Lease cancellation notice period.

No definition available.

Name:	ck0001698538_LeaseCancellationNoticePeriod
Namespace Prefix:	ck0001698538_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum dealer-manager fee as percentage of gross offering proceeds.

+ References

No definition available.

+ Details

Name:	ck0001698538_MaximumDealerManagerFeeAsPercentageOfGrossOfferingProceeds
Namespace Prefix:	ck0001698538_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Maximum dealer manager sales commission as percentage of gross offering proceeds.

+ References

No definition available.

+ Details

Name:	ck0001698538_MaximumDealerManagerSalesCommissionAsPercentageOfGrossOfferingProceeds
Namespace Prefix:	ck0001698538_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Maximum offering cost rate incurred on behalf of entity.

+ References

No definition available.

+ Details

Name:	ck0001698538_MaximumOfferingCostRateIncurredOnBehalfOfEntity
Namespace Prefix:	ck0001698538_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum offering costs as percentage of gross offering proceeds.

+ References

No definition available.

+ Details

Name:	ck0001698538_MaximumOfferingCostsAsPercentageOfGrossOfferingProceeds
Namespace Prefix:	ck0001698538_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Maximum period for reimbursement of offering cost.

+ References

No definition available.

+ Details

Name:	ck0001698538_MaximumPeriodForReimbursementOfOfferingCost
Namespace Prefix:	ck0001698538_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Minimum percentage of ordinary taxable income to be distributed to stockholders.

+ References

No definition available.

+ Details

Name:	ck0001698538_MinimumPercentageOfOrdinaryTaxableIncomeToBeDistributedToStockholders
Namespace Prefix:	ck0001698538_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of properties acquired.

+ References

No definition available.

+ Details

Name:	ck0001698538_NumberOfPropertiesAcquired
Namespace Prefix:	ck0001698538_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Servicing fees accrual description.

+ References

No definition available.

+ Details

Name:	ck0001698538_ServicingFeesAccrualDescription
Namespace Prefix:	ck0001698538_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Summary of significant accounting policies.

+ References

No definition available.

+ Details

Name:	ck0001698538_SummaryOfSignificantAccountingPoliciesLineItems
Namespace Prefix:	ck0001698538_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Underwriting commission rate.

+ References

No definition available.

+ Details

Name:	ck0001698538_UnderwritingCommissionRate
Namespace Prefix:	ck0001698538_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 23
-URI http://asc.fasb.org/extlink&oid=84229725&loc=d3e1043-128460

+ Details

Name:	us-gaap_BusinessCombinationAcquisitionRelatedCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28555-108399

+ Details

Name:	us-gaap_DeferredFinanceCostsNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized in the remainder of the fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

No definition available.

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 928
-SubTopic 340
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6473545&loc=d3e61844-108004

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Term of lessor's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=77888428&loc=SL77919359-209981

+ Details

Name:	us-gaap_LessorOperatingLeaseTermOfContract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfReportableSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The cash outflow to acquire asset without physical form usually arising from contractual or other legal rights, excluding goodwill.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3213-108585

+ Details

Name:	us-gaap_PaymentsToAcquireIntangibleAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References

No definition available.

+ Details

Name:	us-gaap_PropertyPlantAndEquipmentUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of cost capitalized subsequent to acquisition for real estate investment property, including, but not limited to, real estate tax and insurance, by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate. Excludes initial purchase price and improvement, and real estate not held as investment or interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 970
-SubTopic 360
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-28(Column D))
-URI http://asc.fasb.org/extlink&oid=6590653&loc=d3e638233-123024

+ Details

Name:	us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 5A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=108788376&loc=SL6759159-111685

+ Details

Name:	us-gaap_VariableInterestEntityOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=ck0001698538_CommonClassTMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=ck0001698538_CommonClassWMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=ck0001698538_FurnitureFixturesAndEquipmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_LeasesAcquiredInPlaceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Summary of Significant Accounting Policies - Additional Information (Detail) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018 USD ($) Property	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) Property Segment	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)	Nov. 15, 2017
Summary of Significant Accounting Policies [Line Items]
Beneficial interest for ownership percentage			2.60%
Number of properties acquired \| Property	3		3
Capitalized acquisition-related transaction costs	$ 1.7		$ 1.7
Business acquisition, transaction costs	$ 0.1	$ 1.4	$ 0.4	$ 1.4
Initial term of lease	12 months		12 months
Days allowed for lease cancellation			30 days
Estimated amortization expenses of intangible assets in 2018	$ 2.3		$ 2.3
Estimated amortization expenses of intangible assets in 2019	3.5		3.5
Debt issuance costs	$ 1.6		$ 1.6		$ 0.7
Offering cost as percentage of gross offering proceeds	1.00%		1.00%
Maximum period for reimbursement of offering cost			60 days
Maximum offering cost rate			3.50%
Maximum Dealer Manager sales commission as percentage of gross offering proceeds	6.00%		6.00%
Maximum Dealer Manager fee as percentage of gross offering proceeds	3.00%		3.00%			2.00%
Underwriting compensation			10.00%
Minimum percentage of ordinary taxable income to be distributed to stockholders			90.00%
Number of reportable segments \| Segment			2
Class A Common Stock [Member]
Summary of Significant Accounting Policies [Line Items]
Maximum Dealer Manager sales commission as percentage of gross offering proceeds	6.00%		6.00%
Maximum Dealer Manager fee as percentage of gross offering proceeds	3.00%		3.00%
Class T Common Stock [Member]
Summary of Significant Accounting Policies [Line Items]
Maximum Dealer Manager sales commission as percentage of gross offering proceeds	3.00%		3.00%
Maximum Dealer Manager fee as percentage of gross offering proceeds	3.00%		3.00%
Daily stockholder servicing fee accrual description			1/365th of 1% of the purchase price per share
Class W Common Stock [Member]
Summary of Significant Accounting Policies [Line Items]
Maximum Dealer Manager fee as percentage of gross offering proceeds	9.00%		9.00%
Daily stockholder servicing fee accrual description			1/365th of 0.5% of the purchase price per share
Minimum [Member] \| Furniture, Fixtures and Equipment [Member]
Summary of Significant Accounting Policies [Line Items]
Standard depreciable life			3 years
Maximum [Member] \| Furniture, Fixtures and Equipment [Member]
Summary of Significant Accounting Policies [Line Items]
Standard depreciable life			7 years
In-Place Leases [Member]
Summary of Significant Accounting Policies [Line Items]
Payments to acquire intangible assets			$ 6.5		$ 6.3
Gross amount of lease intangibles	$ 12.7		12.7
Accumulated amortization of lease intangibles	$ 7.0		$ 7.0