Partners' Capital - Reconciliation of Change in Total Partners' Capital (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Partners Capital [Line Items]
Earned portion of non-vested stock	$ 1,453	$ 1,124
Carrying value less than redemption value on redeemed noncontrolling interest	(4)
Adjustment to redemption value on noncontrolling redeemable Operating Partnership Units	2,358	(5,542)
Net income attributable to common shareholders/unitholders	47,383	36,433
Amortization of terminated hedge included in AOCL	229	229
Life Storage LP [Member]
Partners Capital [Line Items]
Beginning balance of total controlling partners’ capital	2,378,098	2,132,894
Net proceeds from issuance of Operating Partnership Units	180,529	21,466
Earned portion of non-vested stock	1,453	1,124
Carrying value less than redemption value on redeemed noncontrolling interest	(4)
Adjustment to redemption value on noncontrolling redeemable Operating Partnership Units	(2,358)	5,542
Net income attributable to common shareholders/unitholders	47,383	36,433
Amortization of terminated hedge included in AOCL	229	229
Distributions	(55,840)	(49,969)
Ending balance of total controlling partners’ capital	2,549,490	2,147,719
Life Storage LP [Member] | Life Storage Holdings, Inc. General Partner [Member]
Partners Capital [Line Items]
Beginning balance of total controlling partners’ capital	24,045	21,594
Net proceeds from issuance of Operating Partnership Units	1,807	212
Earned portion of non-vested stock	14	11
Carrying value less than redemption value on redeemed noncontrolling interest	(1)
Net income attributable to common shareholders/unitholders	476	366
Amortization of terminated hedge included in AOCL	2	2
Distributions	(561)	(502)
Ending balance of total controlling partners’ capital	25,782	21,683
Life Storage LP [Member] | Life Storage, Inc. Limited Partner [Member]
Partners Capital [Line Items]
Beginning balance of total controlling partners’ capital	2,359,094	2,117,258
Net proceeds from issuance of Operating Partnership Units	178,722	21,254
Earned portion of non-vested stock	1,439	1,113
Carrying value less than redemption value on redeemed noncontrolling interest	(3)
Adjustment to redemption value on noncontrolling redeemable Operating Partnership Units	(2,358)	5,542
Net income attributable to common shareholders/unitholders	46,907	36,067
Amortization of terminated hedge included in AOCL	(2)	(2)
Distributions	(55,279)	(49,467)
Ending balance of total controlling partners’ capital	2,528,520	2,131,765
Accumulated Other Comprehensive Income (Loss) [Member]
Partners Capital [Line Items]
Amortization of terminated hedge included in AOCL	229	229
Accumulated Other Comprehensive Income (Loss) [Member] | Life Storage LP [Member]
Partners Capital [Line Items]
Beginning balance of total controlling partners’ capital	(5,041)	(5,958)
Amortization of terminated hedge included in AOCL	229	229
Ending balance of total controlling partners’ capital	$ (4,812)	$ (5,729)