Earnings Per Share and Earnings Per Unit - Computation of Basic and Diluted Earnings Per Common Share/Unit (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Numerator:
Net income attributable to common shareholders/unitholders	$ 93,784	$ 98,505	$ 92,264	$ 73,575	$ 74,145	$ 70,274	$ 57,516	$ 47,383	$ 358,128	$ 249,317	$ 151,571
Denominator:
Denominator for basic earnings per share/unit - weighted average shares/units									84,322	78,425	71,055
Effect of Dilutive Securities:
Stock options and non-vested stock									562	183	123
Denominator for diluted earnings per share/unit - adjusted weighted average shares/units and assumed conversion									84,884	78,608	71,178
Basic Earnings per common share/unit attributable to common shareholders/unitholders	$ 1.10	$ 1.16	$ 1.09	$ 0.88	$ 0.90	$ 0.89	$ 0.75	$ 0.63	$ 4.25	$ 3.18	$ 2.13
Diluted Earnings per common share/unit attributable to common shareholders/unitholders	$ 1.10	$ 1.16	$ 1.09	$ 0.88	$ 0.90	$ 0.89	$ 0.74	$ 0.63	$ 4.22	$ 3.17	$ 2.13
Life Storage LP [Member]
Numerator:
Net income attributable to common shareholders/unitholders	$ 93,784	$ 98,505	$ 92,264	$ 73,575	$ 74,145	$ 70,274	$ 57,516	$ 47,383	$ 358,128	$ 249,317	$ 151,571
Denominator:
Denominator for basic earnings per share/unit - weighted average shares/units									84,322	78,425	71,055
Effect of Dilutive Securities:
Stock options and non-vested stock									562	183	123
Denominator for diluted earnings per share/unit - adjusted weighted average shares/units and assumed conversion									84,884	78,608	71,178
Basic Earnings per common share/unit attributable to common shareholders/unitholders	$ 1.10	$ 1.16	$ 1.09	$ 0.88	$ 0.90	$ 0.89	$ 0.75	$ 0.63	$ 4.25	$ 3.18	$ 2.13
Diluted Earnings per common share/unit attributable to common shareholders/unitholders	$ 1.10	$ 1.16	$ 1.09	$ 0.88	$ 0.90	$ 0.89	$ 0.74	$ 0.63	$ 4.22	$ 3.17	$ 2.13