Extra Space Storage (EXR) 10-K 25 Feb 20 2019 FY Annual report Financial data

Cover

Cover - USD ($)	12 Months Ended
	Dec. 31, 2019	Feb. 19, 2020	Jun. 28, 2019
Cover page.
Document Type	10-K
Amendment Flag	false
Document Annual Report	true
Document Period End Date	Dec. 31, 2019
Document Transition Report	false
Entity File Number	001-32269
Entity Registrant Name	EXTRA SPACE STORAGE INC.
Entity Central Index Key	0001289490
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	20-1076777
Entity Address, Address Line One	2795 East Cottonwood Parkway, Suite 300
Entity Address, City or Town	Salt Lake City
Entity Address, State or Province	UT
Entity Address, Postal Zip Code	84121
City Area Code	801
Local Phone Number	365-4600
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	EXR
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Smaller Reporting Company	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 13,214,610,280
Entity Common Stock, Shares Outstanding		129,613,332
Documents Incorporated by Reference	Portions of the registrant’s definitive proxy statement to be issued in connection with the registrant’s annual stockholders’ meeting to be held in 2020 are incorporated by reference into Part III of this Annual Report on Form 10-K.

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Assets:
Real estate assets, net	$ 7,696,864	$ 7,491,831
Real estate assets - operating lease right-of-use assets	264,643
Investments in unconsolidated real estate entities	338,054	125,326
Cash and cash equivalents	65,746	57,496
Restricted cash	4,987	15,194
Other assets, net	162,083	158,131
Total assets	8,532,377	7,847,978
Liabilities, Noncontrolling Interests and Equity:
Notes payable, net	4,318,973	4,137,213
Exchangeable senior notes, net	569,513	562,374
Notes payable to trusts	0	30,928
Revolving lines of credit	158,000	81,000
Operating lease liabilities	274,783
Cash distributions in unconsolidated real estate ventures	45,264	45,197
Accounts payable and accrued expenses	111,382	101,461
Other liabilities	132,768	104,383
Total liabilities	5,610,683	5,062,556
Commitments and contingencies
Extra Space Storage Inc. stockholders' equity:
Preferred stock, $0.01 par value, 50,000,000 shares authorized, no shares issued or outstanding	0	0
Common stock, $0.01 par value, 500,000,000 shares authorized, 129,534,407 and 127,103,750 shares issued and outstanding at December 31, 2019 and December 31, 2018, respectively	1,295	1,271
Additional paid-in capital	2,868,681	2,640,705
Accumulated other comprehensive income (loss)	(28,966)	34,650
Accumulated deficit	(301,049)	(262,902)
Total Extra Space Storage Inc. stockholders' equity	2,539,961	2,413,724
Noncontrolling interest represented by Preferred Operating Partnership units, net	175,948	153,096
Noncontrolling interests in Operating Partnership, net and other noncontrolling interests	205,785	218,602
Total noncontrolling interests and equity	2,921,694	2,785,422
Total liabilities, noncontrolling interests and equity	$ 8,532,377	$ 7,847,978

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	50,000,000	50,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	500,000,000	500,000,000
Common stock, shares issued (in shares)	129,534,407	127,103,750
Common stock, shares outstanding (in shares)	129,534,407	127,103,750

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Property rental	$ 1,130,177	$ 1,039,340
Property rental			$ 967,229
Tenant reinsurance	128,387	115,507	98,401
Management fees and other income	49,890	41,757	39,379
Total revenues	1,308,454	1,196,604	1,105,009
Expenses:
Property operations	336,050	291,695	271,974
Tenant reinsurance	29,376	25,707	19,173
General and administrative	89,418	81,256	78,961
Depreciation and amortization	219,857	209,050	193,296
Total expenses	674,701	607,708	563,404
Gain on real estate transactions and impairment of real estate	1,205	30,807	112,789
Income from operations	634,958	619,703	654,394
Interest expense	(186,526)	(178,436)	(153,511)
Non-cash interest expense related to amortization of discount on equity component of exchangeable senior notes	(4,742)	(4,687)	(5,103)
Interest income	7,467	5,292	6,736
Income before equity in earnings of unconsolidated real estate ventures and income tax expense	451,157	441,872	502,516
Equity in earnings of unconsolidated real estate ventures	11,274	14,452	15,331
Income tax expense	(11,308)	(9,244)	(3,625)
Net income	451,123	447,080	514,222
Net income allocated to Preferred Operating Partnership noncontrolling interests	(12,492)	(13,995)	(14,989)
Net income allocated to Operating Partnership and other noncontrolling interests	(18,664)	(17,796)	(20,220)
Net income attributable to common stockholders	$ 419,967	$ 415,289	$ 479,013
Earnings per common share
Basic (in dollars per share)	$ 3.27	$ 3.29	$ 3.79
Diluted (in dollars per share)	$ 3.24	$ 3.27	$ 3.76
Weighted average number of shares
Basic (in shares)	128,203,568	126,087,487	125,967,831
Diluted (in shares)	136,433,769	133,159,033	134,155,771

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 451,123	$ 447,080	$ 514,222
Other comprehensive income (loss):
Change in fair value of interest rate swaps	(66,843)	1,430	17,308
Total comprehensive income	384,280	448,510	531,530
Less: comprehensive income attributable to noncontrolling interests	27,929	31,861	35,997
Comprehensive income attributable to common stockholders	$ 356,351	$ 416,649	$ 495,533

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Redemption of Operating Partnership units for cash	Preferred Operating Partnership	Operating Partnership	Operating PartnershipRedemption of Operating Partnership units for stock	Operating PartnershipRedemption of Operating Partnership units for cash	Other	Common Stock	Common StockRedemption of Operating Partnership units for stock	Additional Paid-in Capital	Additional Paid-in CapitalRedemption of Operating Partnership units for stock	Additional Paid-in CapitalRedemption of Operating Partnership units for cash	Accumulated Other Comprehensive Income	Accumulated Deficit
Beginning balance at Dec. 31, 2016	$ 2,596,166		$ 147,920	$ 203,354			$ 0	$ 1,259		$ 2,566,120			$ 16,770	$ (339,257)
Beginning balance (in shares) at Dec. 31, 2016								125,881,460
Increase (Decrease) in Stockholders' Equity
Issuance of common stock upon the exercise of options (in shares)	38,418							38,418
Issuance of common stock upon the exercise of options	$ 1,266									1,266
Restricted stock grants issued (in shares)								95,392
Restricted stock grants issued								$ 1		(1)
Restricted stock grants cancelled (in shares)								(8,179)
Compensation expense related to stock-based awards	9,561									9,561
Issuance of Operating Partnership units in conjunction with acquisitions	7,618			7,618
Redemption or purchase of noncontrolling interests		$ (2,510)				$ (1,238)						$ (1,272)
Issuance of Preferred D Units in the Operating Partnership in conjunction with acquisitions	11,161		11,161
Noncontrolling interest in consolidated joint venture	216						216
Repurchase of equity portion of 2013 exchangeable senior notes	(6,189)									(6,189)
Net income (loss)	514,222		14,989	20,317			(97)							479,013
Other comprehensive income (loss)	17,308		106	682									16,520
Distributions to Operating Partnership units held by noncontrolling interests	(31,972)		(14,540)	(17,432)
Dividends paid on common stock	(393,040)													(393,040)
Ending balance at Dec. 31, 2017	$ 2,723,807		159,636	213,301			119	$ 1,260		2,569,485			33,290	(253,284)
Ending balance (in shares) at Dec. 31, 2017								126,007,091
Increase (Decrease) in Stockholders' Equity
Issuance of common stock upon the exercise of options (in shares)	54,575							54,575
Issuance of common stock upon the exercise of options	$ 1,169									1,169
Restricted stock grants issued (in shares)								85,066
Restricted stock grants issued	1							$ 1
Restricted stock grants cancelled (in shares)								(11,771)
Issuance of common stock, net of offering costs (in shares)								933,789
Issuance of common stock, net of offering costs	90,231							$ 10		90,221
Compensation expense related to stock-based awards	11,176									11,176
Repayment of receivable for preferred operating units pledged as collateral on loan	495		495
Issuance of Operating Partnership units in conjunction with acquisitions	1,877			1,877
Redemption or purchase of noncontrolling interests		$ (2,558)			$ (1,337)	$ (1,126)					$ 1,337	$ (1,432)
Redemption or purchase of noncontrolling interests (in shares)								35,000
Conversion of Preferred C Units in the Operating Partnership for Common Operating Partnership Units			(6,851)	6,851
Noncontrolling interest in consolidated joint venture	122						122
Repurchase of equity portion of 2013 exchangeable senior notes	(31,251)									(31,251)
Net income (loss)	447,080		13,995	17,797			(1)							415,289
Other comprehensive income (loss)	1,430		12	58									1,360
Distributions to Operating Partnership units held by noncontrolling interests	(33,250)		(14,191)	(19,059)
Dividends paid on common stock	(424,907)													(424,907)
Ending balance at Dec. 31, 2018	$ 2,785,422		153,096	218,362			240	$ 1,271		2,640,705			34,650	(262,902)
Ending balance (in shares) at Dec. 31, 2018	127,103,750							127,103,750
Increase (Decrease) in Stockholders' Equity
Issuance of common stock upon the exercise of options (in shares)	211,057							211,057
Issuance of common stock upon the exercise of options	$ 3,063							$ 3		3,060
Restricted stock grants issued (in shares)								109,081
Restricted stock grants issued	2							$ 2
Restricted stock grants cancelled (in shares)								(8,863)
Issuance of common stock, net of offering costs (in shares)								1,779,200
Issuance of common stock, net of offering costs	198,827							$ 19		198,808
Compensation expense related to stock-based awards	13,051									13,051
Repayment of receivable for preferred operating units pledged as collateral on loan	1,211			1,211
Redemption or purchase of noncontrolling interests					$ (13,057)						$ 13,057
Redemption or purchase of noncontrolling interests (in shares)									340,182
Issuance of Preferred D Units in the Operating Partnership in conjunction with acquisitions	28,022		28,022
Conversion of Preferred C Units in the Operating Partnership for Common Operating Partnership Units			(4,374)	4,374
Noncontrolling interest in consolidated joint venture	173						173
Net income (loss)	451,123		12,492	18,711			(47)							419,967
Other comprehensive income (loss)	(66,843)		(407)	(2,820)									(63,616)
Distributions to Operating Partnership units held by noncontrolling interests	(34,243)		(12,881)	(21,362)
Dividends paid on common stock	(458,114)													(458,114)
Ending balance at Dec. 31, 2019	$ 2,921,694		$ 175,948	$ 205,419			$ 366	$ 1,295		$ 2,868,681			$ (28,966)	$ (301,049)
Ending balance (in shares) at Dec. 31, 2019	129,534,407							129,534,407

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Stockholders' Equity [Abstract]
Dividends paid on common stock (in dollars per share)	$ 3.56	$ 3.36	$ 3.12

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net income	$ 451,123	$ 447,080	$ 514,222
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	219,857	209,050	193,296
Amortization of deferred financing costs	11,989	14,286	12,289
Non-cash interest expense related to amortization of discount on equity component of exchangeable senior notes	4,742	4,687	5,103
Non-cash lease expense	1,064
Compensation expense related to stock-based awards	13,051	11,176	9,561
Gain on real estate transactions and impairment of real estate	(1,205)	(30,807)	(112,789)
Distributions from unconsolidated real estate ventures in excess of earnings	6,358	6,867	4,567
Changes in operating assets and liabilities:
Other assets	(12,482)	(1,664)	(12,728)
Accounts payable and accrued expenses	15,522	2,736	(10,515)
Other liabilities	(2,333)	14,384	(5,631)
Net cash provided by operating activities	707,686	677,795	597,375
Cash flows from investing activities:
Acquisition of real estate assets	(349,494)	(426,388)	(653,185)
Development and redevelopment of real estate assets	(53,717)	(60,677)	(31,746)
Proceeds from sale of real estate assets	11,254	52,458	312,165
Investment in unconsolidated real estate entities	(197,759)	(65,500)	(17,944)
Return of investment in unconsolidated real estate ventures	3,982	49,130	581
Issuance of notes receivable	(185,993)	(13,850)	0
Principal payments received from notes receivable	157,861	25,226	44,869
Purchase of equipment and fixtures	(7,764)	(4,297)	(7,819)
Net cash used in investing activities	(621,630)	(443,898)	(353,079)
Cash flows from financing activities:
Proceeds from the sale of common stock, net of offering costs	198,827	90,231	0
Proceeds from notes payable and revolving lines of credit	2,214,000	1,413,030	1,325,623
Principal payments on notes payable and revolving lines of credit	(1,977,805)	(1,109,854)	(1,088,679)
Principal payments on notes payable to trusts	(30,928)	(88,662)	0
Deferred financing costs	(2,986)	(12,302)	(6,967)
Repurchase of exchangeable senior notes	0	(80,270)	(19,916)
Net proceeds from exercise of stock options	3,063	1,169	1,266
Redemption of Operating Partnership units held by noncontrolling interests	0	(2,558)	(2,510)
Contributions from noncontrolling interests	173	122	201
Dividends paid on common stock	(458,114)	(424,907)	(393,040)
Distributions to noncontrolling interests	(34,243)	(33,250)	(31,972)
Net cash used in financing activities	(88,013)	(247,251)	(215,994)
Net increase (decrease) in cash, cash equivalents, and restricted cash	(1,957)	(13,354)	28,302
Cash, cash equivalents, and restricted cash, beginning of the period	72,690	86,044	57,742
Cash, cash equivalents, and restricted cash, end of the period	70,733	72,690	86,044
Supplemental schedule of cash flow information
Interest paid	174,155	159,474	136,202
Income taxes paid	10,359	730	5,648
Redemption of Operating Partnership units held by noncontrolling interests for common stock
Noncontrolling interests in Operating Partnership	(13,057)	(1,337)
Common stock and paid-in capital	13,057	1,337
Establishment of operating lease right of use assets and lease liabilities
Real estate assets - operating lease right-of-use assets	277,557
Operating lease liabilities	(286,914)
Accounts payable and accrued expenses	9,357
Acquisitions of real estate assets
Real estate assets, net	21,066	88,842	51,455
Value of Operating Partnership units issued		(1,877)	(14,428)
Notes payable assumed	(17,157)	(87,500)	(24,055)
Investment in unconsolidated real estate ventures	(2,780)	535	(12,957)
Other noncontrolling interests			(15)
Net liabilities assumed	(1,129)
Accrued construction costs and capital expenditures
Acquisition of real estate assets	2,203	778	3,509
Development and redevelopment of real estate assets	1,601	554	1,703
Accounts payable and accrued expenses	(3,804)	(1,332)	(5,212)
Contribution/Issuance of Preferred OP Units for additional investment in unconsolidated real estate venture
Investments in unconsolidated real estate ventures	(28,022)
Preferred OP Units issued	(28,022)		(4,351)
Investment in unconsolidated real estate ventures			$ 4,351
Conversion of Preferred OP Units to common OP Units
Preferred OP Units	4,374	6,851
Common OP Units	$ (4,374)	$ (6,851)

