Life Storage Inc - Registered Shares (LSI) 10-Q 2 Aug 18 2018 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2018	Jul. 19, 2018
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q2
Trading Symbol	LSI
Entity Registrant Name	LIFE STORAGE, INC.
Entity Central Index Key	944,314
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		46,600,427
Life Storage LP [Member]
Document Information [Line Items]
Entity Registrant Name	LIFE STORAGE LP
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Investment in storage facilities:
Land	$ 786,628	$ 786,628
Building, equipment, and construction in progress	3,560,756	3,534,782
Real estate investment property, at cost, total	4,347,384	4,321,410
Less: accumulated depreciation	(671,717)	(624,314)
Investment in storage facilities, net	3,675,667	3,697,096
Cash and cash equivalents	7,327	9,167
Accounts receivable	7,935	7,331
Receivable from unconsolidated joint ventures	994	1,397
Investment in unconsolidated joint ventures	133,225	133,458
Prepaid expenses	16,657	6,757
Fair value of interest rate swap agreements	177	205
Trade name	16,500	16,500
Other assets	4,487	4,863
Total Assets	3,862,969	3,876,774
Liabilities
Line of credit	113,000	105,000
Term notes, net	1,610,062	1,609,089
Accounts payable and accrued liabilities	83,254	92,941
Deferred revenue	10,080	9,374
Mortgages payable	12,489	12,674
Total Liabilities	1,828,885	1,829,078
Noncontrolling redeemable Operating Partnership Units at redemption value	20,644	19,373
Shareholders' Equity/ Partners' Capital
Common stock $.01 par value, 100,000,000 shares authorized, 46,599,927 shares outstanding at June 30, 2018 (46,552,222 at December 31, 2017)	466	466
Additional paid-in capital	2,368,942	2,363,171
Dividends in excess of net income	(348,764)	(327,727)
Accumulated other comprehensive loss	(7,204)	(7,587)
Total Shareholders’ Equity	2,013,440	2,028,323
Noncontrolling interest in consolidated subsidiary	0	0
Total Equity	2,013,440	2,028,323
Total Liabilities and Shareholders' Equity/ Partners' Capital	3,862,969	3,876,774
Life Storage LP [Member]
Investment in storage facilities:
Land	786,628	786,628
Building, equipment, and construction in progress	3,560,756	3,534,782
Real estate investment property, at cost, total	4,347,384	4,321,410
Less: accumulated depreciation	(671,717)	(624,314)
Investment in storage facilities, net	3,675,667	3,697,096
Cash and cash equivalents	7,327	9,167
Accounts receivable	7,935	7,331
Receivable from unconsolidated joint ventures	994	1,397
Investment in unconsolidated joint ventures	133,225	133,458
Prepaid expenses	16,657	6,757
Fair value of interest rate swap agreements	177	205
Trade name	16,500	16,500
Other assets	4,487	4,863
Total Assets	3,862,969	3,876,774
Liabilities
Line of credit	113,000	105,000
Term notes, net	1,610,062	1,609,089
Accounts payable and accrued liabilities	83,254	92,941
Deferred revenue	10,080	9,374
Mortgages payable	12,489	12,674
Total Liabilities	1,828,885	1,829,078
Limited partners’ redeemable capital interest at redemption value (215,009 and 217,481 units outstanding at June 30, 2018 and December 31, 2017, respectively)	20,644	19,373
Shareholders' Equity/ Partners' Capital
General partner (468,174 and 467,697 units outstanding at June 30, 2018 and December 31, 2017, respectively)	20,343	20,478
Limited partners (46,131,753 and 46,084,525 units outstanding at June 30, 2018 and December 31, 2017, respectively)	2,000,301	2,015,432
Accumulated other comprehensive loss	(7,204)	(7,587)
Total Controlling Partners’ Capital	2,013,440	2,028,323
Noncontrolling interest in consolidated subsidiary	0	0
Total Partners' Capital	2,013,440	2,028,323
Total Liabilities and Shareholders' Equity/ Partners' Capital	$ 3,862,969	$ 3,876,774

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2018	Dec. 31, 2017
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares outstanding	46,599,927	46,552,222
Limited partner, units outstanding	215,009	217,481
Life Storage LP [Member]
General partner, units outstanding	468,174	467,697
Limited partner, units outstanding	46,131,753	46,084,525
Life Storage LP [Member] | Limited Partners Redeemable Capital Interest at Redemption Value [Member]
Limited partner, units outstanding	215,009	217,481

Consolidated Statements of Oper

Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues
Rental income	$ 125,892	$ 120,646	$ 247,516	$ 239,240
Other operating income	12,116	12,138	23,586	21,865
Total operating revenues	138,008	132,784	271,102	261,105
Expenses
Property operations and maintenance	29,787	29,719	60,236	59,515
Real estate taxes	15,643	14,498	31,061	28,933
General and administrative	11,728	15,959	23,771	27,396
Payments for rent	141	141	283	141
Depreciation and amortization	24,784	38,105	49,548	75,747
Total operating expenses	82,083	98,422	164,899	191,732
Income from operations	55,925	34,362	106,203	69,373
Other income (expenses)
Interest expense	(17,518)	(15,716)	(34,722)	(30,926)
Interest income	2	1	6	4
Equity in income of joint ventures	1,048	785	2,020	1,506
Net income	39,457	19,432	73,507	39,957
Net income attributable to noncontrolling interest in the Operating Partnership	(183)	(77)	(344)	(172)
Net loss attributable to noncontrolling interest in consolidated subsidiary	0	0	0	0
Net income attributable to common shareholders/unitholders	$ 39,274	$ 19,355	$ 73,163	$ 39,785
Earnings per common share/unit attributable to common shareholders/unitholders - basic	$ 0.84	$ 0.42	$ 1.57	$ 0.86
Earnings per common share/unit attributable to common shareholders/unitholders - diluted	$ 0.84	$ 0.42	$ 1.57	$ 0.86
Common shares/units used in basic earnings per share/unit calculation	46,480,907	46,364,890	46,466,700	46,334,729
Common shares/units used in diluted earnings per share/unit calculation	46,576,352	46,477,680	46,556,512	46,448,286
Dividends/distributions declared per common share/unit	$ 1	$ 1	$ 2	$ 1.95
Life Storage LP [Member]
Revenues
Rental income	$ 125,892	$ 120,646	$ 247,516	$ 239,240
Other operating income	12,116	12,138	23,586	21,865
Total operating revenues	138,008	132,784	271,102	261,105
Expenses
Property operations and maintenance	29,787	29,719	60,236	59,515
Real estate taxes	15,643	14,498	31,061	28,933
General and administrative	11,728	15,959	23,771	27,396
Payments for rent	141	141	283	141
Depreciation and amortization	24,784	38,105	49,548	75,747
Total operating expenses	82,083	98,422	164,899	191,732
Income from operations	55,925	34,362	106,203	69,373
Other income (expenses)
Interest expense	(17,518)	(15,716)	(34,722)	(30,926)
Interest income	2	1	6	4
Equity in income of joint ventures	1,048	785	2,020	1,506
Net income	39,457	19,432	73,507	39,957
Net income attributable to noncontrolling interest in the Operating Partnership	(183)	(77)	(344)	(172)
Net loss attributable to noncontrolling interest in consolidated subsidiary	0	0	0	0
Net income attributable to common shareholders/unitholders	$ 39,274	$ 19,355	$ 73,163	$ 39,785
Earnings per common share/unit attributable to common shareholders/unitholders - basic	$ 0.84	$ 0.42	$ 1.57	$ 0.86
Earnings per common share/unit attributable to common shareholders/unitholders - diluted	$ 0.84	$ 0.42	$ 1.57	$ 0.86
Common shares/units used in basic earnings per share/unit calculation	46,480,907	46,364,890	46,466,700	46,334,729
Common shares/units used in diluted earnings per share/unit calculation	46,576,352	46,477,680	46,556,512	46,448,286
Dividends/distributions declared per common share/unit	$ 1	$ 1	$ 2	$ 1.95
Net income attributable to general partner	$ 395	$ 194	$ 735	$ 400
Net income attributable to limited partners	$ 38,879	$ 19,161	$ 72,428	$ 39,385

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Net income	$ 39,457	$ 19,432	$ 73,507	$ 39,957
Other comprehensive income:
Effective portion of gain on derivatives net of reclassification to interest expense	106	237	383	1,859
Total comprehensive income	39,563	19,669	73,890	41,816
Comprehensive income attributable to noncontrolling interest in the Operating Partnership	(183)	(78)	(346)	(180)
Comprehensive loss attributable to noncontrolling interest in consolidated subsidiary	0	0	0	0
Comprehensive income attributable to common shareholders/unitholders	39,380	19,591	73,544	41,636
Life Storage LP [Member]
Net income	39,457	19,432	73,507	39,957
Other comprehensive income:
Effective portion of gain on derivatives net of reclassification to interest expense	106	237	383	1,859
Total comprehensive income	39,563	19,669	73,890	41,816
Comprehensive income attributable to noncontrolling interest in the Operating Partnership	(183)	(78)	(346)	(180)
Comprehensive loss attributable to noncontrolling interest in consolidated subsidiary	0	0	0	0
Comprehensive income attributable to common shareholders/unitholders	$ 39,380	$ 19,591	$ 73,544	$ 41,636

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Operating Activities
Net income	$ 73,507	$ 39,957
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	49,548	75,747
Amortization of debt issuance costs and bond discount	1,781	1,663
Equity in income of joint ventures	(2,020)	(1,506)
Distributions from unconsolidated joint ventures	4,103	2,852
Non-vested stock earned	2,748	3,246
Stock option expense	7	8
Deferred income taxes	105	(2,832)
Changes in assets and liabilities (excluding the effects of acquisitions):
Accounts receivable	(604)	(720)
Prepaid expenses	(9,900)	(2,045)
Receipts from joint ventures	403	201
Accounts payable and other liabilities	(9,718)	(8,023)
Deferred revenue	706	320
Net cash provided by operating activities	110,666	108,868
Investing Activities
Acquisitions of storage facilities, net of cash acquired		(9,576)
Improvements, equipment additions, and construction in progress	(28,047)	(45,662)
Net proceeds from the sale of real estate		976
Investment in unconsolidated joint ventures	(1,862)	(66,590)
Property deposit	29
Net cash used in investing activities	(29,880)	(120,852)
Financing Activities
Net proceeds from sale of common stock/partnership units	3,045	9,760
Proceeds from line of credit	115,000	179,000
Repayments of line of credit	(107,000)	(101,000)
Dividends paid - common stock	(92,635)	(90,610)
Distributions to noncontrolling interest holders	(435)	(424)
Redemption of operating partnership units	(232)
Mortgage principal payments	(185)	(175)
Net cash used in financing activities	(82,442)	(3,449)
Net decrease in cash and restricted cash	(1,656)	(15,433)
Cash and restricted cash at beginning of period	9,459	23,923
Cash and restricted cash at end of period	7,803	8,490
Supplemental cash flow information
Cash paid for interest, net of interest capitalized	34,406	30,624
Cash paid for income taxes, net of refunds	1,249	1,161
Life Storage LP [Member]
Operating Activities
Net income	73,507	39,957
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	49,548	75,747
Amortization of debt issuance costs and bond discount	1,781	1,663
Equity in income of joint ventures	(2,020)	(1,506)
Distributions from unconsolidated joint ventures	4,103	2,852
Non-vested stock earned	2,748	3,246
Stock option expense	7	8
Deferred income taxes	105	(2,832)
Changes in assets and liabilities (excluding the effects of acquisitions):
Accounts receivable	(604)	(720)
Prepaid expenses	(9,900)	(2,045)
Receipts from joint ventures	403	201
Accounts payable and other liabilities	(9,718)	(8,023)
Deferred revenue	706	320
Net cash provided by operating activities	110,666	108,868
Investing Activities
Acquisitions of storage facilities, net of cash acquired		(9,576)
Improvements, equipment additions, and construction in progress	(28,047)	(45,662)
Net proceeds from the sale of real estate		976
Investment in unconsolidated joint ventures	(1,862)	(66,590)
Property deposit	29
Net cash used in investing activities	(29,880)	(120,852)
Financing Activities
Net proceeds from sale of common stock/partnership units	3,045	9,760
Proceeds from line of credit	115,000	179,000
Repayments of line of credit	(107,000)	(101,000)
Distributions to unitholders	(92,635)	(90,610)
Distributions to noncontrolling interest holders	(435)	(424)
Redemption of operating partnership units	(232)
Mortgage principal payments	(185)	(175)
Net cash used in financing activities	(82,442)	(3,449)
Net decrease in cash and restricted cash	(1,656)	(15,433)
Cash and restricted cash at beginning of period	9,459	23,923
Cash and restricted cash at end of period	7,803	8,490
Supplemental cash flow information
Cash paid for interest, net of interest capitalized	34,406	30,624
Cash paid for income taxes, net of refunds	$ 1,249	$ 1,161

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2018
Accounting Policies [Abstract]
Basis of Presentation	1. BASIS OF PRESENTATION The accompanying unaudited financial statements of Life Storage, Inc. (the “Parent Company”) and Life Storage LP (the “Operating Partnership”) have been prepared in accordance with generally accepted accounting principles for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all information and footnotes required by generally accepted accounting principles for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. Operating results for the six month period ended June 30, 2018 are not necessarily indicative of the results that may be expected for the year ending December 31, 2018.

