling interest and other	0	2,413	$ 1	2,412			(2,413)
Redemption of noncontrolling interest and other (in shares)			91,000
Dividends declared	(63,866)	(62,559)				(62,559)	(1,307)
Net loss	9,983	9,802				9,802	181
Other comprehensive income (loss)	900	883			883		17
Ending balance at Mar. 31, 2018	3,311,263	3,230,119	$ 2,052	4,511,736	1,157	(1,284,826)	81,144
Ending balance (in shares) at Mar. 31, 2018			205,180,000
Beginning balance at Dec. 31, 2017	3,363,448	3,278,782	$ 2,049	4,508,528	274	(1,232,069)	84,666
Beginning balance (in shares) at Dec. 31, 2017			204,892,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income (loss)	382
Ending balance at Sep. 30, 2018	3,433,529	3,353,627	$ 2,072	4,574,913	648	(1,224,006)	79,902
Ending balance (in shares) at Sep. 30, 2018			207,231,000
Beginning balance at Mar. 31, 2018	3,311,263	3,230,119	$ 2,052	4,511,736	1,157	(1,284,826)	81,144
Beginning balance (in shares) at Mar. 31, 2018			205,180,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock in HTA	72,814	72,814	$ 25	72,789
Issuance of common stock in HTA (in shares)			2,550,000
Share-based award transactions, net	2,196	2,196		2,196
Share-based award transactions, net (in shares)			7,000
Repurchase and cancellation of common stock	(8,844)	(8,844)	$ (3)	(8,841)
Repurchase and cancellation of common stock (in shares)			(337,000)
Redemption of noncontrolling interest and other	0	2,494	$ 1	2,493			(2,494)
Redemption of noncontrolling interest and other (in shares)			93,000
Dividends declared	(64,532)	(63,279)				(63,279)	(1,253)
Net loss	15,643	15,346				15,346	297
Other comprehensive income (loss)	214	210			210		4
Ending balance at Jun. 30, 2018	3,328,754	3,251,056	$ 2,075	4,580,373	1,367	(1,332,759)	77,698
Ending balance (in shares) at Jun. 30, 2018			207,493,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based award transactions, net	2,538	2,127		2,127			411
Share-based award transactions, net (in shares)			27,000
Repurchase and cancellation of common stock	(7,878)	(7,878)	$ (3)	(7,875)
Repurchase and cancellation of common stock (in shares)			(300,000)
Redemption of noncontrolling interest and other	0	288		288			(288)
Redemption of noncontrolling interest and other (in shares)			11,000
Dividends declared	(65,483)	(64,233)				(64,233)	(1,250)
Net loss	176,330	172,986				172,986	3,344
Other comprehensive income (loss)	(732)	(719)			(719)		(13)
Ending balance at Sep. 30, 2018	3,433,529	3,353,627	$ 2,072	4,574,913	648	(1,224,006)	79,902
Ending balance (in shares) at Sep. 30, 2018			207,231,000
Beginning balance at Dec. 31, 2018	$ 3,334,914	3,256,024	$ 2,053	4,525,969	307	(1,272,305)	78,890
Beginning balance (in shares) at Dec. 31, 2018	205,267,349		205,267,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based award transactions, net	$ 3,389	3,389	$ 3	3,386
Share-based award transactions, net (in shares)			293,000
Repurchase and cancellation of common stock	(11,926)	(11,926)	$ (5)	(11,921)
Repurchase and cancellation of common stock (in shares)			(478,000)
Redemption of noncontrolling interest and other	0	527		527			(527)
Redemption of noncontrolling interest and other (in shares)			18,000
Dividends declared	(64,884)	(63,578)				(63,578)	(1,306)
Net loss	13,673	13,440				13,440	233
Other comprehensive income (loss)	(390)	(382)			(382)		(8)
Ending balance at Mar. 31, 2019	3,274,776	3,197,494	$ 2,051	4,517,961	(75)	(1,322,443)	77,282
Ending balance (in shares) at Mar. 31, 2019			205,100,000
Beginning balance at Dec. 31, 2018	$ 3,334,914	3,256,024	$ 2,053	4,525,969	307	(1,272,305)	78,890
Beginning balance (in shares) at Dec. 31, 2018	205,267,349		205,267,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income (loss)	$ 1,519
Ending balance at Sep. 30, 2019	$ 3,214,469	3,141,686	$ 2,072	4,581,176	1,798	(1,443,360)	72,783
Ending balance (in shares) at Sep. 30, 2019	207,186,452		207,186,000
Beginning balance at Mar. 31, 2019	$ 3,274,776	3,197,494	$ 2,051	4,517,961	(75)	(1,322,443)	77,282
Beginning balance (in shares) at Mar. 31, 2019			205,100,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of OP Units in HTALP	2,603						2,603
Share-based award transactions, net	2,102	2,102		2,102
Share-based award transactions, net (in shares)			(3,000)
Repurchase and cancellation of common stock	(169)	(169)		(169)
Repurchase and cancellation of common stock (in shares)			(6,000)
Redemption of noncontrolling interest and other	424	1,209		1,209			(785)
Redemption of noncontrolling interest and other (in shares)			27,000
Dividends declared	(64,913)	(63,579)				(63,579)	(1,334)
Net loss	16,560	16,259				16,259	301
Other comprehensive income (loss)	(381)	(374)			(374)		(7)
Ending balance at Jun. 30, 2019	3,231,002	3,152,942	$ 2,051	4,521,103	(449)	(1,369,763)	78,060
Ending balance (in shares) at Jun. 30, 2019			205,118,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of limited partner OP Units in connection with acquisitions	2,000						2,000
Issuance of common stock in HTA	51,804	51,804	$ 19	51,785
Issuance of common stock in HTA (in shares)			1,840,000
Share-based award transactions, net	2,337	2,337		2,337
Share-based award transactions, net (in shares)			31,000
Repurchase and cancellation of common stock	(65)	(65)		(65)
Repurchase and cancellation of common stock (in shares)			(2,000)
Redemption of noncontrolling interest and other	67	6,018	$ 2	6,016			(5,951)
Redemption of noncontrolling interest and other (in shares)			199,000
Dividends declared	(66,389)	(65,134)				(65,134)	(1,255)
Net loss	(8,577)	(8,463)				(8,463)	(114)
Other comprehensive income (loss)	2,290	2,247			2,247		43
Ending balance at Sep. 30, 2019	$ 3,214,469	$ 3,141,686	$ 2,072	$ 4,581,176	$ 1,798	$ (1,443,360)	$ 72,783
Ending balance (in shares) at Sep. 30, 2019	207,186,452		207,186,000