Related Party Transactions - Summary of Fees and Expenses Incurred (Parenthetical) (Detail) - USD ($)	6 Months Ended	12 Months Ended
Jun. 30, 2020	Dec. 31, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Due to related parties	$ 1,861,062	$ 2,057,181	$ 2,742,581
Organization and offering costs incurred by advisor on behalf of Company	$ 9,907,863	$ 8,613,586
Percentage of organization and offering costs to gross offering proceeds	1.00%	1.00%
Unreimbursed Operating Expenses [Member] \| Advisor [Member]
Related Party Transaction [Line Items]
Due to related parties	$ 8,821,870	$ 7,444,222
Fees and expenses, Incurred	1,377,647	3,087,063
Organization And Offering Costs Payable [Member] \| Advisor [Member]
Related Party Transaction [Line Items]
Due to related parties	$ 626,630	$ 789,661

Percentage of organization and offering costs to gross offering proceeds.

No definition available.

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- Definition

Carrying amount as of the balance sheet date of obligations due all related parties.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(k)(1))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.17)
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.15(3),(4))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

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- Definition

The amount of the support provided by the Adviser to help the REIT achieve a certain return for the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 974
-SubTopic 720
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=68059889&loc=SL51753266-203347

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- Definition

Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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