Tax Treatment of Dividends of HTA (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Ordinary income	$ 0.6559	$ 0.7479	$ 0.8970
Return of capital	0.0000	0.3720	0.2880
Capital gain	0.5691	0.0851	0.0000
Total	$ 1.2250	$ 1.2050	$ 1.1850