Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Accounting Policies and General Information [Line Items]
Distributions payable	$ 4,603,228		$ 4,603,228		$ 1,595,148
Deferred rent receivable	5,197,863		5,197,863		1,788,266
Impairment losses			0	$ 0
Deferred financing costs, net	3,118,277		3,118,277		764,753
Accumulated amortization	335,163		335,163		158,042
Amortization of deferred financing costs	121,855	$ 19,274	177,121	57,587
Due from related party	415,835		415,835		275,464
Deferred revenue	1,270,014		1,270,014		570,362
Tenant reimbursement income	1,137,744	300,156	2,613,987	1,177,981
Property operating expenses	2,870,389	$ 286,322	5,688,124	$ 1,264,516
Due to related parties	$ 1,816,091		$ 1,816,091		$ 1,438,450	$ 2,057,181
Percentage of organization and offering costs to gross offering proceeds			1.00%		1.00%
Initial O&O Costs incurred by advisor on behalf of Company			$ 11,030,568		$ 9,946,509
Net income (loss) per common share - basic and diluted	$ (0.01)	$ 0.07	$ 0.10	$ 0.23
Accounting Standards Update 2018-13 [Member]
Accounting Policies and General Information [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true		true
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Jan. 01, 2020		Jan. 01, 2020
Change in Accounting Principle, Accounting Standards Update, Early Adoption [true false]	true		true
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]	true		true
Accounting Standards Update 2018-17 [Member]
Accounting Policies and General Information [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true		true
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Jan. 01, 2020		Jan. 01, 2020
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]	true		true
CFI and Company Reimbursement Agreement [Member]
Accounting Policies and General Information [Line Items]
Due from related party	$ 1,182,925		$ 1,182,925		1,182,925
Due to related parties	0		0
Mezzanine Loan Investment [Member]
Accounting Policies and General Information [Line Items]
Impairment losses			0	$ 0
Preferred Equity Investment [Member]
Accounting Policies and General Information [Line Items]
Impairment losses			0	$ 0
Affiliates [Member]
Accounting Policies and General Information [Line Items]
Distributions payable	540,237		540,237
CFI [Member] | CFI and Company Reimbursement Agreement [Member]
Accounting Policies and General Information [Line Items]
Due from related party	415,835		$ 415,835		275,464
Advisor [Member]
Accounting Policies and General Information [Line Items]
Period of reimbursing the advisor for payment of organization and offering costs.			May 18, 2021
Additional percentage of organization and offering expense of gross offering proceeds			1.00%
Estimated percentage of organization and offering expense of gross offering proceeds			1.00%
Advisor [Member] | Primary Offering [Member]
Accounting Policies and General Information [Line Items]
Period of reimbursing the advisor for payment of organization and offering costs.			May 18, 2021
Additional percentage of organization and offering expense of gross offering proceeds			1.00%
Estimated percentage of organization and offering expense of gross offering proceeds			1.00%
Advisor [Member] | Maximum [Member]
Accounting Policies and General Information [Line Items]
Percentage of organization and offering costs to gross offering proceeds			1.00%
Advisor [Member] | Maximum [Member] | Primary Offering [Member]
Accounting Policies and General Information [Line Items]
Percentage of organization and offering costs to gross offering proceeds			1.00%
Advisor [Member] | Organization And Offering Costs Payable [Member]
Accounting Policies and General Information [Line Items]
Due to related parties	68,260		$ 68,260		312,284
Reimbursement liability beginning period			May 18, 2018
Advisor [Member] | Organization And Offering Costs Payable [Member] | Primary Offering [Member]
Accounting Policies and General Information [Line Items]
Due to related parties	68,260		$ 68,260		312,284
Reimbursement payments for costs incurred			2,074,648		1,329,678
Advisor [Member] | Organizational Costs [Member]
Accounting Policies and General Information [Line Items]
Due to related parties	90,675		90,675		90,675
Advisor [Member] | Offering Costs [Member]
Accounting Policies and General Information [Line Items]
Due to related parties	$ 2,052,233		$ 2,052,233		$ 1,551,287