Organization and Business (Details) $ / shares in Units, ft² in Millions	Jul. 21, 2017 $ / shares	Dec. 31, 2019 ft² property $ / shares	Dec. 31, 2018 $ / shares	Oct. 01, 2018 USD ($) property
Schedule of Equity Method Investments [Line Items]
Number of real estate properties		39
Commercial properties		43
Area of property (in square feet) | ft²		6.7
Common stock, par value (in dollars per share) | $ / shares		$ 0.001	$ 0.001
XIX Merger Agreement
Schedule of Equity Method Investments [Line Items]
Conversion rate	9,171.98
Common stock, par value (in dollars per share) | $ / shares	$ 0.01
HIREIT Merger
Schedule of Equity Method Investments [Line Items]
Conversion rate	0.752222
8% Cumulative Preferred Stock | XIX Merger Agreement
Schedule of Equity Method Investments [Line Items]
Conversion rate	1.238477
Preferred stock dividend rate	8.00%
9% Cumulative Preferred Stock | XIX Merger Agreement
Schedule of Equity Method Investments [Line Items]
Conversion rate	1.238477
Preferred stock dividend rate	9.00%
Common Stock | HIREIT Merger
Schedule of Equity Method Investments [Line Items]
Conversion rate	0.752222
Subordinated Common Stock | HIREIT Merger
Schedule of Equity Method Investments [Line Items]
Conversion rate	0.752222
Richardson, Arlington And Dallas, Texas
Schedule of Equity Method Investments [Line Items]
Number of real estate properties		15
Houston, Texas
Schedule of Equity Method Investments [Line Items]
Number of real estate properties		25
San Antonio, Texas
Schedule of Equity Method Investments [Line Items]
Number of real estate properties		3
TEXAS
Schedule of Equity Method Investments [Line Items]
Number of real estate properties		3
Hartman SPE LLC | Variable Interest Entity, Primary Beneficiary
Schedule of Equity Method Investments [Line Items]
Number of real estate properties				39
Notes Payable to Banks | Hartman SPE LLC
Schedule of Equity Method Investments [Line Items]
Debt instrument, face amount | $				$ 259,000,000