Description of Business

Description of Business	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
DESCRIPTION OF BUSINESS	DESCRIPTION OF BUSINESS Extra Space Storage Inc. (the “Company”) is a fully integrated, self-administered and self-managed real estate investment trust (“REIT”), formed as a Maryland corporation on April 30, 2004, to own, operate, manage, acquire, develop and redevelop professionally managed self-storage properties located throughout the United States. The Company was formed to continue the business of Extra Space Storage LLC and its subsidiaries, which had engaged in the self-storage business since 1977. The Company’s interest in its stores is held through its operating partnership, Extra Space Storage LP (the “Operating Partnership”), which was formed on May 5, 2004. The Company’s primary assets are general partner and limited partner interests in the Operating Partnership. This structure is commonly referred to as an umbrella partnership REIT, or UPREIT. The Company invests in stores by acquiring wholly-owned stores or by acquiring an equity interest in real estate entities. At December 31, 2019 , the Company had direct and indirect equity interests in 1,171 storage facilities. In addition, the Company managed 646 stores for third parties bringing the total number of stores which it owns and/or manages to 1,817 . These stores are located in 40 states, Washington, D.C. and Puerto Rico. The Company also offers tenant reinsurance at its owned and managed stores that insures the value of goods in the storage units.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation The consolidated financial statements are presented on the accrual basis of accounting in accordance with U.S. generally accepted accounting principles (“GAAP”) and include the accounts of the Company and its wholly- or majority-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. Variable Interest Entities The Company accounts for arrangements that are not controlled through voting or similar rights as variable interest entities (“VIEs”). An enterprise is required to consolidate a VIE if it is the primary beneficiary of the VIE. A VIE is created when (i) the equity investment at risk is not sufficient to permit the entity to finance its activities without additional subordinated financial support from other parties, or (ii) the entity’s equity holders as a group either: (a) lack the power, through voting or similar rights, to direct the activities of the entity that most significantly impact the entity’s economic performance, (b) are not obligated to absorb expected losses of the entity if they occur, or (c) do not have the right to receive expected residual returns of the entity if they occur. If an entity is deemed to be a VIE, the enterprise that is deemed to have a variable interest, or combination of variable interests, that provides the enterprise with a controlling financial interest in the VIE, is considered the primary beneficiary and must consolidate the VIE. The Company has concluded that under certain circumstances when the Company enters into arrangements for the formation of joint ventures or when entering into a new bridge loan agreement, a VIE may be created under condition (i), (ii) (b) or (c) of the previous paragraph. For each VIE created, the Company has performed a qualitative analysis, including considering which party, if any, has the power to direct the activities most significant to the economic performance of each VIE and whether that party has the obligation to absorb losses of the VIE or the right to receive benefits from the VIE that could be significant to the VIE. If the Company is determined to be the primary beneficiary of the VIE, the assets, liabilities and operations of the VIE are consolidated with the Company’s financial statements. As of December 31, 2019 and 2018 , the Company had no consolidated VIEs. Additionally, the Operating Partnership had a note payable to a trust that was a VIE under condition (ii)(a) above. Since the Operating Partnership was not the primary beneficiary of the trust, this VIE was not consolidated. The Company’s investments in real estate joint ventures, where the Company has significant influence, but not control, and joint ventures which are VIEs in which the Company is not the primary beneficiary, are recorded under the equity method of accounting on the accompanying consolidated financial statements. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Fair Value Disclosures Derivative financial instruments Currently, the Company uses interest rate swaps to manage its interest rate risk. The valuation of these instruments is determined using widely accepted valuation techniques including discounted cash flow analysis on the expected cash flows of each derivative. This analysis reflects the contractual terms of the derivatives, including the period to maturity, and uses observable market-based inputs, including interest rate curves. The fair values of interest rate swaps are determined using the market standard methodology of netting the discounted future fixed cash payments and the discounted expected variable cash receipts. The variable cash receipts are based on an expectation of future interest rates (forward curves) derived from observable market interest rate forward curves. The Company incorporates credit valuation adjustments to appropriately reflect both its own nonperformance risk and the respective counterparty’s nonperformance risk in the fair value measurements. In adjusting the fair value of its derivative contracts for the effect of nonperformance risk, the Company has considered the impact of netting and any applicable credit enhancements, such as collateral postings, thresholds, mutual puts, and guarantees. In conjunction with the Financial Accounting Standard Board’s fair value measurement guidance, the Company made an accounting policy election to measure the credit risk of its derivative financial instruments that are subject to master netting agreements on a net basis by counterparty portfolio. Although the Company has determined that the majority of the inputs used to value its derivatives fall within Level 2 of the fair value hierarchy, the credit valuation adjustments associated with its derivatives utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default by itself and its counterparties. However, as of December 31, 2019 , the Company has assessed the significance of the impact of the credit valuation adjustments on the overall valuation of its derivative positions and has determined that the credit valuation adjustments are not significant to the overall valuation of its derivatives. As a result, the Company has determined that its derivative valuations in their entirety are classified in Level 2 of the fair value hierarchy. The table below presents the Company’s assets and liabilities measured at fair value on a recurring basis as of December 31, 2019 , aggregated by the level in the fair value hierarchy within which those measurements fall. Fair Value Measurements at Reporting Date Using Description December 31, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Other assets - Cash flow hedge swap agreements $ 6,214 $ — $ 6,214 $ — Other liabilities - Cash flow hedge swap agreements $ 31,400 $ — $ 31,400 $ — There were no transfers of assets and liabilities between Level 1 and Level 2 during the year ended December 31, 2019 . The Company did not have any significant assets or liabilities that are re-measured on a recurring basis using significant unobservable inputs as of December 31, 2019 or 2018 . Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis Long-lived assets held for use are evaluated for impairment when events or circumstances indicate there may be impairment. The Company reviews each store at least annually to determine if any such events or circumstances have occurred or exist. The Company focuses on stores where occupancy and/or rental income have decreased by a significant amount. For these stores, the Company determines whether the decrease is temporary or permanent, and whether the store will likely recover the lost occupancy and/or revenue in the short term. In addition, the Company reviews stores in the lease-up stage and compares actual operating results to original projections. When the Company determines that an event that may indicate impairment has occurred, the Company compares the carrying value of the related long-lived assets to the undiscounted future net operating cash flows attributable to the assets. An impairment loss is recorded if the net carrying value of the assets exceeds the undiscounted future net operating cash flows attributable to the assets. The impairment loss recognized equals the excess of net carrying value over the related fair value of the assets. When real estate assets are identified by management as held for sale, the Company discontinues depreciating the assets and estimates the fair value of the assets, net of selling costs. The Company compares the carrying value of the related long-lived assets to the undiscounted future net operating cash flows attributable to the assets (categorized within Level 3 of the fair value hierarchy). If the estimated fair value, net of selling costs, of the assets that have been identified as held for sale is less than the net carrying value of the assets, the Company would recognize a loss on the assets held for sale. The operations of assets held for sale or sold during the period are presented as part of normal operations for all periods presented. The Company assesses annually whether there are any indicators that the value of the Company’s investments in unconsolidated real estate ventures may be impaired and when events or circumstances indicate that there may be impairment. An investment is impaired if management’s estimate of the fair value of the investment is less than its carrying value. To the extent impairment has occurred, and is considered to be other than temporary, the loss is measured as the excess of the carrying amount of the investment over the fair value of the investment. As of December 31, 2019 and 2018 , the Company did not have any assets or liabilities measured at fair value on a nonrecurring basis. Fair Value of Financial Instruments The carrying values of cash and cash equivalents, restricted cash, receivables, other financial instruments included in other assets, accounts payable and accrued expenses, variable-rate notes payable and notes receivable, revolving lines of credit and other liabilities reflected in the consolidated balance sheets at December 31, 2019 and 2018 , approximate fair value. The fair values of the Company’s notes receivable from Preferred Operating Partnership unit holders were based on the discounted estimated future cash flow of the notes (categorized within Level 3 of the fair value hierarchy); the discount rate used approximated the current market rate for loans with similar maturities and credit quality. The fair values of the Company’s fixed rate notes payable and notes payable to trusts were estimated using the discounted estimated future cash payments to be made on such debt (categorized within Level 3 of the fair value hierarchy); the discount rates used approximated current market rates for loans, or groups of loans, with similar maturities and credit quality. The fair value of the Company’s exchangeable senior notes was estimated using an average market price for similar securities obtained from a third party. The fair values of the Company’s fixed-rate assets and liabilities were as follows for the periods indicated: December 31, 2019 December 31, 2018 Fair Carrying Fair Carrying Notes receivable from Preferred and Common Operating Partnership unit holders $ 116,184 $ 118,524 $ 115,467 $ 119,735 Fixed rate notes payable and notes payable to trusts $ 3,511,151 $ 3,417,928 $ 2,985,731 $ 3,022,414 Exchangeable senior notes $ 673,831 $ 575,000 $ 620,149 $ 575,000 Real Estate Assets Real estate assets are stated at cost, less accumulated depreciation. Direct and allowable internal costs associated with the development, construction, renovation, and improvement of real estate assets are capitalized. Interest, property taxes, and other costs associated with development incurred during the construction period are capitalized. The construction period begins when expenditures for the real estate assets have been made and activities that are necessary to prepare the asset for its intended use are in progress. The construction period ends when the asset is substantially complete and ready for its intended use. Expenditures for maintenance and repairs are charged to expense as incurred. Major replacements and betterments that improve or extend the life of the asset are capitalized and depreciated over their estimated useful lives. Depreciation is computed using the straight-line method over the estimated useful lives of the buildings and improvements, which are generally between five and 39 years. Stores purchased at the time of certificate of occupancy issuance and stores purchased subsequent to the Company's adoption of ASU 2017-01 on January 1, 2017 are considered asset acquisitions. As such, the purchase price is allocated to the real estate assets acquired based on their relative fair values, which are estimated using significant unobservable inputs. The value of the tangible assets, consisting of land and buildings, is determined as if vacant. Intangible assets, which represent the value of existing tenant relationships, are recorded at their relative fair values based on the avoided cost to replace the current leases. The Company measures the value of tenant relationships based on the rent lost due to the amount of time required to replace existing customers, which is based on the Company’s historical experience with turnover in its stores. Any debt assumed as part of the acquisition is recorded at fair value based on current interest rates compared to contractual rates. Acquisition-related transactions costs are capitalized as part of the purchase price. Intangible lease rights represent: (1) purchase price amounts allocated to leases on three stores that cannot be classified as ground or building leases; these rights are amortized to expense over the life of the leases and (2) intangibles related to ground leases on eight stores where the leases were assumed by the Company at rates that were lower than the current market rates for similar leases. The values associated with these assumed leases were recorded as intangibles, which will be amortized over the lease terms. Real Estate Sales In general, sales of real estate and related profits/losses are recognized when all consideration has changed hands and risks and rewards of ownership have been transferred. Certain types of continuing involvement preclude sale treatment and related profit recognition; other forms of continuing involvement allow for sale recognition but require deferral of profit recognition. Investments in Unconsolidated Real Estate Entities The Company’s investments in real estate joint ventures, where the Company has significant influence, but not control and joint ventures which are VIEs in which the Company is not the primary beneficiary, are recorded under the equity method of accounting in the accompanying consolidated financial statements. Under the equity method, the Company’s investment in real estate ventures is stated at cost and adjusted for the Company’s share of net earnings or losses and reduced by distributions. Equity in earnings of real estate ventures is generally recognized based on the Company’s ownership interest in the earnings of each of the unconsolidated real estate ventures. For the purposes of presentation in the statement of cash flows, the Company follows the “look through” approach for classification of distributions from joint ventures. Under this approach, distributions are reported under operating cash flow unless the facts and circumstances of a specific distribution clearly indicate that it is a return of capital (e.g., a liquidating dividend or distribution of the proceeds from the joint venture’s sale of assets), in which case it is reported as an investing activity. The Company evaluated its investments in preferred stock of non-public real estate entities and determined it did not have significant influence over the entity, and the investment in preferred stock does not have a readily determinable fair value, therefore it has been recorded at the transaction price. The Company periodically evaluates the investment for impairment. No impairment indicators were noted as of December 31, 2019 . Cash and Cash Equivalents The Company’s cash is deposited with financial institutions located throughout the United States and at times may exceed federally insured limits. The Company considers all highly liquid debt instruments with a maturity date of three months or less to be cash equivalents. Restricted Cash Restricted cash is comprised of escrowed funds deposited with financial institutions located throughout the United States relating to earnest money deposits on potential acquisitions, real estate taxes, loan collateral, operating reserves and insurance and capital expenditures. Other Assets Other assets consist of equipment and fixtures, rents receivable from our tenants, bridge loan receivables, investments in trusts and other receivables, other intangible assets, deferred tax assets, prepaid expenses and the fair value of interest rate swaps. Depreciation of equipment and fixtures is computed on a straight-line basis over three to five years . Derivative Instruments and Hedging Activities The Company records all derivatives on the balance sheet at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative, whether the Company has elected to designate a derivative in a hedging relationship and apply hedge accounting and whether the hedging relationship has satisfied the criteria necessary to apply hedge accounting. Derivatives designated and qualifying as a hedge of the exposure to changes in the fair value of an asset, liability or firm commitment attributable to a particular risk, such as interest rate risk, are considered fair value hedges. Derivatives designated and qualifying as a hedge of the exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. Hedge accounting generally provides for the matching of the timing of gain or loss recognition on the hedging instrument with the recognition of the changes in the fair value of the hedged asset or liability that are attributable to the hedged risk in a fair value hedge or the earnings effect of the hedged forecasted transactions in a cash flow hedge. The Company may enter into derivative contracts that are intended to economically hedge certain of its risk, even though hedge accounting does not apply or the Company elects not to apply hedge accounting. The Company made an accounting policy election to measure the credit risk of its derivative financial instruments that are subject to master netting agreements on a net basis by counterparty portfolio. Risk Management and Use of Financial Instruments In the normal course of its ongoing business operations, the Company encounters economic risk. There are three main components of economic risk: interest rate risk, credit risk and market risk. The Company is subject to interest rate risk on its interest-bearing liabilities. Credit risk is the risk of inability or unwillingness of tenants to make contractually required payments. Market risk is the risk of declines in the value of stores due to changes in rental rates, interest rates or other market factors affecting the value of stores held by the Company. The Company has entered into interest rate swap agreements to manage a portion of its interest rate risk. Exchange of Common Operating Partnership Units Redemption of common Operating Partnership units for shares of common stock, when redeemed under the original provisions of the Operating Partnership agreement, are accounted for by reclassifying the underlying net book value of the units from noncontrolling interest to the Company’s equity. Revenue and Expense Recognition Rental revenues are recognized as earned based upon amounts that are currently due from tenants. Leases are generally on month-to-month terms. Prepaid rents are recognized on a straight-line basis over the term of the leases. Promotional discounts are recognized as a reduction to rental income over the promotional period. Late charges, administrative fees and merchandise sales are recognized as income when earned. Equity in earnings of unconsolidated real estate ventures is recognized based on the Company's ownership interest in the earnings of each of the unconsolidated real estate entities. Interest income is recognized as earned. The Company's management fees are earned subject to the terms of the related management services agreements ("MSAs"). These MSAs provide that the Company will perform management services, which include leasing and operating the property and providing accounting, marketing, banking, maintenance and other services. These services are provided in exchange for monthly management fees, which are based on a percentage of revenues collected from stores owned by third parties and unconsolidated joint ventures. MSAs generally have original terms from three to five years , after which management services are provided on a month-to-month basis unless terminated. Management fees are due on the last day of each calendar month that management services are provided. The Company accounts for the management services provided to a customer as a single performance obligation which are rendered over time each month. The total amount of consideration from the contract is variable as it is based on monthly revenues, which are influenced by multiple factors, some of which are outside the Company's control. Therefore, the Company recognizes the revenue at the end of each month once the uncertainty is resolved. Due to the standardized terms of the MSAs, the Company accounts for all MSAs in a similar, consistent manner. Therefore, no disaggregated information relating to MSAs is presented. Property expenses, including utilities, property taxes, repairs and maintenance and other costs to manage the facilities are recognized as incurred. The Company accrues for property tax expense based upon invoice amounts and estimates. If these estimates are incorrect, the timing of expense recognition could be affected. Tenant reinsurance premiums are recognized as revenue over the period of insurance coverage. The Company records an unpaid claims liability at the end of each period based on existing unpaid claims and historical claims payment history. The unpaid claims liability represents an estimate of the ultimate cost to settle all unpaid claims as of each period end, including both reported but unpaid claims and claims that may have been incurred but have not been reported. The Company uses a third party claims administrator to adjust all tenant reinsurance claims received. The administrator evaluates each claim to determine the ultimate claim loss and includes an estimate for claims that may have been incurred but not reported. Annually, a third party actuary evaluates the adequacy of the unpaid claims liability. Prior year claim reserves are adjusted as experience develops or new information becomes known. The impact of such adjustments is included in the current period operations. The unpaid claims liability is not discounted to its present value. Each tenant chooses the amount of insurance coverage they want through the tenant reinsurance program. Tenants can purchase policies in amounts of 2,000 dollars to 10,000 dollars of insurance coverage in exchange for a monthly fee. As of December 31, 2019 , the average insurance coverage for tenants was approximately 3,300 dollars. The Company’s exposure per claim is limited by the maximum amount of coverage chosen by each tenant. The Company purchases reinsurance for losses exceeding a set amount for any one event. The Company does not currently have any amounts recoverable under the reinsurance arrangements. For the years ended December 31, 2019 , 2018 and 2017 , the number of claims made were 9,059 , 8,091 and 6,214 , respectively. The following table presents information on the portion of the Company’s unpaid claims liability, which is included in other liabilities on the Company's consolidated balance sheets, that relates to tenant insurance for the periods indicated: For the Year Ended December 31, Tenant Reinsurance Claims: 2019 2018 2017 Unpaid claims liability at beginning of year $ 7,326 $ 5,167 $ 3,896 Claims and claim adjustment expense for claims incurred in the current year 16,280 15,800 11,700 Claims and claim adjustment expense (benefit) for claims incurred in the prior years 98 107 (203 ) Payments for current year claims (11,352 ) (11,010 ) (8,895 ) Payments for prior year claims (4,243 ) (2,738 ) (1,331 ) Unpaid claims liability at the end of the year $ 8,109 $ 7,326 $ 5,167 Advertising Costs The Company incurs advertising costs primarily attributable to digital and other advertising. These costs are expensed as incurred. The Company recognized $25,106 , $16,153 and $14,410 in advertising expense for the years ended December 31, 2019 , 2018 and 2017 , respectively, which are included in property operating expenses on the Company’s consolidated statements of operations. Income Taxes The Company has elected to be treated as a REIT under Sections 856 through 860 of the Internal Revenue Code of 1986, as amended (the "Internal Revenue Code"). In order to maintain its qualification as a REIT, among other things, the Company is required to distribute at least 90% of its REIT taxable income to its stockholders and meet certain tests regarding the nature of its income and assets. As a REIT, the Company is not subject to federal income tax with respect to that portion of its income which meets certain criteria and is distributed annually to stockholders. The Company plans to continue to operate so that it meets the requirements for taxation as a REIT. Many of these requirements, however, are highly technical and complex. For any taxable year that the Company fails to qualify as a REIT and for which applicable statutory relief provisions did not apply, we would be taxed at the regular corporate rates on all of our taxable income for at least that year and the ensuing four years. The Company is subject to certain state and local taxes. Provision for such taxes has been included in income tax expense on the Company’s consolidated statements of operations. For the year ended December 31, 2019 , 0% (unaudited) of all distributions to stockholders qualified as a return of capital. The Company owns and may acquire direct or indirect interests in entities that have elected or will elect to be taxed as REITs under the Internal Revenue Code (each, a “Subsidiary REIT ”). A Subsidiary REIT is subject to the various REIT qualification requirements and other limitations described herein that are applicable to the Company. If a Subsidiary REIT were to fail to qualify as a REIT, then (i) that Subsidiary REIT would become subject to U.S. federal income tax, (ii) shares in such Subsidiary REIT would cease to be qualifying assets for purposes of the asset tests applicable to REITs, and (iii) it is possible that the Company would fail certain of the asset tests applicable to REITs, in which event the Company would fail to qualify as a REIT unless it could avail itself of certain relief provisions. The Company has elected to treat its corporate subsidiary, Extra Space Management, Inc. (“ESMI”), as a taxable REIT subsidiary (“TRS”). In general, the Company’s TRS may perform additional services for tenants and may engage in any real estate or non-real estate related business. A TRS is subject to federal corporate income tax. ESM Reinsurance Limited, a wholly-owned subsidiary of ESMI, generates income from insurance premiums that are subject to federal corporate income tax and state insurance premiums tax. Deferred tax assets and liabilities are determined based on differences between financial reporting and tax bases of assets and liabilities. At December 31, 2019 and 2018 , 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 December 31, 2019 and 2018 , the Company had no interest or penalties related to uncertain tax provisions. Stock-Based Compensation The measurement and recognition of compensation expense for all share-based payment awards to employees and directors are based on estimated fair values. Awards granted are valued at fair value and any compensation expense is recognized over the service periods of each award. Earnings Per Common Share Basic earnings per common share is computed using the two-class method by dividing net income attributable to common stockholders by the weighted average number of common shares outstanding during the period. All outstanding unvested restricted stock awards contain rights to non-forfeitable dividends and participate in undistributed earnings with common stockholders; accordingly, they are considered participating securities that are included in the two-class method. Diluted earnings per common share measures the performance of the Company over the reporting period while giving effect to all potential common shares that were dilutive and outstanding during the period. The denominator includes the weighted average number of basic shares and the number of additional common shares that would have been outstanding if the potential common shares that were dilutive had been issued, and is calculated using either the two-class, treasury stock or as if-converted method, whichever is most dilutive. Potential common shares are securities (such as options, convertible debt, Series A Participating Redeemable Preferred Units (“Series A Units”), Series B Redeemable Preferred Units (“Series B Units”), Series C Convertible Redeemable Preferred Units (“Series C Units”), Series D Redeemable Preferred Units (“Series D Units” and together with the Series A Units, Series B Units and Series C Units, the “Preferred OP Units") and common Operating Partnership units (“OP Units”)) that do not have a current right to participate in earnings of the Company but could do so in the future by virtue of their option, redemption or conversion right. In computing the dilutive effect of convertible securities, net income is adjusted to add back any changes in earnings in the period associated with the convertible security. The numerator also is adjusted for the effects of any other non-discretionary changes in income or loss that would result from the assumed conversion of those potential common shares. In computing diluted earnings per common share, only potential common shares that are dilutive (those that reduce earnings per common share) are included. For the years ended December 31, 2019 , 2018 and 2017 , options to purchase approximately zero , 36,075 , and 45,286 shares of common stock, respectively, were excluded from the computation of earnings per share as their effect would have been anti-dilutive. For the purposes of computing the diluted impact of the potential exchange of the Preferred OP Units for common shares upon redemption, where the Company has the option to redeem in cash or shares and where the Company has stated the intent and ability to settle the redemption in shares, the Company divided the total liquidation value of the Preferred OP Units by the average share price of $106.57 for the year ended December 31, 2019 . The following table presents the number of weighted OP Units and Preferred OP Units, and the potential common shares, that were excluded from the computation of earnings per share as their effect would have been anti-dilutive: For the Year Ended December 31, 2019 2018 2017 Equivalent Shares (if converted) Equivalent Shares (if converted) Equivalent Shares (if converted) Series B Units 393,189 464,033 533,174 Series C Units (1) — 312,075 377,135 Series D Units 1,081,369 1,019,524 — 1,474,558 1,795,632 910,309 (1) The remainder of the Series C Units were converted to OP Units on April 25, 2019. The Operating Partnership had $575,000 of its 3.125% Exchangeable Senior Notes due 2035 (the “2015 Notes”) issued and outstanding as of December 31, 2019 . The 2015 Notes could potentially have a dilutive impact on the Company’s earnings per share calculations. The 2015 Notes are exchangeable by holders into shares of the Company’s common stock under certain circumstances per the terms of the indenture governing the 2015 Notes. The exchange price of the 2015 Notes was $91.76 per share as of December 31, 2019 , and could change over time as described in the indenture. The Company has irrevocably agreed to pay only cash for the accreted principal amount of the 2015 Notes relative to its exchange obligations, but retained the right to satisfy the exchange obligation in excess of the accreted principal amount in cash and/or common stock. Though the Company has retained that right, Accounting Standards Codification (“ASC”) 260, “Earnings per Share,” requires an assumption that shares would be used to pay the exchange obligation in excess of the accreted principal amount, and requires t

Real Estate Assets

Real Estate Assets	12 Months Ended
	Dec. 31, 2019
Real Estate [Abstract]
Real Estate Assets	REAL ESTATE ASSETS The components of real estate assets are summarized as follows: December 31, 2019 December 31, 2018 Land - operating $ 1,935,551 $ 1,825,133 Land - development 3,372 7,359 Buildings, improvements and other intangibles 7,047,654 6,743,355 Right of use asset - finance lease 8,050 — Intangible assets - tenant relationships 122,489 119,557 Intangible lease rights 12,443 12,443 9,129,559 8,707,847 Less: accumulated depreciation and amortization (1,473,852 ) (1,262,438 ) Net operating real estate assets 7,655,707 7,445,409 Real estate under development/redevelopment 41,157 46,422 Net real estate assets $ 7,696,864 $ 7,491,831 Real estate assets held for sale included in net real estate assets $ 2,947 $ 13,032 As of December 31, 2019 , the Company had one parcel of land classified as held for sale. The estimated fair value less selling costs of this asset is greater than the carrying value of the assets, and therefore no loss has been recorded related to this asset. Assets held for sale are included in the self-storage operations segment of the Company’s segment information. The Company amortizes to expense intangible assets—tenant relationships on a straight-line basis over the average period that a tenant is expected to utilize the facility (currently estimated at 18 months ). The Company amortizes to expense the intangible lease rights over the terms of the related leases. Amortization related to the tenant relationships and lease rights was $6,614 , $9,050 , and $14,349 for the years ended December 31, 2019 , 2018 and 2017 , respectively. The remaining balance of the unamortized lease rights will be amortized over the next nine to 42 years . Accumulated amortization related to intangibles was $127,712 and $121,238 as of December 31, 2019 and 2018 , respectively.

Property Acquisitions and Dispo

Property Acquisitions and Dispositions	12 Months Ended
	Dec. 31, 2019
Real Estate [Abstract]
Property Acquisitions and Dispositions	PROPERTY ACQUISITIONS AND DISPOSITIONS The following table shows the Company’s acquisitions of stores for the years ended December 31, 2019 and 2018 . The table excludes purchases of raw land or improvements made to existing assets. Consideration Paid Total Quarter Number of Stores Total Cash Paid Loan Assumed Investments in Real Estate Ventures Net Liabilities/ (Assets) Assumed Value of OP Units Issued Number of OP Units Issued Real estate assets Q4 2019 5 $ 51,278 $ 51,058 $ — $ — $ 220 $ — — $ 51,278 Q3 2019 1 16,937 16,941 — — (4 ) — — 16,937 Q2 2019 1 8,424 8,424 — — — — — 8,424 Q1 2019 14 223,740 202,890 17,157 2,780 913 — — 223,740 21 (1) $ 300,379 $ 279,313 $ 17,157 $ 2,780 $ 1,129 $ — — $ 300,379 Q4 2018 6 $ 74,852 $ 74,868 $ — $ — $ (16 ) $ — — $ 74,852 Q3 2018 6 74,694 71,989 — — 2,705 — — 74,694 Q2 2018 17 237,284 148,650 87,500 (1,024 ) 281 1,877 21,768 237,284 Q1 2018 5 70,787 70,171 — 489 127 — — 70,787 34 (2) $ 457,617 $ 365,678 $ 87,500 $ (535 ) $ 3,097 $ 1,877 21,768 $ 457,617 (1) Store acquisitions during the year ended December 31, 2019 include the acquisition of 12 stores previously held in joint ventures where the Company held a noncontrolling interest. The Company purchased its partners' remaining equity interests in the joint ventures, and the properties owned by the joint ventures became wholly owned by the Company. No gain or loss was recognized as a result of these acquisitions. (2) Store acquisitions during the year ended December 31, 2018 include the acquisition of 15 stores previously held in joint ventures where the Company held a noncontrolling interest. The Company purchased its partners' remaining equity interests in the joint ventures, and the properties owned by the joint ventures became wholly owned by the Company. No gain or loss was recognized as a result of these acquisitions. Store Disposals On April 11, 2019, the Company closed on the sale of a store located in New York that had been classified as held for sale for $11,272 in cash. The Company recorded a gain on the sale of $1,205 . On August 16, 2018, the Company sold a store located in California that had been classified as held for sale for $40,235 in cash. The Company recorded a gain on the sale of $30,671 . On November 30, 2017, the Company sold 36 stores located in various states that had been classified as held for sale for an aggregate sales price of $295,000 . The buyer of these properties was Storage Portfolio II JV, LLC ("SP II"), a newly formed joint venture in which the Company has a 10.0% equity interest. The Company recognized a gain of $118,776 related to this disposition, which represented 90.0% of the total gain. This amount is included in Gain on real estate transactions and impairment of real estate on the Company's consolidated statements of operations. The Company deferred 10.0% of the gain due to the fact that it held an equity interest in the buyer, which resulted in a reduction in the carrying value of the Company's investment in SP II. On September 13, 2017, the Company closed on the sale of a parcel of land located in New York that had been classified as held for sale for $ 19,000 in cash. This parcel of land had been written down to its fair value less selling costs during the six months ended June 30, 2017, and a loss of $3,500 was recorded. Therefore, no additional gain or loss was recorded related to this sale at the time of closing.

Investments in Unconsolidated R

Investments in Unconsolidated Real Estate Entities	12 Months Ended
	Dec. 31, 2019
Equity Method Investments and Joint Ventures [Abstract]
Investments in Unconsolidated Real Estate Entities	INVESTMENTS IN UNCONSOLIDATED REAL ESTATE ENTITIES Investments in unconsolidated real estate entities and cash distributions in unconsolidated real estate ventures represent the Company's interest in preferred stock of SmartStop Self Storage REIT, Inc. ("SmartStop") and the Company's noncontrolling interest in real estate joint ventures that own stores. The Company accounts for its investment in SmartStop preferred stock, which does not have a readily determinable fair value, at the transaction price less impairment, if any. The Company accounts for its investments in joint ventures using the equity method of accounting. The Company initially records these investments at cost and subsequently adjusts for cash contributions, distributions and net equity in income or loss, which is allocated in accordance with the provisions of the applicable partnership or joint venture agreement. In these joint ventures, the Company and the joint venture partner generally receive a preferred return on their invested capital. To the extent that cash or profits in excess of these preferred returns are generated through operations or capital transactions, the Company would receive a higher percentage of the excess cash or profits, as applicable, than its equity interest. The Company separately reports investments with net equity less than zero in cash distributions in unconsolidated real estate ventures in the consolidated balance sheets. The net equity of certain joint ventures is less than zero because distributions have exceeded the Company's investment in and share of income from these joint ventures. This is generally the result of financing distributions, capital events or operating distributions that are usually greater than net income, as net income includes non-cash charges for depreciation and amortization while distributions do not. Net Investments in unconsolidated real estate entities and cash distributions in unconsolidated real estate ventures consist of the following: Number of Stores Equity Ownership % Excess Profit % (1) December 31, 2019 2018 PRISA Self Storage LLC 85 4% 4% $ 9,133 $ 9,334 Storage Portfolio II JV LLC 36 10% 30% (4,827 ) (4,233 ) Storage Portfolio I LLC 24 34% 49% (38,345 ) (38,129 ) VRS Self Storage, LLC 16 45% 54% 17,639 18,281 ESS-NYFL JV LP 11 16% 24% 13,320 — WICNN JV LLC (3) 10 10% 25% 36,552 26,885 Extra Space Northern Properties Six LLC 10 10% 35% (2,091 ) (1,700 ) Alan Jathoo JV LLC 9 10% 10% 7,977 8,180 PR EXR Self Storage, LLC 5 25% 40% 59,391 19,841 ESS Bristol Investments LLC 8 10% 28% 3,046 2,331 GFN JV, LLC (3) 5 10% 30% 12,168 10,586 Extra Space West Two LLC (4) — 5% 40% — 3,818 Extra Space West One LLC (4) — 5% 40% — (1,038 ) Other minority owned stores 22 10-50% 19-50% 28,827 25,973 SmartStop Self Storage REIT, Inc. Preferred Stock (2) n/a n/a n/a 150,000 — Net Investments in and Cash distributions in unconsolidated real estate entities 241 $ 292,790 $ 80,129 (1) Includes pro-rata equity ownership share and promoted interest. (2) In October 2019, the Company invested $150,000 in shares of newly issued convertible preferred stock of SmartStop, with an additional commitment to purchase up to $ 50,000 of the preferred shares over the 12 months after the original purchase. The dividend rate for the preferred shares is 6.25% per annum, subject to increase after five years . The preferred shares are generally not redeemable for five years , except in the case of a change of control or initial listing of SmartStop. Dividend income from this investment is included on the management fees and other income line on the Company's consolidated statements of operations. (3) The Company had $31,500 and $10,335 of preferred equity in the WICNN JV LLC and GFN JV, LLC joint ventures, respectively, as of December 31, 2019 . The Company earns an 8.0% return on its preferred equity in these joint ventures, which has priority over other distributions. (4) In January 2019, the Company purchased its joint venture partners' interests in the Extra Space West One LLC and Extra Space West Two LLC joint ventures, which owned a total of 12 stores. The Company paid $172,505 of cash to acquire the equity interests, and subsequent to this acquisition, the Company owned 100.0% of the joint ventures and the related stores. In accordance with ASC 810, the Company reviews all of its joint venture relationships annually to ensure that there are no entities that require consolidation. As of December 31, 2019 , there were no previously unconsolidated entities that were required to be consolidated as a result of this review. The Company has entered into several new unconsolidated real estate ventures. The Company accounts for its investment in the following ventures under the equity method of accounting. Information about these new real estate ventures is summarized as follows: Number of Stores Equity ownership % Total initial investment For the Year Ended December 31, 2019 16 10.0%-50.0% $ 19,663 For the Year Ended December 31, 2018 28 10.0% -50.0% $ 63,723 For the Year Ended December 31, 2017 39 10.0% - 25.0% $ 13,341 During the year ended December 31, 2019 , the Company contributed a total of $104,338 to its joint ventures (new and existing) for the purchase of 15 operating stores and nine stores acquired at the issuance of certificate of occupancy. On April 30, 2018, the Company acquired its partner's interest in the WCOT Self Storage LLC joint venture. The Company paid cash of $115,797 and assumed a loan of $87,500 . The 14 properties owned by this joint venture became wholly-owned properties of the Company subsequent to this acquisition. Equity in earnings of unconsolidated real estate ventures consists of the following: For the Year Ended December 31, 2019 2018 2017 Equity in earnings of PRISA Self Storage LLC $ 2,327 $ 2,338 $ 2,430 Equity in earnings of Storage Portfolio II JV LLC 291 79 33 Equity in earnings of Storage Portfolio I LLC 1,809 1,886 2,684 Equity in earnings of VRS Self Storage, LLC 3,583 3,640 3,562 Equity in earnings of ESS-NYFL JV LLC (96 ) — — Equity in earnings of WICNN JV LLC 1,373 622 — Equity in earnings of Extra Space Northern Properties Six LLC 1,091 1,014 918 Equity in earnings of Alan Jathoo JV LLC (47 ) (12 ) — Equity in earnings of Bristol Investments LLC (262 ) (152 ) — Equity in earnings of GFN JV, LLC 450 22 — Equity in earnings of PR EXR Self Storage, LLC (443 ) (75 ) (105 ) Equity in earnings of WCOT Self Storage LLC — 359 1,033 Equity in earnings of Extra Space West Two LLC — 1,042 1,210 Equity in earnings of Extra Space West One LLC — 2,526 2,502 Equity in earnings of other minority owned stores 1,198 1,163 1,064 $ 11,274 $ 14,452 $ 15,331 Equity in earnings of certain of our joint ventures includes the amortization of the Company’s excess purchase price of $27,867 of these equity investments over its original basis. The excess basis is amortized over 40 years. The Company provides management services to certain joint ventures for a fee. Management fee revenues for affiliated real estate joint ventures for the years ended December 31, 2019 , 2018 and 2017 were $14,624 , $14,123 and $12,650 , respectively.