Organization

Organization	6 Months Ended
	Jun. 30, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization	2. ORGANIZATION The Parent Company operates as a self-administered and self-managed real estate investment trust (a “REIT”) that owns and operates self-storage facilities throughout the United States. All of the Parent Company’s assets are owned by, and all its operations are conducted through, the Operating Partnership. Life Storage Holdings, Inc., a wholly-owned subsidiary of the Parent Company (“Holdings”), is the sole general partner of the Operating Partnership; the Parent Company is a limited partner of the Operating Partnership, and, through its ownership of Holdings and its limited partnership interest, controls the operations of the Operating Partnership, holding a 99.5% ownership interest therein as of June 30, 2018. The remaining ownership interests in the Operating Partnership (the “Units”) are held by certain former owners of assets acquired by the Operating Partnership. The Parent Company, the Operating Partnership and their consolidated subsidiaries are collectively referred to in this report as the “Company.” In addition, terms such as “we,” “us,” or “our” used in this report may refer to the Company, the Parent Company and/or the Operating Partnership. At June 30, 2018, we had an ownership interest in, and/or managed 718 self-storage properties in 28 states under the name Life Storage ® We consolidate all wholly-owned subsidiaries and joint ventures are consolidated when we control the entity. Our consolidated financial statements include the accounts of the Parent Company, the Operating Partnership, Life Storage Solutions, LLC (the Parent Company’s taxable REIT subsidiary), Warehouse Anywhere LLC (an entity owned 60% by Life Storage Solutions, LLC), and all other wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated. Investments in joint ventures that we do not control but for which we have significant influence over are accounted for using the equity method. Included in the Parent Company’s consolidated balance sheets are noncontrolling redeemable Operating Partnership Units and included in the Operating Partnership’s consolidated balance sheets are limited partners’ redeemable capital interest at redemption value. These interests are presented in the “mezzanine” section of the consolidated balance sheet because they do not meet the functional definition of a liability or equity under current accounting literature. These represent the outside ownership interests of the limited partners in the Operating Partnership. There were 215,009 and 217,481 noncontrolling redeemable Operating Partnership Units outstanding at June 30, 2018 and December 31, 2017, respectively. These unitholders are entitled to receive distributions per unit equivalent to the dividends declared per share on the Parent Company’s common stock. The Operating Partnership is obligated to redeem each of these limited partnership units in the Operating Partnership at the request of the holder thereof for cash equal to the fair market value of a share of the Parent Company’s common stock based on a 10-day average of the daily market price, at the time of such redemption, provided that the Company at its option may elect to acquire any such Unit presented for redemption for one common share or cash. The Company accounts for these noncontrolling redeemable Operating Partnership Units under the provisions of Accounting Standards Codification (ASC) Topic 480-10-S99. The application of the ASC Topic 480-10-S99 accounting model requires the noncontrolling interest to follow normal noncontrolling interest accounting and then be marked to redemption value at the end of each reporting period if higher (but never adjusted below that normal noncontrolling interest accounting amount). The offset to the adjustment to the carrying amount of the noncontrolling interests is reflected in the Company’s dividends in excess of net income and in the Operating Partnership’s general partner and limited partners capital balances. Accordingly, in the accompanying consolidated balance sheets, noncontrolling interests are reflected at redemption value at June 30, 2018 and December 31, 2017, equal to the number of noncontrolling interest units outstanding multiplied by the fair market value of the Parent Company’s common stock at that date. Redemption value exceeded the value determined under the Company’s historical basis of accounting at those dates. The following is a reconciliation of the Parent Company’s noncontrolling redeemable Operating Partnership Units and the Operating Partnership’s limited partners’ redeemable capital interest for the period: (dollars in thousands) Six Months Ended June 30, 2018 Beginning balance $ 19,373 Redemption of units (203 ) Net income attributable to noncontrolling interest in the Operating Partnership 344 Distributions (435 ) Adjustment to redemption value 1,565 Ending balance $ 20,644 The disaggregated revenues of the Company presented in accordance with ASC Topic 606 “Revenue from Contracts with Customers” (dollars in thousands) Three Months Ended June 30, 2018 Three Months Ended June 30, 2017 Six Months Ended June 30, 2018 Six Months Ended June 30, 2017 Rental income $ 125,892 $ 120,646 $ 247,516 $ 239,240 Management and acquisition fee income 2,546 3,183 4,941 5,001 Revenues related to tenant insurance 5,768 5,622 11,485 10,974 Other 3,802 3,333 7,160 5,890 Total operating revenues $ 138,008 $ 132,784 $ 271,102 $ 261,105 Revenues related to tenant insurance and management and acquisition fee income are included in other operating income in the consolidated statements of operations. During 2018, approximately 22% and 13% of the Company’s revenue was derived from self-storage facilities in the states of Texas and Florida, respectively.

Stock Based Compensation

Stock Based Compensation	6 Months Ended
	Jun. 30, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Based Compensation	3. STOCK BASED COMPENSATION The Company accounts for stock-based compensation under the provisions of ASC Topic 718, “ Compensation - Stock Compensation For awards with graded vesting, compensation cost is recognized on a straight-line basis over the related vesting period. For the three months ended June 30, 2018 and 2017, the Company recorded compensation expense (included in general and administrative expense) of $3,000 and $4,000, respectively, related to stock options and $1,252,000 and $1,657,000, respectively, related to amortization of non-vested stock grants and performance-based awards. For the six months ended June 30, 2018 and 2017, the Company recorded compensation expense of $7,000 and $8,000, respectively, related to stock options and $2,748,000 and $3,246,000, respectively, related to amortization of non-vested stock grants and performance-based awards. During the three and six months ended June 30, 2018, 71,606 stock options were exercised by employees and directors. No stock options were exercised by employees and directors during the three and six months ended June 30, 2017. During the three months ended June 30, 2018 and 2017, 3,762 and 2,239 shares of non-vested stock, respectively, vested. During the six months ended June 30, 2018 and 2017, 39,953 and 47,028 shares of non-vested stock, respectively, vested. During the six months ended June 30, 2018, the Company issued 14,865 shares of non-vested stock to certain employees and non-employee directors which vest over periods ranging from one year to eight years. The fair market value on the date of grant of the non-vested stock issued during the six months ended June 30, 2018 ranged from $81.86 to $94.08, resulting in an aggregate fair value of $1.4 million. During the six months ended June 30, 2018, the Company granted performance-based awards that entitle the recipient to earn up to 6,766 shares if certain performance criteria are achieved over a three-year period. The Company estimated the aggregate fair value of the awards on the grant date to be $0.3 million.

Cash and Restricted Cash

Cash and Restricted Cash	6 Months Ended
	Jun. 30, 2018
Cash And Cash Equivalents [Abstract]
Cash and Restricted Cash	4. CASH AND RESTRICTED CASH Restricted cash represents those amounts required to be placed in escrow by banks with whom the Company has entered into mortgages and is included in other assets in the consolidated balance sheets. The following table provides a reconciliation of cash and restricted cash reported within the consolidated statement of cash flows: (Dollars in thousands) June 30, 2018 December 31, 2017 June 30, 2017 Cash $ 7,327 $ 9,167 $ 7,998 Restricted cash 476 292 492 Total cash and restricted cash 7,803 9,459 8,490

Investment in Storage Facilitie

Investment in Storage Facilities and Intangible Assets	6 Months Ended
	Jun. 30, 2018
Real Estate [Abstract]
Investment in Storage Facilities and Intangible Assets	5. INVESTMENT IN STORAGE FACILITIES AND INTANGIBLE ASSETS The following summarizes our activity in storage facilities during the six months ended June 30, 2018: (dollars in thousands) Cost: Beginning balance $ 4,321,410 Improvements and equipment additions 14,123 Net increase in construction in progress 14,040 Dispositions (2,189 ) Ending balance $ 4,347,384 Accumulated Depreciation: Beginning balance $ 624,314 Additions during the period 49,557 Dispositions (2,154 ) Ending balance $ 671,717 We did not acquire any self-storage facilities during the six months ended June 30, 2018. The Company measures the fair value of in-place customer lease intangible assets based on the Company’s experience with customer turnover and the cost to replace the in-place leases. The Company amortizes in-place customer leases on a straight-line basis over 12 months (the estimated future benefit period). The Company measures the value of trade names, which have an indefinite life and are not amortized, by calculating discounted cash flows utilizing the relief from royalty method. In-place customer leases are included in other assets on the Company’s consolidated balance sheets as follows: (Dollars in thousands) June 30, 2018 December 31, 2017 In-place customer leases $ 75,241 $ 75,241 Accumulated amortization (75,241 ) (75,241 ) Net carrying value at the end of period — — Amortization expense related to in-place customer leases was $11.9 million and $24.7 million for the three and six months ended June 30, 2017, respectively. The Company did not record any amortization expense during the three and six months ended June 30, 2018 as all in-place customer leases were fully amortized at the beginning of the period. Change in Useful Life Estimates As part of the Company’s capital improvement efforts during 2017 and 2018, buildings at certain self-storage facilities were identified for replacement. As a result of the decision to replace these buildings, the Company reassessed the estimated useful lives of the then existing buildings. This useful life reassessment resulted in an increase in depreciation expense of approximately $0.3 million during the six months ended June 30, 2018 and $1.4 million and $1.5 million, respectively, during the three and six months ended June 30, 2017. There was de minimis impact on the three months ended June 30, 2018. The Company estimates that the change in estimated useful lives of buildings identified for replacement as of June 30, 2018 will have minimal additional impact on depreciation expense during the remainder of 2018. The accelerated depreciation resulting from the events discussed above reduced both basic and diluted earnings per share/unit by approximately $0.01, respectively, for the six month period ended June 30, 2018 and by approximately $0.03 for both the three and six months ended June 30, 2017.

Unsecured Line of Credit and Te

Unsecured Line of Credit and Term Notes	6 Months Ended
	Jun. 30, 2018
Debt Disclosure [Abstract]
Unsecured Line of Credit and Term Notes	6. UNSECURED LINE OF CREDIT AND TERM NOTES Borrowings outstanding on our unsecured line of credit and term notes are as follows: (Dollars in thousands) June 30, 2018 December 31, 2017 Revolving line of credit borrowings $ 113,000 $ 105,000 Term note due June 4, 2020 100,000 100,000 Term note due August 5, 2021 100,000 100,000 Term note due April 8, 2024 175,000 175,000 Senior term note due July 1, 2026 600,000 600,000 Senior term note due December 15, 2027 450,000 450,000 Term note due July 21, 2028 200,000 200,000 Total term note principal balance outstanding $ 1,625,000 $ 1,625,000 Less: unamortized debt issuance costs (10,262 ) (10,962 ) Less: unamortized senior term note discount (4,676 ) (4,949 ) Term notes payable $ 1,610,062 $ 1,609,089 The Company’s unsecured amended credit agreement includes a revolving credit facility with a limit of $500 million. The interest rate on the revolving credit facility bears interest at a variable annual rate equal to LIBOR plus a margin based on the Company’s credit rating (at June 30, 2018 the margin is 1.10%), and requires an annual 0.15% facility fee. The interest rate at June 30, 2018 on the Company’s line of credit was approximately 3.19% (2.63% at December 31, 2017). At June 30, 2018, there was $386.2 million available on the unsecured revolving line of credit. The revolving line of credit has a maturity date of December 10, 2019. The Company’s unsecured credit agreement also includes an unsecured term note maturing June 4, 2020, which term note was initially in the principal amount of $325 million. In 2017, the Company repaid $225 million under this term note, resulting in $100 million outstanding at June 30, 2018. The term note bears interest at LIBOR plus a margin based on the Company’s credit rating (at June 30, 2018 the margin is 1.15%). The interest rate at June 30, 2018 on the term note was approximately 3.15% (2.53% at December 31, 2017). On December 7, 2017, the Operating Partnership issued $450 million in aggregate principal amount of 3.875% unsecured senior notes due December 15, 2027 (the “2027 Senior Notes”). The 2027 Senior Notes were issued at a 0.477% discount to par value. Interest on the 2027 Senior Notes is payable semi-annually on each June 15 and December 15, beginning on June 15, 2018. The 2027 Senior Notes are fully and unconditionally guaranteed by the Parent Company. Proceeds received upon issuance, net of discount to par of $2.1 million and underwriting discount and other offering expenses of $4.0 million, totaled $443.9 million. On June 20, 2016, the Operating Partnership issued $600 million in aggregate principal amount of 3.50% unsecured senior notes due July 1, 2026 (the “2026 Senior Notes”). The 2026 Senior Notes were issued at a 0.553% discount to par value. Interest on the 2026 Senior Notes is payable semi-annually in arrears on each January 1 and July 1. The 2026 Senior Notes are fully and unconditionally guaranteed by the Parent Company. Proceeds received upon issuance, net of discount to par of $3.3 million and underwriting discount and other offering expenses of $5.5 million, totaled $591.2 million. The indenture under which the 2027 Senior Notes and the 2026 Senior Notes were issued restricts the ability of the Company and its subsidiaries to incur debt unless the Company and its consolidated subsidiaries comply with a leverage ratio not to exceed 60% and an interest coverage ratio of more than 1.5:1 on all outstanding debt, after giving effect to the incurrence of the debt. The indenture also restricts the ability of the Company and its subsidiaries to incur secured debt unless the Company and its consolidated subsidiaries comply with a secured debt leverage ratio not to exceed 40% after giving effect to the incurrence of the debt. The indenture also contains other financial and customary covenants, including a covenant not to own unencumbered assets with a value less than 150% of the unsecured indebtedness of the Company and its consolidated subsidiaries. At June 30, 2018, the Company was in compliance with such covenants. On July 21, 2016, the Company entered into a $200 million term note maturing July 21, 2028 bearing interest at a fixed rate of 3.67%. On April 8, 2014, the Company entered into a $175 million term note maturing April 8, 2024 bearing interest at a fixed rate of 4.533%. The interest rate on the term note increases to 6.283% if the Company is not rated by at least one rating agency or if the Company’s credit rating is downgraded. In 2011, the Company entered into a $100 million term note maturing August 5, 2021 bearing interest at a fixed rate of 5.54%. The interest rate on the term note increases to 7.29% if the notes are not rated by at least one rating agency, the credit rating on the notes is downgraded or if the Company’s credit rating is downgraded. The line of credit and term notes require the Company to meet certain financial covenants, measured on a quarterly basis, including prescribed leverage, fixed charge coverage, minimum net worth, limitations on additional indebtedness and limitations on dividend payouts. At June 30, 2018, the Company was in compliance with such covenants. We believe that if operating results remain consistent with historical levels and levels of other debt and liabilities remain consistent with amounts outstanding at June 30, 2018, the entire availability on the line of credit could be drawn without violating our debt covenants. The Company’s fixed rate term notes contain a provision that allows for the noteholders to call the debt upon a change of control of the Company at an amount that includes a make whole premium based on rates in effect on the date of the change of control. Deferred debt issuance costs and the discount on the outstanding term notes are both presented as reductions of term notes in the accompanying consolidated balance sheets at June 30, 2018 and December 31, 2017. Amortization expense related to deferred debt issuance costs was $0.5 million for each of the three months ended June 30, 2018 and 2017, and $1.0 million for each of the six months ended June 30, 2018 and 2017, and is included in interest expense in the consolidated statements of operations.

