Organization - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2021 Property State shares	Dec. 31, 2020 shares	Jun. 30, 2020
Organization [Line Items]
Number of self-storage properties owned and managed	955
Number of states in which self-storage properties owned and managed | State	32
Number of properties managed under joint ventures	91
Number of properties managed with no ownership	251
Noncontrolling limited partnership unit redemption value	one common share or cash
Geographic Concentration Risk [Member] | Texas [Member] | Revenue [Member]
Organization [Line Items]
Concentration risk, percentage	18.00%
Geographic Concentration Risk [Member] | Florida [Member] | Revenue [Member]
Organization [Line Items]
Concentration risk, percentage	13.00%
Life Storage LP [Member]
Organization [Line Items]
Units of redeemable noncontrolling interest in operating partnership | shares	333,399	334,149
Life Storage LP [Member]
Organization [Line Items]
Percentage of ownership interest of the subsidiary and its limited partnership which controls the operations of the Operating Partnership	99.60%
Warehouse Anywhere LLC [Member]
Organization [Line Items]
Percentage of ownership interest of the subsidiary and its limited partnership which controls the operations of the Operating Partnership			60.00%