Summary of Significant Accounting Policies (Details)		1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	Oct. 01, 2018 extension	Sep. 09, 2020	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Property, Plant and Equipment [Line Items]
Impairment of real estate					$ 0		$ 0
Goodwill impairment loss			$ 0	$ 0	0	$ 0
Net income (loss)			$ 2,706,000	$ (931,000)	$ 4,590,000	$ (571,000)
Notes Payable to Banks | Hartman SPE, LLC
Property, Plant and Equipment [Line Items]
Number of extensions | extension	3
Extension term	1 year
Debt instrument, covenant, debt yield, minimum					12.50%
Debt yield			13.25%		13.25%		13.29%
Notes Payable to Banks | Hartman SPE, LLC | Scenario, Forecast | Subsequent Event
Property, Plant and Equipment [Line Items]
Written notice extension		1 year
Debt yield threshold minimum		0.1250
Building and Building Improvements | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life					5 years
Building and Building Improvements | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life					39 years