Mortgages Payable and Debt Matu

Mortgages Payable and Debt Maturities	6 Months Ended
	Jun. 30, 2018
Debt Disclosure [Abstract]
Mortgages Payable and Debt Maturities	7. MORTGAGES PAYABLE AND DEBT MATURITIES Mortgages payable at June 30, 2018 and December 31, 2017 consist of the following: (dollars in thousands) June 30, 2018 December 31, 2017 4.98% mortgage note due January 1, 2021, secured by one self-storage facility with an aggregate net book value of $9.5 million, principal and interest paid monthly (effective interest rate 5.22%) $ 2,890 $ 2,916 4.065% mortgage note due April 1, 2023, secured by one self- storage facility with an aggregate net book value of $7.5 million, principal and interest paid monthly (effective interest rate 4.30%) 4,073 4,119 5.26% mortgage note due November 1, 2023, secured by one self-storage facility with an aggregate net book value of $8.0 million, principal and interest paid monthly (effective interest rate 5.56%) 3,905 3,939 5.99% mortgage note due May 1, 2026, secured by one self- storage facility with an aggregate net book value of $6.5 million, principal and interest paid monthly (effective interest rate 6.29%) 1,621 1,700 Total mortgages payable $ 12,489 $ 12,674 The table below summarizes the Company’s debt obligations at June 30, 2018. The estimated fair value of financial instruments is subjective in nature and is dependent on a number of important assumptions, including discount rates and relevant comparable market information associated with each financial instrument. The fair value of the fixed rate term notes and mortgage notes were estimated by discounting the future cash flows using the current rates at which similar loans would be made to borrowers with similar credit ratings and for the same remaining maturities. These assumptions are considered Level 2 inputs within the fair value hierarchy as described in Note 9. The carrying values of our variable rate debt instruments approximate their fair values as these debt instruments bear interest at current market rates that approximate market participant rates. This is considered a Level 2 input within the fair value hierarchy. The use of different market assumptions and estimation methodologies may have a material effect on the reported estimated fair value amounts. Accordingly, the estimates presented below are not necessarily indicative of the amounts the Company would realize in a current market exchange. Expected Maturity Date Including Discount (dollars in thousands) 2018 2019 2020 2021 2022 Thereafter Total Fair Value Line of credit - variable rate LIBOR + 1.10% (3.19% at June 30, 2018) — $ 113,000 — — — — $ 113,000 $ 113,000 Notes Payable: Term note - variable rate LIBOR+1.15% (3.15% at June 30, 2018) — — $ 100,000 — — — $ 100,000 $ 100,000 Term note - fixed rate 5.54% — — — $ 100,000 — — $ 100,000 $ 105,217 Term note - fixed rate 4.533% — — — — — $ 175,000 $ 175,000 $ 177,784 Term note - fixed rate 3.50% — — — — — $ 600,000 $ 600,000 $ 565,717 Term note - fixed rate 3.875% — — — — — $ 450,000 $ 450,000 $ 425,118 Term note - fixed rate 3.67% — — — — — $ 200,000 $ 200,000 $ 181,530 Mortgage note - fixed rate 4.98% $ 27 $ 56 $ 59 $ 2,748 — — $ 2,890 $ 2,913 Mortgage note - fixed rate 4.065% $ 45 $ 96 $ 99 $ 104 $ 108 $ 3,621 $ 4,073 $ 3,961 Mortgage note - fixed rate 5.26% $ 34 $ 71 $ 74 $ 78 $ 83 $ 3,565 $ 3,905 $ 4,001 Mortgage note - fixed rate 5.99% $ 81 $ 170 $ 181 $ 192 $ 203 $ 794 $ 1,621 $ 1,694 Total $ 187 $ 113,393 $ 100,413 $ 103,122 $ 394 $ 1,432,980 $ 1,750,489

Derivative Financial Instrument

Derivative Financial Instruments	6 Months Ended
	Jun. 30, 2018
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	8. DERIVATIVE FINANCIAL INSTRUMENTS Interest rate swaps are used to adjust the proportion of total debt that is subject to variable interest rates. The interest rate swaps require the Company to pay an amount equal to a specific fixed rate of interest times a notional principal amount and to receive in return an amount equal to a variable rate of interest times the same notional amount. The notional amounts are not exchanged. Forward starting interest rate swaps are also used by the Company to hedge the risk of changes in the interest-related cash outflows associated with the potential issuance of long-term debt. No other cash payments are made unless the contract is terminated prior to its maturity, in which case the contract would likely be settled for an amount equal to its fair value. The Company enters into interest rate swaps with a number of major financial institutions to minimize counterparty credit risk. Interest rate swaps qualify and are designated as hedges of the amount of future cash flows related to interest payments on variable rate debt. Therefore, interest rate swaps are recorded in the consolidated balance sheets at fair value and the related gains or losses are deferred in shareholders’ equity or partners’ capital as Accumulated Other Comprehensive Loss (“AOCL”). These deferred gains and losses are recognized in interest expense during the period or periods in which the related interest payments affect earnings. However, to the extent that the interest rate swaps are not perfectly effective in offsetting the change in value of the interest payments being hedged, the ineffective portion of these contracts is recognized in earnings immediately. Ineffectiveness was de minimis for the three and six months ended June 30, 2018 and 2017. The Company has interest rate swap agreements in effect at June 30, 2018 as detailed below to effectively convert a total of $100 million of variable-rate debt to fixed-rate debt. Notional Amount Effective Date Expiration Date Fixed Rate Paid Floating Rate Received $100 Million 9/4/13 9/4/18 1.3710 % 1 month LIBOR In 2017, the Company terminated hedges and settled interest rate swap agreements on $225 million of the Company’s variable rate debt in connection with repayment of the related variable rate term notes. As a result of the termination, no gains or losses related to the terminated interest rate swaps are included in AOCL at June 30, 2018 or December 31, 2017. In the fourth quarter of 2015, the Company entered into forward starting interest rate swap agreements with a total notional value of $50 million. In the first quarter of 2016, the Company entered into additional forward starting interest rate swap agreements with a total notional value of $100 million. These forward starting interest rate swap agreements were entered into to hedge the risk of changes in the interest-related cash flows associated with the potential issuance of fixed rate long-term debt. In conjunction with the issuance of the $600 million 2026 Senior Notes (see Note 6), the Company terminated these hedges and settled the forward starting swap agreements for approximately $9.2 million. The $9.2 million has been deferred in AOCL and is being amortized as additional interest expense over the ten-year term of the $600 million 2026 Senior Notes or until such time as interest payments on the 2026 Senior Notes are no longer probable. The interest rate swap agreements are the only derivative instruments, as defined by FASB ASC Topic 815 “ Derivatives and Hedging The Company’s agreements with its interest rate swap counterparties contain provisions pursuant to which the Company could be declared in default of its derivative obligations, if any, if the Company defaults on any of its indebtedness, including default where repayment of the indebtedness has not been accelerated by the lender. The interest rate swap agreements also incorporate other loan covenants of the Company. Failure to comply with the loan covenant provisions would result in the Company being in default on the interest rate swap agreements. As of June 30, 2018, the Company had not posted any collateral related to the interest rate swap agreements. The changes in AOCL for the three and six months ended June 30, 2018 and 2017 are summarized as follows: (dollars in thousands) Three Months Ended June 30, 2018 Three Months Ended June 30, 2017 Six Months Ended June 30, 2018 Six Months Ended June 30, 2017 Accumulated other comprehensive loss beginning of period $ (7,310 ) $ (19,853 ) $ (7,587 ) $ (21,475 ) Realized loss reclassified from accumulated other comprehensive loss to interest expense 113 956 309 2,076 Unrealized (loss) gain from changes in the fair value of the effective portion of the interest rate swaps (7 ) (719 ) 74 (217 ) Gain included in other comprehensive loss 106 237 383 1,859 Accumulated other comprehensive loss end of period $ (7,204 ) $ (19,616 ) $ (7,204 ) $ (19,616 )

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	9. FAIR VALUE MEASUREMENTS The Company applies the provisions of ASC Topic 820 “ Fair Value Measurements and Disclosures Refer to Note 7 for presentation of the fair values of debt obligations which are disclosed at fair value on a recurring basis. The following table provides the assets carried at fair value measured on a recurring basis as of June 30, 2018 and December 31, 2017 (dollars in thousands): Asset (Liability) Level 1 Level 2 Level 3 June 30, 2018 Interest rate swaps $ 177 — $ 177 — December 31, 2017 Interest rate swaps $ 205 — $ 205 — Interest rate swaps are over the counter securities with no quoted readily available Level 1 inputs, and therefore are measured at fair value using inputs that are directly observable in active markets and are classified within Level 2 of the valuation hierarchy, using the income approach.

Investment in Joint Ventures

Investment in Joint Ventures	6 Months Ended
	Jun. 30, 2018
Equity Method Investments And Joint Ventures [Abstract]
Investment in Joint Ventures	10. INVESTMENT IN JOINT VENTURES A summary of the Company’s unconsolidated joint ventures is as follows: Venture Number of Properties at June 30, 2018 Company common ownership interest at June 30, 2018 Carrying value of investment at June 30, 2018 Carrying value of investment at Dec. 31, 2017 Sovran HHF Storage Holdings LLC (“Sovran HHF”) 1 57 20% $84.0 million $85.1 million Sovran HHF Storage Holdings II LLC (“Sovran HHF II”) 2 30 15% $13.2 million $13.3 million 191 III Holdings LLC (“191 III”) 3 6 20% $9.3 million $9.4 million Life Storage-SERS Storage LLC (“SERS”) 4 3 20% $3.6 million $3.6 million Iskalo Office Holdings, LLC (“Iskalo”) 5 N/A 49% ($0.4 million) ($0.4 million) Urban Box Coralway Storage, LLC (“Urban Box”) 6 1 85% $4.4 million $4.1 million SNL/Orix 1200 McDonald Ave., LLC (“McDonald”) 7 1 5% $2.7 million $2.7 million SNL Orix Merrick, LLC (“Merrick”) 8 1 5% $2.4 million $2.5 million Review Avenue Partners, LLC (“RAP”) 9 1 40% $11.3 million $11.5 million N 32nd Street Self Storage, LLC (“N32”) 10 1 46% $1.3 million $1.3 million NYX Don Mills Storage LP ("Don Mills") 11 1 17% $1.0 million N/A 1 2 3 4 5 6 7 8 9 10 11 Based on the facts and circumstances of each of the Company’s joint ventures, the Company has determined that none of the joint ventures is a variable interest entity (VIE) in accordance with ASC 810, Consolidation The carrying values of the Company’s investments in joint ventures are assessed for other-than-temporary impairment on a periodic basis and no such impairments have been recorded on any of the Company’s investments in joint ventures. The Company earns management and/or call center fees ranging from 6% to 7% of joint venture gross revenues as property manager of the self-storage facilities owned by HHF, HHF II, 191 III, SERS, RAP and Merrick. These fees, which are included in other operating income in the consolidated statements of operations, totaled $1.9 million and $1.5 million for the three months ended June 30, 2018 and 2017, respectively, and $3.8 million and $2.9 million for the six months ended June 30, 2018 and 2017, respectively. The Company will also earn management fees as property manager upon commencement of the operation of storage facilities owned by Urban Box, McDonald, and N32. The Company’s share of the unconsolidated joint ventures’ income (loss) is as follows: (dollars in thousands) Venture Three Months Ended June 30, 2018 Three Months Ended June 30, 2017 Six Months Ended June 30, 2018 Six Months Ended June 30, 2017 Sovran HHF $ 739 $ 624 $ 1,428 $ 1,162 Sovran HHF II 432 362 800 702 191 III 18 (10 ) 36 25 SERS 25 — 86 — RAP (217 ) (255 ) (432 ) (501 ) Merrick (16 ) — (32 ) — Iskalo 67 64 134 118 $ 1,048 $ 785 $ 2,020 $ 1,506 A summary of the unconsolidated joint ventures’ financial statements as of and for the six months ended June 30, 2018 is as follows: (dollars in thousands) Balance Sheet Data: Investment in storage facilities, net $ 1,076,193 Investment in office building, net 4,712 Other assets 20,821 Total Assets $ 1,101,726 Due to the Company $ 994 Mortgages payable 468,606 Other liabilities 8,290 Total Liabilities $ 477,890 Unaffiliated partners’ equity 491,003 Company equity 132,833 Total Partners’ Equity 623,836 Total Liabilities and Partners’ Equity $ 1,101,726 Income Statement Data: Total revenues $ 55,627 Property operating expenses (17,295 ) Administrative, management and call center fees (4,314 ) Depreciation and amortization of customer list (12,822 ) Amortization of financing fees (653 ) Income tax expense (155 ) Interest expense (8,716 ) Net income $ 11,672 The Company does not guarantee the debt of any of its equity method investees. We do not expect to have material future cash outlays relating to these joint ventures outside of our share of capital for future acquisitions of properties and our share of the payoff of secured debt held by these joint ventures.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	11. INCOME TAXES The Company qualifies as a REIT under the Internal Revenue Code of 1986, as amended, and will generally not be subject to corporate income taxes to the extent it distributes its taxable income to its shareholders and complies with certain other requirements. The Company has elected to treat one of its subsidiaries as a taxable REIT subsidiary. In general, the Company’s taxable REIT subsidiary may perform additional services for tenants and generally may engage in certain real estate or non-real estate related business. A taxable REIT subsidiary is subject to corporate federal and state income taxes. Deferred tax assets and liabilities are determined based on differences between financial reporting and tax bases of assets and liabilities. The Company recorded federal and state income tax expense of $0.7 million for the three months ended June 30, 2018 and federal and state income tax benefit of $2.5 million for the three months ended June 30, 2017. The Company recorded federal and state income tax expense of $1.2 million for the six months ended June 30, 2018 and federal and state income tax benefit of $2.2 million for the six months ended June 30, 2017. At June 30, 2018 and 2017, there were no material unrecognized tax benefits. Interest and penalties relating to uncertain tax positions will be recognized in income tax expense when incurred. As of June 30, 2018 and 2017, the Company had no interest or penalties related to uncertain tax positions. Income taxes payable at June 30, 2018 and December 31, 2017 are classified within accounts payable and accrued liabilities in the consolidated balance sheets. Prepaid income taxes at June 30, 2018 and December 31, 2017 are classified within prepaid expenses, while the net deferred tax assets of our taxable REIT subsidiary at June 30, 2018 and December 31, 2017 are classified within other assets in the consolidated balance sheets. As of June 30, 2018, the Company’s taxable REIT subsidiary has prepaid taxes of $0.2 million, deferred tax assets totaling $3.4 million, and a deferred tax liability of $1.6 million. As of December 31, 2017, the Company’s taxable REIT subsidiary has prepaid taxes of $0.1 million, deferred tax assets of $3.6 million and a deferred tax liability of $1.7 million. The tax years 2013-2017 remain open to examination by the major taxing jurisdictions to which the Company is subject. The Tax Cuts and Jobs Act (the “TCJA”) was passed by Congress on December 20, 2017 and signed into law by President Trump on December 22, 2017. The TCJA significantly changed the U.S. federal income tax laws applicable to businesses and their owners, including REITs and their shareholders. Under the TCJA, the corporate income tax rate is reduced from a maximum rate of 35% to a flat 21% rate. The reduced corporate income tax rate, which is effective for taxable years beginning after December 31, 2017, applies to income earned by our taxable REIT subsidiary. As a result, the deferred tax assets and deferred tax liabilities of our taxable REIT subsidiary are measured at June 30, 2018 using the 21% corporate income tax rate.

