Selected Quarterly Financial Data of HTA (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Selected Quarterly Financial Data [Line Items]
Revenues									$ 696,426	$ 613,990	$ 460,928
Net income									217,626	65,577	47,345
Net income attributable to common stockholders									$ 213,463	$ 63,916	$ 45,912
Earnings per common share - basic
Net income attributable to common stockholders/unitholders (in dollars per share)									$ 1.04	$ 0.35	$ 0.34
Earnings per common share - diluted
Net income attributable to common stockholders/unitholders (in dollars per share)									$ 1.02	$ 0.34	$ 0.33
HTA, Inc.
Selected Quarterly Financial Data [Line Items]
Revenues	$ 172,298	$ 175,135	$ 173,332	$ 175,661	$ 173,770	$ 175,994	$ 139,879	$ 124,347
Net income	15,605	176,348	15,657	10,016	43,472	13,957	(5,852)	14,000
Net income attributable to common stockholders	$ 15,329	$ 172,986	$ 15,346	$ 9,802	$ 42,526	$ 13,763	$ (5,918)	$ 13,545
Earnings per common share - basic
Net income attributable to common stockholders/unitholders (in dollars per share)	$ 0.07	$ 0.83	$ 0.07	$ 0.05	$ 0.21	$ 0.07	$ (0.03)	$ 0.10
Earnings per common share - diluted
Net income attributable to common stockholders/unitholders (in dollars per share)	$ 0.07	$ 0.82	$ 0.07	$ 0.05	$ 0.20	$ 0.07	$ (0.03)	$ 0.09