Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Operating Activities
Net income	$ 37,288	$ 140,746	$ 110,560	$ 216,346
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	33,018	26,854	90,335	79,239
Amortization of debt issuance costs and bond discount			3,033	2,873
Gain on sale of storage facilities		(100,222)		(100,222)
Gain on sale of real estate			(302)	(1,076)
Equity in income of joint ventures	(1,829)	(1,175)	(3,915)	(3,095)
Distributions from unconsolidated joint ventures			9,246	7,419
Non-vested stock earned			3,380	3,284
Deferred income taxes			1,266	429
Other			(178)
Changes in assets and liabilities (excluding the effects of acquisitions):
Accounts receivable			(1,562)	(3,132)
Prepaid expenses			(2,710)	(2,296)
Advances to joint ventures			(2,254)	(118)
Accounts payable and other liabilities			1,396	(968)
Deferred revenue			3,421	1,311
Net cash provided by operating activities			211,716	199,994
Investing Activities
Acquisition of storage facilities, net of cash acquired			(417,930)	(354,712)
Improvements, equipment additions, and construction in progress			(37,622)	(63,645)
Net proceeds from the sale of real estate				207,568
Return of investment in unconsolidated joint ventures			28,008
Investment in unconsolidated joint ventures			(21,862)	(19,347)
Loans to unconsolidated subsidiaries			(35,850)
Loan payments received from unconsolidated subsidiaries			35,850
Property deposits			(129)	(767)
Net cash used in investing activities			(449,535)	(230,903)
Financing Activities
Net proceeds from sale of common stock\partnership units			155,614	375
Proceeds from line of credit			285,000	225,000
Repayments of line of credit			(350,000)	(291,000)
Proceeds from term notes, net of discount			398,096	348,166
Repayment of term notes				(100,000)
Debt issuance costs			(3,480)	(3,099)
Dividends paid - common stock			(150,357)	(139,914)
Distributions to noncontrolling interest holders			(785)	(745)
Payments to acquire equity in consolidated subsidiary from noncontrolling interests			(2,000)
Redemption of Operating Partnership Units			(265)	(145)
Mortgage principal payments			(306)	(293)
Net cash provided by financing activities			331,517	38,345
Net increase in cash and restricted cash			93,698	7,436
Cash and restricted cash at beginning of period			21,556	14,065	$ 14,065
Cash and restricted cash at end of period	115,254	21,501	115,254	21,501	21,556
Supplemental cash flow information
Cash paid for interest, net of interest capitalized			57,816	52,267
Cash paid for income taxes, net of refunds			859	1,485
Life Storage LP [Member]
Operating Activities
Net income	37,288	140,746	110,560	216,346
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	33,018	26,854	90,335	79,239
Amortization of debt issuance costs and bond discount			3,033	2,873
Gain on sale of storage facilities		(100,222)		(100,222)
Gain on sale of real estate			(302)	(1,076)
Equity in income of joint ventures	(1,829)	(1,175)	(3,915)	(3,095)
Distributions from unconsolidated joint ventures			9,246	7,419
Non-vested stock earned			3,380	3,284
Deferred income taxes			1,266	429
Other			(178)
Changes in assets and liabilities (excluding the effects of acquisitions):
Accounts receivable			(1,562)	(3,132)
Prepaid expenses			(2,710)	(2,296)
Advances to joint ventures			(2,254)	(118)
Accounts payable and other liabilities			1,396	(968)
Deferred revenue			3,421	1,311
Net cash provided by operating activities			211,716	199,994
Investing Activities
Acquisition of storage facilities, net of cash acquired			(417,930)	(354,712)
Improvements, equipment additions, and construction in progress			(37,622)	(63,645)
Net proceeds from the sale of real estate				207,568
Return of investment in unconsolidated joint ventures			28,008
Investment in unconsolidated joint ventures			(21,862)	(19,347)
Loans to unconsolidated subsidiaries			(35,850)
Loan payments received from unconsolidated subsidiaries			35,850
Property deposits			(129)	(767)
Net cash used in investing activities			(449,535)	(230,903)
Financing Activities
Net proceeds from sale of common stock\partnership units			155,614	375
Proceeds from line of credit			285,000	225,000
Repayments of line of credit			(350,000)	(291,000)
Proceeds from term notes, net of discount			398,096	348,166
Repayment of term notes				(100,000)
Debt issuance costs			(3,480)	(3,099)
Distributions to unitholders			(150,357)	(139,914)
Distributions to noncontrolling interest holders			(785)	(745)
Payments to acquire equity in consolidated subsidiary from noncontrolling interests			(2,000)
Redemption of Operating Partnership Units			(265)	(145)
Mortgage principal payments			(306)	(293)
Net cash provided by financing activities			331,517	38,345
Net increase in cash and restricted cash			93,698	7,436
Cash and restricted cash at beginning of period			21,556	14,065	14,065
Cash and restricted cash at end of period	$ 115,254	$ 21,501	115,254	21,501	$ 21,556
Supplemental cash flow information
Cash paid for interest, net of interest capitalized			57,816	52,267
Cash paid for income taxes, net of refunds			$ 859	$ 1,485