Notes Payable and Revolving Lin

Notes Payable and Revolving Lines of Credit	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Notes Payable and Revolving Lines of Credit	NOTES PAYABLE AND REVOLVING LINES OF CREDIT The components of notes payable are summarized as follows: Notes Payable December 31, 2019 December 31, 2018 Fixed Rate Variable Rate Basis Rate (2) Maturity Dates Secured fixed rate notes payable (1) $ 1,365,408 $ 2,032,414 2.53% - 6.00% September 2020 - February 2030 Secured variable rate notes payable (1) 878,093 834,835 3.01% - 3.31% Libor plus 1.3% - 1.6% April 2020 - August 2028 Unsecured fixed rate notes payable 2,052,521 990,000 2.80% - 4.39% October 2023 - October 2029 Unsecured variable rate notes payable 47,480 310,000 2.76% - 3.31% Libor plus 1.0% - 1.6% January 2025 - June 2026 Total 4,343,502 4,167,249 Less: unamortized debt issuance costs (24,529 ) (29,936 ) Total $ 4,318,973 $ 4,137,313 (1) The loans are collateralized by mortgages on real estate assets and the assignment of rents. (2) 30-day USD LIBOR On July 1, 2019, and December 20, 2019, the Company executed amendments to the credit agreement originally entered into on October 14, 2016 and amended and restated as of December 7, 2018 (the "Credit Agreement"), which sets forth the terms of the revolving credit facility and loans comprising the Company's "Credit Facility." The July 1 amendment increased total commitments in the Credit Facility by creating two new term loan tranches (the "Tranche 3 Term Loan Facility" and the "Tranche 4 Term Loan Facility"), which total $245 million and $255 million , respectively, and mature January 2025 and June 2026, respectively. The proceeds from these new tranches were used to pay off existing secured debt. The December 20th amendment changed the requirements for the Investment Grade Election and increased the limit of total maximum potential borrowings under the facility to $2.5 billion from $2.0 billion at December 31, 2018. As part of the Investment Grade Election which the company completed on December 20, 2019, on December 27, 2019, the Company released all but 4 Guarantors under the Credit Facility. At December 31, 2019, the amended Credit Facility provided for aggregate borrowings of up to $1.85 billion consisting of a senior unsecured four -year revolving credit facility of $650 million maturing January 2023 (the “Revolving Credit Facility”), a senior unsecured loan of $480 million maturing January 2024 (the "Tranche 1 Term Loan Facility”), a senior unsecured loan of $220 million maturing October 2023 (the “Tranche 2 Term Loan Facility), the Tranche 3 Term Loan Facility of $245 million , and the Tranche 4 Term Loan Facility of $255 million . The Company may request an extension of the term of the Credit Facility for up to two additional periods of six months each, after satisfying certain conditions. As of December 31, 2019, amounts outstanding under the Credit Facility bore interest at floating rates, at the Company’s option, equal to either (i) LIBOR plus the applicable Eurodollar rate margin or (ii) the applicable base rate which is the applicable margin plus the highest of (a) 0.0% , (b) the federal funds rate plus 0.50% , (c) U.S. Bank’s prime rate or (d) the Eurodollar rate plus 1.00% . Per the Credit Agreement, the applicable Eurodollar rate margin and applicable base rate margin are based on the Company’s achieved debt rating pursuant to the ‘Investment Grade Election,’ with the Eurodollar rate margin ranging from 0.75% to 2.25% per annum and the applicable base rate margin ranging from 0.0% to 1.3% per annum. The Credit Agreement is guaranteed by the Company and is not secured by any assets of the Company. The Company is subject to certain restrictive covenants relating to its outstanding debt. As of December 31, 2019, the Company was in compliance with all of its financial covenants. The following table summarizes the scheduled maturities of notes payable, excluding available extensions, at December 31, 2019 : 2020 $ 568,431 2021 252,053 2022 150,796 2023 767,405 2024 712,972 Thereafter 1,891,845 $ 4,343,502 Real estate assets are pledged as collateral for the secured loans. Of the Company’s $4,343,502 principal amount of notes payable outstanding at December 31, 2019 , $2,012,791 was recourse due to guarantees or other security provisions. All of the Company’s lines of credit are guaranteed by the Company. The following table presents information on the Company’s lines of credit, the proceeds of which are used to repay debt and for general corporate purposes, for the periods indicated: As of December 31, 2019 Revolving Lines of Credit Amount Drawn Capacity Interest Rate Origination Date Maturity Basis Rate (1) Credit Line 1 (2) $ 38,000 $ 140,000 3.2% 6/4/2010 7/1/2021 LIBOR plus 1.45% Credit Line 2 (3)(4) 120,000 650,000 2.7% 12/7/2018 1/29/2023 LIBOR plus 0.9% $ 158,000 $ 790,000 (1) 30-day USD LIBOR (2) Secured by mortgages on certain real estate assets. One two-year extension available. (3) Unsecured. Two six-month extensions available. (4) Basis Rate as of December 31, 2019. Rate is subject to change based on our investment grade rating. In September 2015, the Operating Partnership issued $575,000 of its 3.125% Exchangeable Senior Notes due 2035. Costs incurred to issue the 2015 Notes were approximately $11,992 , consisting primarily of a 2.0% underwriting fee. These costs are being amortized as an adjustment to interest expense over five years , which represents the estimated term based on the first available redemption date, and are included in exchangeable senior notes, net, in the consolidated balance sheets. The 2015 Notes are general unsecured senior obligations of the Operating Partnership and are fully guaranteed by the Company. Interest is payable on April 1 and October 1 of each year beginning April 1, 2016, until the maturity date of October 1, 2035. The Notes bear interest at 3.125% per annum and contain an exchange settlement feature, which provides that the 2015 Notes may, under certain circumstances, be exchangeable for cash (for the principal amount of the 2015 Notes) and, with respect to any excess exchange value, for cash, shares of the Company’s common stock, or a combination of cash and shares of the Company’s common stock, at the Company’s option. The exchange rate of the 2015 Notes as of December 31, 2019 was approximately 10.90 shares of the Company’s common stock per $1,000 principal amount of the 2015 Notes. The Operating Partnership may redeem the 2015 Notes at any time to preserve the Company’s status as a REIT. In addition, on or after October 5, 2020, the Operating Partnership may redeem the 2015 Notes for cash, in whole or in part, at 100% of the principal amount plus accrued and unpaid interest, upon at least 30 days but not more than 60 days prior written notice to the holders of the 2015 Notes. The holders of the 2015 Notes have the right to require the Operating Partnership to repurchase the 2015 Notes for cash, in whole or in part, on October 1 of the years 2020, 2025 and 2030, (unless the Operating Partnership has called the 2015 Notes for redemption), and upon the occurrence of certain designated events, in each case for a repurchase price equal to 100% of the principal amount of the 2015 Notes plus accrued and unpaid interest. Certain events are considered “Events of Default,” as defined in the indenture governing the 2015 Notes, which may result in the accelerated maturity of the 2015 Notes. Additionally, the 2015 Notes can be exchanged during any calendar quarter, if the last reported sale price of the common stock of the Company is greater than or equal to 130% of the exchange price for at least 20 trading days during a period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter. The price of the Company’s common stock did not exceed 130% of the exchange price for the required time period for the 2015 Notes during the quarter ended December 31, 2019. On June 21, 2013, the Operating Partnership issued $250,000 of its 2013 Notes at a 1.5% discount, or $3,750 . Costs incurred to issue the 2013 Notes were approximately $1,672 . These costs were amortized as an adjustment to interest expense over five years , which represented the estimated term based on the first available redemption date. The 2013 Notes bore interest at 2.375% per annum and contained an exchange settlement feature. The Operating Partnership redeemed all remaining outstanding 2013 Notes on July 5, 2018. GAAP requires entities with convertible debt instruments that may be settled entirely or partially in cash upon conversion to separately account for the liability and equity components of the instrument in a manner that reflects the issuer’s economic interest cost. The Company therefore accounts for the liability and equity component of the 2015 Notes separately. The equity components are included in paid-in capital in stockholders’ equity in the consolidated balance sheets, and the value of the equity components are treated as original issue discount for purposes of accounting for the debt components. The discount is being amortized as interest expense over the remaining period of the debt through its first redemption date, October 1, 2020 for the 2015 Notes. The effective interest rate on the liability components of the 2015 Notes is 4.0% , which approximates the market rate of interest of similar debt without exchange features (i.e. nonconvertible debt) at the time of issuance. Information about the 2015 Notes, including the total carrying amounts of the equity component, the principal amount of the liability component, the unamortized discount and net carrying amount, was as follows for the periods indicated: December 31, 2019 December 31, 2018 Carrying amount of equity component $ 22,597 $ 22,597 Principal amount of liability component $ 575,000 $ 575,000 Unamortized discount - equity component (3,675 ) (8,417 ) Unamortized debt issuance costs (1,812 ) (4,209 ) Net carrying amount of liability component $ 569,513 $ 562,374 The amount of interest cost recognized relating to the contractual interest rate and the amortization of the discount on the liability component for the Notes were as follows for the periods indicated: For the Year Ended December 31, 2019 2018 2017 Contractual interest $ 17,968 $ 18,106 $ 19,303 Amortization of discount 4,742 4,687 5,103 Total interest expense recognized $ 22,710 $ 22,793 $ 24,406 Repurchase of 2013 Notes During the year ended December 31, 2018, the Company repurchased a total principal amount of $49,259 of the 2013 Notes, which represented all of the remaining principal amount outstanding. The Company paid cash of $80,270 for the total of the principal amount and the exchange value in excess of the principal amount. During the year ended December 31, 2017, the Company repurchased a total principal amount of $13,911 of the 2013 Notes. The Company paid cash of $20,042 for the total of the principal amount and the exchange value in excess of the principal amount. The Company allocated the value of the consideration paid to repurchase the 2013 Notes (1) to the extinguishment of the liability component and (2) to the reacquisition of the equity component. The amount allocated to the extinguishment of the liability component is equal to the fair value of that component immediately prior to extinguishment. The difference between the consideration attributed to the extinguishment of the liability component and the sum of (a) the net carrying amount of the repurchased liability component, and (b) the related unamortized debt issuance costs, is recognized as a gain on debt extinguishment. The remaining settlement consideration is allocated to the reacquisition of the equity component of the repurchased 2013 Notes and recognized as a reduction of stockholders’ equity. Information about the repurchases is as follows: For the Year Ended December 31, 2018 2017 Principal amount repurchased $ 49,259 $ 13,911 Amount allocated to: Extinguishment of liability component $ 49,019 $ 13,692 Reacquisition of equity component 31,251 6,350 Total consideration paid for repurchase $ 80,270 $ 20,042 Exchangeable senior notes repurchased $ 49,259 $ 13,911 Extinguishment of liability component (49,019 ) (13,692 ) Discount on exchangeable senior notes (230 ) (184 ) Related debt issuance costs (10 ) (35 ) Gain/(loss) on repurchase $ — $ —

Derivatives

Derivatives	12 Months Ended
	Dec. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	DERIVATIVES The Company is exposed to certain risk arising from both its business operations and economic conditions. The Company principally manages its exposures to a wide variety of business and operational risks through management of its core business activities. The Company manages economic risks, including interest rate, liquidity, and credit risk primarily by managing the amount, sources and duration of its debt funding and the use of derivative financial instruments. Specifically, the Company enters into derivative financial instruments to manage exposures that arise from business activities that result in the receipt or payment of future known and uncertain cash amounts, the value of which are determined by interest rates. The Company’s derivative financial instruments are used to manage differences in the amount, timing and duration of the Company’s known or expected cash receipts and its known or expected cash payments principally related to the Company’s investments and borrowings. Cash Flow Hedges of Interest Rate Risk The Company’s objectives in using interest rate derivatives are to add stability to interest expense and to manage its exposure to interest rate movements. To accomplish this objective, the Company primarily uses interest rate swaps as part of its interest rate risk management strategy. Interest rate swaps designated as cash flow hedges involve the receipt of variable amounts from a counterparty in exchange for the Company making fixed-rate payments over the life of the agreements without exchange of the underlying notional amount. The effective portion of changes in the fair value of derivatives designated and that qualify as cash flow hedges is recorded in accumulated other comprehensive income (“OCI”) and is subsequently reclassified into earnings in the period that the hedged forecasted transaction affects earnings. A portion of these changes is excluded from accumulated other comprehensive income as it is allocated to noncontrolling interests. During the years ended December 31, 2019 , 2018 and 2017 , such derivatives were used to hedge the variable cash flows associated with existing variable-rate debt. During 2020 , the Company estimates that $4,374 will be reclassified as an increase to interest expense. The following table summarizes the terms of the Company’s 24 derivative financial instruments, which have a total combined notional amount of $2,354,609 as of December 31, 2019 : Hedge Product Range of Notional Amounts Strike Effective Dates Maturity Dates Swap Agreements $30,943 - $267,431 1.13% - 4.60% 1/1/2014 - 7/29/2019 9/14/2020 - 6/29/2026 Fair Values of Derivative Instruments The table below presents the fair value of the Company’s derivative financial instruments as well as their classification on the consolidated balance sheets: Asset / Liability Derivatives December 31, 2019 December 31, 2018 Derivatives designated as hedging instruments: Fair Value Other assets $ 6,214 $ 42,324 Other liabilities $ 31,400 $ 2,131 Effect of Derivative Instruments The tables below present the effect of the Company’s derivative financial instruments on the consolidated statements of operations for the periods presented. No tax effect has been presented as the derivative instruments are held by the Company: Gain (loss) recognized in OCI For the Year Ended December 31, Location of amounts reclassified from OCI into income Gain (loss) reclassified from OCI For the Year Ended December 31, Type 2019 2018 2019 2018 2017 Swap Agreements $ (54,680 ) $ 9,889 Interest expense $ 12,322 $ 8,258 $ (8,853 ) Credit-Risk-Related Contingent Features The Company has agreements with some of its derivative counterparties that contain provisions pursuant to which, the Company could be declared in default of its derivative obligations if the Company defaults on any of its indebtedness, including default where repayment of the indebtedness has not been accelerated by the lender. The Company also has an agreement with some of its derivative counterparties that incorporates the loan covenant provisions of the Company’s indebtedness with a lender affiliate of the derivative counterparty. Failure to comply with the loan covenant provisions would result in the Company being in default on any derivative instrument obligations covered by the agreement. As of December 31, 2019 , the fair value of derivatives in a net liability position, which includes accrued interest but excludes any adjustment for nonperformance risk, related to these agreements was $30,269 . As of December 31, 2019 , the Company had not posted any collateral related to these agreements. If the Company had breached any of these provisions as of December 31, 2019 , it could have been required to cash settle its obligations under these agreements at their termination value of $32,245 .

Notes Payable to Trusts

Notes Payable to Trusts	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Notes Payable to Trusts	NOTES PAYABLE TO TRUSTS During 2005, the Company's Operating Partnership formed three wholly-owned unconsolidated subsidiaries: ESS Statutory Trust I (“Trust") ESS Statutory Trust II, (“Trust II”) and ESS Statutory Trust III (“Trust III,” and together with Trust and Trust II, the "Trusts"). The Trusts issued trust preferred securities to third parties and common securities to the Operating Partnership. The Trust loaned the proceeds from the sale of the preferred and common securities to the Operating Partnership in the form of notes. The Trusts were VIEs because the holders of the equity investment at risk (that is the Trusts' preferred securities) did not have the power to direct the activities of the entities that most significantly affected the entities’ economic performance due to their lack of voting or similar rights. Because the Operating Partnership’s investment in the Trusts’ common securities was financed directly by the Trusts as a result of its loan of the proceeds to the Operating Partnership, that investment was not considered an equity investment at risk. The Operating Partnership’s investment in the Trusts was not a variable interest because equity interests are variable interests only to the extent that the investment is considered to be at risk, and therefore the Operating Partnership was not the primary beneficiary of the Trusts. Since the Company was not the primary beneficiary of the Trusts, they were not consolidated. A debt obligation was recorded in the form of notes for the proceeds as discussed above, which were owed to the Trusts. The Company had also included its investment in the Trusts’ common securities in other assets on the Company's consolidated balance sheets. During the year ended December 31, 2018, the Company repaid a total principal amount of $88,662 of the notes payable to Trusts, representing all of the notes payable to Trust III, all of the notes payable to Trust II, and all but $30,928 of the notes payable to Trust. The Trusts used the proceeds from these repayments to redeem their preferred and common securities. In January 2019, the Company repaid the remaining balance of $30,928 of notes payable to Trust. During the time they were outstanding, the Company did not provide financing or other support during the periods presented to the Trusts that it was not previously contractually obligated to provide. The Company’s maximum exposure to loss as a result of its involvement with the Trusts was equal to the total amount of the notes discussed above less the amounts of the Company’s investments in the Trusts’ common securities. The net amount was equal to the notes payable that the Trusts owed to third parties for their investments in the Trusts’ preferred securities. The Company had no consolidated VIEs during the years ended December 31, 2019 or December 31, 2018

Exchangeable Senior Notes

Exchangeable Senior Notes	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Exchangeable Senior Notes	NOTES PAYABLE AND REVOLVING LINES OF CREDIT The components of notes payable are summarized as follows: Notes Payable December 31, 2019 December 31, 2018 Fixed Rate Variable Rate Basis Rate (2) Maturity Dates Secured fixed rate notes payable (1) $ 1,365,408 $ 2,032,414 2.53% - 6.00% September 2020 - February 2030 Secured variable rate notes payable (1) 878,093 834,835 3.01% - 3.31% Libor plus 1.3% - 1.6% April 2020 - August 2028 Unsecured fixed rate notes payable 2,052,521 990,000 2.80% - 4.39% October 2023 - October 2029 Unsecured variable rate notes payable 47,480 310,000 2.76% - 3.31% Libor plus 1.0% - 1.6% January 2025 - June 2026 Total 4,343,502 4,167,249 Less: unamortized debt issuance costs (24,529 ) (29,936 ) Total $ 4,318,973 $ 4,137,313 (1) The loans are collateralized by mortgages on real estate assets and the assignment of rents. (2) 30-day USD LIBOR On July 1, 2019, and December 20, 2019, the Company executed amendments to the credit agreement originally entered into on October 14, 2016 and amended and restated as of December 7, 2018 (the "Credit Agreement"), which sets forth the terms of the revolving credit facility and loans comprising the Company's "Credit Facility." The July 1 amendment increased total commitments in the Credit Facility by creating two new term loan tranches (the "Tranche 3 Term Loan Facility" and the "Tranche 4 Term Loan Facility"), which total $245 million and $255 million , respectively, and mature January 2025 and June 2026, respectively. The proceeds from these new tranches were used to pay off existing secured debt. The December 20th amendment changed the requirements for the Investment Grade Election and increased the limit of total maximum potential borrowings under the facility to $2.5 billion from $2.0 billion at December 31, 2018. As part of the Investment Grade Election which the company completed on December 20, 2019, on December 27, 2019, the Company released all but 4 Guarantors under the Credit Facility. At December 31, 2019, the amended Credit Facility provided for aggregate borrowings of up to $1.85 billion consisting of a senior unsecured four -year revolving credit facility of $650 million maturing January 2023 (the “Revolving Credit Facility”), a senior unsecured loan of $480 million maturing January 2024 (the "Tranche 1 Term Loan Facility”), a senior unsecured loan of $220 million maturing October 2023 (the “Tranche 2 Term Loan Facility), the Tranche 3 Term Loan Facility of $245 million , and the Tranche 4 Term Loan Facility of $255 million . The Company may request an extension of the term of the Credit Facility for up to two additional periods of six months each, after satisfying certain conditions. As of December 31, 2019, amounts outstanding under the Credit Facility bore interest at floating rates, at the Company’s option, equal to either (i) LIBOR plus the applicable Eurodollar rate margin or (ii) the applicable base rate which is the applicable margin plus the highest of (a) 0.0% , (b) the federal funds rate plus 0.50% , (c) U.S. Bank’s prime rate or (d) the Eurodollar rate plus 1.00% . Per the Credit Agreement, the applicable Eurodollar rate margin and applicable base rate margin are based on the Company’s achieved debt rating pursuant to the ‘Investment Grade Election,’ with the Eurodollar rate margin ranging from 0.75% to 2.25% per annum and the applicable base rate margin ranging from 0.0% to 1.3% per annum. The Credit Agreement is guaranteed by the Company and is not secured by any assets of the Company. The Company is subject to certain restrictive covenants relating to its outstanding debt. As of December 31, 2019, the Company was in compliance with all of its financial covenants. The following table summarizes the scheduled maturities of notes payable, excluding available extensions, at December 31, 2019 : 2020 $ 568,431 2021 252,053 2022 150,796 2023 767,405 2024 712,972 Thereafter 1,891,845 $ 4,343,502 Real estate assets are pledged as collateral for the secured loans. Of the Company’s $4,343,502 principal amount of notes payable outstanding at December 31, 2019 , $2,012,791 was recourse due to guarantees or other security provisions. All of the Company’s lines of credit are guaranteed by the Company. The following table presents information on the Company’s lines of credit, the proceeds of which are used to repay debt and for general corporate purposes, for the periods indicated: As of December 31, 2019 Revolving Lines of Credit Amount Drawn Capacity Interest Rate Origination Date Maturity Basis Rate (1) Credit Line 1 (2) $ 38,000 $ 140,000 3.2% 6/4/2010 7/1/2021 LIBOR plus 1.45% Credit Line 2 (3)(4) 120,000 650,000 2.7% 12/7/2018 1/29/2023 LIBOR plus 0.9% $ 158,000 $ 790,000 (1) 30-day USD LIBOR (2) Secured by mortgages on certain real estate assets. One two-year extension available. (3) Unsecured. Two six-month extensions available. (4) Basis Rate as of December 31, 2019. Rate is subject to change based on our investment grade rating. In September 2015, the Operating Partnership issued $575,000 of its 3.125% Exchangeable Senior Notes due 2035. Costs incurred to issue the 2015 Notes were approximately $11,992 , consisting primarily of a 2.0% underwriting fee. These costs are being amortized as an adjustment to interest expense over five years , which represents the estimated term based on the first available redemption date, and are included in exchangeable senior notes, net, in the consolidated balance sheets. The 2015 Notes are general unsecured senior obligations of the Operating Partnership and are fully guaranteed by the Company. Interest is payable on April 1 and October 1 of each year beginning April 1, 2016, until the maturity date of October 1, 2035. The Notes bear interest at 3.125% per annum and contain an exchange settlement feature, which provides that the 2015 Notes may, under certain circumstances, be exchangeable for cash (for the principal amount of the 2015 Notes) and, with respect to any excess exchange value, for cash, shares of the Company’s common stock, or a combination of cash and shares of the Company’s common stock, at the Company’s option. The exchange rate of the 2015 Notes as of December 31, 2019 was approximately 10.90 shares of the Company’s common stock per $1,000 principal amount of the 2015 Notes. The Operating Partnership may redeem the 2015 Notes at any time to preserve the Company’s status as a REIT. In addition, on or after October 5, 2020, the Operating Partnership may redeem the 2015 Notes for cash, in whole or in part, at 100% of the principal amount plus accrued and unpaid interest, upon at least 30 days but not more than 60 days prior written notice to the holders of the 2015 Notes. The holders of the 2015 Notes have the right to require the Operating Partnership to repurchase the 2015 Notes for cash, in whole or in part, on October 1 of the years 2020, 2025 and 2030, (unless the Operating Partnership has called the 2015 Notes for redemption), and upon the occurrence of certain designated events, in each case for a repurchase price equal to 100% of the principal amount of the 2015 Notes plus accrued and unpaid interest. Certain events are considered “Events of Default,” as defined in the indenture governing the 2015 Notes, which may result in the accelerated maturity of the 2015 Notes. Additionally, the 2015 Notes can be exchanged during any calendar quarter, if the last reported sale price of the common stock of the Company is greater than or equal to 130% of the exchange price for at least 20 trading days during a period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter. The price of the Company’s common stock did not exceed 130% of the exchange price for the required time period for the 2015 Notes during the quarter ended December 31, 2019. On June 21, 2013, the Operating Partnership issued $250,000 of its 2013 Notes at a 1.5% discount, or $3,750 . Costs incurred to issue the 2013 Notes were approximately $1,672 . These costs were amortized as an adjustment to interest expense over five years , which represented the estimated term based on the first available redemption date. The 2013 Notes bore interest at 2.375% per annum and contained an exchange settlement feature. The Operating Partnership redeemed all remaining outstanding 2013 Notes on July 5, 2018. GAAP requires entities with convertible debt instruments that may be settled entirely or partially in cash upon conversion to separately account for the liability and equity components of the instrument in a manner that reflects the issuer’s economic interest cost. The Company therefore accounts for the liability and equity component of the 2015 Notes separately. The equity components are included in paid-in capital in stockholders’ equity in the consolidated balance sheets, and the value of the equity components are treated as original issue discount for purposes of accounting for the debt components. The discount is being amortized as interest expense over the remaining period of the debt through its first redemption date, October 1, 2020 for the 2015 Notes. The effective interest rate on the liability components of the 2015 Notes is 4.0% , which approximates the market rate of interest of similar debt without exchange features (i.e. nonconvertible debt) at the time of issuance. Information about the 2015 Notes, including the total carrying amounts of the equity component, the principal amount of the liability component, the unamortized discount and net carrying amount, was as follows for the periods indicated: December 31, 2019 December 31, 2018 Carrying amount of equity component $ 22,597 $ 22,597 Principal amount of liability component $ 575,000 $ 575,000 Unamortized discount - equity component (3,675 ) (8,417 ) Unamortized debt issuance costs (1,812 ) (4,209 ) Net carrying amount of liability component $ 569,513 $ 562,374 The amount of interest cost recognized relating to the contractual interest rate and the amortization of the discount on the liability component for the Notes were as follows for the periods indicated: For the Year Ended December 31, 2019 2018 2017 Contractual interest $ 17,968 $ 18,106 $ 19,303 Amortization of discount 4,742 4,687 5,103 Total interest expense recognized $ 22,710 $ 22,793 $ 24,406 Repurchase of 2013 Notes During the year ended December 31, 2018, the Company repurchased a total principal amount of $49,259 of the 2013 Notes, which represented all of the remaining principal amount outstanding. The Company paid cash of $80,270 for the total of the principal amount and the exchange value in excess of the principal amount. During the year ended December 31, 2017, the Company repurchased a total principal amount of $13,911 of the 2013 Notes. The Company paid cash of $20,042 for the total of the principal amount and the exchange value in excess of the principal amount. The Company allocated the value of the consideration paid to repurchase the 2013 Notes (1) to the extinguishment of the liability component and (2) to the reacquisition of the equity component. The amount allocated to the extinguishment of the liability component is equal to the fair value of that component immediately prior to extinguishment. The difference between the consideration attributed to the extinguishment of the liability component and the sum of (a) the net carrying amount of the repurchased liability component, and (b) the related unamortized debt issuance costs, is recognized as a gain on debt extinguishment. The remaining settlement consideration is allocated to the reacquisition of the equity component of the repurchased 2013 Notes and recognized as a reduction of stockholders’ equity. Information about the repurchases is as follows: For the Year Ended December 31, 2018 2017 Principal amount repurchased $ 49,259 $ 13,911 Amount allocated to: Extinguishment of liability component $ 49,019 $ 13,692 Reacquisition of equity component 31,251 6,350 Total consideration paid for repurchase $ 80,270 $ 20,042 Exchangeable senior notes repurchased $ 49,259 $ 13,911 Extinguishment of liability component (49,019 ) (13,692 ) Discount on exchangeable senior notes (230 ) (184 ) Related debt issuance costs (10 ) (35 ) Gain/(loss) on repurchase $ — $ —

