Secured Revolving Credit Facility - Additional Information (Detail) - USD ($)						6 Months Ended
	Mar. 27, 2020	Sep. 11, 2019	Jul. 31, 2018	Jul. 27, 2017	Dec. 02, 2015	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Line Of Credit Facility [Line Items]
Credit facility, outstanding						$ 50,000,000		$ 50,000,000
Proceeds from secured revolving credit facility							$ 10,000,000
Key Bank [Member] | Operating Partnership [Member]
Line Of Credit Facility [Line Items]
Line of Credit facility, maximum borrowing capacity					$ 50,000,000.0
Line of Credit facility term					2 years
Line of Credit facility extended maturity period					1 year
Line Of Credit facility description						line of credit facility, with an initial term of two years, with a one-year extension option, subject to certain other customary conditions.
Minimum principal amount						$ 25,000,000.0
Line of credit facility, maturity date		Jun. 30, 2022	Jun. 30, 2020	Feb. 28, 2018
Line of credit facility, additional extension option maturity date						Jun. 30, 2019
Proceeds from secured revolving credit facility	$ 10,000,000.0
Key Bank [Member] | Operating Partnership [Member] | Minimum [Member]
Line Of Credit Facility [Line Items]
Applicable margin range on credit facility		1.40%	1.50%		2.00%
Key Bank [Member] | Operating Partnership [Member] | Maximum [Member]
Line Of Credit Facility [Line Items]
Applicable margin range on credit facility		1.90%	2.00%		2.50%
Swing loan						$ 5,000,000.0
Key Bank [Member] | Operating Partnership [Member] | Federal Reserve Bank Of Cleveland [Member]
Line Of Credit Facility [Line Items]
Applicable margin range on credit facility		0.50%	0.50%		0.50%
Key Bank [Member] | Operating Partnership [Member] | LIBOR [Member]
Line Of Credit Facility [Line Items]
Applicable margin range on credit facility		1.00%	1.00%		1.00%
Reduction of applicable margin on credit facility		0.10%
Credit facility, outstanding						$ 50,000,000.0		$ 50,000,000.0
Key Bank [Member] | Operating Partnership [Member] | LIBOR [Member] | Secured Revolving Credit Facility [Member]
Line Of Credit Facility [Line Items]
Reduction of applicable margin on credit facility			0.50%
Key Bank [Member] | Operating Partnership [Member] | LIBOR [Member] | Minimum [Member]
Line Of Credit Facility [Line Items]
Applicable margin range on credit facility		2.40%	2.50%		3.00%
Key Bank [Member] | Operating Partnership [Member] | LIBOR [Member] | Maximum [Member]
Line Of Credit Facility [Line Items]
Applicable margin range on credit facility		2.90%	3.00%		3.50%
Key Bank [Member] | Operating Partnership [Member] | If less than 50% of facility used [Member]
Line Of Credit Facility [Line Items]
Line of Credit facility, commitment fee percentage						0.30%
Key Bank [Member] | Operating Partnership [Member] | If more than 50% of facility used [Member]
Line Of Credit Facility [Line Items]
Line of Credit facility, commitment fee percentage						0.20%
Key Bank [Member] | Operating Partnership [Member] | Base Rate [Member]
Line Of Credit Facility [Line Items]
Reduction of applicable margin on credit facility		0.10%
Key Bank [Member] | Operating Partnership [Member] | Base Rate [Member] | Secured Revolving Credit Facility [Member]
Line Of Credit Facility [Line Items]
Reduction of applicable margin on credit facility			0.50%