Earnings Per Share and Earnings

Earnings Per Share and Earnings Per Unit	6 Months Ended
	Jun. 30, 2018
Earnings Per Share [Abstract]
Earnings Per Share and Earnings Per Unit	12. EARNINGS PER SHARE AND EARNINGS PER UNIT The Company reports earnings per share and earnings per unit data in accordance ASC Topic 260, “ Earnings Per Share The following table sets forth the computation of basic and diluted earnings per common share utilizing the two-class method. Earnings Per Share (in thousands except per share data) Three Months Ended June 30, 2018 Three Months Ended June 30, 2017 Six Months Ended June 30, 2018 Six Months Ended June 30, 2017 Numerator: Net income attributable to common shareholders $ 39,274 $ 19,355 $ 73,163 $ 39,785 Denominator: Denominator for basic earnings per share – weighted average shares 46,481 46,365 46,467 46,335 Effect of Dilutive Securities: Stock options and non-vested stock 95 113 90 113 Denominator for diluted earnings per share – adjusted weighted average shares and assumed conversion 46,576 46,478 46,557 46,448 Basic earnings per common share attributable to common shareholders $ 0.84 $ 0.42 $ 1.57 $ 0.86 Diluted earnings per common share attributable to common shareholders $ 0.84 $ 0.42 $ 1.57 $ 0.86 Earnings Per Unit The following table sets forth the computation of basic and diluted earnings per common unit utilizing the two-class method. (in thousands except per unit data) Three Months Ended June 30, 2018 Three Months Ended June 30, 2017 Six Months Ended June 30, 2018 Six Months Ended June 30, 2017 Numerator: Net income attributable to common unitholders $ 39,274 $ 19,355 $ 73,163 $ 39,785 Denominator: Denominator for basic earnings per unit – weighted average units 46,481 46,365 46,467 46,335 Effect of Dilutive Securities: Stock options and non-vested stock 95 113 90 113 Denominator for diluted earnings per unit – adjusted weighted average units and assumed conversion 46,576 46,478 46,557 46,448 Basic earnings per common unit attributable to common unitholders $ 0.84 $ 0.42 $ 1.57 $ 0.86 Diluted earnings per common unit attributable to common unitholders $ 0.84 $ 0.42 $ 1.57 $ 0.86 Not included in the effect of dilutive securities above for both earnings per share and earnings per unit are 11,000 stock options and 111,122 unvested restricted shares for the three months ended June 30, 2018, and 15,500 stock options and 133,094 unvested restricted shares for the three months ended June 30, 2017, because their effect would be antidilutive. Not included in the effect of dilutive securities above are 11,000 stock options and 114,592 unvested restricted shares for the six months ended June 30, 2018, and 13,250 stock options and 142,074 unvested restricted shares for the six months ended June 30, 2017, because their effect would be antidilutive.

Shareholders' Equity

Shareholders' Equity	6 Months Ended
	Jun. 30, 2018
Equity [Abstract]
Shareholders' Equity	13. SHAREHOLDERS’ EQUITY The following is a reconciliation of the changes in the Parent Company’s total shareholders’ equity for the period: (dollars in thousands) Six Months Ended June 30, 2018 Beginning balance of total shareholders’ equity $ 2,028,323 Exercise of stock options 3,045 Earned portion of non-vested stock 2,748 Stock option expense 7 Carrying value less than redemption value on redeemed noncontrolling interest (30 ) Adjustment to redemption value on noncontrolling redeemable Operating Partnership units (1,565 ) Net income attributable to common shareholders 73,163 Amortization of terminated hedge included in AOCL 458 Change in fair value of derivatives (74 ) Dividends (92,635 ) Ending balance of total shareholders’ equity $ 2,013,440 On June 14, 2018, the Company entered into a continuous equity offering program (“Equity Program”) with Wells Fargo Securities, LLC, Jefferies LLC, SunTrust Robinson Humphrey, Inc., HSBC Securities (USA) Inc., BB&T Capital Markets, a division of BB&T Securities, LLC, and BTIG, LLC, pursuant to which the Company may sell up to $300 million in aggregate offering price of shares of the Company’s common stock. Actual sales under the Equity Program will depend on a variety of factors and conditions, including, but not limited to, market conditions, the trading price of the Company’s common stock, and determinations of the appropriate sources of funding for the Company. The Company expects to continue to offer, sell and issue shares of common stock under the Equity Program from time to time based on various factors and conditions, although the Company is under no obligation to sell any shares under the Equity program. During the six months ended June 30, 2018, the Company did not issue any shares of common stock under the Equity Program and as of June 30, 2018, the entire $300 million authorized under the Equity Program remains available for issuance. On August 2, 2017, the Company’s Board of Directors authorized the repurchase of up to $200 million of the Company’s outstanding common shares (“Buyback Program”). The Buyback Program allows the Company to purchase shares of its common stock in accordance with applicable securities laws on the open market, through privately negotiated transactions, or through other methods of acquiring shares. The Buyback Program may be suspended or discontinued at any time. The Company did not repurchase any outstanding common shares under the Buyback Program during the six months ended June 30, 2018. In 2013, the Company implemented a Dividend Reinvestment Plan. The Company issued 118,656 shares under the plan during the six months ended June 30, 2017. On August 2, 2017, the Company’s Board of Directors suspended the Dividend Reinvestment Plan.

Partners' Capital

Partners' Capital	6 Months Ended
	Jun. 30, 2018
Equity [Abstract]
Partners' Capital	14. PARTNERS’ CAPITAL The following is a reconciliation of the changes in total partners’ capital for the period: (dollars in thousands) Six Months Ended June 30, 2018 Beginning balance of total controlling partners’ capital $ 2,028,323 Exercise of stock options 3,045 Earned portion of non-vested stock 2,748 Stock option expense 7 Carrying value less than redemption value on redeemed noncontrolling interest (30 ) Adjustment to redemption value on limited partners’ redeemable capital interests (1,565 ) Net income attributable to common unitholders 73,163 Amortization of terminated hedge included in AOCL 458 Change in fair value of derivatives (74 ) Distributions (92,635 ) Ending balance of total controlling partners’ capital $ 2,013,440

Recent Accounting Pronouncement

Recent Accounting Pronouncements	6 Months Ended
	Jun. 30, 2018
Accounting Changes And Error Corrections [Abstract]
Recent Accounting Pronouncements	15. RECENT ACCOUNTING PRONOUNCEMENTS In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers (Topic 606),” which supersedes the revenue recognition requirements in “Revenue Recognition (Topic 605),” and requires an entity to recognize revenue in a way that depicts the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. ASU 2014-09 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2017 and is therefore effective for the Company as of January 1, 2018. The Company had the option to apply the provisions of ASU 2014-09 either retrospectively to each prior reporting period presented or retrospectively with the cumulative effect of initially applying the new guidance recognized at the date of initial application (the modified retrospective transition method). The Company elected to adopt the standard using the modified retrospective transition method. Leases are specifically excluded from the scope of ASU 2014-09, therefore, upon analysis, the Company concluded that the adoption of the new standard did not have any impact on the timing or amounts of the Company’s rental revenue from customers which represents over of the Company’s total operating revenues. We have evaluated the other revenue streams material to the Company and have concluded that the adoption of the new standard did not have any material impact on the timing or amounts of the Company’s material revenue streams and no cumulative effect adjustment is required as of the date of initial application. Payment from such revenue streams is due and generally collected upon invoice. Also, as part of the Company’s adoption of ASU 2014-09, the Company has elected to apply the guidance only to contracts that are not completed contracts at the date of initial application. Further, related to the Company’s management fee revenue stream which relates to managing self-storage facilities for third-parties and unconsolidated joint ventures, the Company has elected to apply a practical expedient provided in the new standard which allows the Company to recognize revenue in the amount of management fees to which the Company has a right to invoice as that amount corresponds directly with the value to the customer of the entity’s performance completed to date In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842)”. This guidance revises existing practice related to accounting for leases under Accounting Standards Codification Topic 840 Leases In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (a Consensus of the Emerging Issues Task Force)” in an effort to reduce existing diversity in practice related to the classification of certain cash receipts and cash payments on the statements of cash flows. The guidance addresses the classification of cash flows related to, among other things, distributions received from equity method investees. The amendments in this update are effective for annual periods beginning after December 15, 2017, and interim periods within those annual periods. The Company has elected to use the nature of the distribution approach to classify distributions received from its equity method investees. This approach requires distributions to be classified in the statement of cash flows on the basis of the nature of the activity or activities of the investee that generated the distribution as either a return on investment (classified as a cash inflow from operating activities) or a return of investment (classified as a cash inflow from investing activities). The adoption of ASU 2016-15 effective January 1, 2018 did not have a material impact on the Company’s consolidated financial statements. In November 2016, the FASB issued ASU 2016-18, “Statement of Cash Flows (Topic 230): Restricted Cash (a Consensus of the Emerging Issues Task Force)” which requires restricted cash and restricted cash equivalents to be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The amendments in this update are effective for annual periods beginning after December 15, 2017 and interim periods within those fiscal years. Early adoption of this update is permitted. Other than modifications to the statement of cash flows and the additional disclosures in Note 4, the adoption of ASU 2016-18 on January 1, 2018 did not have an impact on the Company’s consolidated financial statements. The consolidated statement of cash flows for the six months ended June 30, 2017 has been modified to conform to the presentation requirements of ASU 2016-18 which entail including restricted cash along with cash in the beginning balance, ending balance and net change in cash and restricted cash on the consolidated statement of cash flows. In January 2017, the FASB issued ASU 2017-01, “Business Combinations (Topic 805): Clarifying the Definition of a Business” which is intended to assist entities with evaluating whether a set of transferred assets and activities is a business. The amendments in this update are effective for annual periods beginning after December 15, 2017 and interim periods within those fiscal years. Early adoption of this update is permitted and the Company adopted this update effective January 1, 2017. The adoption of ASU 2017-01 is expected to have potential impact on the accounting treatment of properties acquired subsequent to the adoption date. Property acquisitions treated as business combinations under previous guidance may no longer be treated as business combinations subsequent to the adoption of ASU 2017-01. To the extent that properties that we acquire do not meet the definition of a “business” under ASU 2017-01, future acquisitions of properties may be accounted for as asset acquisitions resulting in the capitalization of acquisition costs incurred in connection with these transactions and the allocation of the purchase price and related acquisition costs to the assets acquired based on their relative fair values. There were no properties acquired during the six months ended June 30, 2018 that would have been accounted for as business combinations prior to the adoption of ASU 2017-01. In February 2017, the FASB issued ASU 2017-05, “Other Income – Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets” which clarifies the scope and application of ASC 610-20 on the sale or transfer of nonfinancial assets, including real estate, and in substance nonfinancial assets to noncustomers, including partial sales. The amendments in this update are effective for annual periods beginning after December 15, 2017, and interim periods within those annual periods. The implementation of this update as of January 1, 2018 could potentially impact the accounting treatment of future real estate sales of the Company if such sales are to parties who are also customers of the Company, though the implementation did not have an impact on the Company’s consolidated financial statements for the period ending June 30, 2018. In May 2017, the FASB issued ASU 2017-09, “Compensation – Stock Compensation (Topic 718): Scope of Modification Accounting” which provides guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting in Topic 718. The amendments in this update are effective for annual periods beginning after December 15, 2017, and interim periods within those annual periods. The implementation of this update as of January 1, 2018 did not have a material impact on the Company’s financial statements, however, all future changes to the terms or conditions of any of the Company’s share-based payment awards are subject to the guidance in ASU 2017-09 and could potentially be accounted for differently than under the previous guidance concerning such changes.

Commitment and Contingencies

Commitment and Contingencies	6 Months Ended
	Jun. 30, 2018
Commitments And Contingencies Disclosure [Abstract]
Commitment and Contingencies	16. COMMITMENT AND CONTINGENCIES On or about August 25, 2014, a putative class action was filed against the Company in the Superior Court of New Jersey Law Division Burlington County. The action sought to obtain declaratory, injunctive and monetary relief for a class of consumers based upon alleged violations by the Company of various statutory laws. On October 17, 2014, the action was removed from the Superior Court of New Jersey Law Division Burlington County to the United States District Court for the District of New Jersey. The parties subsequently reached a settlement of all claims for an aggregate amount of $8.0 million, and the settlement was approved by the court on June 12, 2018. The Company is in the process of making payments under the settlement to the members of the class. The aggregate settlement amount of $8.0 million ($6.0 million after considering income tax impact) has been recorded as a liability in the Company’s consolidated balance sheet. A portion of the settlement expense relates to self-storage facilities that are managed by the Company through its taxable REIT subsidiary. There is an income tax impact to the Company on that portion of the settlement expense as a result.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2018
Subsequent Events [Abstract]
Subsequent Events	17. SUBSEQUENT EVENTS On July 5, 2018, the Company declared a quarterly dividend of $1.00 per common share. The dividend was paid on July 26, 2018 to shareholders of record on July 16, 2018. The total dividend paid amounted to $46.6 million. Subsequent to June 30, 2018, the Company entered into contracts to acquire three self-storage facilities for an aggregate purchase price of $27.6 million. The purchases of these facilities are subject to customary conditions to closing, and there is no assurance that these facilities will be acquired.