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Stockholders' Equity	STOCKHOLDERS’ EQUITY The Company’s charter provides that it can issue up to 500,000,000 shares of common stock, $0.01 par value per share and 50,000,000 shares of preferred stock, $0.01 par value per share. As of December 31, 2019 , 129,534,407 shares of common stock were issued and outstanding, and no shares of preferred stock were issued or outstanding. All holders of the Company's common stock are entitled to receive dividends and to one vote on all matters submitted to a vote of stockholders. The transfer agent and registrar for the Company’s common stock is American Stock Transfer & Trust Company. On May 15, 2019, the Company filed its current $500,000 "at the market" equity program with the Securities and Exchange Commission using a shelf registration statement on Form S-3, and entered into separate equity distribution agreements with nine sales agents. Under the terms of the current equity distribution agreements, the Company may from time to time offer and sell shares of common stock, up to the aggregate offering price of $500,000 , through its sales agents. During the year ended December 31, 2019 , the Company sold 1,779,200 shares of common stock under its "at the market" equity program at an average sales price of $113.19 per share, resulting in net proceeds of $198,827 . At December 31, 2019 , the Company had $298,621 available for issuance under the current equity distribution agreements. During the year ended December 31, 2018 , the Company sold 933,789 shares of common stock under its prior "at the market" equity program at an average sales price of $97.93 per share, resulting in net proceeds of $90,531

Noncontrolling Interest Represe

Noncontrolling Interest Represented By Preferred Operating Partnership Units	12 Months Ended
	Dec. 31, 2019
Noncontrolling Interest [Abstract]
Noncontrolling Interest Represented By Preferred Operating Partnership Units	NONCONTROLLING INTEREST REPRESENTED BY PREFERRED OPERATING PARTNERSHIP UNITS Classification of Noncontrolling Interests GAAP requires a company to present ownership interests in subsidiaries held by parties other than the company in the consolidated financial statements within the equity section, but separate from the company’s equity. It also requires the amount of consolidated net income attributable to the parent and to the noncontrolling interest to be clearly identified and presented on the face of the consolidated statement of operations and requires changes in ownership interest to be accounted for similarly as equity transactions. If noncontrolling interests are determined to be redeemable, they are to be carried at their redemption value as of the balance sheet date and reported as temporary equity. The Company has evaluated the terms of the Operating Partnership’s preferred units and classifies the noncontrolling interest represented by such preferred units as stockholders’ equity in the accompanying consolidated balance sheets. The Company will periodically evaluate individual noncontrolling interests for the ability to continue to recognize the noncontrolling amount as permanent equity in the consolidated balance sheets. Any noncontrolling interests that fail to qualify as permanent equity will be reclassified as temporary equity and adjusted to the greater of (1) the carrying amount, or (2) its redemption value as of the end of the period in which the determination is made. At December 31, 2019 and 2018 , the noncontrolling interests represented by the Preferred OP Units qualified for classification as permanent equity on the Company's consolidated balance sheets. The partnership agreement of the Operating Partnership (as amended, the "Partnership Agreement") provides for the designation and issuance of the OP Units. Noncontrolling interests in Preferred OP Units were presented net of notes receivable from preferred Operating Partnership unit holders of $100,000 and $108,644 as of December 31, 2019 and 2018 , respectively, as more fully described below. Series A Participating Redeemable Preferred Units The Series A Units were issued in June 2007. Series A Units in the amount of $101,700 bear a fixed priority return of 2.3% , and originally had a fixed liquidation value of $115,000 . The remaining balance participates in distributions with, and has a liquidation value equal to, that of the common OP Units. The Series A Units became redeemable at the option of the holder on September 1, 2008, which redemption obligation may be satisfied, at the Company’s option, in cash or shares of its common stock. As a result of the redemption of 114,500 Series A Units in October 2014, the remaining fixed liquidation value was reduced to $101,700 which represents 875,480 Series A Units. On April 18, 2017, the holder of the Series A Units and the Operating Partnership agreed to reduce the fixed priority return on the Series A Units from 5.0% to 2.3% in exchange for a reduction in the interest rate of the related loan, as more fully described below. The Partnership Agreement provides for the designation and issuance of the Series A Units. The Series A Units have priority over all other partnership interests of the Operating Partnership with respect to distributions and liquidation. On June 25, 2007, the Operating Partnership loaned the holders of the Series A Units $100,000 . The note receivable bears interest at 2.1% . On April 18, 2017, a loan amendment was signed modifying the maturity date of the loan to the later of the death of the Series A Unit holder or his spouse and also lowering the interest rate of the loan from 4.9% to 2.1% . The loan amendment was determined to be a loan modification under GAAP, and therefore no change in value was recognized. The loan is secured by the borrower’s Series A Units. No future redemption of Series A Units can be made unless the loan secured by the Series A Units is also repaid. The Series A Units are shown on the balance sheet net of the $100,000 loan because the borrower under the loan is also the holder of the Series A Units. Series B Redeemable Preferred Units The Partnership Agreement provides for the designation and issuance of the Series B Units. The Series B Units rank junior to the Series A Units, on parity with the Series C Units and Series D Units, and senior to all other partnership interests of the Operating Partnership with respect to distributions and liquidation. The Series B Units were issued in 2013 and 2014 and have a liquidation value of $25.00 per unit for a current fixed liquidation value of $41,902 which represents 1,676,087 Series B Units. Holders of the Series B Units receive distributions at an annual rate of 6.0% . These distributions are cumulative. The Series B Units are redeemable at the option of the holder on the first anniversary of the date of issuance, which redemption obligations may be satisfied at the Company’s option in cash or shares of its common stock. The Series B Units rank junior to the Series A Units, on parity with the Series C Units and Series D Units, and senior to all other partnership interests of the Operating Partnership with respect to distributions and liquidation. Series C Convertible Redeemable Preferred Units The Partnership Agreement provides for the designation and issuance of the Series C Units. The Series C Units rank junior to the Series A Units, on parity with the Series B Units and Series D Units, and senior to all other partnership interests of the Operating Partnership with respect to distributions and liquidation. The Series C Units were issued in 2013 and 2014 and had a liquidation value of $42.10 per unit. From issuance to the fifth anniversary of issuance, each Series C Unit holder received quarterly distributions equal to the quarterly distribution for common OP Unit plus $0.18 . These distributions were cumulative. The Series C Units became redeemable at the option of the holder one year from the date of issuance, which redemption obligation could be satisfied at the Company’s option in cash or shares of its common stock. The Series C Units were convertible into common OP Units at the option of the holder one year from the date of issuance, at a rate of 0.9145 common OP Units per Series C Unit converted. This conversion option expired upon the fifth anniversary of the date of issuance. In December 2014, the Operating Partnership loaned holders of the Series C Units $20,230 . The note receivable, which was collateralized by the Series C Units, bears interest at 5.0% and matures on December 15, 2024. The Series C Units were shown on the balance sheet net of the loan because the borrower under the loan receivable was also the holder of the Series C Units. On December 1, 2018, certain holders of the Series C Units converted their Series C Units into common OP Units, with a total of 407,996 Series C Units being converted into a total of 373,113 common OP Units. As part of this conversion, the holders of the Series C Units agreed to pledge the common OP Units received in the conversion as collateral on the loan receivable to replace the Series C Units that were converted. As of December 31, 2018, the total outstanding balance of the loan receivable was $19,735 , of which $8,644 was shown as a reduction of the noncontrolling interests related to the Series C Units and $11,091 was shown as a reduction of the noncontrolling interests related to the common OP Units on the Company's consolidated balance sheets. On April 25, 2019, the remaining 296,020 Series C Units were converted into 270,709 OP Units. The remaining outstanding balance of the loan receivable of $18,524 is shown as a reduction of the noncontrolling interests related to the OP Units as of December 31, 2019 . See footnote 12 for further discussion of noncontrolling interests. Series D Redeemable Preferred Units The Partnership Agreement provides for the designation and issuance of the Series D Units. The Series D Units rank junior to the Series A Units, on parity with the Series B Units and Series C Units, and senior to all other partnership interest of the Operating Partnership with respect to distributions and liquidation. The Series D Units have been issued at various times from 2014 to 2019. During the year ended December 31, 2019, the Operating Partnership issued a total of 1,120,924 Series D Units valued at $28,023 in conjunction with joint venture acquisitions. During the year ended December 31, 2017, the Operating Partnership issued 446,420 Series D Units valued at $11,161 in conjunction with wholly-owned and joint venture acquisitions. The Series D Units have a liquidation value of $25.00 per unit, for a current fixed liquidation value of $120,086 which represents 4,803,445 Series D Units. Holders of the Series D Units receive distributions at an annual rate between 3.0% and 5.0% . These distributions are cumulative. The Series D Units will become redeemable at the option of the holder on the first anniversary of the date of issuance, which redemption obligation may be satisfied at the Company’s option in cash or shares of its common stock. In addition, certain of the Series D Units are exchangeable for common OP Units until the tenth anniversary of the date of issuance, with the number of common OP Units to be issued equal to $25.00 per Series D Unit, divided by the value of a share of common stock as of the exchange date. NONCONTROLLING INTEREST IN OPERATING PARTNERSHIP AND OTHER NONCONTROLLING INTERESTS Noncontrolling interest in Operating Partnership The Company’s interest in its stores is held through the Operating Partnership. Between its general partner and limited partner interests, the Company held a 90.7% majority ownership interest therein as of December 31, 2019 . The remaining ownership interests in the Operating Partnership (including Preferred OP Units) of 9.3% are held by certain former owners of assets acquired by the Operating Partnership. The noncontrolling interest in the Operating Partnership represents OP Units that are not owned by the Company. OP Units are redeemable at the option of the holder, which redemption may be satisfied at the Company's option in cash based upon the fair market value of an equivalent number of shares of the Company’s common stock (based on the ten -day average trading price) at the time of the redemption. Alternatively, the Company may, at its sole discretion, elect to acquire those OP Units in exchange for shares of its common stock on a one-for-one basis , subject to anti-dilution adjustments provided in the Operating Partnership agreement. The ten -day average closing stock price at December 31, 2019 , was $104.18 and there were 5,924,778 OP Units outstanding. Assuming that all of the OP Unit holders exercised their right to redeem all of their OP Units on December 31, 2019 and the Company elected to pay the OP Unit holders cash, the Company would have paid $617,243 in cash consideration to redeem the units. OP Unit activity is summarized as follows for the periods presented: For the Year Ended December 31, 2019 2018 2017 OP Units redeemed for common stock 340,182 35,000 — OP Units redeemed for cash — 30,000 33,896 Cash paid for OP Units redeemed $ — $ 2,558 $ 2,510 OP Units issued in conjunction with acquisitions — 21,768 90,228 Value of OP Units issued in conjunction with acquisitions $ — $ 1,877 $ 7,618 OP Units issued upon redemption of Series C Units 270,709 373,113 — On December 1, 2018, 373,113 common OP Units were issued in the conversion of 407,996 Series C Units. These newly issued OP Units were pledged as collateral on the existing loan receivable to the Series C Unit holders. As a result, noncontrolling interests in the Operating Partnership was reported net of $11,091 of the loan receivable as of December 31, 2018, which represents the portion of the note receivable that is collateralized by the OP Units. The remaining 296,020 Series C Units were converted into 270,709 OP Units on April 25, 2019 and the remainder of the loan receivable was reported net with the OP Units. The remaining total outstanding balance of the loan receivable of $18,524 is shown as a reduction of the noncontrolling interests related to the OP Units as of December 31, 2019. GAAP requires a company to present ownership interests in subsidiaries held by parties other than the company in the consolidated financial statements within the equity section but separate from the company’s equity. It also requires the amount of consolidated net income attributable to the parent and to the noncontrolling interest to be clearly identified and presented on the face of the consolidated statement of operations and requires changes in ownership interest to be accounted for similarly as equity transactions. If noncontrolling interests are determined to be redeemable, they are to be carried at their redemption value as of the balance sheet date and reported as temporary equity. The Company has evaluated the terms of the common OP Units and classifies the noncontrolling interest represented by the common OP Units as stockholders’ equity in the accompanying consolidated balance sheets. The Company will periodically evaluate individual noncontrolling interests for the ability to continue to recognize the noncontrolling amount as permanent equity in the consolidated balance sheets. Any noncontrolling interests that fail to qualify as permanent equity will be reclassified as temporary equity and adjusted to the greater of (1) the carrying amount, or (2) its redemption value as of the end of the period in which the determination is made. Other Noncontrolling Interests Other noncontrolling interests represent the ownership interest of third parties in two consolidated joint ventures as of December 31, 2019 . One joint venture owns two operating stores in Texas and two operating stores in Colorado, and the other owns an operating store in Pennsylvania and a development property in New Jersey. The voting interests of the third-party owners are between 5.0% and 20.0%

Noncontrolling Interests In Ope

Noncontrolling Interests In Operating Partnership and Other Noncontrolling Interests	12 Months Ended
	Dec. 31, 2019
Noncontrolling Interest [Abstract]
Noncontrolling Interests In Operating Partnership and Other Noncontrolling Interests	NONCONTROLLING INTEREST REPRESENTED BY PREFERRED OPERATING PARTNERSHIP UNITS Classification of Noncontrolling Interests GAAP requires a company to present ownership interests in subsidiaries held by parties other than the company in the consolidated financial statements within the equity section, but separate from the company’s equity. It also requires the amount of consolidated net income attributable to the parent and to the noncontrolling interest to be clearly identified and presented on the face of the consolidated statement of operations and requires changes in ownership interest to be accounted for similarly as equity transactions. If noncontrolling interests are determined to be redeemable, they are to be carried at their redemption value as of the balance sheet date and reported as temporary equity. The Company has evaluated the terms of the Operating Partnership’s preferred units and classifies the noncontrolling interest represented by such preferred units as stockholders’ equity in the accompanying consolidated balance sheets. The Company will periodically evaluate individual noncontrolling interests for the ability to continue to recognize the noncontrolling amount as permanent equity in the consolidated balance sheets. Any noncontrolling interests that fail to qualify as permanent equity will be reclassified as temporary equity and adjusted to the greater of (1) the carrying amount, or (2) its redemption value as of the end of the period in which the determination is made. At December 31, 2019 and 2018 , the noncontrolling interests represented by the Preferred OP Units qualified for classification as permanent equity on the Company's consolidated balance sheets. The partnership agreement of the Operating Partnership (as amended, the "Partnership Agreement") provides for the designation and issuance of the OP Units. Noncontrolling interests in Preferred OP Units were presented net of notes receivable from preferred Operating Partnership unit holders of $100,000 and $108,644 as of December 31, 2019 and 2018 , respectively, as more fully described below. Series A Participating Redeemable Preferred Units The Series A Units were issued in June 2007. Series A Units in the amount of $101,700 bear a fixed priority return of 2.3% , and originally had a fixed liquidation value of $115,000 . The remaining balance participates in distributions with, and has a liquidation value equal to, that of the common OP Units. The Series A Units became redeemable at the option of the holder on September 1, 2008, which redemption obligation may be satisfied, at the Company’s option, in cash or shares of its common stock. As a result of the redemption of 114,500 Series A Units in October 2014, the remaining fixed liquidation value was reduced to $101,700 which represents 875,480 Series A Units. On April 18, 2017, the holder of the Series A Units and the Operating Partnership agreed to reduce the fixed priority return on the Series A Units from 5.0% to 2.3% in exchange for a reduction in the interest rate of the related loan, as more fully described below. The Partnership Agreement provides for the designation and issuance of the Series A Units. The Series A Units have priority over all other partnership interests of the Operating Partnership with respect to distributions and liquidation. On June 25, 2007, the Operating Partnership loaned the holders of the Series A Units $100,000 . The note receivable bears interest at 2.1% . On April 18, 2017, a loan amendment was signed modifying the maturity date of the loan to the later of the death of the Series A Unit holder or his spouse and also lowering the interest rate of the loan from 4.9% to 2.1% . The loan amendment was determined to be a loan modification under GAAP, and therefore no change in value was recognized. The loan is secured by the borrower’s Series A Units. No future redemption of Series A Units can be made unless the loan secured by the Series A Units is also repaid. The Series A Units are shown on the balance sheet net of the $100,000 loan because the borrower under the loan is also the holder of the Series A Units. Series B Redeemable Preferred Units The Partnership Agreement provides for the designation and issuance of the Series B Units. The Series B Units rank junior to the Series A Units, on parity with the Series C Units and Series D Units, and senior to all other partnership interests of the Operating Partnership with respect to distributions and liquidation. The Series B Units were issued in 2013 and 2014 and have a liquidation value of $25.00 per unit for a current fixed liquidation value of $41,902 which represents 1,676,087 Series B Units. Holders of the Series B Units receive distributions at an annual rate of 6.0% . These distributions are cumulative. The Series B Units are redeemable at the option of the holder on the first anniversary of the date of issuance, which redemption obligations may be satisfied at the Company’s option in cash or shares of its common stock. The Series B Units rank junior to the Series A Units, on parity with the Series C Units and Series D Units, and senior to all other partnership interests of the Operating Partnership with respect to distributions and liquidation. Series C Convertible Redeemable Preferred Units The Partnership Agreement provides for the designation and issuance of the Series C Units. The Series C Units rank junior to the Series A Units, on parity with the Series B Units and Series D Units, and senior to all other partnership interests of the Operating Partnership with respect to distributions and liquidation. The Series C Units were issued in 2013 and 2014 and had a liquidation value of $42.10 per unit. From issuance to the fifth anniversary of issuance, each Series C Unit holder received quarterly distributions equal to the quarterly distribution for common OP Unit plus $0.18 . These distributions were cumulative. The Series C Units became redeemable at the option of the holder one year from the date of issuance, which redemption obligation could be satisfied at the Company’s option in cash or shares of its common stock. The Series C Units were convertible into common OP Units at the option of the holder one year from the date of issuance, at a rate of 0.9145 common OP Units per Series C Unit converted. This conversion option expired upon the fifth anniversary of the date of issuance. In December 2014, the Operating Partnership loaned holders of the Series C Units $20,230 . The note receivable, which was collateralized by the Series C Units, bears interest at 5.0% and matures on December 15, 2024. The Series C Units were shown on the balance sheet net of the loan because the borrower under the loan receivable was also the holder of the Series C Units. On December 1, 2018, certain holders of the Series C Units converted their Series C Units into common OP Units, with a total of 407,996 Series C Units being converted into a total of 373,113 common OP Units. As part of this conversion, the holders of the Series C Units agreed to pledge the common OP Units received in the conversion as collateral on the loan receivable to replace the Series C Units that were converted. As of December 31, 2018, the total outstanding balance of the loan receivable was $19,735 , of which $8,644 was shown as a reduction of the noncontrolling interests related to the Series C Units and $11,091 was shown as a reduction of the noncontrolling interests related to the common OP Units on the Company's consolidated balance sheets. On April 25, 2019, the remaining 296,020 Series C Units were converted into 270,709 OP Units. The remaining outstanding balance of the loan receivable of $18,524 is shown as a reduction of the noncontrolling interests related to the OP Units as of December 31, 2019 . See footnote 12 for further discussion of noncontrolling interests. Series D Redeemable Preferred Units The Partnership Agreement provides for the designation and issuance of the Series D Units. The Series D Units rank junior to the Series A Units, on parity with the Series B Units and Series C Units, and senior to all other partnership interest of the Operating Partnership with respect to distributions and liquidation. The Series D Units have been issued at various times from 2014 to 2019. During the year ended December 31, 2019, the Operating Partnership issued a total of 1,120,924 Series D Units valued at $28,023 in conjunction with joint venture acquisitions. During the year ended December 31, 2017, the Operating Partnership issued 446,420 Series D Units valued at $11,161 in conjunction with wholly-owned and joint venture acquisitions. The Series D Units have a liquidation value of $25.00 per unit, for a current fixed liquidation value of $120,086 which represents 4,803,445 Series D Units. Holders of the Series D Units receive distributions at an annual rate between 3.0% and 5.0% . These distributions are cumulative. The Series D Units will become redeemable at the option of the holder on the first anniversary of the date of issuance, which redemption obligation may be satisfied at the Company’s option in cash or shares of its common stock. In addition, certain of the Series D Units are exchangeable for common OP Units until the tenth anniversary of the date of issuance, with the number of common OP Units to be issued equal to $25.00 per Series D Unit, divided by the value of a share of common stock as of the exchange date. NONCONTROLLING INTEREST IN OPERATING PARTNERSHIP AND OTHER NONCONTROLLING INTERESTS Noncontrolling interest in Operating Partnership The Company’s interest in its stores is held through the Operating Partnership. Between its general partner and limited partner interests, the Company held a 90.7% majority ownership interest therein as of December 31, 2019 . The remaining ownership interests in the Operating Partnership (including Preferred OP Units) of 9.3% are held by certain former owners of assets acquired by the Operating Partnership. The noncontrolling interest in the Operating Partnership represents OP Units that are not owned by the Company. OP Units are redeemable at the option of the holder, which redemption may be satisfied at the Company's option in cash based upon the fair market value of an equivalent number of shares of the Company’s common stock (based on the ten -day average trading price) at the time of the redemption. Alternatively, the Company may, at its sole discretion, elect to acquire those OP Units in exchange for shares of its common stock on a one-for-one basis , subject to anti-dilution adjustments provided in the Operating Partnership agreement. The ten -day average closing stock price at December 31, 2019 , was $104.18 and there were 5,924,778 OP Units outstanding. Assuming that all of the OP Unit holders exercised their right to redeem all of their OP Units on December 31, 2019 and the Company elected to pay the OP Unit holders cash, the Company would have paid $617,243 in cash consideration to redeem the units. OP Unit activity is summarized as follows for the periods presented: For the Year Ended December 31, 2019 2018 2017 OP Units redeemed for common stock 340,182 35,000 — OP Units redeemed for cash — 30,000 33,896 Cash paid for OP Units redeemed $ — $ 2,558 $ 2,510 OP Units issued in conjunction with acquisitions — 21,768 90,228 Value of OP Units issued in conjunction with acquisitions $ — $ 1,877 $ 7,618 OP Units issued upon redemption of Series C Units 270,709 373,113 — On December 1, 2018, 373,113 common OP Units were issued in the conversion of 407,996 Series C Units. These newly issued OP Units were pledged as collateral on the existing loan receivable to the Series C Unit holders. As a result, noncontrolling interests in the Operating Partnership was reported net of $11,091 of the loan receivable as of December 31, 2018, which represents the portion of the note receivable that is collateralized by the OP Units. The remaining 296,020 Series C Units were converted into 270,709 OP Units on April 25, 2019 and the remainder of the loan receivable was reported net with the OP Units. The remaining total outstanding balance of the loan receivable of $18,524 is shown as a reduction of the noncontrolling interests related to the OP Units as of December 31, 2019. GAAP requires a company to present ownership interests in subsidiaries held by parties other than the company in the consolidated financial statements within the equity section but separate from the company’s equity. It also requires the amount of consolidated net income attributable to the parent and to the noncontrolling interest to be clearly identified and presented on the face of the consolidated statement of operations and requires changes in ownership interest to be accounted for similarly as equity transactions. If noncontrolling interests are determined to be redeemable, they are to be carried at their redemption value as of the balance sheet date and reported as temporary equity. The Company has evaluated the terms of the common OP Units and classifies the noncontrolling interest represented by the common OP Units as stockholders’ equity in the accompanying consolidated balance sheets. The Company will periodically evaluate individual noncontrolling interests for the ability to continue to recognize the noncontrolling amount as permanent equity in the consolidated balance sheets. Any noncontrolling interests that fail to qualify as permanent equity will be reclassified as temporary equity and adjusted to the greater of (1) the carrying amount, or (2) its redemption value as of the end of the period in which the determination is made. Other Noncontrolling Interests Other noncontrolling interests represent the ownership interest of third parties in two consolidated joint ventures as of December 31, 2019 . One joint venture owns two operating stores in Texas and two operating stores in Colorado, and the other owns an operating store in Pennsylvania and a development property in New Jersey. The voting interests of the third-party owners are between 5.0% and 20.0%

