Investment in Joint Ventures - Summary of Company's Unconsolidated Joint Ventures (Detail) $ in Millions	3 Months Ended
Mar. 31, 2023 USD ($) Property	Dec. 31, 2022 USD ($)
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	$ 63.0	$ 63.6
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	$ (2.6)	(2.4)
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	$ 13.8	13.7
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	$ 26.9	27.5
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	$ 48.0	48.6
LS HF8 ComRef LLC ("HF8") [Member]
Schedule of Equity Method Investments [Line Items]
Number of Properties \| Property	3
Company common ownership interest	20.00%
Carrying value of investment	$ 11.8	11.9
LS HF9 ComRef Texas LLC ("HF9") [Member]
Schedule of Equity Method Investments [Line Items]
Number of Properties \| Property	4
Company common ownership interest	20.00%
Carrying value of investment	$ 13.6	13.7
Life Storage HHF Wasatch Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of Properties \| Property	16
Company common ownership interest	20.00%
Carrying value of investment	$ 56.4	52.8
Iskalo Office Holdings, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Company common ownership interest	49.00%
Carrying value of investment	$ (2.3)	(2.3)
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	$ 13.5	13.7
Life Storage ArrowMark Venture LLC [Member]
Schedule of Equity Method Investments [Line Items]
Company common ownership interest	50.00%
Carrying value of investment	$ 5.9	5.9
Joint Ventures with Properties in Development Stage [Member]
Schedule of Equity Method Investments [Line Items]
Number of Properties \| Property	5
Company common ownership interest	Various
Carrying value of investment	$ 16.1	16.1
Other Unconsolidated Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Number of Properties \| Property	6
Company common ownership interest	Various
Carrying value of investment	$ 7.4	$ 7.6

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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