Investment in Joint Ventures - Summary of Company's Unconsolidated Joint Ventures (Detail)	9 Months Ended
Sep. 30, 2022 USD ($) Property	Dec. 31, 2021 USD ($)
Sovran HHF Storage Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of Properties \| Property	37
Company common ownership interest	20.00%
Carrying value of investment	$ 63,800,000	$ 58,700,000
Sovran HHF Storage Holdings II LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of Properties \| Property	22
Company common ownership interest	15.00%
Carrying value of investment	$ (2,500,000)	(2,400,000)
Life Storage-HIERS Storage LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of Properties \| Property	17
Company common ownership interest	20.00%
Carrying value of investment	$ 13,600,000	13,900,000
191 V Life Storage Holdings, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of Properties \| Property	17
Company common ownership interest	20.00%
Carrying value of investment	$ 27,800,000	27,400,000
GII Life Storage Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of Properties \| Property	13
Company common ownership interest	35.00%
Carrying value of investment	$ 49,000,000.0	51,500,000
Life Storage HHF Wasatch Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of Properties \| Property	15
Company common ownership interest	20.00%
Carrying value of investment	$ 51,200	0
Iskalo Office Holdings, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Company common ownership interest	49.00%
Carrying value of investment	$ (2,300,000)	(2,400,000)
Life Storage Spacemax, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of Properties \| Property	6
Company common ownership interest	40.00%
Carrying value of investment	$ 13,900,000	14,500,000
Life Storage 898 McDonald, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of Properties \| Property	0
Company common ownership interest	0.00%
Carrying value of investment		30,000,000.0
Life Storage ArrowMark Venture LLC [Member]
Schedule of Equity Method Investments [Line Items]
Company common ownership interest	50.00%
Carrying value of investment	$ 4,600,000	1,500,000
Joint Ventures with Properties in Development Stage [Member]
Schedule of Equity Method Investments [Line Items]
Number of Properties \| Property	6
Company common ownership interest	Various
Carrying value of investment	$ 18,800,000	4,700,000
Other Unconsolidated Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Number of Properties \| Property	10
Company common ownership interest	Various
Carrying value of investment	$ 12,000,000.0	$ 10,800,000

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+ References

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Topic 323
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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-Topic 280
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