Leases

Leases	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Leases	LEASES The Company adopted ASC 842, "Leases," effective January 1, 2019 on a modified retrospective basis as allowed under the standard and thus prior periods have not been restated. The Company elected the package of transition practical expedients, and has therefore (1) not reassessed whether any expired or existing contracts are or contain leases, (2) not reassessed the lease classification for any expired or existing leases, and (3) not reassessed initial direct costs for any expired or existing leases. Lessee Accounting The Company recognized right-of-use assets related to operating leases totaling $95,506 and lease liabilities of $104,863 as of the adoption date, January 1, 2019. These are presented as “Operating lease liabilities” and “Real estate assets-operating lease right-of-use assets” on the Company’s consolidated balance sheets. In June and August 2019, the Company entered into new triple-net lease agreements to lease land and buildings at 22 and five operating stores, respectively. These leases are categorized as operating leases, and have contractual lease terms of 25 years , but have termination options after 10 years that result in lease terms of 10 years under ASC 842. The Company recorded new operating lease right-of-use assets and operating lease liabilities of $127,532 and $52,224 , respectively, in conjunction with these new lease agreements. The Company is lessee under several types of lease agreements. Generally, these leases fall into the following categories: • Leases of real estate at 49 stores classified as wholly-owned. These leases generally have original lease terms between 10 - 67 years . Under these leases, the Company typically has the option to extend the lease term for additional terms of 5 - 35 years . • Leases of its corporate offices and call center. These leases have original lease terms between 5.3 and 12.1 years , with no extension options. • Leases of 13 regional offices. These leases have original lease terms between three and five years . The Company has the option on five of these leases to extend the lease term for three additional years. • Leases of small district offices. These leases generally have terms of 12 months or less. The Company has made an election to account for these under the short-term lease exception outlined under ASC 842. Therefore, no lease assets or liabilities are recorded related to these leases. The Company has included lease extension options in the lease term for calculations of its right-of-use assets and liabilities related to the real estate asset leases at its stores when it is reasonably certain that the Company plans to extend the lease terms as the options arise. Several of the leases of real estate at the Company’s stores include escalation clauses based on an index or rate, such as the Consumer Price Index (CPI). The Company included these lease payments in its calculations of right-of-use assets and liabilities based on the prevailing index or rate as of the adoption date. The Company will recognize changes to these variable lease payments in earnings in the period of change. One of the real estate leases includes variable lease payments that are based upon a percentage of gross revenues. Certain other leases include additional variable payments relating to a percentage of sales in excess of a specified amount, common area maintenance, property taxes, and similar items. These payments are variable lease payments that do not depend on an index or rate and are excluded from the measurement of the lease liabilities and right-of-use-assets for these leases. The Company will recognize costs from these variable lease payments in the period in which the obligation for those payments is incurred. The Company has signed a lease agreement for a store in New Jersey. The store is currently under construction by the lessor, and the Company will take possession of the leased asset upon completion of construction, which is estimated to be completed in early to mid-2020. The lease term is 75 years from the lease commencement date, with three 10 -year extension options. The Company has also signed a lease agreement for a store in California. The store is under construction by the lessor, and the Company will take possession of the leased asset upon completion of construction, which is estimated to be completed in late 2020. The lease term is 15 years from the lease commencement date, with three 10 -year extension options and one 5 -year extension option. The Company has not recorded right-of-use assets or lease liabilities related to these leases as of December 31, 2019 as the lease term has not yet commenced for either lease. The lease commencement date will occur when the Company takes possession of the leased asset, and the Company will recognize a lease liability and right-of-use asset relating to the leases at that time. As the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available surrounding the Company’s unsecured borrowing rates and implied secured spread at the lease commencement date in determining the present value of lease payments. These discount rates vary depending on the term of the specific leases. Following is information on our total lease costs as of the period indicated: For the Year Ended December 31, 2019 Finance lease cost: Amortization of finance lease right-of-use assets $ 168 Interest expense related to finance lease liabilities 290 Operating lease cost 20,268 Variable lease cost 5,068 Short-term lease cost 164 Total lease cost $ 25,958 Cash paid for amounts included in the measurement of lease liabilities Operating cash outflows for finance lease payments $ 231 Operating cash outflows for operating lease payments 19,226 Total cash flows for lease liability measurement $ 19,457 Right-of-use assets obtained in exchange for new operating lease liabilities $ 277,557 Right-of-use assets obtained in exchange for new finance lease liabilities $ 8,050 Weighted average remaining lease term - finance leases (years) 46.9 Weighted average remaining lease term - operating leases (years) 14.7 Weighted average discount rate - finance leases 6.07 % Weighted average discount rate - operating leases 3.65 % The Company recorded lease expense of $8,229 and $6,898 related to operating leases in the years ended December 31, 2018 and 2017, respectively. The following table presents information about the Company’s undiscounted cash flows on an annual basis for operating and finance leases, including a reconciliation of the undiscounted cash flows to the finance lease and operating lease liabilities recognized in the Company’s consolidated balance sheets: Operating Finance Total 2020 $ 28,369 $ 232 $ 28,601 2021 28,628 237 28,865 2022 28,651 255 28,906 2023 28,707 255 28,962 2024 29,198 255 29,453 Thereafter 223,823 16,522 240,345 Total $ 367,376 $ 17,756 $ 385,132 Present value adjustments (92,593 ) (12,918 ) (105,511 ) Lease liabilities $ 274,783 $ 4,838 $ 279,621 The Company elected the package of practical expedients upon adoption of ASC 842, which allows for the application of the standard solely to the transition period in 2019 and does not require application to prior fiscal comparative periods presented. Disclosures required under the previous leasing standard are presented for prior years. The following table summarizes future minimum lease payments required under operating leases as of December 31, 2018: 2019 $ 8,203 2020 8,307 2021 8,137 2022 7,837 2023 7,021 Thereafter 111,653 $ 151,158 Lessor Accounting
Leases	LEASES The Company adopted ASC 842, "Leases," effective January 1, 2019 on a modified retrospective basis as allowed under the standard and thus prior periods have not been restated. The Company elected the package of transition practical expedients, and has therefore (1) not reassessed whether any expired or existing contracts are or contain leases, (2) not reassessed the lease classification for any expired or existing leases, and (3) not reassessed initial direct costs for any expired or existing leases. Lessee Accounting The Company recognized right-of-use assets related to operating leases totaling $95,506 and lease liabilities of $104,863 as of the adoption date, January 1, 2019. These are presented as “Operating lease liabilities” and “Real estate assets-operating lease right-of-use assets” on the Company’s consolidated balance sheets. In June and August 2019, the Company entered into new triple-net lease agreements to lease land and buildings at 22 and five operating stores, respectively. These leases are categorized as operating leases, and have contractual lease terms of 25 years , but have termination options after 10 years that result in lease terms of 10 years under ASC 842. The Company recorded new operating lease right-of-use assets and operating lease liabilities of $127,532 and $52,224 , respectively, in conjunction with these new lease agreements. The Company is lessee under several types of lease agreements. Generally, these leases fall into the following categories: • Leases of real estate at 49 stores classified as wholly-owned. These leases generally have original lease terms between 10 - 67 years . Under these leases, the Company typically has the option to extend the lease term for additional terms of 5 - 35 years . • Leases of its corporate offices and call center. These leases have original lease terms between 5.3 and 12.1 years , with no extension options. • Leases of 13 regional offices. These leases have original lease terms between three and five years . The Company has the option on five of these leases to extend the lease term for three additional years. • Leases of small district offices. These leases generally have terms of 12 months or less. The Company has made an election to account for these under the short-term lease exception outlined under ASC 842. Therefore, no lease assets or liabilities are recorded related to these leases. The Company has included lease extension options in the lease term for calculations of its right-of-use assets and liabilities related to the real estate asset leases at its stores when it is reasonably certain that the Company plans to extend the lease terms as the options arise. Several of the leases of real estate at the Company’s stores include escalation clauses based on an index or rate, such as the Consumer Price Index (CPI). The Company included these lease payments in its calculations of right-of-use assets and liabilities based on the prevailing index or rate as of the adoption date. The Company will recognize changes to these variable lease payments in earnings in the period of change. One of the real estate leases includes variable lease payments that are based upon a percentage of gross revenues. Certain other leases include additional variable payments relating to a percentage of sales in excess of a specified amount, common area maintenance, property taxes, and similar items. These payments are variable lease payments that do not depend on an index or rate and are excluded from the measurement of the lease liabilities and right-of-use-assets for these leases. The Company will recognize costs from these variable lease payments in the period in which the obligation for those payments is incurred. The Company has signed a lease agreement for a store in New Jersey. The store is currently under construction by the lessor, and the Company will take possession of the leased asset upon completion of construction, which is estimated to be completed in early to mid-2020. The lease term is 75 years from the lease commencement date, with three 10 -year extension options. The Company has also signed a lease agreement for a store in California. The store is under construction by the lessor, and the Company will take possession of the leased asset upon completion of construction, which is estimated to be completed in late 2020. The lease term is 15 years from the lease commencement date, with three 10 -year extension options and one 5 -year extension option. The Company has not recorded right-of-use assets or lease liabilities related to these leases as of December 31, 2019 as the lease term has not yet commenced for either lease. The lease commencement date will occur when the Company takes possession of the leased asset, and the Company will recognize a lease liability and right-of-use asset relating to the leases at that time. As the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available surrounding the Company’s unsecured borrowing rates and implied secured spread at the lease commencement date in determining the present value of lease payments. These discount rates vary depending on the term of the specific leases. Following is information on our total lease costs as of the period indicated: For the Year Ended December 31, 2019 Finance lease cost: Amortization of finance lease right-of-use assets $ 168 Interest expense related to finance lease liabilities 290 Operating lease cost 20,268 Variable lease cost 5,068 Short-term lease cost 164 Total lease cost $ 25,958 Cash paid for amounts included in the measurement of lease liabilities Operating cash outflows for finance lease payments $ 231 Operating cash outflows for operating lease payments 19,226 Total cash flows for lease liability measurement $ 19,457 Right-of-use assets obtained in exchange for new operating lease liabilities $ 277,557 Right-of-use assets obtained in exchange for new finance lease liabilities $ 8,050 Weighted average remaining lease term - finance leases (years) 46.9 Weighted average remaining lease term - operating leases (years) 14.7 Weighted average discount rate - finance leases 6.07 % Weighted average discount rate - operating leases 3.65 % The Company recorded lease expense of $8,229 and $6,898 related to operating leases in the years ended December 31, 2018 and 2017, respectively. The following table presents information about the Company’s undiscounted cash flows on an annual basis for operating and finance leases, including a reconciliation of the undiscounted cash flows to the finance lease and operating lease liabilities recognized in the Company’s consolidated balance sheets: Operating Finance Total 2020 $ 28,369 $ 232 $ 28,601 2021 28,628 237 28,865 2022 28,651 255 28,906 2023 28,707 255 28,962 2024 29,198 255 29,453 Thereafter 223,823 16,522 240,345 Total $ 367,376 $ 17,756 $ 385,132 Present value adjustments (92,593 ) (12,918 ) (105,511 ) Lease liabilities $ 274,783 $ 4,838 $ 279,621 The Company elected the package of practical expedients upon adoption of ASC 842, which allows for the application of the standard solely to the transition period in 2019 and does not require application to prior fiscal comparative periods presented. Disclosures required under the previous leasing standard are presented for prior years. The following table summarizes future minimum lease payments required under operating leases as of December 31, 2018: 2019 $ 8,203 2020 8,307 2021 8,137 2022 7,837 2023 7,021 Thereafter 111,653 $ 151,158 Lessor Accounting
Leases	LEASES The Company adopted ASC 842, "Leases," effective January 1, 2019 on a modified retrospective basis as allowed under the standard and thus prior periods have not been restated. The Company elected the package of transition practical expedients, and has therefore (1) not reassessed whether any expired or existing contracts are or contain leases, (2) not reassessed the lease classification for any expired or existing leases, and (3) not reassessed initial direct costs for any expired or existing leases. Lessee Accounting The Company recognized right-of-use assets related to operating leases totaling $95,506 and lease liabilities of $104,863 as of the adoption date, January 1, 2019. These are presented as “Operating lease liabilities” and “Real estate assets-operating lease right-of-use assets” on the Company’s consolidated balance sheets. In June and August 2019, the Company entered into new triple-net lease agreements to lease land and buildings at 22 and five operating stores, respectively. These leases are categorized as operating leases, and have contractual lease terms of 25 years , but have termination options after 10 years that result in lease terms of 10 years under ASC 842. The Company recorded new operating lease right-of-use assets and operating lease liabilities of $127,532 and $52,224 , respectively, in conjunction with these new lease agreements. The Company is lessee under several types of lease agreements. Generally, these leases fall into the following categories: • Leases of real estate at 49 stores classified as wholly-owned. These leases generally have original lease terms between 10 - 67 years . Under these leases, the Company typically has the option to extend the lease term for additional terms of 5 - 35 years . • Leases of its corporate offices and call center. These leases have original lease terms between 5.3 and 12.1 years , with no extension options. • Leases of 13 regional offices. These leases have original lease terms between three and five years . The Company has the option on five of these leases to extend the lease term for three additional years. • Leases of small district offices. These leases generally have terms of 12 months or less. The Company has made an election to account for these under the short-term lease exception outlined under ASC 842. Therefore, no lease assets or liabilities are recorded related to these leases. The Company has included lease extension options in the lease term for calculations of its right-of-use assets and liabilities related to the real estate asset leases at its stores when it is reasonably certain that the Company plans to extend the lease terms as the options arise. Several of the leases of real estate at the Company’s stores include escalation clauses based on an index or rate, such as the Consumer Price Index (CPI). The Company included these lease payments in its calculations of right-of-use assets and liabilities based on the prevailing index or rate as of the adoption date. The Company will recognize changes to these variable lease payments in earnings in the period of change. One of the real estate leases includes variable lease payments that are based upon a percentage of gross revenues. Certain other leases include additional variable payments relating to a percentage of sales in excess of a specified amount, common area maintenance, property taxes, and similar items. These payments are variable lease payments that do not depend on an index or rate and are excluded from the measurement of the lease liabilities and right-of-use-assets for these leases. The Company will recognize costs from these variable lease payments in the period in which the obligation for those payments is incurred. The Company has signed a lease agreement for a store in New Jersey. The store is currently under construction by the lessor, and the Company will take possession of the leased asset upon completion of construction, which is estimated to be completed in early to mid-2020. The lease term is 75 years from the lease commencement date, with three 10 -year extension options. The Company has also signed a lease agreement for a store in California. The store is under construction by the lessor, and the Company will take possession of the leased asset upon completion of construction, which is estimated to be completed in late 2020. The lease term is 15 years from the lease commencement date, with three 10 -year extension options and one 5 -year extension option. The Company has not recorded right-of-use assets or lease liabilities related to these leases as of December 31, 2019 as the lease term has not yet commenced for either lease. The lease commencement date will occur when the Company takes possession of the leased asset, and the Company will recognize a lease liability and right-of-use asset relating to the leases at that time. As the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available surrounding the Company’s unsecured borrowing rates and implied secured spread at the lease commencement date in determining the present value of lease payments. These discount rates vary depending on the term of the specific leases. Following is information on our total lease costs as of the period indicated: For the Year Ended December 31, 2019 Finance lease cost: Amortization of finance lease right-of-use assets $ 168 Interest expense related to finance lease liabilities 290 Operating lease cost 20,268 Variable lease cost 5,068 Short-term lease cost 164 Total lease cost $ 25,958 Cash paid for amounts included in the measurement of lease liabilities Operating cash outflows for finance lease payments $ 231 Operating cash outflows for operating lease payments 19,226 Total cash flows for lease liability measurement $ 19,457 Right-of-use assets obtained in exchange for new operating lease liabilities $ 277,557 Right-of-use assets obtained in exchange for new finance lease liabilities $ 8,050 Weighted average remaining lease term - finance leases (years) 46.9 Weighted average remaining lease term - operating leases (years) 14.7 Weighted average discount rate - finance leases 6.07 % Weighted average discount rate - operating leases 3.65 % The Company recorded lease expense of $8,229 and $6,898 related to operating leases in the years ended December 31, 2018 and 2017, respectively. The following table presents information about the Company’s undiscounted cash flows on an annual basis for operating and finance leases, including a reconciliation of the undiscounted cash flows to the finance lease and operating lease liabilities recognized in the Company’s consolidated balance sheets: Operating Finance Total 2020 $ 28,369 $ 232 $ 28,601 2021 28,628 237 28,865 2022 28,651 255 28,906 2023 28,707 255 28,962 2024 29,198 255 29,453 Thereafter 223,823 16,522 240,345 Total $ 367,376 $ 17,756 $ 385,132 Present value adjustments (92,593 ) (12,918 ) (105,511 ) Lease liabilities $ 274,783 $ 4,838 $ 279,621 The Company elected the package of practical expedients upon adoption of ASC 842, which allows for the application of the standard solely to the transition period in 2019 and does not require application to prior fiscal comparative periods presented. Disclosures required under the previous leasing standard are presented for prior years. The following table summarizes future minimum lease payments required under operating leases as of December 31, 2018: 2019 $ 8,203 2020 8,307 2021 8,137 2022 7,837 2023 7,021 Thereafter 111,653 $ 151,158 Lessor Accounting

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	STOCK-BASED COMPENSATION As of December 31, 2019 , 1,438,073 shares were available for issuance under the Company’s 2015 Incentive Award Plan (the “Plan”). Option grants are issued with an exercise price equal to the closing price of stock on the date of grant. Unless otherwise determined by the Compensation, Nominating and Governance Committee (“CNG Committee”) at the time of grant, options shall vest ratably over a four -year period beginning on the date of grant. Each option wi ll be exercisable once it has vested. Options are exercisable at such times and subject to such terms as deter mined by the CNG Committee, but under no circumstances may be exercised if such exercise would cause a violation of the ownership limit in the Company’s charter. Options expire 10 years from the date of grant. Beginning in 2017, the CNG Committee decided to the replace stock options granted to executives with performance based stock units for executive compensation. See the "Performance-Based Stock Units" section below. Also as defined under the terms of the Plan, restricted stock grants may be awarded. The stock grants are subject to a vesting period over which the restrictions are released and the stock certificates are given to the grantee. During the performance or vesting period, the grantee is not permitted to sell, transfer, pledge, encumber or assign shares of restricted stock granted under the Plan; however, the grantee has the ability to vote the shares and receive nonforfeitable dividends paid on shares. Unless otherwise determined by the CNG Committee at the time of grant, the forfeiture and transfer restrictions on the shares lapse over a four -year period beginning on the date of grant. Option Grants A summary of stock option activity is as follows: Options Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Life (Years) Aggregate Intrinsic Value as of December 31, 2019 Outstanding at December 31, 2016 510,574 $ 30.60 Exercised (38,418 ) 32.94 Outstanding at December 31, 2017 472,156 $ 30.41 Exercised (54,575 ) 21.45 Outstanding at December 31, 2018 417,581 $ 31.58 Exercised (211,057 ) 14.65 Outstanding at December 31, 2019 206,524 $ 48.88 3.43 $11,719 Vested and Expected to Vest 206,460 $ 48.87 3.43 $11,717 Ending Exercisable 197,576 $ 47.20 3.30 $11,543 The aggregate intrinsic value in the table above represents the total value (the difference between the Company’s closing stock price on the last trading day of 2019 and the exercise price, multiplied by the number of in-the-money options) that would have been received by the option holders had all option holders exercised their options on December 31, 2019 . The amount of aggregate intrinsic value will change based on the fair market value of the Company’s stock. The total intrinsic value of options exercised for the years ended December 31, 2019 , 2018 and 2017 was $18,089 , $3,693 and $1,786 , respectively. There have been no options granted since 2016. The fair value of each option grant was estimated on the date of grant using the Black-Scholes option-pricing model. The Black-Scholes model incorporates assumptions to value stock-based awards. The risk-free rate is based on the U.S. Treasury yield curve in effect at the time of the grant for the estimated life of the option. The Company uses actual historical data to calculate the expected price volatility, dividend yield and average expected term. The forfeiture rate, which is estimated at a weighted-average of 7.4% of unvested options outstanding as of December 31, 2019 , is adjusted periodically based on the extent to which actual forfeitures differ, or are expected to differ, from the previous estimates. A summary of stock options outstanding and exercisable as of December 31, 2019 , is as follows: Options Outstanding Options Exercisable Exercise Price Shares Weighted Average Remaining Contractual Life Weighted Average Exercise Price Shares Weighted Average Exercise Price $12.21 - $12.21 77,400 0.18 $ 12.21 77,400 $ 12.21 $38.40 - $38.40 8,085 3.14 38.40 8,085 38.40 $47.50 - $47.50 9,800 4.13 47.50 9,800 47.50 $65.36 - $65.36 15,647 5.15 65.36 15,647 65.36 $65.45 - $65.45 11,960 5.13 65.45 11,960 64.45 $73.52 - $73.52 50,000 5.58 73.52 50,000 73.52 $85.99 - $85.99 33,632 6.15 85.99 24,684 85.99 206,524 3.42 $ 48.88 197,576 $ 47.20 The Company recorded compensation expense relating to outstanding options of $364 , $570 and $649 in general and administrative expense for the years ended December 31, 2019 , 2018 and 2017 , respectively. Net proceeds received for the years ended December 31, 2019 , 2018 and 2017 , related to option exercises was $3,063 , $1,169 and $1,266 , respectively. At December 31, 2019 , there was no unrecognized compensation expense related to non-vested stock options under the Plan. The valuation model applied in this calculation utilizes subjective assumptions that could potentially change over time, including the expected forfeiture rate. Common Stock Granted to Employees and Directors The Company recorded $9,173 , $8,733 and $7,232 of expense in general and administrative expense in its statement of operations related to restricted stock awards granted to employees and directors for the years ended December 31, 2019 , 2018 and 2017 , respectively. The forfeiture rate, which is estimated at a weighted-average of 9.7% of unvested awards outstanding as of December 31, 2019 , is adjusted periodically based on the extent to which actual forfeitures differ, or are expected to differ, from the previous estimates. At December 31, 2019 there was $11,712 of total unrecognized compensation expense related to non-vested restricted stock awards under the Plan. That cost is expected to be recognized over a weighted-average period of 2.17 years . The fair value of common stock awards is determined based on the closing trading price of the Company’s common stock on the grant date. A summary of the Company’s employee and director share grant activity is as follows: Restricted Stock Grants Shares Weighted-Average Grant-Date Fair Value Unreleased at December 31, 2016 299,585 $ 70.57 Granted 95,392 74.49 Released (120,323 ) 63.95 Cancelled (8,179 ) 77.25 Unreleased at December 31, 2017 266,475 $ 74.76 Granted 85,066 86.14 Released (116,656 ) 72.38 Cancelled (11,771 ) 80.96 Unreleased at December 31, 2018 223,114 $ 80.02 Granted 109,081 101.52 Released (110,724 ) 79.58 Cancelled (8,863 ) 90.11 Unreleased at December 31, 2019 212,608 $ 90.85 Performance-based Stock Units In 2017, the CNG Committee changed its compensation for executives to issue performance-based stock units (the "PSUs") as a replacement for stock option awards. The PSUs granted to executives represent the right to earn shares of the Company's common stock. These awards have two financial performance components: (1) the Company's core FFO performance ("FFO Target"), and (2) the Company's total stockholder return relative to the performance of a defined group of peers ("TSR Target"). Each of these performance components are weighted 50% and are measured over the performance period, which is defined as the three -year period ending December 31 from the year of grant. At the end of the performance period, the financial performance components are reviewed to determine the number of shares actually granted to executives, which can be as low as zero shares and up to a maximum of two shares issued for each PSU. A summary of the PSU activity is as follows: Performance-Based Stock Units Units Weighted-Average Grant-Date Fair Value Unvested at December 31, 2016 — $ — Granted 30,071 83.84 Unvested at December 31, 2017 30,071 $ 83.84 Granted 28,735 96.19 Unvested at December 31, 2018 58,806 $ 89.87 Granted 49,334 103.18 Unvested at December 31, 2019 108,140 $ 95.94 The Company recorded $3,514 , $1,873 and $840 of expense in general and administrative expense in its statement of operations related to PSUs granted to employees and directors for the years ended December 31, 2019 , 2018 and 2017 , respectively. The Company estimated the fair value of the PSUs as of the grant date, using the closing trading price of the Company's common stock on the grant date to value the FFO Target portion. A Monte Carlo simulation model was used to calculate the fair value of the TSR Target portion of the PSUs, using the following assumptions: For the Year Ended December 31, 2019 2018 2017 Intrinsic value $6,211 $5,321 $2,630 Risk-free rate 2.53% 2.37% 1.62% Volatility 20.7% 22.6% 21.4% Expected term (in years) 2.8 2.9 2.8 Dividend yield —% —% —% Unrecognized compensation cost $4,315 $2,739 $1,681 Term over which compensation cost recognized 3 3 3 Under the terms of the PSUs, dividends for the entire measurement period are paid in cash when the shares are issued, so a dividend yield of zero was used. The valuation model applied in this calculation utilizes subjective assumptions that could potentially change over time, including the probabilities associated with achieving the FFO Targets (categorized within Level 3 of the fair value hierarchy). Therefore, the amount of unrecognized compensation expense at December 31, 2019 noted above does not necessarily represent the expense that will ultimately be realized by the Company in the statement of operations.

