Partners' Capital - Reconciliation of Change in Total Partners' Capital (Detail) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021
Partners Capital [Line Items]
Exercise of stock options			$ 173
Earned portion of non-vested stock	$ 1,822	$ 1,743	1,661	$ 1,683	$ 1,467	$ 1,453
Carrying value less than redemption value on redeemed noncontrolling interest	(191)	(2)		(15)	(13)	(4)
Adjustment to redemption value on noncontrolling redeemable Operating Partnership Units	(1,958)	27,930	10,924	(3,570)	(7,142)	(2,358)
Net income attributable to common shareholders/unitholders	98,505	92,264	73,575	70,274	57,516	47,383	$ 264,344	$ 175,172
Amortization of terminated hedge included in AOCL	229	229	229	229	229	229
Life Storage LP [Member]
Partners Capital [Line Items]
Beginning balance of total controlling partners’ capital	3,520,361	3,474,695	3,378,999	2,692,999	2,549,490	2,378,098	3,378,999	2,378,098
Net proceeds from issuance of Operating Partnership Units	80,219	7,865	92,771	478,331	148,325	180,529
Exercise of stock options			173
Earned portion of non-vested stock	1,822	1,743	1,661	1,683	1,467	1,453
Issuance of common Operating Partnership Units	0	0		0
Issuance of preferred Operating Partnership Units				0
Carrying value less than redemption value on redeemed noncontrolling interest	(191)	(2)	0	(15)	(13)	(4)
Adjustment to redemption value on noncontrolling redeemable Operating Partnership Units	(1,958)	27,930	10,924	(3,570)	(7,142)	(2,358)
Net income attributable to common shareholders/unitholders	98,505	92,264	73,575	70,274	57,516	47,383	264,344	175,172
Amortization of terminated hedge included in AOCL	229	229	229	229	229	229
Distributions	(91,135)	(84,363)	(83,637)	(57,953)	(56,873)	(55,840)
Ending balance of total controlling partners’ capital	3,607,852	3,520,361	3,474,695	3,181,978	2,692,999	2,549,490	3,607,852	3,181,978
Life Storage LP [Member] | Life Storage Holdings, Inc. General Partner [Member]
Partners Capital [Line Items]
Beginning balance of total controlling partners’ capital	37,277	36,986	36,131	27,287	25,782	24,045	36,131	24,045
Net proceeds from issuance of Operating Partnership Units	802	80	927	4,783	1,483	1,807
Exercise of stock options			2
Earned portion of non-vested stock	18	17	17	17	15	14
Issuance of common Operating Partnership Units	17	103		15
Issuance of preferred Operating Partnership Units				898
Carrying value less than redemption value on redeemed noncontrolling interest	(19)	(2)	(1)	1	(1)	(1)
Adjustment to redemption value on noncontrolling redeemable Operating Partnership Units	0	0	0	0	0	0
Net income attributable to common shareholders/unitholders	1,011	944	754	711	578	476
Amortization of terminated hedge included in AOCL	2	2	2	2	2	2
Distributions	(923)	(853)	(846)	(582)	(572)	(561)
Ending balance of total controlling partners’ capital	38,185	37,277	36,986	33,130	27,287	25,782	38,185	33,130
Life Storage LP [Member] | Life Storage, Inc. Limited Partner [Member]
Partners Capital [Line Items]
Beginning balance of total controlling partners’ capital	3,486,750	3,441,604	3,346,992	2,670,295	2,528,520	2,359,094	3,346,992	2,359,094
Net proceeds from issuance of Operating Partnership Units	79,417	7,785	91,844	473,548	146,842	178,722
Exercise of stock options			171
Earned portion of non-vested stock	1,804	1,726	1,644	1,666	1,452	1,439
Issuance of common Operating Partnership Units	(17)	(103)		(15)
Issuance of preferred Operating Partnership Units				(898)
Carrying value less than redemption value on redeemed noncontrolling interest	(172)	0	1	(14)	(12)	(3)
Adjustment to redemption value on noncontrolling redeemable Operating Partnership Units	(1,958)	27,930	10,924	(3,570)	(7,142)	(2,358)
Net income attributable to common shareholders/unitholders	97,494	91,320	72,821	69,563	56,938	46,907
Amortization of terminated hedge included in AOCL	(2)	(2)	(2)	(2)	(2)	(2)
Distributions	(90,212)	(83,510)	(82,791)	(57,371)	(56,301)	(55,279)
Ending balance of total controlling partners’ capital	3,573,104	3,486,750	3,441,604	3,153,202	2,670,295	2,528,520	3,573,104	3,153,202
Accumulated Other Comprehensive Income (Loss) [Member]
Partners Capital [Line Items]
Exercise of stock options			0
Earned portion of non-vested stock	0	0	0	0	0	0
Carrying value less than redemption value on redeemed noncontrolling interest	0	0		0	0	0
Adjustment to redemption value on noncontrolling redeemable Operating Partnership Units	0	0	0	0	0	0
Net income attributable to common shareholders/unitholders	0	0	0	0	0	0
Amortization of terminated hedge included in AOCL	229	229	229	229	229	229
Accumulated Other Comprehensive Income (Loss) [Member] | Life Storage LP [Member]
Partners Capital [Line Items]
Beginning balance of total controlling partners’ capital	(3,666)	(3,895)	(4,124)	(4,583)	(4,812)	(5,041)	(4,124)	(5,041)
Net proceeds from issuance of Operating Partnership Units	0	0	0	0	0	0
Exercise of stock options			0
Earned portion of non-vested stock	0	0	0	0	0	0
Issuance of common Operating Partnership Units	0	0		0
Issuance of preferred Operating Partnership Units				0
Carrying value less than redemption value on redeemed noncontrolling interest	0	0	0	0	0	0
Adjustment to redemption value on noncontrolling redeemable Operating Partnership Units	0	0	0	0	0	0
Net income attributable to common shareholders/unitholders	0	0	0	0	0	0
Amortization of terminated hedge included in AOCL	229	229	229	229	229	229
Distributions	0	0	0	0	0	0
Ending balance of total controlling partners’ capital	$ (3,437)	$ (3,666)	$ (3,895)	$ (4,354)	$ (4,583)	$ (4,812)	$ (3,437)	$ (4,354)