Recent Accounting Pronounceme24

Recent Accounting Pronouncements (Policies)	6 Months Ended
	Jun. 30, 2018
Accounting Changes And Error Corrections [Abstract]
Revenue from Contracts with Customers	In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers (Topic 606),” which supersedes the revenue recognition requirements in “Revenue Recognition (Topic 605),” and requires an entity to recognize revenue in a way that depicts the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. ASU 2014-09 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2017 and is therefore effective for the Company as of January 1, 2018. The Company had the option to apply the provisions of ASU 2014-09 either retrospectively to each prior reporting period presented or retrospectively with the cumulative effect of initially applying the new guidance recognized at the date of initial application (the modified retrospective transition method). The Company elected to adopt the standard using the modified retrospective transition method. Leases are specifically excluded from the scope of ASU 2014-09, therefore, upon analysis, the Company concluded that the adoption of the new standard did not have any impact on the timing or amounts of the Company’s rental revenue from customers which represents over of the Company’s total operating revenues. We have evaluated the other revenue streams material to the Company and have concluded that the adoption of the new standard did not have any material impact on the timing or amounts of the Company’s material revenue streams and no cumulative effect adjustment is required as of the date of initial application. Payment from such revenue streams is due and generally collected upon invoice. Also, as part of the Company’s adoption of ASU 2014-09, the Company has elected to apply the guidance only to contracts that are not completed contracts at the date of initial application. Further, related to the Company’s management fee revenue stream which relates to managing self-storage facilities for third-parties and unconsolidated joint ventures, the Company has elected to apply a practical expedient provided in the new standard which allows the Company to recognize revenue in the amount of management fees to which the Company has a right to invoice as that amount corresponds directly with the value to the customer of the entity’s performance completed to date
Leases	In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842)”. This guidance revises existing practice related to accounting for leases under Accounting Standards Codification Topic 840 Leases
Statement of Cash Flows	In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (a Consensus of the Emerging Issues Task Force)” in an effort to reduce existing diversity in practice related to the classification of certain cash receipts and cash payments on the statements of cash flows. The guidance addresses the classification of cash flows related to, among other things, distributions received from equity method investees. The amendments in this update are effective for annual periods beginning after December 15, 2017, and interim periods within those annual periods. The Company has elected to use the nature of the distribution approach to classify distributions received from its equity method investees. This approach requires distributions to be classified in the statement of cash flows on the basis of the nature of the activity or activities of the investee that generated the distribution as either a return on investment (classified as a cash inflow from operating activities) or a return of investment (classified as a cash inflow from investing activities). The adoption of ASU 2016-15 effective January 1, 2018 did not have a material impact on the Company’s consolidated financial statements. In November 2016, the FASB issued ASU 2016-18, “Statement of Cash Flows (Topic 230): Restricted Cash (a Consensus of the Emerging Issues Task Force)” which requires restricted cash and restricted cash equivalents to be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The amendments in this update are effective for annual periods beginning after December 15, 2017 and interim periods within those fiscal years. Early adoption of this update is permitted. Other than modifications to the statement of cash flows and the additional disclosures in Note 4, the adoption of ASU 2016-18 on January 1, 2018 did not have an impact on the Company’s consolidated financial statements. The consolidated statement of cash flows for the six months ended June 30, 2017 has been modified to conform to the presentation requirements of ASU 2016-18 which entail including restricted cash along with cash in the beginning balance, ending balance and net change in cash and restricted cash on the consolidated statement of cash flows.
Business Combinations	In January 2017, the FASB issued ASU 2017-01, “Business Combinations (Topic 805): Clarifying the Definition of a Business” which is intended to assist entities with evaluating whether a set of transferred assets and activities is a business. The amendments in this update are effective for annual periods beginning after December 15, 2017 and interim periods within those fiscal years. Early adoption of this update is permitted and the Company adopted this update effective January 1, 2017. The adoption of ASU 2017-01 is expected to have potential impact on the accounting treatment of properties acquired subsequent to the adoption date. Property acquisitions treated as business combinations under previous guidance may no longer be treated as business combinations subsequent to the adoption of ASU 2017-01. To the extent that properties that we acquire do not meet the definition of a “business” under ASU 2017-01, future acquisitions of properties may be accounted for as asset acquisitions resulting in the capitalization of acquisition costs incurred in connection with these transactions and the allocation of the purchase price and related acquisition costs to the assets acquired based on their relative fair values. There were no properties acquired during the six months ended June 30, 2018 that would have been accounted for as business combinations prior to the adoption of ASU 2017-01.
Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets	In February 2017, the FASB issued ASU 2017-05, “Other Income – Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets” which clarifies the scope and application of ASC 610-20 on the sale or transfer of nonfinancial assets, including real estate, and in substance nonfinancial assets to noncustomers, including partial sales. The amendments in this update are effective for annual periods beginning after December 15, 2017, and interim periods within those annual periods. The implementation of this update as of January 1, 2018 could potentially impact the accounting treatment of future real estate sales of the Company if such sales are to parties who are also customers of the Company, though the implementation did not have an impact on the Company’s consolidated financial statements for the period ending June 30, 2018.
Compensation – Stock Compensation	In May 2017, the FASB issued ASU 2017-09, “Compensation – Stock Compensation (Topic 718): Scope of Modification Accounting” which provides guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting in Topic 718. The amendments in this update are effective for annual periods beginning after December 15, 2017, and interim periods within those annual periods. The implementation of this update as of January 1, 2018 did not have a material impact on the Company’s financial statements, however, all future changes to the terms or conditions of any of the Company’s share-based payment awards are subject to the guidance in ASU 2017-09 and could potentially be accounted for differently than under the previous guidance concerning such changes.

Organization (Tables)

Organization (Tables)	6 Months Ended
	Jun. 30, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Summary of Reconciliation of Noncontrolling Interests	The following is a reconciliation of the Parent Company’s noncontrolling redeemable Operating Partnership Units and the Operating Partnership’s limited partners’ redeemable capital interest for the period: (dollars in thousands) Six Months Ended June 30, 2018 Beginning balance $ 19,373 Redemption of units (203 ) Net income attributable to noncontrolling interest in the Operating Partnership 344 Distributions (435 ) Adjustment to redemption value 1,565 Ending balance $ 20,644
Summary of Disaggregated Revenues	The disaggregated revenues of the Company presented in accordance with ASC Topic 606 “Revenue from Contracts with Customers” (dollars in thousands) Three Months Ended June 30, 2018 Three Months Ended June 30, 2017 Six Months Ended June 30, 2018 Six Months Ended June 30, 2017 Rental income $ 125,892 $ 120,646 $ 247,516 $ 239,240 Management and acquisition fee income 2,546 3,183 4,941 5,001 Revenues related to tenant insurance 5,768 5,622 11,485 10,974 Other 3,802 3,333 7,160 5,890 Total operating revenues $ 138,008 $ 132,784 $ 271,102 $ 261,105

Cash and Restricted Cash (Table

Cash and Restricted Cash (Tables)	6 Months Ended
	Jun. 30, 2018
Cash And Cash Equivalents [Abstract]
Summary of Reconciliation of Cash and Restricted Cash	The following table provides a reconciliation of cash and restricted cash reported within the consolidated statement of cash flows: (Dollars in thousands) June 30, 2018 December 31, 2017 June 30, 2017 Cash $ 7,327 $ 9,167 $ 7,998 Restricted cash 476 292 492 Total cash and restricted cash 7,803 9,459 8,490

Investment in Storage Facilit27

Investment in Storage Facilities and Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 2018
Real Estate [Abstract]
Summary of Activity in Storage Facilities	The following summarizes our activity in storage facilities during the six months ended June 30, 2018: (dollars in thousands) Cost: Beginning balance $ 4,321,410 Improvements and equipment additions 14,123 Net increase in construction in progress 14,040 Dispositions (2,189 ) Ending balance $ 4,347,384 Accumulated Depreciation: Beginning balance $ 624,314 Additions during the period 49,557 Dispositions (2,154 ) Ending balance $ 671,717
Schedule of Fair Value of In-Place Customer Lease Intangible Assets	In-place customer leases are included in other assets on the Company’s consolidated balance sheets as follows: (Dollars in thousands) June 30, 2018 December 31, 2017 In-place customer leases $ 75,241 $ 75,241 Accumulated amortization (75,241 ) (75,241 ) Net carrying value at the end of period — —

Unsecured Line of Credit and 28

Unsecured Line of Credit and Term Notes (Tables)	6 Months Ended
	Jun. 30, 2018
Debt Disclosure [Abstract]
Borrowings Outstanding on Unsecured Line of Credit and Term Notes	Borrowings outstanding on our unsecured line of credit and term notes are as follows: (Dollars in thousands) June 30, 2018 December 31, 2017 Revolving line of credit borrowings $ 113,000 $ 105,000 Term note due June 4, 2020 100,000 100,000 Term note due August 5, 2021 100,000 100,000 Term note due April 8, 2024 175,000 175,000 Senior term note due July 1, 2026 600,000 600,000 Senior term note due December 15, 2027 450,000 450,000 Term note due July 21, 2028 200,000 200,000 Total term note principal balance outstanding $ 1,625,000 $ 1,625,000 Less: unamortized debt issuance costs (10,262 ) (10,962 ) Less: unamortized senior term note discount (4,676 ) (4,949 ) Term notes payable $ 1,610,062 $ 1,609,089

Mortgages Payable and Debt Ma29

Mortgages Payable and Debt Maturities (Tables)	6 Months Ended
	Jun. 30, 2018
Debt Disclosure [Abstract]
Summary of Mortgage Payable	Mortgages payable at June 30, 2018 and December 31, 2017 consist of the following: (dollars in thousands) June 30, 2018 December 31, 2017 4.98% mortgage note due January 1, 2021, secured by one self-storage facility with an aggregate net book value of $9.5 million, principal and interest paid monthly (effective interest rate 5.22%) $ 2,890 $ 2,916 4.065% mortgage note due April 1, 2023, secured by one self- storage facility with an aggregate net book value of $7.5 million, principal and interest paid monthly (effective interest rate 4.30%) 4,073 4,119 5.26% mortgage note due November 1, 2023, secured by one self-storage facility with an aggregate net book value of $8.0 million, principal and interest paid monthly (effective interest rate 5.56%) 3,905 3,939 5.99% mortgage note due May 1, 2026, secured by one self- storage facility with an aggregate net book value of $6.5 million, principal and interest paid monthly (effective interest rate 6.29%) 1,621 1,700 Total mortgages payable $ 12,489 $ 12,674
Summary of Debt Obligations and Interest Rate Derivatives	Accordingly, the estimates presented below are not necessarily indicative of the amounts the Company would realize in a current market exchange. Expected Maturity Date Including Discount (dollars in thousands) 2018 2019 2020 2021 2022 Thereafter Total Fair Value Line of credit - variable rate LIBOR + 1.10% (3.19% at June 30, 2018) — $ 113,000 — — — — $ 113,000 $ 113,000 Notes Payable: Term note - variable rate LIBOR+1.15% (3.15% at June 30, 2018) — — $ 100,000 — — — $ 100,000 $ 100,000 Term note - fixed rate 5.54% — — — $ 100,000 — — $ 100,000 $ 105,217 Term note - fixed rate 4.533% — — — — — $ 175,000 $ 175,000 $ 177,784 Term note - fixed rate 3.50% — — — — — $ 600,000 $ 600,000 $ 565,717 Term note - fixed rate 3.875% — — — — — $ 450,000 $ 450,000 $ 425,118 Term note - fixed rate 3.67% — — — — — $ 200,000 $ 200,000 $ 181,530 Mortgage note - fixed rate 4.98% $ 27 $ 56 $ 59 $ 2,748 — — $ 2,890 $ 2,913 Mortgage note - fixed rate 4.065% $ 45 $ 96 $ 99 $ 104 $ 108 $ 3,621 $ 4,073 $ 3,961 Mortgage note - fixed rate 5.26% $ 34 $ 71 $ 74 $ 78 $ 83 $ 3,565 $ 3,905 $ 4,001 Mortgage note - fixed rate 5.99% $ 81 $ 170 $ 181 $ 192 $ 203 $ 794 $ 1,621 $ 1,694 Total $ 187 $ 113,393 $ 100,413 $ 103,122 $ 394 $ 1,432,980 $ 1,750,489

Derivative Financial Instrume30

Derivative Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2018
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Summary of Interest Rate Swap Agreements	The Company has interest rate swap agreements in effect at June 30, 2018 as detailed below to effectively convert a total of $100 million of variable-rate debt to fixed-rate debt. Notional Amount Effective Date Expiration Date Fixed Rate Paid Floating Rate Received $100 Million 9/4/13 9/4/18 1.3710 % 1 month LIBOR
Summary of Changes in AOCL	The changes in AOCL for the three and six months ended June 30, 2018 and 2017 are summarized as follows: (dollars in thousands) Three Months Ended June 30, 2018 Three Months Ended June 30, 2017 Six Months Ended June 30, 2018 Six Months Ended June 30, 2017 Accumulated other comprehensive loss beginning of period $ (7,310 ) $ (19,853 ) $ (7,587 ) $ (21,475 ) Realized loss reclassified from accumulated other comprehensive loss to interest expense 113 956 309 2,076 Unrealized (loss) gain from changes in the fair value of the effective portion of the interest rate swaps (7 ) (719 ) 74 (217 ) Gain included in other comprehensive loss 106 237 383 1,859 Accumulated other comprehensive loss end of period $ (7,204 ) $ (19,616 ) $ (7,204 ) $ (19,616 )

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2018
Fair Value Disclosures [Abstract]
Assets and Liabilities Carried at Fair Value Measured on Recurring Basis	The following table provides the assets carried at fair value measured on a recurring basis as of June 30, 2018 and December 31, 2017 (dollars in thousands): Asset (Liability) Level 1 Level 2 Level 3 June 30, 2018 Interest rate swaps $ 177 — $ 177 — December 31, 2017 Interest rate swaps $ 205 — $ 205 —