Employee Benefit Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2019
Retirement Benefits [Abstract]
Employee Benefit Plan	EMPLOYEE BENEFIT PLAN The Company has a retirement savings plan under Section 401(k) of the Internal Revenue Code under which eligible employees can contribute up to 60% of their annual salary, subject to a statutory prescribed annual limit. For the years ended December 31, 2019 , 2018 and 2017 , the Company made matching contributions to the plan of $3,355 , $2,833 and $2,212 , respectively, based on 100% of the first 3% and up to 50% of the next 2% of an employee’s compensation.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES As a REIT, the Company is generally not subject to federal income tax with respect to that portion of its income which is distributed annually to its stockholders. However, the Company has elected to treat one of its corporate subsidiaries, Extra Space Management, Inc., as a TRS. In general, the Company’s TRS may perform additional services for tenants and generally may engage in any real estate or non-real estate related business. A TRS is subject to federal corporate income tax. The Company accounts for income taxes in accordance with the provisions of ASC 740, “Income Taxes.” Deferred tax assets and liabilities are determined based on differences between financial reporting and tax bases of assets and liabilities. The Company has elected to use the Tax-Law-Ordering approach to determine when excess tax benefits will be realized. The income tax provision for the years ended December 31, 2019 , 2018 and 2017 , is comprised of the following components: For the Year Ended December 31, 2019 Federal State Total Current expense $ 10,164 $ 2,936 $ 13,100 Tax credits/true-up (3,633 ) (30 ) (3,663 ) Change in deferred expense/(benefit) 1,787 84 1,871 Total tax expense $ 8,318 $ 2,990 $ 11,308 For the Year Ended December 31, 2018 Federal State Total Current expense $ 9,136 $ 2,426 $ 11,562 Tax credits/true-up (5,841 ) (175 ) (6,016 ) Change in deferred expense 3,730 (32 ) 3,698 Total tax expense $ 7,025 $ 2,219 $ 9,244 For the Year Ended December 31, 2017 Federal State Total Current expense $ 5,677 $ 1,662 $ 7,339 Tax credits/true-up (5,573 ) (383 ) (5,956 ) Change in deferred benefit 1,700 542 2,242 Total tax expense $ 1,804 $ 1,821 $ 3,625 A reconciliation of the statutory income tax provisions to the effective income tax provisions for the periods indicated is as follows: For the Year Ended December 31, 2019 2018 2017 Expected tax at statutory rate $ 97,110 21.0 % $ 95,828 21.0 % $ 186,274 35.0 % Non-taxable REIT income (82,717 ) (17.9 )% (83,022 ) (18.2 )% (170,811 ) (32.1 )% State and local tax expense - net of federal benefit 2,837 0.6 % 2,385 0.5 % 2,306 0.4 % Change in valuation allowance (207 ) — % (1,052 ) (0.2 )% 159 — % Tax credits/true-up (3,663 ) (0.8 )% (6,016 ) (1.3 )% (5,956 ) (1.1 )% Remeasurement of deferred balances — — % — — % (8,460 ) (1.6 )% Miscellaneous (2,052 ) (0.4 )% 1,121 0.2 % 113 — % Total provision $ 11,308 2.5 % $ 9,244 2.0 % $ 3,625 0.6 % The major sources of temporary differences stated at their deferred tax effects are as follows: December 31, 2019 December 31, 2018 Deferred tax liabilities: Fixed assets $ (23,805 ) $ (20,907 ) Operating lease right-of-use assets (2,475 ) — Other (84 ) (96 ) State deferred taxes (3,405 ) (3,076 ) Total deferred tax liabilities (29,769 ) (24,079 ) Deferred tax assets: Captive insurance subsidiary 312 324 Accrued liabilities 2,006 1,772 Stock compensation 2,118 1,604 Operating lease liabilities 2,478 — SmartStop TRS 219 219 Other 50 53 State deferred taxes 7,250 7,196 Total deferred tax assets 14,433 11,168 Valuation allowance (3,665 ) (3,872 ) Net deferred income tax liabilities $ (19,001 ) $ (16,783 ) The state income tax net operating losses expire between 2020 and 2037. The valuation allowance is associated with the state income tax net operating losses. The tax years 2015 through 2018 remain open related to the state returns, and 2016 through 2018 for the federal returns.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Segment Information	SEGMENT INFORMATION The Company’s segment disclosures present the measure used by the chief operating decision makers ("CODMs") for purposes of assessing each segment’s performance. The Company’s CODMs are comprised of several members of its executive management team who use net operating income ("NOI") to assess the performance of the business for the Company’s reportable operating segments. NOI for our self-storage operations represents total property revenue less direct property operating expenses. NOI for our tenant reinsurance segment represents tenant reinsurance revenues less tenant reinsurance expense. The Company’s segments are comprised of two reportable segments: (1) self-storage operations and (2) tenant reinsurance. The self-storage operations activities include rental operations of wholly-owned stores. The Company's consolidated revenues equal total segment revenues plus property management fees and other income. Tenant reinsurance activities include the reinsurance of risks relating to the loss of goods stored by tenants in the stores operated by the Company. Excluded from segment revenues and net operating income is property management fees and other income. For all periods presented, substantially all of our real estate assets, intangible assets, other assets, and accrued and other liabilities are associated with the self-storage operations segment. Financial information for the Company’s business segments is set forth below: Year Ended December 31, 2019 2018 2017 Revenues: Self-Storage Operations $ 1,130,177 $ 1,039,340 $ 967,229 Tenant Reinsurance 128,387 115,507 98,401 Total segment revenues $ 1,258,564 $ 1,154,847 $ 1,065,630 Operating expenses: Self-Storage Operations $ 336,050 $ 291,695 $ 271,974 Tenant Reinsurance 29,376 25,707 19,173 Total segment operating expenses $ 365,426 $ 317,402 $ 291,147 Net operating income: Self-Storage Operations $ 794,127 $ 747,645 $ 695,255 Tenant Reinsurance 99,011 89,800 79,228 Total segment net operating income: $ 893,138 $ 837,445 $ 774,483 Total segment net operating income $ 893,138 $ 837,445 $ 774,483 Other components of net income (loss): Property management fees and other income 49,890 41,757 39,379 General and administrative expense (89,418 ) (81,256 ) (78,961 ) Depreciation and amortization expense (219,857 ) (209,050 ) (193,296 ) Gain on real estate transactions and impairment of real estate 1,205 30,807 112,789 Interest expense (186,526 ) (178,436 ) (153,511 ) Non-cash interest expense related to the amortization of discount on equity component of exchangeable senior notes (4,742 ) (4,687 ) (5,103 ) Interest income 7,467 5,292 6,736 Equity in earnings of unconsolidated real estate entities 11,274 14,452 15,331 Income tax expense (11,308 ) (9,244 ) (3,625 ) Net income $ 451,123 $ 447,080 $ 514,222

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES The Company is involved in various legal proceedings and is subject to various claims and complaints arising in the ordinary course of business. Because litigation is inherently unpredictable, the outcome of these matters cannot presently be determined with any degree of certainty. In accordance with applicable accounting guidance, management establishes an accrued liability for litigation when those matters present loss contingencies that are both probable and reasonably estimable. In such cases, there may be an exposure to loss in excess of any amounts accrued. The estimated loss, if any, is based upon currently available information and is subject to significant judgment, a variety of assumptions, and known and unknown uncertainties. The Company could in the future incur judgments or enter into settlements of claims that could have a material adverse effect on its results of operations in any particular period, notwithstanding the fact that the Company is currently vigorously defending any legal proceedings against it. As of December 31, 2019 , the Company was involved in various legal proceedings and was subject to various claims and complaints arising in the ordinary course of business. In the opinion of management, such litigation, claims and complaints are not expected to have a material adverse effect on the Company’s financial condition or results of operations. As of December 31, 2019 , the Company was under agreement to acquire three stores at a total purchase price of $27,400 . Of these stores, two are scheduled to close in 2020 at a purchase price of $16,000 , and one is scheduled to close in 2021 at a purchase price of $11,400 . Additionally, the Company is under agreement to acquire seven stores in 2020 with joint venture partners, for a total investment of $25,095 . Although there can be no assurance, the Company is not aware of any material environmental liability, for which it believes it will be ultimately responsible, that could have a material adverse effect on its financial condition or results of operations. However, changes in applicable environmental laws and regulations, the uses and conditions of properties in the vicinity of the Company’s properties, the activities of its tenants and other environmental conditions of which the Company is unaware with respect to its properties could result in future material environmental liabilities.

Supplementary Quarterly Financi

Supplementary Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Supplementary Quarterly Financial Data (Unaudited)	SUPPLEMENTARY QUARTERLY FINANCIAL DATA (UNAUDITED) For the Three Months Ended March 31, 2019 June 30, 2019 September 30, 2019 December 31, 2019 Revenues $ 311,546 $ 323,602 $ 337,505 $ 335,801 Cost of operations 163,069 165,609 174,867 171,156 Revenues less cost of operations $ 148,477 $ 157,993 $ 162,638 $ 164,645 Net income $ 102,160 $ 112,689 $ 115,995 $ 120,279 Net income attributable to common stockholders $ 94,770 $ 104,828 $ 108,087 $ 112,282 Earnings per common share—basic $ 0.74 $ 0.82 $ 0.84 $ 0.87 Earnings per common share—diluted $ 0.74 $ 0.81 $ 0.83 $ 0.86 For the Three Months Ended March 31, 2018 June 30, 2018 September 30, 2018 December 31, 2018 Revenues $ 285,485 $ 296,813 $ 306,953 $ 307,353 Cost of operations 151,573 152,097 153,362 150,676 Revenues less cost of operations $ 133,912 $ 144,716 $ 153,591 $ 156,677 Net income $ 95,430 $ 102,713 $ 139,687 $ 109,250 Net income attributable to common stockholders $ 88,256 $ 95,153 $ 130,418 $ 101,462 Earnings per common share—basic $ 0.70 $ 0.75 $ 1.03 $ 0.80 Earnings per common share—diluted $ 0.70 $ 0.75 $ 1.02 $ 0.80

Schedule III - Real Estate and

Schedule III - Real Estate and Accumulated Depreciation	12 Months Ended
	Dec. 31, 2019
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation Disclosure [Abstract]
Schedule III - Real Estate and Accumulated Depreciation	Extra Space Storage Inc. Schedule III Real Estate and Accumulated Depreciation (Dollars in thousands) As of December 31, 2019 Building and Improvements Initial Cost Adjustments and Costs to Land and Building Subsequent to Acquisition Gross carrying amount at December 31, 2019 Self - Storage Facilities by State: Store Count Land Initial Cost Building and Improvements Accumulated Depreciation Debt Land Total AL 8 $ 29,567 $ 7,690 $ 42,770 $ 3,693 $ 7,691 $ 46,462 $ 54,153 $ 8,277 AZ 23 21,845 27,535 117,304 9,574 27,533 126,880 154,413 24,239 CA 165 531,406 539,355 1,166,591 109,246 540,043 1,275,149 1,815,192 264,874 CO 16 30,432 16,809 71,894 16,652 17,527 87,828 105,355 19,546 CT 7 23,557 9,875 50,966 4,766 9,874 55,733 65,607 9,934 FL 91 263,634 163,455 588,353 56,727 163,919 644,616 808,535 134,121 GA 63 85,820 83,742 406,477 27,502 83,726 433,995 517,721 60,262 HI 13 31,029 17,663 133,870 6,025 17,663 139,895 157,558 25,676 IL 37 50,669 45,435 234,396 25,785 44,888 260,728 305,616 43,160 IN 15 10,987 12,447 58,247 5,850 12,447 64,097 76,544 11,698 KS 1 — 366 1,897 866 366 2,763 3,129 1,087 KY 11 34,066 8,640 68,679 18,260 9,412 86,167 95,579 12,296 LA 2 — 6,114 8,541 1,312 6,115 9,852 15,967 4,221 MA 46 105,046 73,544 270,243 50,778 73,725 320,840 394,565 80,863 MD 32 118,007 99,147 284,253 16,756 97,180 302,976 400,156 70,387 MI 7 5,792 9,583 51,359 3,239 9,583 54,598 64,181 5,740 MN 5 — 7,377 50,057 514 7,377 50,571 57,948 2,585 MO 5 — 4,129 15,444 4,107 4,086 19,594 23,680 7,392 MS 3 — 2,420 20,849 1,450 2,420 22,299 24,719 2,635 NC 19 28,221 31,969 104,104 7,379 31,967 111,485 143,452 11,241 NH 2 5,938 754 4,054 1,278 817 5,269 6,086 2,388 NJ 59 155,754 134,032 560,512 41,422 137,258 598,708 735,966 129,970 NM 11 17,689 32,252 71,142 5,049 32,252 76,191 108,443 9,373 NV 14 37,557 15,252 74,376 4,671 15,252 79,047 94,299 10,422 NY 27 43,218 121,945 230,875 34,801 122,680 264,941 387,621 59,450 OH 17 34,470 17,788 50,493 6,733 17,787 57,227 75,014 13,318 OR 6 30,267 7,906 39,576 2,042 7,906 41,618 49,524 7,545 PA 18 34,475 24,297 149,144 12,297 23,589 162,149 185,738 24,480 RI 2 11,841 3,191 6,926 1,253 3,191 8,179 11,370 2,939 SC 23 43,543 37,075 135,760 10,029 37,076 145,788 182,864 22,598 TN 17 45,601 25,938 91,497 8,750 25,938 100,247 126,185 18,046 TX 100 213,291 169,160 648,128 57,365 169,012 705,641 874,653 112,790 UT 10 13,181 9,008 39,295 2,247 9,008 41,542 50,550 9,854 VA 46 163,675 139,318 414,335 19,385 139,319 433,719 573,038 69,063 WA 8 20,345 12,528 47,645 2,694 12,530 50,337 62,867 11,380 DC 1 8,762 14,394 18,172 429 14,394 18,601 32,995 1,824 Other corporate assets — — 2,202 138,483 — 140,685 140,685 40,298 Intangible tenant relationships and lease rights — — 132,000 2,932 — 134,932 134,932 127,712 Construction in Progress/Undeveloped Land — 5,978 — 39,788 3,372 42,394 45,766 — Right of use asset - finance lease (1) — — — 8,050 — 8,050 8,050 168 Totals (1) 930 $ 2,249,685 $ 1,938,111 $ 6,462,425 $ 770,180 $ 1,938,923 $ 7,231,793 $ 9,170,716 $ 1,473,852 (1) No right-of-use assets related to operating leases are included in the ending net real estate assets information above. As of December 31, 2019 , there was a right-of-use asset relating to a finance lease in the amount of $8,050 included in net real estate assets on the Company's consolidated balance sheets. Activity in real estate facilities during the years ended December 31, 2019 , 2018 and 2017 is as follows: 2019 2018 2017 Operating facilities Balance at beginning of year $ 8,709,315 $ 8,158,741 $ 7,649,448 Acquisitions 303,588 459,223 628,391 Improvements 68,459 64,336 71,090 Transfers from construction in progress 59,614 49,449 19,079 Dispositions and other (11,418 ) (22,434 ) (209,267 ) Balance at end of year $ 9,129,558 $ 8,709,315 $ 8,158,741 Accumulated depreciation: Balance at beginning of year $ 1,262,438 $ 1,060,060 $ 900,861 Depreciation expense 212,202 203,030 185,903 Dispositions and other (789 ) (652 ) (26,704 ) Balance at end of year $ 1,473,851 $ 1,262,438 $ 1,060,060 Real estate under development/redevelopment: Balance at beginning of year $ 44,954 $ 33,750 $ 21,860 Current development 55,817 60,677 33,484 Transfers to operating facilities (59,614 ) (49,449 ) (19,079 ) Dispositions and other — (24 ) (2,515 ) Balance at end of year $ 41,157 $ 44,954 $ 33,750 Net non-lease real estate assets (1) $ 7,696,864 $ 7,491,831 $ 7,132,431 (1) No right-of-use assets related to operating leases leases are included in the ending net real estate assets information above. As of December 31, 2019 , there was a right-of-use asset relating to a finance lease in the amount of $8,050 included in net real estate assets on the Company's consolidated balance sheets. As of December 31, 2019 , the aggregate cost of real estate for U.S. federal income tax purposes was $7,721,422 .

