Amendment suspension or termination period of share.

No definition available.

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- Definition

Commitments and Contingencies [Line Items]

+ References

No definition available.

+ Details

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- Definition

Conversion of partnership units requisite minimum period outstanding.

+ References

No definition available.

+ Details

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- Definition

Loss contingency other non-cancellable future payment due year one.

+ References

No definition available.

+ Details

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- Definition

Loss contingency other non-cancellable future payment due year three.

+ References

No definition available.

+ Details

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- Definition

Loss contingency other non-cancellable future payment due year two.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Loss contingency other non cancellable future payments due in year one.

+ References

No definition available.

+ Details

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Namespace Prefix:	ck0001585389_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Loss contingency other non-cancellable future payments due in year three.

+ References

No definition available.

+ Details

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Namespace Prefix:	ck0001585389_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Loss contingency other non-cancellable future payments due in year two.

+ References

No definition available.

+ Details

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Namespace Prefix:	ck0001585389_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Number of shares issuable upon conversion of partnership units.

+ References

No definition available.

+ Details

Name:	ck0001585389_NumberOfSharesIssuableUponConversionOfPartnershipUnits
Namespace Prefix:	ck0001585389_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Termination date.

+ References

No definition available.

+ Details

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Namespace Prefix:	ck0001585389_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares issued during the period from a dividend reinvestment plan (DRIP). A dividend reinvestment plan allows the shareholders to reinvest dividends paid to them by the entity on new issues of stock by the entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-SubTopic 10
-Topic 505
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478448/946-505-50-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-09(4)(b))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of stock bought back by the entity at the exercise price or redemption price.

+ References

+ Details

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Equity impact of the value of stock bought back by the entity at the exercise price or redemption price.

+ References

+ Details

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

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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- Details

Name:	us-gaap_StatementClassOfStockAxis=ck0001585389_CommonClassTMember
Namespace Prefix:
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Balance Type:
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- Details

Name:	us-gaap_StatementClassOfStockAxis=ck0001585389_RedeemableCommonStockMember
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Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Thousands			3 Months Ended	9 Months Ended		12 Months Ended
	Jul. 30, 2025	May 11, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Commitments And Contingencies [Line Items]
Redemptions of common stock (in shares)	8,000
Redemptions of common stock, value	$ 300		$ 1		$ 1
Loss contingency other non-cancellable future payments due in year one				$ 3,500
Loss contingency other non-cancellable future payment due year two				3,700
Loss contingency other non-cancellable future payment due year three				$ 3,900
Loss contingency other non-cancellable future payment due year one				2025
Loss contingency other non-cancellable future payment due year two				2026
Loss contingency other non-cancellable future payment due year three				2027
Share Redemption Program
Commitments And Contingencies [Line Items]
Termination date				Apr. 29, 2025
Amendment, suspension or termination period of share				30 days
Redemptions of common stock (in shares)						500,000
Redemptions of common stock, value						$ 29,900
Operating Partnership Redemption Rights
Commitments And Contingencies [Line Items]
Number of shares issuable upon conversion of partnership units				1
Requisite minimum outstanding period for conversion eligibility				1 year
Class A Common stock \| Distribution Reinvestment Plan
Commitments And Contingencies [Line Items]
Shares issued pursuant to distribution reinvestment plan		2,700,000
Class T Common stock \| Distribution Reinvestment Plan
Commitments And Contingencies [Line Items]
Shares issued pursuant to distribution reinvestment plan		300,000
Redeemable Common Stock \| Share Redemption Program
Commitments And Contingencies [Line Items]
Redemptions of common stock, value						$ 29,900