Investment in Joint Ventures (T

Investment in Joint Ventures (Tables)	6 Months Ended
	Jun. 30, 2018
Equity Method Investments And Joint Ventures [Abstract]
Summary of Company's Unconsolidated Joint Ventures	A summary of the Company’s unconsolidated joint ventures is as follows: Venture Number of Properties at June 30, 2018 Company common ownership interest at June 30, 2018 Carrying value of investment at June 30, 2018 Carrying value of investment at Dec. 31, 2017 Sovran HHF Storage Holdings LLC (“Sovran HHF”) 1 57 20% $84.0 million $85.1 million Sovran HHF Storage Holdings II LLC (“Sovran HHF II”) 2 30 15% $13.2 million $13.3 million 191 III Holdings LLC (“191 III”) 3 6 20% $9.3 million $9.4 million Life Storage-SERS Storage LLC (“SERS”) 4 3 20% $3.6 million $3.6 million Iskalo Office Holdings, LLC (“Iskalo”) 5 N/A 49% ($0.4 million) ($0.4 million) Urban Box Coralway Storage, LLC (“Urban Box”) 6 1 85% $4.4 million $4.1 million SNL/Orix 1200 McDonald Ave., LLC (“McDonald”) 7 1 5% $2.7 million $2.7 million SNL Orix Merrick, LLC (“Merrick”) 8 1 5% $2.4 million $2.5 million Review Avenue Partners, LLC (“RAP”) 9 1 40% $11.3 million $11.5 million N 32nd Street Self Storage, LLC (“N32”) 10 1 46% $1.3 million $1.3 million NYX Don Mills Storage LP ("Don Mills") 11 1 17% $1.0 million N/A 1 2 3 4 5 6 7 8 9 10 11
Company's Share of Unconsolidated Joint Ventures' Income (Loss)	The Company’s share of the unconsolidated joint ventures’ income (loss) is as follows: (dollars in thousands) Venture Three Months Ended June 30, 2018 Three Months Ended June 30, 2017 Six Months Ended June 30, 2018 Six Months Ended June 30, 2017 Sovran HHF $ 739 $ 624 $ 1,428 $ 1,162 Sovran HHF II 432 362 800 702 191 III 18 (10 ) 36 25 SERS 25 — 86 — RAP (217 ) (255 ) (432 ) (501 ) Merrick (16 ) — (32 ) — Iskalo 67 64 134 118 $ 1,048 $ 785 $ 2,020 $ 1,506
Summary of Unconsolidated Joint Ventures' Financial Statements	A summary of the unconsolidated joint ventures’ financial statements as of and for the six months ended June 30, 2018 is as follows: (dollars in thousands) Balance Sheet Data: Investment in storage facilities, net $ 1,076,193 Investment in office building, net 4,712 Other assets 20,821 Total Assets $ 1,101,726 Due to the Company $ 994 Mortgages payable 468,606 Other liabilities 8,290 Total Liabilities $ 477,890 Unaffiliated partners’ equity 491,003 Company equity 132,833 Total Partners’ Equity 623,836 Total Liabilities and Partners’ Equity $ 1,101,726 Income Statement Data: Total revenues $ 55,627 Property operating expenses (17,295 ) Administrative, management and call center fees (4,314 ) Depreciation and amortization of customer list (12,822 ) Amortization of financing fees (653 ) Income tax expense (155 ) Interest expense (8,716 ) Net income $ 11,672

Earnings Per Share and Earnin33

Earnings Per Share and Earnings Per Unit (Tables)	6 Months Ended
	Jun. 30, 2018
Earnings Per Share [Abstract]
Computation of Basic and Diluted Earnings Per Common Share/Unit	The following table sets forth the computation of basic and diluted earnings per common share utilizing the two-class method. Earnings Per Share (in thousands except per share data) Three Months Ended June 30, 2018 Three Months Ended June 30, 2017 Six Months Ended June 30, 2018 Six Months Ended June 30, 2017 Numerator: Net income attributable to common shareholders $ 39,274 $ 19,355 $ 73,163 $ 39,785 Denominator: Denominator for basic earnings per share – weighted average shares 46,481 46,365 46,467 46,335 Effect of Dilutive Securities: Stock options and non-vested stock 95 113 90 113 Denominator for diluted earnings per share – adjusted weighted average shares and assumed conversion 46,576 46,478 46,557 46,448 Basic earnings per common share attributable to common shareholders $ 0.84 $ 0.42 $ 1.57 $ 0.86 Diluted earnings per common share attributable to common shareholders $ 0.84 $ 0.42 $ 1.57 $ 0.86 Earnings Per Unit The following table sets forth the computation of basic and diluted earnings per common unit utilizing the two-class method. (in thousands except per unit data) Three Months Ended June 30, 2018 Three Months Ended June 30, 2017 Six Months Ended June 30, 2018 Six Months Ended June 30, 2017 Numerator: Net income attributable to common unitholders $ 39,274 $ 19,355 $ 73,163 $ 39,785 Denominator: Denominator for basic earnings per unit – weighted average units 46,481 46,365 46,467 46,335 Effect of Dilutive Securities: Stock options and non-vested stock 95 113 90 113 Denominator for diluted earnings per unit – adjusted weighted average units and assumed conversion 46,576 46,478 46,557 46,448 Basic earnings per common unit attributable to common unitholders $ 0.84 $ 0.42 $ 1.57 $ 0.86 Diluted earnings per common unit attributable to common unitholders $ 0.84 $ 0.42 $ 1.57 $ 0.86

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	6 Months Ended
	Jun. 30, 2018
Equity [Abstract]
Reconciliation of Changes in Parent Company's Total Shareholders' Equity	The following is a reconciliation of the changes in the Parent Company’s total shareholders’ equity for the period: (dollars in thousands) Six Months Ended June 30, 2018 Beginning balance of total shareholders’ equity $ 2,028,323 Exercise of stock options 3,045 Earned portion of non-vested stock 2,748 Stock option expense 7 Carrying value less than redemption value on redeemed noncontrolling interest (30 ) Adjustment to redemption value on noncontrolling redeemable Operating Partnership units (1,565 ) Net income attributable to common shareholders 73,163 Amortization of terminated hedge included in AOCL 458 Change in fair value of derivatives (74 ) Dividends (92,635 ) Ending balance of total shareholders’ equity $ 2,013,440

Partners' Capital (Tables)

Partners' Capital (Tables)	6 Months Ended
	Jun. 30, 2018
Equity [Abstract]
Reconciliation of Changes in Total Partners' Capital	The following is a reconciliation of the changes in total partners’ capital for the period: (dollars in thousands) Six Months Ended June 30, 2018 Beginning balance of total controlling partners’ capital $ 2,028,323 Exercise of stock options 3,045 Earned portion of non-vested stock 2,748 Stock option expense 7 Carrying value less than redemption value on redeemed noncontrolling interest (30 ) Adjustment to redemption value on limited partners’ redeemable capital interests (1,565 ) Net income attributable to common unitholders 73,163 Amortization of terminated hedge included in AOCL 458 Change in fair value of derivatives (74 ) Distributions (92,635 ) Ending balance of total controlling partners’ capital $ 2,013,440

Organization - Additional Infor

Organization - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2018PropertyStateshares	Dec. 31, 2017shares
Organization [Line Items]
Percentage of ownership interest of the subsidiary and its limited partnership which controls the operations of the Operating Partnership	99.50%
Number of self-storage properties owned and managed	718
Number of states in which self-storage properties owned and managed | State	28
Number of properties managed under joint ventures	98
Number of properties managed with no ownership	54
Units of redeemable noncontrolling interest in operating partnership | shares	215,009	217,481
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	22.00%
Geographic Concentration Risk [Member] | Florida [Member] | Revenue [Member]
Organization [Line Items]
Concentration risk, percentage	13.00%
Life Storage Solutions, LLC [Member]
Organization [Line Items]
Percentage of ownership by subsidiary	60.00%

Organization - Summary of Recon

Organization - Summary of Reconciliation of Noncontrolling Interests (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Redeemable Noncontrolling Interest Equity Fair Value [Abstract]
Noncontrolling interest, beginning balance			$ 19,373
Redemption of units			(203)
Net income attributable to noncontrolling interest in the Operating Partnership	$ 183	$ 77	344	$ 172
Distributions			(435)
Adjustment to redemption value			1,565
Noncontrolling interest, ending balance	$ 20,644		$ 20,644

Organization - Summary of Disag

Organization - Summary of Disaggregated Revenues (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disaggregation Of Revenue [Line Items]
Total operating revenues	$ 138,008	$ 132,784	$ 271,102	$ 261,105
Rental Income [Member]
Disaggregation Of Revenue [Line Items]
Total operating revenues	125,892	120,646	247,516	239,240
Management and Acquisition Fee Income [Member]
Disaggregation Of Revenue [Line Items]
Total operating revenues	2,546	3,183	4,941	5,001
Revenues Related to Tenant Insurance [Member]
Disaggregation Of Revenue [Line Items]
Total operating revenues	5,768	5,622	11,485	10,974
Other Operating Income [Member]
Disaggregation Of Revenue [Line Items]
Total operating revenues	$ 3,802	$ 3,333	$ 7,160	$ 5,890

Stock Based Compensation - Addi

Stock Based Compensation - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option expense	$ 3,000	$ 4,000	$ 7,000	$ 8,000
Amortization of non-vested stock grants and performance-based awards	$ 1,252,000	$ 1,657,000	$ 2,748,000	$ 3,246,000
Stock options exercised by employees and directors	71,606	0	71,606	0
Number of shares of non-vested stock that vested	3,762	2,239	39,953	47,028
Non-Vested Shares [Member] | Employees and Non-employee Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of non-vested stock issued			14,865
Aggregate fair value			$ 1,400,000
Non-Vested Shares [Member] | Employees and Non-employee Directors [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option plan, share based compensation, vesting period (in years)			8 years
Fair market value of the non-vested stock on the date of grant			$ 94.08
Non-Vested Shares [Member] | Employees and Non-employee Directors [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option plan, share based compensation, vesting period (in years)			1 year
Fair market value of the non-vested stock on the date of grant			$ 81.86
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option plan, share based compensation, vesting period (in years)			3 years
Aggregate fair value			$ 300,000
Performance Shares [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted under performance plan			6,766

Cash and Restricted Cash - Summ

Cash and Restricted Cash - Summary of Reconciliation of Cash and Restricted Cash (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Cash And Cash Equivalents [Abstract]
Cash and cash equivalents	$ 7,327	$ 9,167	$ 7,998
Restricted cash	476	292	492
Total cash and restricted cash	$ 7,803	$ 9,459	$ 8,490	$ 23,923

Investment in Storage Facilit41

Investment in Storage Facilities and Intangible Assets - Summary of Activity in Storage Facilities (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2018USD ($)
Cost:
Beginning balance	$ 4,321,410
Improvements and equipment additions	14,123
Net increase in construction in progress	14,040
Dispositions	(2,189)
Ending balance	4,347,384
Accumulated Depreciation:
Beginning balance	624,314
Additions during the period	49,557
Dispositions	(2,154)
Ending balance	$ 671,717

Investment in Storage Facilit42

Investment in Storage Facilities and Intangible Assets - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)$ / shares	Jun. 30, 2018USD ($)Property$ / shares	Jun. 30, 2017USD ($)$ / shares
Real Estate [Abstract]
Number of storage facilities acquired | Property			0
Amortization period for in-place customer leases on a straight-line basis			12 months
Amortization expense related to in-place customer leases	$ 0	$ 11,900,000	$ 0	$ 24,700,000
Increase in depreciation expense due to facility replacement		$ 1,400,000	$ 300,000	$ 1,500,000
Accelerated depreciation reduced basic and diluted earnings per share | $ / shares		$ 0.03	$ 0.01	$ 0.03

Investment in Storage Facilit43

Investment in Storage Facilities and Intangible Assets - Schedule of Fair Value of In-Place Customer Lease Intangible Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Real Estate [Abstract]
In-place customer leases	$ 75,241	$ 75,241
Accumulated amortization	$ (75,241)	$ (75,241)

Unsecured Line of Credit and 44

Unsecured Line of Credit and Term Notes - Borrowings Outstanding on Unsecured Line of Credit and Term Notes (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Unsecured Line Of Credit And Term Notes [Line Items]
Revolving line of credit borrowings	$ 113,000	$ 105,000
Total term notes payable - gross	1,625,000	1,625,000
Less: unamortized debt issuance costs	(10,262)	(10,962)
Less: unamortized senior term note discount	(4,676)	(4,949)
Term notes payable	1,610,062	1,609,089
Term Note Due June 4, 2020 [Member]
Unsecured Line Of Credit And Term Notes [Line Items]
Total term notes payable - gross	100,000	100,000
Term Note Due August 5, 2021 [Member]
Unsecured Line Of Credit And Term Notes [Line Items]
Total term notes payable - gross	100,000	100,000
Term Note Due April 8, 2024 [Member]
Unsecured Line Of Credit And Term Notes [Line Items]
Total term notes payable - gross	175,000	175,000
Senior Term Note Due July 1, 2026 [Member]
Unsecured Line Of Credit And Term Notes [Line Items]
Total term notes payable - gross	600,000	600,000
Senior Term Note Due December 15, 2027 [Member]
Unsecured Line Of Credit And Term Notes [Line Items]
Total term notes payable - gross	450,000	450,000
Term Note Due July 21, 2028 [Member]
Unsecured Line Of Credit And Term Notes [Line Items]
Total term notes payable - gross	$ 200,000	$ 200,000