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The consolidated financial statements are presented on the accrual basis of accounting in accordance with U.S. generally accepted accounting principles (“GAAP”) and include the accounts of the Company and its wholly- or majority-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.
Variable Interest Entities	Variable Interest Entities The Company accounts for arrangements that are not controlled through voting or similar rights as variable interest entities (“VIEs”). An enterprise is required to consolidate a VIE if it is the primary beneficiary of the VIE. A VIE is created when (i) the equity investment at risk is not sufficient to permit the entity to finance its activities without additional subordinated financial support from other parties, or (ii) the entity’s equity holders as a group either: (a) lack the power, through voting or similar rights, to direct the activities of the entity that most significantly impact the entity’s economic performance, (b) are not obligated to absorb expected losses of the entity if they occur, or (c) do not have the right to receive expected residual returns of the entity if they occur. If an entity is deemed to be a VIE, the enterprise that is deemed to have a variable interest, or combination of variable interests, that provides the enterprise with a controlling financial interest in the VIE, is considered the primary beneficiary and must consolidate the VIE. The Company has concluded that under certain circumstances when the Company enters into arrangements for the formation of joint ventures or when entering into a new bridge loan agreement, a VIE may be created under condition (i), (ii) (b) or (c) of the previous paragraph. For each VIE created, the Company has performed a qualitative analysis, including considering which party, if any, has the power to direct the activities most significant to the economic performance of each VIE and whether that party has the obligation to absorb losses of the VIE or the right to receive benefits from the VIE that could be significant to the VIE. If the Company is determined to be the primary beneficiary of the VIE, the assets, liabilities and operations of the VIE are consolidated with the Company’s financial statements. As of December 31, 2019 and 2018 , the Company had no consolidated VIEs. Additionally, the Operating Partnership had a note payable to a trust that was a VIE under condition (ii)(a) above. Since the Operating Partnership was not the primary beneficiary of the trust, this VIE was not consolidated. The Company’s investments in real estate joint ventures, where the Company has significant influence, but not control, and joint ventures which are VIEs in which the Company is not the primary beneficiary, are recorded under the equity method of accounting on the accompanying consolidated financial statements.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Fair Value Disclosures	Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis Long-lived assets held for use are evaluated for impairment when events or circumstances indicate there may be impairment. The Company reviews each store at least annually to determine if any such events or circumstances have occurred or exist. The Company focuses on stores where occupancy and/or rental income have decreased by a significant amount. For these stores, the Company determines whether the decrease is temporary or permanent, and whether the store will likely recover the lost occupancy and/or revenue in the short term. In addition, the Company reviews stores in the lease-up stage and compares actual operating results to original projections. When the Company determines that an event that may indicate impairment has occurred, the Company compares the carrying value of the related long-lived assets to the undiscounted future net operating cash flows attributable to the assets. An impairment loss is recorded if the net carrying value of the assets exceeds the undiscounted future net operating cash flows attributable to the assets. The impairment loss recognized equals the excess of net carrying value over the related fair value of the assets. When real estate assets are identified by management as held for sale, the Company discontinues depreciating the assets and estimates the fair value of the assets, net of selling costs. The Company compares the carrying value of the related long-lived assets to the undiscounted future net operating cash flows attributable to the assets (categorized within Level 3 of the fair value hierarchy). If the estimated fair value, net of selling costs, of the assets that have been identified as held for sale is less than the net carrying value of the assets, the Company would recognize a loss on the assets held for sale. The operations of assets held for sale or sold during the period are presented as part of normal operations for all periods presented. The Company assesses annually whether there are any indicators that the value of the Company’s investments in unconsolidated real estate ventures may be impaired and when events or circumstances indicate that there may be impairment. An investment is impaired if management’s estimate of the fair value of the investment is less than its carrying value. To the extent impairment has occurred, and is considered to be other than temporary, the loss is measured as the excess of the carrying amount of the investment over the fair value of the investment. As of December 31, 2019 and 2018 , the Company did not have any assets or liabilities measured at fair value on a nonrecurring basis. Fair Value of Financial Instruments The carrying values of cash and cash equivalents, restricted cash, receivables, other financial instruments included in other assets, accounts payable and accrued expenses, variable-rate notes payable and notes receivable, revolving lines of credit and other liabilities reflected in the consolidated balance sheets at December 31, 2019 and 2018 , approximate fair value. The fair values of the Company’s notes receivable from Preferred Operating Partnership unit holders were based on the discounted estimated future cash flow of the notes (categorized within Level 3 of the fair value hierarchy); the discount rate used approximated the current market rate for loans with similar maturities and credit quality. The fair values of the Company’s fixed rate notes payable and notes payable to trusts were estimated using the discounted estimated future cash payments to be made on such debt (categorized within Level 3 of the fair value hierarchy); the discount rates used approximated current market rates for loans, or groups of loans, with similar maturities and credit quality. The fair value of the Company’s exchangeable senior notes was estimated using an average market price for similar securities obtained from a third party. Fair Value Disclosures Derivative financial instruments Currently, the Company uses interest rate swaps to manage its interest rate risk. The valuation of these instruments is determined using widely accepted valuation techniques including discounted cash flow analysis on the expected cash flows of each derivative. This analysis reflects the contractual terms of the derivatives, including the period to maturity, and uses observable market-based inputs, including interest rate curves. The fair values of interest rate swaps are determined using the market standard methodology of netting the discounted future fixed cash payments and the discounted expected variable cash receipts. The variable cash receipts are based on an expectation of future interest rates (forward curves) derived from observable market interest rate forward curves. The Company incorporates credit valuation adjustments to appropriately reflect both its own nonperformance risk and the respective counterparty’s nonperformance risk in the fair value measurements. In adjusting the fair value of its derivative contracts for the effect of nonperformance risk, the Company has considered the impact of netting and any applicable credit enhancements, such as collateral postings, thresholds, mutual puts, and guarantees. In conjunction with the Financial Accounting Standard Board’s fair value measurement guidance, the Company made an accounting policy election to measure the credit risk of its derivative financial instruments that are subject to master netting agreements on a net basis by counterparty portfolio. Although the Company has determined that the majority of the inputs used to value its derivatives fall within Level 2 of the fair value hierarchy, the credit valuation adjustments associated with its derivatives utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default by itself and its counterparties. However, as of December 31, 2019 , the Company has assessed the significance of the impact of the credit valuation adjustments on the overall valuation of its derivative positions and has determined that the credit valuation adjustments are not significant to the overall valuation of its derivatives. As a result, the Company has determined that its derivative valuations in their entirety are classified in Level 2 of the fair value hierarchy.
Real Estate Assets and Sales	Real Estate Assets Real estate assets are stated at cost, less accumulated depreciation. Direct and allowable internal costs associated with the development, construction, renovation, and improvement of real estate assets are capitalized. Interest, property taxes, and other costs associated with development incurred during the construction period are capitalized. The construction period begins when expenditures for the real estate assets have been made and activities that are necessary to prepare the asset for its intended use are in progress. The construction period ends when the asset is substantially complete and ready for its intended use. Expenditures for maintenance and repairs are charged to expense as incurred. Major replacements and betterments that improve or extend the life of the asset are capitalized and depreciated over their estimated useful lives. Depreciation is computed using the straight-line method over the estimated useful lives of the buildings and improvements, which are generally between five and 39 years. Stores purchased at the time of certificate of occupancy issuance and stores purchased subsequent to the Company's adoption of ASU 2017-01 on January 1, 2017 are considered asset acquisitions. As such, the purchase price is allocated to the real estate assets acquired based on their relative fair values, which are estimated using significant unobservable inputs. The value of the tangible assets, consisting of land and buildings, is determined as if vacant. Intangible assets, which represent the value of existing tenant relationships, are recorded at their relative fair values based on the avoided cost to replace the current leases. The Company measures the value of tenant relationships based on the rent lost due to the amount of time required to replace existing customers, which is based on the Company’s historical experience with turnover in its stores. Any debt assumed as part of the acquisition is recorded at fair value based on current interest rates compared to contractual rates. Acquisition-related transactions costs are capitalized as part of the purchase price. Intangible lease rights represent: (1) purchase price amounts allocated to leases on three stores that cannot be classified as ground or building leases; these rights are amortized to expense over the life of the leases and (2) intangibles related to ground leases on eight stores where the leases were assumed by the Company at rates that were lower than the current market rates for similar leases. The values associated with these assumed leases were recorded as intangibles, which will be amortized over the lease terms. Real Estate Sales In general, sales of real estate and related profits/losses are recognized when all consideration has changed hands and risks and rewards of ownership have been transferred. Certain types of continuing involvement preclude sale treatment and related profit recognition; other forms of continuing involvement allow for sale recognition but require deferral of profit recognition.
Investments in Unconsolidated Real Estate Entities	Investments in Unconsolidated Real Estate Entities The Company’s investments in real estate joint ventures, where the Company has significant influence, but not control and joint ventures which are VIEs in which the Company is not the primary beneficiary, are recorded under the equity method of accounting in the accompanying consolidated financial statements. Under the equity method, the Company’s investment in real estate ventures is stated at cost and adjusted for the Company’s share of net earnings or losses and reduced by distributions. Equity in earnings of real estate ventures is generally recognized based on the Company’s ownership interest in the earnings of each of the unconsolidated real estate ventures. For the purposes of presentation in the statement of cash flows, the Company follows the “look through” approach for classification of distributions from joint ventures. Under this approach, distributions are reported under operating cash flow unless the facts and circumstances of a specific distribution clearly indicate that it is a return of capital (e.g., a liquidating dividend or distribution of the proceeds from the joint venture’s sale of assets), in which case it is reported as an investing activity.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company’s cash is deposited with financial institutions located throughout the United States and at times may exceed federally insured limits. The Company considers all highly liquid debt instruments with a maturity date of three months or less to be cash equivalents.
Restricted Cash	Restricted Cash Restricted cash is comprised of escrowed funds deposited with financial institutions located throughout the United States relating to earnest money deposits on potential acquisitions, real estate taxes, loan collateral, operating reserves and insurance and capital expenditures.
Other Assets	Other Assets Other assets consist of equipment and fixtures, rents receivable from our tenants, bridge loan receivables, investments in trusts and other receivables, other intangible assets, deferred tax assets, prepaid expenses and the fair value of interest rate swaps. Depreciation of equipment and fixtures is computed on a straight-line basis over three to five years
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities The Company records all derivatives on the balance sheet at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative, whether the Company has elected to designate a derivative in a hedging relationship and apply hedge accounting and whether the hedging relationship has satisfied the criteria necessary to apply hedge accounting. Derivatives designated and qualifying as a hedge of the exposure to changes in the fair value of an asset, liability or firm commitment attributable to a particular risk, such as interest rate risk, are considered fair value hedges. Derivatives designated and qualifying as a hedge of the exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. Hedge accounting generally provides for the matching of the timing of gain or loss recognition on the hedging instrument with the recognition of the changes in the fair value of the hedged asset or liability that are attributable to the hedged risk in a fair value hedge or the earnings effect of the hedged forecasted transactions in a cash flow hedge. The Company may enter into derivative contracts that are intended to economically hedge certain of its risk, even though hedge accounting does not apply or the Company elects not to apply hedge accounting. The Company made an accounting policy election to measure the credit risk of its derivative financial instruments that are subject to master netting agreements on a net basis by counterparty portfolio.
Risk Management and Use of Financial Instruments	Risk Management and Use of Financial Instruments In the normal course of its ongoing business operations, the Company encounters economic risk. There are three main components of economic risk: interest rate risk, credit risk and market risk. The Company is subject to interest rate risk on its interest-bearing liabilities. Credit risk is the risk of inability or unwillingness of tenants to make contractually required payments. Market risk is the risk of declines in the value of stores due to changes in rental rates, interest rates or other market factors affecting the value of stores held by the Company. The Company has entered into interest rate swap agreements to manage a portion of its interest rate risk.
Exchange of Common Operating Partnership Units	Exchange of Common Operating Partnership Units Redemption of common Operating Partnership units for shares of common stock, when redeemed under the original provisions of the Operating Partnership agreement, are accounted for by reclassifying the underlying net book value of the units from noncontrolling interest to the Company’s equity.
Revenue and Expense Recognition	Revenue and Expense Recognition Rental revenues are recognized as earned based upon amounts that are currently due from tenants. Leases are generally on month-to-month terms. Prepaid rents are recognized on a straight-line basis over the term of the leases. Promotional discounts are recognized as a reduction to rental income over the promotional period. Late charges, administrative fees and merchandise sales are recognized as income when earned. Equity in earnings of unconsolidated real estate ventures is recognized based on the Company's ownership interest in the earnings of each of the unconsolidated real estate entities. Interest income is recognized as earned. The Company's management fees are earned subject to the terms of the related management services agreements ("MSAs"). These MSAs provide that the Company will perform management services, which include leasing and operating the property and providing accounting, marketing, banking, maintenance and other services. These services are provided in exchange for monthly management fees, which are based on a percentage of revenues collected from stores owned by third parties and unconsolidated joint ventures. MSAs generally have original terms from three to five years , after which management services are provided on a month-to-month basis unless terminated. Management fees are due on the last day of each calendar month that management services are provided. The Company accounts for the management services provided to a customer as a single performance obligation which are rendered over time each month. The total amount of consideration from the contract is variable as it is based on monthly revenues, which are influenced by multiple factors, some of which are outside the Company's control. Therefore, the Company recognizes the revenue at the end of each month once the uncertainty is resolved. Due to the standardized terms of the MSAs, the Company accounts for all MSAs in a similar, consistent manner. Therefore, no disaggregated information relating to MSAs is presented. Property expenses, including utilities, property taxes, repairs and maintenance and other costs to manage the facilities are recognized as incurred. The Company accrues for property tax expense based upon invoice amounts and estimates. If these estimates are incorrect, the timing of expense recognition could be affected. Tenant reinsurance premiums are recognized as revenue over the period of insurance coverage. The Company records an unpaid claims liability at the end of each period based on existing unpaid claims and historical claims payment history. The unpaid claims liability represents an estimate of the ultimate cost to settle all unpaid claims as of each period end, including both reported but unpaid claims and claims that may have been incurred but have not been reported. The Company uses a third party claims administrator to adjust all tenant reinsurance claims received. The administrator evaluates each claim to determine the ultimate claim loss and includes an estimate for claims that may have been incurred but not reported. Annually, a third party actuary evaluates the adequacy of the unpaid claims liability. Prior year claim reserves are adjusted as experience develops or new information becomes known. The impact of such adjustments is included in the current period operations. The unpaid claims liability is not discounted to its present value. Each tenant chooses the amount of insurance coverage they want through the tenant reinsurance program. Tenants can purchase policies in amounts of 2,000 dollars to 10,000 dollars of insurance coverage in exchange for a monthly fee. As of December 31, 2019 , the average insurance coverage for tenants was approximately 3,300 dollars. The Company’s exposure per claim is limited by the maximum amount of coverage chosen by each tenant. The Company purchases reinsurance for losses exceeding a set amount for any one event. The Company does not currently have any amounts recoverable under the reinsurance arrangements.
Advertising Costs	Advertising Costs The Company incurs advertising costs primarily attributable to digital and other advertising. These costs are expensed as incurred. The Company recognized $25,106 , $16,153 and $14,410 in advertising expense for the years ended December 31, 2019 , 2018 and 2017 , respectively, which are included in property operating expenses on the Company’s consolidated statements of operations.
Income Taxes	Income Taxes The Company has elected to be treated as a REIT under Sections 856 through 860 of the Internal Revenue Code of 1986, as amended (the "Internal Revenue Code"). In order to maintain its qualification as a REIT, among other things, the Company is required to distribute at least 90% of its REIT taxable income to its stockholders and meet certain tests regarding the nature of its income and assets. As a REIT, the Company is not subject to federal income tax with respect to that portion of its income which meets certain criteria and is distributed annually to stockholders. The Company plans to continue to operate so that it meets the requirements for taxation as a REIT. Many of these requirements, however, are highly technical and complex. For any taxable year that the Company fails to qualify as a REIT and for which applicable statutory relief provisions did not apply, we would be taxed at the regular corporate rates on all of our taxable income for at least that year and the ensuing four years. The Company is subject to certain state and local taxes. Provision for such taxes has been included in income tax expense on the Company’s consolidated statements of operations. For the year ended December 31, 2019 , 0% (unaudited) of all distributions to stockholders qualified as a return of capital. The Company owns and may acquire direct or indirect interests in entities that have elected or will elect to be taxed as REITs under the Internal Revenue Code (each, a “Subsidiary REIT ”). A Subsidiary REIT is subject to the various REIT qualification requirements and other limitations described herein that are applicable to the Company. If a Subsidiary REIT were to fail to qualify as a REIT, then (i) that Subsidiary REIT would become subject to U.S. federal income tax, (ii) shares in such Subsidiary REIT would cease to be qualifying assets for purposes of the asset tests applicable to REITs, and (iii) it is possible that the Company would fail certain of the asset tests applicable to REITs, in which event the Company would fail to qualify as a REIT unless it could avail itself of certain relief provisions. The Company has elected to treat its corporate subsidiary, Extra Space Management, Inc. (“ESMI”), as a taxable REIT subsidiary (“TRS”). In general, the Company’s TRS may perform additional services for tenants and may engage in any real estate or non-real estate related business. A TRS is subject to federal corporate income tax. ESM Reinsurance Limited, a wholly-owned subsidiary of ESMI, generates income from insurance premiums that are subject to federal corporate income tax and state insurance premiums tax. Deferred tax assets and liabilities are determined based on differences between financial reporting and tax bases of assets and liabilities. At December 31, 2019 and 2018 , 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 December 31, 2019 and 2018 , the Company had no interest or penalties related to uncertain tax provisions.
Stock-Based Compensation	Stock-Based Compensation The measurement and recognition of compensation expense for all share-based payment awards to employees and directors are based on estimated fair values. Awards granted are valued at fair value and any compensation expense is recognized over the service periods of each award.
Earnings Per Common Share	Earnings Per Common Share Basic earnings per common share is computed using the two-class method by dividing net income attributable to common stockholders by the weighted average number of common shares outstanding during the period. All outstanding unvested restricted stock awards contain rights to non-forfeitable dividends and participate in undistributed earnings with common stockholders; accordingly, they are considered participating securities that are included in the two-class method. Diluted earnings per common share measures the performance of the Company over the reporting period while giving effect to all potential common shares that were dilutive and outstanding during the period. The denominator includes the weighted average number of basic shares and the number of additional common shares that would have been outstanding if the potential common shares that were dilutive had been issued, and is calculated using either the two-class, treasury stock or as if-converted method, whichever is most dilutive. Potential common shares are securities (such as options, convertible debt, Series A Participating Redeemable Preferred Units (“Series A Units”), Series B Redeemable Preferred Units (“Series B Units”), Series C Convertible Redeemable Preferred Units (“Series C Units”), Series D Redeemable Preferred Units (“Series D Units” and together with the Series A Units, Series B Units and Series C Units, the “Preferred OP Units") and common Operating Partnership units (“OP Units”)) that do not have a current right to participate in earnings of the Company but could do so in the future by virtue of their option, redemption or conversion right. In computing the dilutive effect of convertible securities, net income is adjusted to add back any changes in earnings in the period associated with the convertible security. The numerator also is adjusted for the effects of any other non-discretionary changes in income or loss that would result from the assumed conversion of those potential common shares. In computing diluted earnings per common share, only potential common shares that are dilutive (those that reduce earnings per common share) are included. For the years ended December 31, 2019 , 2018 and 2017 , options to purchase approximately zero , 36,075 , and 45,286 shares of common stock, respectively, were excluded from the computation of earnings per share as their effect would have been anti-dilutive. For the purposes of computing the diluted impact of the potential exchange of the Preferred OP Units for common shares upon redemption, where the Company has the option to redeem in cash or shares and where the Company has stated the intent and ability to settle the redemption in shares, the Company divided the total liquidation value of the Preferred OP Units by the average share price of $106.57 for the year ended December 31, 2019 . The following table presents the number of weighted OP Units and Preferred OP Units, and the potential common shares, that were excluded from the computation of earnings per share as their effect would have been anti-dilutive: For the Year Ended December 31, 2019 2018 2017 Equivalent Shares (if converted) Equivalent Shares (if converted) Equivalent Shares (if converted) Series B Units 393,189 464,033 533,174 Series C Units (1) — 312,075 377,135 Series D Units 1,081,369 1,019,524 — 1,474,558 1,795,632 910,309 (1) The remainder of the Series C Units were converted to OP Units on April 25, 2019. The Operating Partnership had $575,000 of its 3.125% Exchangeable Senior Notes due 2035 (the “2015 Notes”) issued and outstanding as of December 31, 2019 . The 2015 Notes could potentially have a dilutive impact on the Company’s earnings per share calculations. The 2015 Notes are exchangeable by holders into shares of the Company’s common stock under certain circumstances per the terms of the indenture governing the 2015 Notes. The exchange price of the 2015 Notes was $91.76 per share as of December 31, 2019 , and could change over time as described in the indenture. The Company has irrevocably agreed to pay only cash for the accreted principal amount of the 2015 Notes relative to its exchange obligations, but retained the right to satisfy the exchange obligation in excess of the accreted principal amount in cash and/or common stock. Though the Company has retained that right, Accounting Standards Codification (“ASC”) 260, “Earnings per Share,” requires an assumption that shares would be used to pay the exchange obligation in excess of the accreted principal amount, and requires that those shares be included in the Company’s calculation of weighted average common shares outstanding for the diluted earnings per share computation. For the years ended December 31, 2019 and 2018, the Company had repaid the principal and accrued interest of its Exchangeable Senior Notes due 2033 (the “2013 Notes”), and therefore, no shares relating to the 2013 Notes were included in the computation of diluted earnings per share. For the year ended December 31, 2017, 344,430 shares related to the 2013 Notes were included in the computation of diluted earnings per share. For the year ended December 31, 2019 , 993,114 shares related to the 2015 Notes were included in the computation of diluted earnings per share. For the years ended December 31, 2018 and 2017 , no shares related to the 2015 Notes were included in the computation of diluted earnings per share as the exchange price exceeded the per share price of the Company’s common stock during these periods. For the purposes of computing the diluted impact on earnings per share of the potential exchange of Series A Units for common shares upon redemption, where the Company has the option to redeem in cash or shares and where the Company has stated the positive intent and ability to settle at least $101,700 of the instrument in cash (or net settle a portion of the Series A Units against the related outstanding note receivable), only the amount of the instrument in excess of $101,700 is considered in the calculation of shares contingently issuable for the purposes of computing diluted earnings per share as allowed by ASC 260-10-45-46.
Recently Issued Accounting Standards	Recently Issued Accounting Standards In May 2014, the Financial Accounting Standards Board ("FASB") issued ASU 2014-9, “ Revenue from Contracts with Customers, ” ("Topic 606") which amends the guidance for revenue recognition to replace numerous, industry-specific requirements and converges areas under this topic with those of the International Financial Reporting Standards. Topic 606 outlines a five-step process for customer contract revenue recognition that focuses on transfer of control, as opposed to transfer of risk and rewards. The amendment also requires enhanced disclosures regarding the nature, amount, timing and uncertainty of revenues and cash flows from contracts with customers. Topic 606 became effective for annual and interim periods beginning after December 15, 2017. The Company determined that its property rental revenue and tenant reinsurance revenue are not subject to the guidance in Topic 606, as they qualify as lease contract and insurance contracts, which are excluded from its scope. The Company's management fee revenue is included in the scope of Topic 606, and revenue recognized under the standard does not differ materially from revenue recognized under previous guidance. The Company adopted the standard using the modified retrospective transition method as of January 1, 2018. The Company's adoption of Topic 606 did not result in a cumulative catch-up adjustment or any significant changes to financial statement line items. In February 2016, the FASB issued ASU 2016-02, "Leases (Topic 842)," which modifies the accounting for leases, intending to increase transparency and comparability of organizations by requiring balance sheet presentation of leased assets and increased financial statement disclosure of leasing arrangements. ASU 2016-02 requires entities to recognize a liability for their lease obligations and a corresponding asset representing the right to use the underlying asset over the lease term. ASU 2016-02 became effective for annual and interim periods beginning after December 15, 2018. The Company adopted the standard using the modified retrospective approach as of January 1, 2019. The Company elected the package of practical expedients upon adoption, which allows for the application of the standard solely to the transition period in 2019 but does not require application to prior fiscal comparative periods presented. The Company also elected the practical expedient provided in a subsequent amendment to ASU 2016-02 that removed the requirement to separate lease and nonlease components. The Company did not record a significant cumulative catch-up adjustment upon the adoption of ASC 2016-02. The primary impact was related to the Company's 22 operating ground leases and two corporate facility leases under which it served as lessee as of the adoption date. The Company recognized lease liabilities totaling $104,863 and right-of-use assets related to operating leases totaling $ 95,506 as of the adoption date. Refer to footnote 13 for further discussion of the Company's leases. In October 2016, the FASB issued ASU 2016-18, " Statement of Cash Flows (Topic 230): Restricted Cash," which requires that a statement of cash flows explains the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. This guidance is effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. The Company adopted this guidance as of January 1, 2018, and now presents restricted cash along with cash and cash equivalents in its consolidated statements of cash flows. Prior periods were reclassified to conform to this presentation. In June 2016, the FASB issued ASU 2016-13, " Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments." ASU 2016-13 changes how entities measure credit losses for most financial assets. This standard requires an entity to estimate its lifetime "expected credit loss" and record an allowance that, when deducted from the amortized cost basis of the financial asset, presents the net amount expected to be collected on the financial asset. In November 2018, the FASB issued ASU 2018-19, "Codification Improvements to Topic 326, Financial Instruments - Credit Losses," which clarified that receivables arising from operating leases are within the scope of the leasing standard (ASU 2016-02), and not within the scope of ASU 2016-13. This new standard was effective for the Company on January 1, 2020. The Company does not expect this new standard to have a material impact on the Company's consolidated financial statements.
Convertible Debt	GAAP requires entities with convertible debt instruments that may be settled entirely or partially in cash upon conversion to separately account for the liability and equity components of the instrument in a manner that reflects the issuer’s economic interest cost. The Company therefore accounts for the liability and equity component of the 2015 Notes separately. The equity components are included in paid-in capital in stockholders’ equity in the consolidated balance sheets, and the value of the equity components are treated as original issue discount for purposes of accounting for the debt components. The discount is being amortized as interest expense over the remaining period of the debt through its first redemption date, October 1, 2020 for the 2015 Notes. The effective interest rate on the liability components of the 2015 Notes is 4.0% , which approximates the market rate of interest of similar debt without exchange features (i.e. nonconvertible debt) at the time of issuance.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis	The table below presents the Company’s assets and liabilities measured at fair value on a recurring basis as of December 31, 2019 , aggregated by the level in the fair value hierarchy within which those measurements fall. Fair Value Measurements at Reporting Date Using Description December 31, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Other assets - Cash flow hedge swap agreements $ 6,214 $ — $ 6,214 $ — Other liabilities - Cash flow hedge swap agreements $ 31,400 $ — $ 31,400 $ —
Schedule of Fair Value of Financial Instruments	The fair values of the Company’s fixed-rate assets and liabilities were as follows for the periods indicated: December 31, 2019 December 31, 2018 Fair Carrying Fair Carrying Notes receivable from Preferred and Common Operating Partnership unit holders $ 116,184 $ 118,524 $ 115,467 $ 119,735 Fixed rate notes payable and notes payable to trusts $ 3,511,151 $ 3,417,928 $ 2,985,731 $ 3,022,414 Exchangeable senior notes $ 673,831 $ 575,000 $ 620,149 $ 575,000
Schedule of Unpaid Claims Liability	The following table presents information on the portion of the Company’s unpaid claims liability, which is included in other liabilities on the Company's consolidated balance sheets, that relates to tenant insurance for the periods indicated: For the Year Ended December 31, Tenant Reinsurance Claims: 2019 2018 2017 Unpaid claims liability at beginning of year $ 7,326 $ 5,167 $ 3,896 Claims and claim adjustment expense for claims incurred in the current year 16,280 15,800 11,700 Claims and claim adjustment expense (benefit) for claims incurred in the prior years 98 107 (203 ) Payments for current year claims (11,352 ) (11,010 ) (8,895 ) Payments for prior year claims (4,243 ) (2,738 ) (1,331 ) Unpaid claims liability at the end of the year $ 8,109 $ 7,326 $ 5,167
Schedule of Antidilutive Shares Excluded from Computation of Earnings Per Share	The following table presents the number of weighted OP Units and Preferred OP Units, and the potential common shares, that were excluded from the computation of earnings per share as their effect would have been anti-dilutive: For the Year Ended December 31, 2019 2018 2017 Equivalent Shares (if converted) Equivalent Shares (if converted) Equivalent Shares (if converted) Series B Units 393,189 464,033 533,174 Series C Units (1) — 312,075 377,135 Series D Units 1,081,369 1,019,524 — 1,474,558 1,795,632 910,309 (1) The remainder of the Series C Units were converted to OP Units on April 25, 2019.
Schedule of Computation of Earnings Per Common Share	The computation of earnings per share is as follows for the periods presented: For the Year Ended December 31, 2019 2018 2017 Net income attributable to common stockholders $ 419,967 $ 415,289 $ 479,013 Earnings and dividends allocated to participating securities (680 ) (723 ) (975 ) Earnings for basic computations 419,287 414,566 478,038 Earnings and dividends allocated to participating securities 680 723 — Income allocated to noncontrolling interest - Preferred Operating Partnership Units and Operating Partnership Units 23,727 22,831 30,088 Fixed component of income allocated to noncontrolling interest - Preferred Operating Partnership (Series A Units) (2,288 ) (2,288 ) (3,119 ) Net income for diluted computations $ 441,406 $ 435,832 $ 505,007 Weighted average common shares outstanding: Average number of common shares outstanding - basic 128,203,568 126,087,487 125,967,831 OP Units 6,006,114 5,675,547 5,590,831 Series A Units 875,480 875,480 875,480 Series D Units — — 1,081,561 Unvested restricted stock awards included for treasury stock method 212,402 244,215 — Shares related to exchangeable senior notes and dilutive stock options 1,136,205 276,304 640,068 Average number of common shares outstanding - diluted 136,433,769 133,159,033 134,155,771 Earnings per common share Basic $ 3.27 $ 3.29 $ 3.79 Diluted $ 3.24 $ 3.27 $ 3.76

Real Estate Assets (Tables)

Real Estate Assets (Tables)	12 Months Ended
	Dec. 31, 2019
Real Estate [Abstract]
Schedule of Components of Real Estate Assets	The components of real estate assets are summarized as follows: December 31, 2019 December 31, 2018 Land - operating $ 1,935,551 $ 1,825,133 Land - development 3,372 7,359 Buildings, improvements and other intangibles 7,047,654 6,743,355 Right of use asset - finance lease 8,050 — Intangible assets - tenant relationships 122,489 119,557 Intangible lease rights 12,443 12,443 9,129,559 8,707,847 Less: accumulated depreciation and amortization (1,473,852 ) (1,262,438 ) Net operating real estate assets 7,655,707 7,445,409 Real estate under development/redevelopment 41,157 46,422 Net real estate assets $ 7,696,864 $ 7,491,831 Real estate assets held for sale included in net real estate assets $ 2,947 $ 13,032

Property Acquisitions and Dis_2

Property Acquisitions and Dispositions (Tables)	12 Months Ended
	Dec. 31, 2019
Real Estate [Abstract]
Schedule of Operating Properties Acquired	The following table shows the Company’s acquisitions of stores for the years ended December 31, 2019 and 2018 . The table excludes purchases of raw land or improvements made to existing assets. Consideration Paid Total Quarter Number of Stores Total Cash Paid Loan Assumed Investments in Real Estate Ventures Net Liabilities/ (Assets) Assumed Value of OP Units Issued Number of OP Units Issued Real estate assets Q4 2019 5 $ 51,278 $ 51,058 $ — $ — $ 220 $ — — $ 51,278 Q3 2019 1 16,937 16,941 — — (4 ) — — 16,937 Q2 2019 1 8,424 8,424 — — — — — 8,424 Q1 2019 14 223,740 202,890 17,157 2,780 913 — — 223,740 21 (1) $ 300,379 $ 279,313 $ 17,157 $ 2,780 $ 1,129 $ — — $ 300,379 Q4 2018 6 $ 74,852 $ 74,868 $ — $ — $ (16 ) $ — — $ 74,852 Q3 2018 6 74,694 71,989 — — 2,705 — — 74,694 Q2 2018 17 237,284 148,650 87,500 (1,024 ) 281 1,877 21,768 237,284 Q1 2018 5 70,787 70,171 — 489 127 — — 70,787 34 (2) $ 457,617 $ 365,678 $ 87,500 $ (535 ) $ 3,097 $ 1,877 21,768 $ 457,617 (1) Store acquisitions during the year ended December 31, 2019 include the acquisition of 12 stores previously held in joint ventures where the Company held a noncontrolling interest. The Company purchased its partners' remaining equity interests in the joint ventures, and the properties owned by the joint ventures became wholly owned by the Company. No gain or loss was recognized as a result of these acquisitions. (2) Store acquisitions during the year ended December 31, 2018 include the acquisition of 15 stores previously held in joint ventures where the Company held a noncontrolling interest. The Company purchased its partners' remaining equity interests in the joint ventures, and the properties owned by the joint ventures became wholly owned by the Company. No gain or loss was recognized as a result of these acquisitions.

