Per Share Data of HTA (Details) $ / shares in Units, shares in Thousands, $ in Thousands		1 Months Ended		3 Months Ended	12 Months Ended
		Jun. 30, 2018 USD ($) $ / shares	Oct. 31, 2017 shares	Dec. 31, 2019 USD ($) Arrangement $ / shares	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2017 USD ($) $ / shares shares
Earnings Per Share
Forward equity agreement, to be sold (in shares)					21,600	2,600
Stock issued, value, issued on a forward basis | $				$ 306,200	$ 629,500	$ 73,800
Forward equity agreements, number of arrangements | Arrangement				3
Antidilutive effect of forward equity sales agreement (in shares)					57	330
Numerator:
Net income | $					$ 30,758	$ 217,626	$ 65,577
Net income attributable to noncontrolling interests | $	[1]				(604)	(4,163)	(1,661)
Net income (loss) attributable to common stockholders/unitholders | $					$ 30,154	$ 213,463	$ 63,916
Denominator:
Weighted average shares/units outstanding - basic (in shares)					205,720	206,065	181,064
Dilutive shares - OP Unit convertible into common stock (in shares)					3,885	3,996	4,197
Dilutive effect of forward equity sales agreement (in shares)					0	0	17
Adjusted weighted average number of shares/units outstanding — diluted (in shares)					209,605	210,061	185,278
Earnings per common share - basic
Net income attributable to common stockholders/unitholders (in dollars per share) | $ / shares					$ 0.15	$ 1.04	$ 0.35
Earnings per common share - diluted
Net income attributable to common stockholders/unitholders (in dollars per share) | $ / shares					$ 0.14	$ 1.02	$ 0.34
ATM Offering Program
Earnings Per Share
Forward equity agreement, to be sold (in shares)			2,600
Stock issued, value, issued on a forward basis | $		$ 73,800			$ 323,400
Stock issued share price (in dollars per share) | $ / shares		$ 28.94
Issuance of common stock in HTA (in shares)					11,100
Shares issued (in dollars per share) | $ / shares				$ 29.14	$ 29.14

[1] Includes amounts attributable to redeemable noncontrolling interests.