Unsecured Line of Credit and 45

Unsecured Line of Credit and Term Notes - Additional Information (Detail) - USD ($)	Dec. 07, 2017	Jul. 21, 2016	Jun. 20, 2016	Apr. 08, 2014	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2011	Dec. 31, 2017
Unsecured Line Of Credit And Term Notes [Line Items]
Unsecured term note					$ 1,625,000,000		$ 1,625,000,000			$ 1,625,000,000
Term notes, outstanding amount					1,750,489,000		1,750,489,000
Unamortized senior term note discount					4,676,000		4,676,000			$ 4,949,000
Amortization expense related to deferred debt issuance costs							1,781,000	$ 1,663,000
Maximum [Member]
Unsecured Line Of Credit And Term Notes [Line Items]
Leverage ratio percentage			60.00%
Indenture covenant percentage on unencumbered assets			150.00%
Minimum [Member]
Unsecured Line Of Credit And Term Notes [Line Items]
Interest coverage ratio on debt			150.00%
Secured Debt [Member] | Maximum [Member]
Unsecured Line Of Credit And Term Notes [Line Items]
Leverage ratio percentage			40.00%
Revolving Credit Facility [Member]
Unsecured Line Of Credit And Term Notes [Line Items]
Revolving credit limit					$ 500,000,000		$ 500,000,000
Maturity on December 10, 2019 [Member]
Unsecured Line Of Credit And Term Notes [Line Items]
Basis spread over LIBOR							1.10%
Facility fee							0.15%
Interest rate, line of credit facility					3.19%		3.19%			2.63%
Amount available on unsecured revolving line of credit					$ 386,200,000		$ 386,200,000
Line of credit facility, expiration date							Dec. 10, 2019
Maturity on June 4, 2020 [Member]
Unsecured Line Of Credit And Term Notes [Line Items]
Basis spread over LIBOR							1.15%
Unsecured term note					325,000,000		$ 325,000,000
Repayments of unsecured term note							225,000,000
Term notes, outstanding amount					$ 100,000,000		$ 100,000,000
Debt instrument variable interest rate					3.15%		3.15%			2.53%
Maturity in April 8, 2024 [Member]
Unsecured Line Of Credit And Term Notes [Line Items]
Line of credit facility, expiration date				Apr. 8, 2024
Debt instrument stated interest rate				4.533%
Additional secured term note				$ 175,000,000
Maturity in April 8, 2024 [Member] | Maximum [Member]
Unsecured Line Of Credit And Term Notes [Line Items]
Debt instrument stated interest rate				6.283%
Maturity in August 2021 [Member]
Unsecured Line Of Credit And Term Notes [Line Items]
Line of credit facility, expiration date									Aug. 5, 2021
Debt instrument stated interest rate									5.54%
Additional secured term note									$ 100,000,000
Maturity in August 2021 [Member] | Maximum [Member]
Unsecured Line Of Credit And Term Notes [Line Items]
Debt instrument stated interest rate									7.29%
Senior Term Note Due July 1, 2026 [Member]
Unsecured Line Of Credit And Term Notes [Line Items]
Unsecured term note					$ 600,000,000		$ 600,000,000			$ 600,000,000
Senior Term Note Due July 1, 2026 [Member] | Unsecured Senior Notes [Member]
Unsecured Line Of Credit And Term Notes [Line Items]
Debt instrument principal amount			$ 600,000,000		600,000,000		600,000,000
Debt instrument stated interest rate			3.50%
Debt instrument percentage discount to par			0.553%
Unamortized senior term note discount			$ 3,300,000
Underwriting discount and other offering expenses			5,500,000
Proceeds from senior notes, net			$ 591,200,000
Term Note Due July 21, 2028 [Member]
Unsecured Line Of Credit And Term Notes [Line Items]
Unsecured term note					200,000,000		200,000,000			200,000,000
Line of credit facility, expiration date		Jul. 21, 2028
Debt instrument stated interest rate		3.67%
Additional secured term note		$ 200,000,000
Senior Notes and Term Notes [Member]
Unsecured Line Of Credit And Term Notes [Line Items]
Amortization expense related to deferred debt issuance costs					500,000	$ 500,000	1,000,000	$ 1,000,000
Senior Term Note Due December 15, 2027 [Member]
Unsecured Line Of Credit And Term Notes [Line Items]
Unsecured term note					$ 450,000,000		$ 450,000,000			$ 450,000,000
Senior Term Note Due December 15, 2027 [Member] | Unsecured Senior Notes [Member]
Unsecured Line Of Credit And Term Notes [Line Items]
Debt instrument principal amount	$ 450,000,000
Debt instrument stated interest rate	3.875%
Debt instrument percentage discount to par	0.477%
Unamortized senior term note discount	$ 2,100,000
Underwriting discount and other offering expenses	4,000,000
Proceeds from senior notes, net	$ 443,900,000

Mortgages Payable and Debt Ma46

Mortgages Payable and Debt Maturities - Summary of Mortgage Payable (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Mortgages payable	$ 12,489	$ 12,674
4.98% Mortgage Note Due January 1, 2021 [Member]
Debt Instrument [Line Items]
Mortgages payable	2,890	2,916
4.065% Mortgage Note Due April 1, 2023 [Member]
Debt Instrument [Line Items]
Mortgages payable	4,073	4,119
5.26% Mortgage Note Due November 1, 2023 [Member]
Debt Instrument [Line Items]
Mortgages payable	3,905	3,939
5.99% Mortgage Note Due May 1, 2026 [Member]
Debt Instrument [Line Items]
Mortgages payable	$ 1,621	$ 1,700

Mortgages Payable and Debt Ma47

Mortgages Payable and Debt Maturities - Summary of Mortgage Payable (Parenthetical) (Detail) $ in Millions	6 Months Ended
	Jun. 30, 2018USD ($)Facility
4.98% Mortgage Note Due January 1, 2021 [Member]
Debt Instrument [Line Items]
Interest rate	4.98%
Mortgage note due date	Jan. 1, 2021
Self-storage facilities | Facility	1
Aggregate net book value of property pledged for mortgage note | $	$ 9.5
Effective interest rate	5.22%
4.065% Mortgage Note Due April 1, 2023 [Member]
Debt Instrument [Line Items]
Interest rate	4.065%
Mortgage note due date	Apr. 1, 2023
Self-storage facilities | Facility	1
Aggregate net book value of property pledged for mortgage note | $	$ 7.5
Effective interest rate	4.30%
5.26% Mortgage Note Due November 1, 2023 [Member]
Debt Instrument [Line Items]
Interest rate	5.26%
Mortgage note due date	Nov. 1, 2023
Self-storage facilities | Facility	1
Aggregate net book value of property pledged for mortgage note | $	$ 8
Effective interest rate	5.56%
5.99% Mortgage Note Due May 1, 2026 [Member]
Debt Instrument [Line Items]
Interest rate	5.99%
Mortgage note due date	May 1, 2026
Self-storage facilities | Facility	1
Aggregate net book value of property pledged for mortgage note | $	$ 6.5
Effective interest rate	6.29%

Mortgages Payable and Debt Ma48

Mortgages Payable and Debt Maturities - Summary of Debt Obligation and Interest Rate Derivatives (Detail) $ in Thousands	Jun. 30, 2018USD ($)
Debt Instrument [Line Items]
Payables due 2018	$ 187
Payables due 2019	113,393
Payables due 2020	100,413
Payables due 2021	103,122
Payables due 2022	394
Payables due Thereafter	1,432,980
Debt obligations	1,750,489
Line of credit - variable rate LIBOR + 1.10% (3.19% at June 30, 2018) [Member]
Debt Instrument [Line Items]
Payables due 2019	113,000
Debt obligations	113,000
Debt instrument, fair value	113,000
Term note - variable rate LIBOR+1.15% (3.15% at June 30, 2018) [Member]
Debt Instrument [Line Items]
Payables due 2020	100,000
Debt obligations	100,000
Term note, fair value	100,000
Term Note - Fixed Rate 5.54% [Member]
Debt Instrument [Line Items]
Payables due 2021	100,000
Debt obligations	100,000
Term note, fair value	105,217
Term Note - Fixed Rate 4.533% [Member]
Debt Instrument [Line Items]
Payables due Thereafter	175,000
Debt obligations	175,000
Term note, fair value	177,784
Term Note - Fixed Rate 3.50% [Member]
Debt Instrument [Line Items]
Payables due Thereafter	600,000
Debt obligations	600,000
Term note, fair value	565,717
Term Note - Fixed Rate 3.875% [Member]
Debt Instrument [Line Items]
Payables due Thereafter	450,000
Debt obligations	450,000
Term note, fair value	425,118
Term Note - Fixed Rate 3.67% [Member]
Debt Instrument [Line Items]
Payables due Thereafter	200,000
Debt obligations	200,000
Term note, fair value	181,530
Mortgage Note - Fixed Rate 4.98% [Member]
Debt Instrument [Line Items]
Payables due 2018	27
Payables due 2019	56
Payables due 2020	59
Payables due 2021	2,748
Debt obligations	2,890
Debt instrument, fair value	2,913
Mortgage Note - Fixed Rate 4.065% [Member]
Debt Instrument [Line Items]
Payables due 2018	45
Payables due 2019	96
Payables due 2020	99
Payables due 2021	104
Payables due 2022	108
Payables due Thereafter	3,621
Debt obligations	4,073
Debt instrument, fair value	3,961
Mortgage Note - Fixed Rate 5.26% [Member]
Debt Instrument [Line Items]
Payables due 2018	34
Payables due 2019	71
Payables due 2020	74
Payables due 2021	78
Payables due 2022	83
Payables due Thereafter	3,565
Debt obligations	3,905
Debt instrument, fair value	4,001
Mortgage Note - Fixed Rate 5.99% [Member]
Debt Instrument [Line Items]
Payables due 2018	81
Payables due 2019	170
Payables due 2020	181
Payables due 2021	192
Payables due 2022	203
Payables due Thereafter	794
Debt obligations	1,621
Debt instrument, fair value	$ 1,694

Mortgages Payable and Debt Ma49

Mortgages Payable and Debt Maturities - Summary of Debt Obligation and Interest Rate Derivatives (Parenthetical) (Detail)	6 Months Ended
	Jun. 30, 2018
Line of credit - variable rate LIBOR + 1.10% (3.19% at June 30, 2018) [Member]
Debt Instrument [Line Items]
Interest rate at end of period	3.19%
Basis spread over LIBOR	1.10%
Term note - variable rate LIBOR+1.15% (3.15% at June 30, 2018) [Member]
Debt Instrument [Line Items]
Basis spread over LIBOR	1.15%
Interest rate	3.15%
Term Note - Fixed Rate 5.54% [Member]
Debt Instrument [Line Items]
Interest rate	5.54%
Term Note - Fixed Rate 4.533% [Member]
Debt Instrument [Line Items]
Interest rate	4.533%
Term Note - Fixed Rate 3.50% [Member]
Debt Instrument [Line Items]
Interest rate	3.50%
Term Note - Fixed Rate 3.875% [Member]
Debt Instrument [Line Items]
Interest rate	3.875%
Term Note - Fixed Rate 3.67% [Member]
Debt Instrument [Line Items]
Interest rate	3.67%
Mortgage Note - Fixed Rate 4.98% [Member]
Debt Instrument [Line Items]
Interest rate	4.98%
Mortgage Note - Fixed Rate 4.065% [Member]
Debt Instrument [Line Items]
Interest rate	4.065%
Mortgage Note - Fixed Rate 5.26% [Member]
Debt Instrument [Line Items]
Interest rate	5.26%
Mortgage Note - Fixed Rate 5.99% [Member]
Debt Instrument [Line Items]
Interest rate	5.99%

Derivative Financial Instrume50

Derivative Financial Instruments - Additional Information (Detail) - USD ($)	Jun. 20, 2016	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Mar. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Cash flow hedge ineffectiveness				Ineffectiveness was de minimis for the three and six months ended June 30, 2018 and 2017.
Unsecured term note		$ 1,625,000,000		$ 1,625,000,000		$ 1,625,000,000
Repayments of variable rate term notes						225,000,000
Effective portion of gain (loss) on derivatives net of reclassification to interest expense		106,000	$ 237,000	383,000	$ 1,859,000
Derivative notional amount							$ 100,000,000	$ 50,000,000
Realized loss reclassified from accumulated other comprehensive loss to interest expense		(113,000)	(956,000)	(309,000)	(2,076,000)
Fair value of interest rate swap agreements, asset		177,000		177,000		205,000
Senior Term Note Due July 1, 2026 [Member]
Derivative [Line Items]
Unsecured term note		600,000,000		$ 600,000,000		600,000,000
Settlement of forward starting swap agreements	$ 9,200,000
Amortized period on interest expense				10 years
Interest Expense [Member]
Derivative [Line Items]
Realized loss reclassified from accumulated other comprehensive loss to interest expense		(100,000)	$ 700,000	$ (100,000)	$ 1,600,000
Unsecured Senior Notes [Member] | Senior Term Note Due July 1, 2026 [Member]
Derivative [Line Items]
Debt instrument principal amount	$ 600,000,000	600,000,000		600,000,000
Interest Rate Swap [Member]
Derivative [Line Items]
Unsecured term note		100,000,000		100,000,000
Effective portion of gain (loss) on derivatives net of reclassification to interest expense				0		$ 0
Derivative notional amount		$ 100,000,000		$ 100,000,000

Derivative Financial Instrume51

Derivative Financial Instruments - Summary of Interest Rate Swap Agreements (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2018	Mar. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Notional Amount		$ 100,000,000	$ 50,000,000
Interest Rate Swap [Member]
Derivative [Line Items]
Notional Amount	$ 100,000,000
Effective Date	Sep. 4, 2013
Expiration Date	Sep. 4, 2018
Fixed Rate Paid	1.371%
Interest Rate Swap [Member] | London Interbank Offered Rate (LIBOR) [Member]
Derivative [Line Items]
Floating Rate Received	1 month LIBOR

Derivative Financial Instrume52

Derivative Financial Instruments - Summary of Changes in AOCL (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Accumulated other comprehensive loss beginning of period	$ (7,310)	$ (19,853)	$ (7,587)	$ (21,475)	$ (21,475)
Realized loss reclassified from accumulated other comprehensive loss to interest expense	113	956	309	2,076
Unrealized (loss) gain from changes in the fair value of the effective portion of the interest rate swaps	(7)	(719)	74	(217)
Gain included in other comprehensive loss	106	237	383	1,859
Accumulated other comprehensive loss end of period	$ (7,204)	$ (19,616)	$ (7,204)	$ (19,616)	$ (7,587)

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Carried at Fair Value Measured on Recurring Basis (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of interest rate swap agreements, asset	$ 177	$ 205
Interest Rate Swap [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of interest rate swap agreements, asset	177	205
Interest Rate Swap [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of interest rate swap agreements, asset	$ 177	$ 205

Investment in Joint Ventures -

Investment in Joint Ventures - Summary of Company's Unconsolidated Joint Ventures (Detail) $ in Thousands	Jun. 30, 2018USD ($)Property	Dec. 31, 2017USD ($)
Schedule of Equity Method Investments [Line Items]
Carrying value of investment	$ 133,225	$ 133,458
Sovran HHF Storage Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of Properties | Property	57
Company common ownership interest	20.00%
Carrying value of investment	$ 84,000	85,100
Sovran HHF Storage Holdings II LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of Properties | Property	30
Company common ownership interest	15.00%
Carrying value of investment	$ 13,200	13,300
191 III Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of Properties | Property	6
Company common ownership interest	20.00%
Carrying value of investment	$ 9,300	9,400
Life Storage-SERS Storage LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of Properties | Property	3
Company common ownership interest	20.00%
Carrying value of investment	$ 3,600	3,600
Iskalo Office Holdings, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Company common ownership interest	49.00%
Carrying value of investment	$ (400)	(400)
Urban Box Coralway Storage, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of Properties | Property	1
Company common ownership interest	85.00%
Carrying value of investment	$ 4,400	4,100
SNL/Orix 1200 McDonald Ave., LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of Properties | Property	1
Company common ownership interest	5.00%
Carrying value of investment	$ 2,700	2,700
SNL Orix Merrick, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of Properties | Property	1
Company common ownership interest	5.00%
Carrying value of investment	$ 2,400	2,500
Review Avenue Partners LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of Properties | Property	1
Company common ownership interest	40.00%
Carrying value of investment	$ 11,300	11,500
N 32nd Street Self Storage, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of Properties | Property	1
Company common ownership interest	46.00%
Carrying value of investment	$ 1,300	$ 1,300
NYX Don Mills Storage LP [Member]
Schedule of Equity Method Investments [Line Items]
Number of Properties | Property	1
Company common ownership interest	17.00%
Carrying value of investment	$ 1,000

