Non-controlling Interests (Summary of Non-controlling Interests) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Noncontrolling Interest [Line Items]
Third Party Net Investment Amount	$ 6,704	$ 4,387
Investments in real estate, net	2,049,927	2,108,948
Distributions	92	201	$ 346
Non-controlling Interests
Noncontrolling Interest [Line Items]
Distributions	92	201	346
Plaza Del Rio Medical Office Campus Portfolio AZ | Non-controlling Interests
Noncontrolling Interest [Line Items]
Third Party Net Investment Amount	368
Investments in real estate, net	12,925	12,790
Distributions	$ 0	$ 0	$ 0
Plaza Del Rio Medical Office Campus Portfolio AZ | Non-controlling Interests | Healthcare Trust Operating Partnership, L.P.
Noncontrolling Interest [Line Items]
Non-Controlling Ownership Percentage	2.40%