Investment in Joint Ventures 55

Investment in Joint Ventures - Summary of Company's Unconsolidated Joint Ventures (Parenthetical) (Detail) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2018USD ($)Property	Jun. 30, 2017USD ($)	Dec. 31, 2017USD ($)Property
Schedule of Equity Method Investments [Line Items]
Number of storage facilities acquired | Property	0
Mortgages payable	$ 12,489		$ 12,674
Distributions from unconsolidated joint ventures	4,103	$ 2,852
Sovran HHF Storage Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Contribution of company to joint venture as share in capital	200
Distributions from unconsolidated joint ventures	2,700
Excess of investment over net asset due to capitalization of acquisition related costs	1,700
Sovran HHF Storage Holdings II LLC [Member]
Schedule of Equity Method Investments [Line Items]
Distributions from unconsolidated joint ventures	1,000
191 III Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Contribution of company to joint venture as share in capital	100
Distributions from unconsolidated joint ventures	200
Iskalo Office Holdings, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Distributions from unconsolidated joint ventures	100
Rent paid during the period	600	$ 600
Urban Box Coralway Storage, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Contribution of company to joint venture as share in capital	300
SNL/Orix 1200 McDonald Ave., LLC [Member]
Schedule of Equity Method Investments [Line Items]
Non-recourse mortgage loan principal outstanding	8,600
SNL Orix Merrick, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Non-recourse mortgage loan principal outstanding	11,300
Review Avenue Partners LLC [Member] | Common Stock Shares [Member]
Schedule of Equity Method Investments [Line Items]
Contribution of company to joint venture as share in capital	200
NYX Don Mills Storage LP [Member] | Common Stock Shares [Member]
Schedule of Equity Method Investments [Line Items]
Contribution of company to joint venture as share in capital	$ 1,000
Arizona [Member] | Sovran HHF Storage Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of self-storage facilities | Property	11
Colorado [Member] | Sovran HHF Storage Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of self-storage facilities | Property	4
Florida [Member] | Sovran HHF Storage Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of self-storage facilities | Property	3
Georgia [Member] | Sovran HHF Storage Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of self-storage facilities | Property	1
Georgia [Member] | Life Storage-SERS Storage LLC [Member] | Additional Storage Facilities [Member]
Schedule of Equity Method Investments [Line Items]
Number of storage facilities acquired | Property	3		3
Payment for property acquisition			$ 39,100
Mortgages payable			$ 22,000
Kentucky [Member] | Sovran HHF Storage Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of self-storage facilities | Property	2
Nevada [Member] | Sovran HHF Storage Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of self-storage facilities | Property	5
New Jersey [Member] | Sovran HHF Storage Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of self-storage facilities | Property	2
New Jersey [Member] | Sovran HHF Storage Holdings II LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of self-storage facilities | Property	17
Ohio [Member] | Sovran HHF Storage Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of self-storage facilities | Property	6
Pennsylvania [Member] | Sovran HHF Storage Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of self-storage facilities | Property	1
Pennsylvania [Member] | Sovran HHF Storage Holdings II LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of self-storage facilities | Property	3
Tennessee [Member] | Sovran HHF Storage Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of self-storage facilities | Property	2
Texas [Member] | Sovran HHF Storage Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of self-storage facilities | Property	20
Texas [Member] | Sovran HHF Storage Holdings II LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of self-storage facilities | Property	10
Arizona, Nevada and Tennessee [Member] | Sovran HHF Storage Holdings LLC [Member] | Storage Facilities [Member]
Schedule of Equity Method Investments [Line Items]
Number of storage facilities acquired | Property			18
Payment for property acquisition			$ 330,000
Mortgages payable			$ 135,000
Number of properties collateral for debt | Property			16
California [Member] | 191 III Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of self-storage facilities | Property	6
California [Member] | 191 III Holdings LLC [Member] | Six Storage Facilities [Member]
Schedule of Equity Method Investments [Line Items]
Number of storage facilities acquired | Property			6
Payment for property acquisition			$ 104,100
Mortgages payable			$ 57,200

Investment in Joint Ventures 56

Investment in Joint Ventures - Additional Information (Detail) - Sovran HHF, Sovran HHF II, 191 III, SERS, RAP and Merrick [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Schedule of Equity Method Investments [Line Items]
Management and call center fee earned	$ 1.9	$ 1.5	$ 3.8	$ 2.9
Minimum [Member]
Schedule of Equity Method Investments [Line Items]
Management and call center fee as a percentage of revenues			6.00%
Maximum [Member]
Schedule of Equity Method Investments [Line Items]
Management and call center fee as a percentage of revenues			7.00%

Investment in Joint Ventures 57

Investment in Joint Ventures - Company's Share of Unconsolidated Joint Ventures' Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Schedule of Equity Method Investments [Line Items]
Income (loss) from equity method investments	$ 1,048	$ 785	$ 2,020	$ 1,506
Sovran HHF Storage Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Income (loss) from equity method investments	739	624	1,428	1,162
Sovran HHF Storage Holdings II LLC [Member]
Schedule of Equity Method Investments [Line Items]
Income (loss) from equity method investments	432	362	800	702
191 III Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Income (loss) from equity method investments	18	(10)	36	25
Life Storage-SERS Storage LLC [Member]
Schedule of Equity Method Investments [Line Items]
Income (loss) from equity method investments	25		86
Review Avenue Partners LLC [Member]
Schedule of Equity Method Investments [Line Items]
Income (loss) from equity method investments	(217)	(255)	(432)	(501)
SNL Orix Merrick, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Income (loss) from equity method investments	(16)		(32)
Iskalo Office Holdings, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Income (loss) from equity method investments	$ 67	$ 64	$ 134	$ 118

Investment in Joint Ventures 58

Investment in Joint Ventures - Summary of Unconsolidated Joint Ventures' Financial Statements (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Investment in storage facilities, net	$ 3,675,667		$ 3,675,667		$ 3,697,096
Other assets	4,487		4,487		4,863
Total Assets	3,862,969		3,862,969		3,876,774
Mortgages payable	12,489		12,489		12,674
Total Liabilities	1,828,885		1,828,885		1,829,078
Unaffiliated partners’ equity	0		0		0
Company equity	2,013,440		2,013,440		2,028,323
Total Equity	2,013,440		2,013,440		$ 2,028,323
Depreciation and amortization of customer list	(24,784)	$ (38,105)	(49,548)	$ (75,747)
Amortization of financing fees			(1,781)	(1,663)
Income tax expense	(700)	2,500	(1,200)	2,200
Interest expense	(17,518)	$ (15,716)	(34,722)	$ (30,926)
Unconsolidated Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Investment in storage facilities, net	1,076,193		1,076,193
Investment in office building, net	4,712		4,712
Other assets	20,821		20,821
Total Assets	1,101,726		1,101,726
Due to the Company	994		994
Mortgages payable	468,606		468,606
Other liabilities	8,290		8,290
Total Liabilities	477,890		477,890
Unaffiliated partners’ equity	491,003		491,003
Company equity	132,833		132,833
Total Equity	623,836		623,836
Total Liabilities and Partners’ Equity	$ 1,101,726		1,101,726
Total revenues			55,627
Property operating expenses			(17,295)
Administrative, management and call center fees			(4,314)
Depreciation and amortization of customer list			(12,822)
Amortization of financing fees			(653)
Income tax expense			(155)
Interest expense			(8,716)
Net income			$ 11,672

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Schedule Of Income Taxes [Line Items]
Federal and state income tax expense (benefit)	$ 700,000	$ (2,500,000)	$ 1,200,000	$ (2,200,000)
Unrecognized tax benefits	0	$ 0	0	0
Interest or penalties related to uncertain tax positions			0	$ 0
Prepaid taxes	200,000		200,000		$ 100,000
Deferred tax assets	3,400,000		3,400,000		3,600,000
Deferred tax liability	$ 1,600,000		$ 1,600,000		$ 1,700,000
Corporate income tax rate			21.00%		35.00%
Tax Year 2013 [Member]
Schedule Of Income Taxes [Line Items]
Tax years open to examination			2,013
Latest Tax Year [Member]
Schedule Of Income Taxes [Line Items]
Tax years open to examination			2,017

Earnings Per Share and Earnin60

Earnings Per Share and Earnings Per Unit - Computation of Basic and Diluted Earnings Per Common Share/Unit (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Numerator:
Net income attributable to common shareholders/unitholders	$ 39,274	$ 19,355	$ 73,163	$ 39,785
Denominator:
Denominator for basic earnings per share/unit – weighted average shares/units	46,480,907	46,364,890	46,466,700	46,334,729
Effect of Dilutive Securities:
Stock options and non-vested stock	95,000	113,000	90,000	113,000
Denominator for diluted earnings per share/unit - adjusted weighted average shares/units and assumed conversion	46,576,352	46,477,680	46,556,512	46,448,286
Basic earnings per common share/unit attributable to common shareholders/unitholders	$ 0.84	$ 0.42	$ 1.57	$ 0.86
Diluted earnings per common share/unit attributable to common shareholders/unitholders	$ 0.84	$ 0.42	$ 1.57	$ 0.86
Life Storage LP [Member]
Numerator:
Net income attributable to common shareholders/unitholders	$ 39,274	$ 19,355	$ 73,163	$ 39,785
Denominator:
Denominator for basic earnings per share/unit – weighted average shares/units	46,480,907	46,364,890	46,466,700	46,334,729
Effect of Dilutive Securities:
Stock options and non-vested stock	95,000	113,000	90,000	113,000
Denominator for diluted earnings per share/unit - adjusted weighted average shares/units and assumed conversion	46,576,352	46,477,680	46,556,512	46,448,286
Basic earnings per common share/unit attributable to common shareholders/unitholders	$ 0.84	$ 0.42	$ 1.57	$ 0.86
Diluted earnings per common share/unit attributable to common shareholders/unitholders	$ 0.84	$ 0.42	$ 1.57	$ 0.86

Earnings Per Share and Earnin61

Earnings Per Share and Earnings Per Unit - Additional Information (Detail) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securities not included in the effect of dilutive securities	111,122	133,094	114,592	142,074
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securities not included in the effect of dilutive securities	11,000	15,500	11,000	13,250

Shareholders' Equity - Reconcil

Shareholders' Equity - Reconciliation of Changes in Parent Company's Total Shareholders' Equity (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Equity [Abstract]
Beginning balance			$ 2,028,323
Exercise of stock options			3,045
Earned portion of non-vested stock			2,748
Stock option expense			7
Carrying value less than redemption value on redeemed noncontrolling interest			(30)
Adjustment to redemption value on noncontrolling redeemable Operating Partnership units			(1,565)
Net income attributable to common shareholders	$ 39,274	$ 19,355	73,163	$ 39,785
Amortization of terminated hedge included in AOCL			458
Change in fair value of derivatives			(74)
Dividends			(92,635)
Ending balance	$ 2,013,440		$ 2,013,440

Shareholders' Equity - Addition

Shareholders' Equity - Additional Information (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2018	Jun. 14, 2018	Aug. 02, 2017
Stockholders Equity [Line Items]
Common stock value authorized under equity offering program			$ 300,000,000
Buyback Program, authorized repurchase amount		$ 0		$ 200,000,000
Shares issued under dividend reinvestment plan	118,656
Equity Program [Member]
Stockholders Equity [Line Items]
Common stock remains available for issuance		$ 300,000,000

Partners' Capital - Reconciliat

Partners' Capital - Reconciliation of Change in Total Partners' Capital (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Partners Capital [Line Items]
Exercise of stock options			$ 3,045
Earned portion of non-vested stock			2,748
Stock option expense			7
Carrying value less than redemption value on redeemed noncontrolling interest			(30)
Adjustment to redemption value on limited partners’ redeemable capital interests			(1,565)
Net income attributable to common unitholders	$ 39,274	$ 19,355	73,163	$ 39,785
Amortization of terminated hedge included in AOCL			458
Change in fair value of derivatives			(74)
Life Storage LP [Member]
Partners Capital [Line Items]
Beginning balance of total controlling partners’ capital			2,028,323
Exercise of stock options			3,045
Earned portion of non-vested stock			2,748
Stock option expense			7
Carrying value less than redemption value on redeemed noncontrolling interest			(30)
Adjustment to redemption value on limited partners’ redeemable capital interests			(1,565)
Net income attributable to common unitholders	39,274	$ 19,355	73,163	$ 39,785
Amortization of terminated hedge included in AOCL			458
Change in fair value of derivatives			(74)
Distributions			(92,635)
Ending balance of total controlling partners’ capital	$ 2,013,440		$ 2,013,440

Recent Accounting Pronounceme65

Recent Accounting Pronouncements - Additional Information (Detail) $ in Millions	6 Months Ended
	Jun. 30, 2018USD ($)
Land and Building [Member]
Product Information [Line Items]
Accumulated operating leases, aggregate annual minimum payments	$ 3
Revenue [Member] | Product Concentration [Member] | Revenue From Rental Products [Member] | Minimum [Member]
Product Information [Line Items]
Concentration risk, percentage	90.00%

Commitment and Contingencies -

Commitment and Contingencies - Additional Information (Detail) - New Jersey [Member] - Class Action [Member] $ in Millions	6 Months Ended
	Jun. 30, 2018USD ($)
Commitment And Contingencies [Line Items]
Settlement agreement, amount	$ 8
Settlement agreement, amount after tax	$ 6

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) $ / shares in Units, $ in Millions	Aug. 02, 2018USD ($)Property	Jul. 26, 2018USD ($)	Jun. 30, 2018Property	Jul. 05, 2018$ / shares
Subsequent Event [Line Items]
Dividend declared, date			Jul. 5, 2018
Dividend paid, date			Jul. 26, 2018
Dividend record, date			Jul. 16, 2018
Number of storage facilities acquired | Property			0
Subsequent Event [Member]
Subsequent Event [Line Items]
Dividend per common share | $ / shares				$ 1
Dividend paid | $		$ 46.6
Number of storage facilities acquired | Property	3
Aggregate purchase price | $	$ 27.6