Investments in Unconsolidated_2

Investments in Unconsolidated Real Estate Entities (Tables)	12 Months Ended
	Dec. 31, 2019
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Investments in Unconsolidated Real Estate Entities	Net Investments in unconsolidated real estate entities and cash distributions in unconsolidated real estate ventures consist of the following: Number of Stores Equity Ownership % Excess Profit % (1) December 31, 2019 2018 PRISA Self Storage LLC 85 4% 4% $ 9,133 $ 9,334 Storage Portfolio II JV LLC 36 10% 30% (4,827 ) (4,233 ) Storage Portfolio I LLC 24 34% 49% (38,345 ) (38,129 ) VRS Self Storage, LLC 16 45% 54% 17,639 18,281 ESS-NYFL JV LP 11 16% 24% 13,320 — WICNN JV LLC (3) 10 10% 25% 36,552 26,885 Extra Space Northern Properties Six LLC 10 10% 35% (2,091 ) (1,700 ) Alan Jathoo JV LLC 9 10% 10% 7,977 8,180 PR EXR Self Storage, LLC 5 25% 40% 59,391 19,841 ESS Bristol Investments LLC 8 10% 28% 3,046 2,331 GFN JV, LLC (3) 5 10% 30% 12,168 10,586 Extra Space West Two LLC (4) — 5% 40% — 3,818 Extra Space West One LLC (4) — 5% 40% — (1,038 ) Other minority owned stores 22 10-50% 19-50% 28,827 25,973 SmartStop Self Storage REIT, Inc. Preferred Stock (2) n/a n/a n/a 150,000 — Net Investments in and Cash distributions in unconsolidated real estate entities 241 $ 292,790 $ 80,129 (1) Includes pro-rata equity ownership share and promoted interest. (2) In October 2019, the Company invested $150,000 in shares of newly issued convertible preferred stock of SmartStop, with an additional commitment to purchase up to $ 50,000 of the preferred shares over the 12 months after the original purchase. The dividend rate for the preferred shares is 6.25% per annum, subject to increase after five years . The preferred shares are generally not redeemable for five years , except in the case of a change of control or initial listing of SmartStop. Dividend income from this investment is included on the management fees and other income line on the Company's consolidated statements of operations. (3) The Company had $31,500 and $10,335 of preferred equity in the WICNN JV LLC and GFN JV, LLC joint ventures, respectively, as of December 31, 2019 . The Company earns an 8.0% return on its preferred equity in these joint ventures, which has priority over other distributions. (4) In January 2019, the Company purchased its joint venture partners' interests in the Extra Space West One LLC and Extra Space West Two LLC joint ventures, which owned a total of 12 stores. The Company paid $172,505 of cash to acquire the equity interests, and subsequent to this acquisition, the Company owned 100.0%
Equity Method Investments	Information about these new real estate ventures is summarized as follows: Number of Stores Equity ownership % Total initial investment For the Year Ended December 31, 2019 16 10.0%-50.0% $ 19,663 For the Year Ended December 31, 2018 28 10.0% -50.0% $ 63,723 For the Year Ended December 31, 2017 39 10.0% - 25.0% $ 13,341
Schedule of Equity in Earnings of Unconsolidated Real Estate Ventures	Equity in earnings of unconsolidated real estate ventures consists of the following: For the Year Ended December 31, 2019 2018 2017 Equity in earnings of PRISA Self Storage LLC $ 2,327 $ 2,338 $ 2,430 Equity in earnings of Storage Portfolio II JV LLC 291 79 33 Equity in earnings of Storage Portfolio I LLC 1,809 1,886 2,684 Equity in earnings of VRS Self Storage, LLC 3,583 3,640 3,562 Equity in earnings of ESS-NYFL JV LLC (96 ) — — Equity in earnings of WICNN JV LLC 1,373 622 — Equity in earnings of Extra Space Northern Properties Six LLC 1,091 1,014 918 Equity in earnings of Alan Jathoo JV LLC (47 ) (12 ) — Equity in earnings of Bristol Investments LLC (262 ) (152 ) — Equity in earnings of GFN JV, LLC 450 22 — Equity in earnings of PR EXR Self Storage, LLC (443 ) (75 ) (105 ) Equity in earnings of WCOT Self Storage LLC — 359 1,033 Equity in earnings of Extra Space West Two LLC — 1,042 1,210 Equity in earnings of Extra Space West One LLC — 2,526 2,502 Equity in earnings of other minority owned stores 1,198 1,163 1,064 $ 11,274 $ 14,452 $ 15,331

Notes Payable and Revolving L_2

Notes Payable and Revolving Lines of Credit (Tables)	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Schedule of Components of Notes Payable	The components of notes payable are summarized as follows: Notes Payable December 31, 2019 December 31, 2018 Fixed Rate Variable Rate Basis Rate (2) Maturity Dates Secured fixed rate notes payable (1) $ 1,365,408 $ 2,032,414 2.53% - 6.00% September 2020 - February 2030 Secured variable rate notes payable (1) 878,093 834,835 3.01% - 3.31% Libor plus 1.3% - 1.6% April 2020 - August 2028 Unsecured fixed rate notes payable 2,052,521 990,000 2.80% - 4.39% October 2023 - October 2029 Unsecured variable rate notes payable 47,480 310,000 2.76% - 3.31% Libor plus 1.0% - 1.6% January 2025 - June 2026 Total 4,343,502 4,167,249 Less: unamortized debt issuance costs (24,529 ) (29,936 ) Total $ 4,318,973 $ 4,137,313 (1) The loans are collateralized by mortgages on real estate assets and the assignment of rents. (2) 30-day USD LIBOR
Schedule of Maturities of Notes Payable	The following table summarizes the scheduled maturities of notes payable, excluding available extensions, at December 31, 2019 : 2020 $ 568,431 2021 252,053 2022 150,796 2023 767,405 2024 712,972 Thereafter 1,891,845 $ 4,343,502
Schedule of Information on Lines of Credit	The following table presents information on the Company’s lines of credit, the proceeds of which are used to repay debt and for general corporate purposes, for the periods indicated: As of December 31, 2019 Revolving Lines of Credit Amount Drawn Capacity Interest Rate Origination Date Maturity Basis Rate (1) Credit Line 1 (2) $ 38,000 $ 140,000 3.2% 6/4/2010 7/1/2021 LIBOR plus 1.45% Credit Line 2 (3)(4) 120,000 650,000 2.7% 12/7/2018 1/29/2023 LIBOR plus 0.9% $ 158,000 $ 790,000 (1) 30-day USD LIBOR (2) Secured by mortgages on certain real estate assets. One two-year extension available. (3) Unsecured. Two six-month extensions available. (4) Basis Rate as of December 31, 2019. Rate is subject to change based on our investment grade rating.

Derivatives (Tables)

Derivatives (Tables)	12 Months Ended
	Dec. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule Summarizing Terms of Entity's Derivative Financial Instruments	The following table summarizes the terms of the Company’s 24 derivative financial instruments, which have a total combined notional amount of $2,354,609 as of December 31, 2019 : Hedge Product Range of Notional Amounts Strike Effective Dates Maturity Dates Swap Agreements $30,943 - $267,431 1.13% - 4.60% 1/1/2014 - 7/29/2019 9/14/2020 - 6/29/2026
Schedule of Balance Sheet Classification and Fair Value of Entity's Derivative Financial Instruments	The table below presents the fair value of the Company’s derivative financial instruments as well as their classification on the consolidated balance sheets: Asset / Liability Derivatives December 31, 2019 December 31, 2018 Derivatives designated as hedging instruments: Fair Value Other assets $ 6,214 $ 42,324 Other liabilities $ 31,400 $ 2,131
Schedule of Information Relating to Gain (Loss) Recognized on Swap Agreements	The tables below present the effect of the Company’s derivative financial instruments on the consolidated statements of operations for the periods presented. No tax effect has been presented as the derivative instruments are held by the Company: Gain (loss) recognized in OCI For the Year Ended December 31, Location of amounts reclassified from OCI into income Gain (loss) reclassified from OCI For the Year Ended December 31, Type 2019 2018 2019 2018 2017 Swap Agreements $ (54,680 ) $ 9,889 Interest expense $ 12,322 $ 8,258 $ (8,853 )

Exchangeable Senior Notes (Tabl

Exchangeable Senior Notes (Tables)	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Schedule of Information about Carrying Amount of Equity Component, Principal Amount of Liability Component, Unamortized Discount and Net Carrying Amount for Notes	Information about the 2015 Notes, including the total carrying amounts of the equity component, the principal amount of the liability component, the unamortized discount and net carrying amount, was as follows for the periods indicated: December 31, 2019 December 31, 2018 Carrying amount of equity component $ 22,597 $ 22,597 Principal amount of liability component $ 575,000 $ 575,000 Unamortized discount - equity component (3,675 ) (8,417 ) Unamortized debt issuance costs (1,812 ) (4,209 ) Net carrying amount of liability component $ 569,513 $ 562,374
Summary of Amount of Interest Cost Recognized Relating to Contractual Interest Rate and Amortization of Discount on Liability Component of Notes	The amount of interest cost recognized relating to the contractual interest rate and the amortization of the discount on the liability component for the Notes were as follows for the periods indicated: For the Year Ended December 31, 2019 2018 2017 Contractual interest $ 17,968 $ 18,106 $ 19,303 Amortization of discount 4,742 4,687 5,103 Total interest expense recognized $ 22,710 $ 22,793 $ 24,406
Summary of Repurchase of Debt	Information about the repurchases is as follows: For the Year Ended December 31, 2018 2017 Principal amount repurchased $ 49,259 $ 13,911 Amount allocated to: Extinguishment of liability component $ 49,019 $ 13,692 Reacquisition of equity component 31,251 6,350 Total consideration paid for repurchase $ 80,270 $ 20,042 Exchangeable senior notes repurchased $ 49,259 $ 13,911 Extinguishment of liability component (49,019 ) (13,692 ) Discount on exchangeable senior notes (230 ) (184 ) Related debt issuance costs (10 ) (35 ) Gain/(loss) on repurchase $ — $ —

Noncontrolling Interests In O_2

Noncontrolling Interests In Operating Partnership and Other Noncontrolling Interests (Tables)	12 Months Ended
	Dec. 31, 2019
Noncontrolling Interest [Abstract]
Redeemable Noncontrolling Interest	OP Unit activity is summarized as follows for the periods presented: For the Year Ended December 31, 2019 2018 2017 OP Units redeemed for common stock 340,182 35,000 — OP Units redeemed for cash — 30,000 33,896 Cash paid for OP Units redeemed $ — $ 2,558 $ 2,510 OP Units issued in conjunction with acquisitions — 21,768 90,228 Value of OP Units issued in conjunction with acquisitions $ — $ 1,877 $ 7,618 OP Units issued upon redemption of Series C Units 270,709 373,113 —

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Lease Costs	Following is information on our total lease costs as of the period indicated: For the Year Ended December 31, 2019 Finance lease cost: Amortization of finance lease right-of-use assets $ 168 Interest expense related to finance lease liabilities 290 Operating lease cost 20,268 Variable lease cost 5,068 Short-term lease cost 164 Total lease cost $ 25,958 Cash paid for amounts included in the measurement of lease liabilities Operating cash outflows for finance lease payments $ 231 Operating cash outflows for operating lease payments 19,226 Total cash flows for lease liability measurement $ 19,457 Right-of-use assets obtained in exchange for new operating lease liabilities $ 277,557 Right-of-use assets obtained in exchange for new finance lease liabilities $ 8,050 Weighted average remaining lease term - finance leases (years) 46.9 Weighted average remaining lease term - operating leases (years) 14.7 Weighted average discount rate - finance leases 6.07 % Weighted average discount rate - operating leases 3.65 %
Undiscounted Cash Flows on an Annual Basis, Operating Leases	The following table presents information about the Company’s undiscounted cash flows on an annual basis for operating and finance leases, including a reconciliation of the undiscounted cash flows to the finance lease and operating lease liabilities recognized in the Company’s consolidated balance sheets: Operating Finance Total 2020 $ 28,369 $ 232 $ 28,601 2021 28,628 237 28,865 2022 28,651 255 28,906 2023 28,707 255 28,962 2024 29,198 255 29,453 Thereafter 223,823 16,522 240,345 Total $ 367,376 $ 17,756 $ 385,132 Present value adjustments (92,593 ) (12,918 ) (105,511 ) Lease liabilities $ 274,783 $ 4,838 $ 279,621
Undiscounted Cash Flows on an Annual Basis, Financing Leases	The following table presents information about the Company’s undiscounted cash flows on an annual basis for operating and finance leases, including a reconciliation of the undiscounted cash flows to the finance lease and operating lease liabilities recognized in the Company’s consolidated balance sheets: Operating Finance Total 2020 $ 28,369 $ 232 $ 28,601 2021 28,628 237 28,865 2022 28,651 255 28,906 2023 28,707 255 28,962 2024 29,198 255 29,453 Thereafter 223,823 16,522 240,345 Total $ 367,376 $ 17,756 $ 385,132 Present value adjustments (92,593 ) (12,918 ) (105,511 ) Lease liabilities $ 274,783 $ 4,838 $ 279,621
Future Minimum Lease Payments Under Operating Leases	The following table summarizes future minimum lease payments required under operating leases as of December 31, 2018: 2019 $ 8,203 2020 8,307 2021 8,137 2022 7,837 2023 7,021 Thereafter 111,653 $ 151,158

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Summary of Stock Option Activity	A summary of stock option activity is as follows: Options Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Life (Years) Aggregate Intrinsic Value as of December 31, 2019 Outstanding at December 31, 2016 510,574 $ 30.60 Exercised (38,418 ) 32.94 Outstanding at December 31, 2017 472,156 $ 30.41 Exercised (54,575 ) 21.45 Outstanding at December 31, 2018 417,581 $ 31.58 Exercised (211,057 ) 14.65 Outstanding at December 31, 2019 206,524 $ 48.88 3.43 $11,719 Vested and Expected to Vest 206,460 $ 48.87 3.43 $11,717 Ending Exercisable 197,576 $ 47.20 3.30 $11,543
Schedule of Stock Options Outstanding and Exercisable	A summary of stock options outstanding and exercisable as of December 31, 2019 , is as follows: Options Outstanding Options Exercisable Exercise Price Shares Weighted Average Remaining Contractual Life Weighted Average Exercise Price Shares Weighted Average Exercise Price $12.21 - $12.21 77,400 0.18 $ 12.21 77,400 $ 12.21 $38.40 - $38.40 8,085 3.14 38.40 8,085 38.40 $47.50 - $47.50 9,800 4.13 47.50 9,800 47.50 $65.36 - $65.36 15,647 5.15 65.36 15,647 65.36 $65.45 - $65.45 11,960 5.13 65.45 11,960 64.45 $73.52 - $73.52 50,000 5.58 73.52 50,000 73.52 $85.99 - $85.99 33,632 6.15 85.99 24,684 85.99 206,524 3.42 $ 48.88 197,576 $ 47.20
Summary of Company's Employee and Director Share Grant Activity	A summary of the Company’s employee and director share grant activity is as follows: Restricted Stock Grants Shares Weighted-Average Grant-Date Fair Value Unreleased at December 31, 2016 299,585 $ 70.57 Granted 95,392 74.49 Released (120,323 ) 63.95 Cancelled (8,179 ) 77.25 Unreleased at December 31, 2017 266,475 $ 74.76 Granted 85,066 86.14 Released (116,656 ) 72.38 Cancelled (11,771 ) 80.96 Unreleased at December 31, 2018 223,114 $ 80.02 Granted 109,081 101.52 Released (110,724 ) 79.58 Cancelled (8,863 ) 90.11 Unreleased at December 31, 2019 212,608 $ 90.85
Schedule of Nonvested Performance-based Units Activity	A summary of the PSU activity is as follows: Performance-Based Stock Units Units Weighted-Average Grant-Date Fair Value Unvested at December 31, 2016 — $ — Granted 30,071 83.84 Unvested at December 31, 2017 30,071 $ 83.84 Granted 28,735 96.19 Unvested at December 31, 2018 58,806 $ 89.87 Granted 49,334 103.18 Unvested at December 31, 2019 108,140 $ 95.94
Schedule of Weighted Average Assumptions Used to Estimate Fair Value of Awards	A Monte Carlo simulation model was used to calculate the fair value of the TSR Target portion of the PSUs, using the following assumptions: For the Year Ended December 31, 2019 2018 2017 Intrinsic value $6,211 $5,321 $2,630 Risk-free rate 2.53% 2.37% 1.62% Volatility 20.7% 22.6% 21.4% Expected term (in years) 2.8 2.9 2.8 Dividend yield —% —% —% Unrecognized compensation cost $4,315 $2,739 $1,681 Term over which compensation cost recognized 3 3 3

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Summarized Statement of Components of Income Tax Provision	The income tax provision for the years ended December 31, 2019 , 2018 and 2017 , is comprised of the following components: For the Year Ended December 31, 2019 Federal State Total Current expense $ 10,164 $ 2,936 $ 13,100 Tax credits/true-up (3,633 ) (30 ) (3,663 ) Change in deferred expense/(benefit) 1,787 84 1,871 Total tax expense $ 8,318 $ 2,990 $ 11,308 For the Year Ended December 31, 2018 Federal State Total Current expense $ 9,136 $ 2,426 $ 11,562 Tax credits/true-up (5,841 ) (175 ) (6,016 ) Change in deferred expense 3,730 (32 ) 3,698 Total tax expense $ 7,025 $ 2,219 $ 9,244 For the Year Ended December 31, 2017 Federal State Total Current expense $ 5,677 $ 1,662 $ 7,339 Tax credits/true-up (5,573 ) (383 ) (5,956 ) Change in deferred benefit 1,700 542 2,242 Total tax expense $ 1,804 $ 1,821 $ 3,625
Schedule of Reconciliation of Statutory Income Tax Provisions to the Effective Income Tax Provisions	A reconciliation of the statutory income tax provisions to the effective income tax provisions for the periods indicated is as follows: For the Year Ended December 31, 2019 2018 2017 Expected tax at statutory rate $ 97,110 21.0 % $ 95,828 21.0 % $ 186,274 35.0 % Non-taxable REIT income (82,717 ) (17.9 )% (83,022 ) (18.2 )% (170,811 ) (32.1 )% State and local tax expense - net of federal benefit 2,837 0.6 % 2,385 0.5 % 2,306 0.4 % Change in valuation allowance (207 ) — % (1,052 ) (0.2 )% 159 — % Tax credits/true-up (3,663 ) (0.8 )% (6,016 ) (1.3 )% (5,956 ) (1.1 )% Remeasurement of deferred balances — — % — — % (8,460 ) (1.6 )% Miscellaneous (2,052 ) (0.4 )% 1,121 0.2 % 113 — % Total provision $ 11,308 2.5 % $ 9,244 2.0 % $ 3,625 0.6 %
Schedule of Major Sources of Temporary Differences Stated at their Deferred Tax Effects	The major sources of temporary differences stated at their deferred tax effects are as follows: December 31, 2019 December 31, 2018 Deferred tax liabilities: Fixed assets $ (23,805 ) $ (20,907 ) Operating lease right-of-use assets (2,475 ) — Other (84 ) (96 ) State deferred taxes (3,405 ) (3,076 ) Total deferred tax liabilities (29,769 ) (24,079 ) Deferred tax assets: Captive insurance subsidiary 312 324 Accrued liabilities 2,006 1,772 Stock compensation 2,118 1,604 Operating lease liabilities 2,478 — SmartStop TRS 219 219 Other 50 53 State deferred taxes 7,250 7,196 Total deferred tax assets 14,433 11,168 Valuation allowance (3,665 ) (3,872 ) Net deferred income tax liabilities $ (19,001 ) $ (16,783 )

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Schedule of Financial Information of Business Segments	Financial information for the Company’s business segments is set forth below: Year Ended December 31, 2019 2018 2017 Revenues: Self-Storage Operations $ 1,130,177 $ 1,039,340 $ 967,229 Tenant Reinsurance 128,387 115,507 98,401 Total segment revenues $ 1,258,564 $ 1,154,847 $ 1,065,630 Operating expenses: Self-Storage Operations $ 336,050 $ 291,695 $ 271,974 Tenant Reinsurance 29,376 25,707 19,173 Total segment operating expenses $ 365,426 $ 317,402 $ 291,147 Net operating income: Self-Storage Operations $ 794,127 $ 747,645 $ 695,255 Tenant Reinsurance 99,011 89,800 79,228 Total segment net operating income: $ 893,138 $ 837,445 $ 774,483 Total segment net operating income $ 893,138 $ 837,445 $ 774,483 Other components of net income (loss): Property management fees and other income 49,890 41,757 39,379 General and administrative expense (89,418 ) (81,256 ) (78,961 ) Depreciation and amortization expense (219,857 ) (209,050 ) (193,296 ) Gain on real estate transactions and impairment of real estate 1,205 30,807 112,789 Interest expense (186,526 ) (178,436 ) (153,511 ) Non-cash interest expense related to the amortization of discount on equity component of exchangeable senior notes (4,742 ) (4,687 ) (5,103 ) Interest income 7,467 5,292 6,736 Equity in earnings of unconsolidated real estate entities 11,274 14,452 15,331 Income tax expense (11,308 ) (9,244 ) (3,625 ) Net income $ 451,123 $ 447,080 $ 514,222

Supplementary Quarterly Finan_2

Supplementary Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Schedule of Supplementary Quarterly Financial Data	For the Three Months Ended March 31, 2019 June 30, 2019 September 30, 2019 December 31, 2019 Revenues $ 311,546 $ 323,602 $ 337,505 $ 335,801 Cost of operations 163,069 165,609 174,867 171,156 Revenues less cost of operations $ 148,477 $ 157,993 $ 162,638 $ 164,645 Net income $ 102,160 $ 112,689 $ 115,995 $ 120,279 Net income attributable to common stockholders $ 94,770 $ 104,828 $ 108,087 $ 112,282 Earnings per common share—basic $ 0.74 $ 0.82 $ 0.84 $ 0.87 Earnings per common share—diluted $ 0.74 $ 0.81 $ 0.83 $ 0.86 For the Three Months Ended March 31, 2018 June 30, 2018 September 30, 2018 December 31, 2018 Revenues $ 285,485 $ 296,813 $ 306,953 $ 307,353 Cost of operations 151,573 152,097 153,362 150,676 Revenues less cost of operations $ 133,912 $ 144,716 $ 153,591 $ 156,677 Net income $ 95,430 $ 102,713 $ 139,687 $ 109,250 Net income attributable to common stockholders $ 88,256 $ 95,153 $ 130,418 $ 101,462 Earnings per common share—basic $ 0.70 $ 0.75 $ 1.03 $ 0.80 Earnings per common share—diluted $ 0.70 $ 0.75 $ 1.02 $ 0.80

Description of Business (Detail

Description of Business (Details)	Dec. 31, 2019storestate
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of storage facilities in which the entity had equity interests	1,171
Number of stores managed for third parties	646
Number of stores owned and/or managed	1,817
Number of states in which storage facilities are located | state	40

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - Recurring $ in Thousands	Dec. 31, 2019USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets - Cash flow hedge swap agreements	$ 6,214
Other liabilities - Cash flow hedge swap agreements	31,400
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets - Cash flow hedge swap agreements	0
Other liabilities - Cash flow hedge swap agreements	0
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets - Cash flow hedge swap agreements	6,214
Other liabilities - Cash flow hedge swap agreements	31,400
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets - Cash flow hedge swap agreements	0
Other liabilities - Cash flow hedge swap agreements	$ 0

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value
Fair Value of Financial Instruments [Line Items]
Notes receivable from Preferred and Common Operating Partnership unit holders	$ 116,184	$ 115,467
Fixed rate notes payable and notes payable to trusts	3,511,151	2,985,731
Exchangeable senior notes	673,831	620,149
Carrying Value
Fair Value of Financial Instruments [Line Items]
Notes receivable from Preferred and Common Operating Partnership unit holders	118,524	119,735
Fixed rate notes payable and notes payable to trusts	3,417,928	3,022,414
Exchangeable senior notes	$ 575,000	$ 575,000

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Real Estate Assets (Details)	12 Months Ended
	Dec. 31, 2019store
Property, Plant and Equipment [Line Items]
Number of properties whereby leases cannot be classified as ground or building leases	3
Number of properties whereby leases have been assumed at rates lower than the current market rates	8
Buildings, improvements and other intangibles | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Buildings, improvements and other intangibles | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	39 years

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Other Assets (Details) - Equipment and fixtures	12 Months Ended
	Dec. 31, 2019
Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Risk Management and Use of Financial Instruments (Details)	12 Months Ended
	Dec. 31, 2019item
Accounting Policies [Abstract]
Number of main components of economic risk	3

Summary of Significant Accoun_9

Summary of Significant Accounting Policies - Revenue and Expense Recognition (Details)	12 Months Ended
	Dec. 31, 2019USD ($)claim	Dec. 31, 2018claim	Dec. 31, 2017claim
Disaggregation of Revenue [Line Items]
Minimum amount of insurance coverage	$ 2,000
Maximum amount of insurance coverage	10,000
Average amount of insurance coverage	$ 3,300
Number of claims made | claim	9,059	8,091	6,214
Management Services Agreements (MSA) | Minimum
Disaggregation of Revenue [Line Items]
Contract term	3 years
Management Services Agreements (MSA) | Maximum
Disaggregation of Revenue [Line Items]
Contract term	5 years

Summary of Significant Accou_10

Summary of Significant Accounting Policies - Schedule of Unpaid Claims Liability (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Tenant Reinsurance Claims:
Unpaid claims liability at beginning of year	$ 7,326	$ 5,167	$ 3,896
Claims and claim adjustment expense for claims incurred in the current year	16,280	15,800	11,700
Claims and claim adjustment expense (benefit) for claims incurred in the prior years	98	107	(203)
Payments for current year claims	(11,352)	(11,010)	(8,895)
Payments for prior year claims	(4,243)	(2,738)	(1,331)
Unpaid claims liability at the end of the year	$ 8,109	$ 7,326	$ 5,167

Summary of Significant Accou_11

Summary of Significant Accounting Policies - Advertising Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Advertising expense	$ 25,106	$ 16,153	$ 14,410

Summary of Significant Accou_12

Summary of Significant Accounting Policies - Income Taxes (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Percentage of all distributions to stockholders which qualified as a return of capital	0.00%
Unrecognized tax benefits	$ 0	$ 0
Interest or penalties related to uncertain tax provisions	$ 0	$ 0

Summary of Significant Accou_13

Summary of Significant Accounting Policies - Earnings Per Common Share (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Sep. 30, 2015	Jun. 21, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per common share (in shares)	1,474,558	1,795,632	910,309
Average share price (in dollars per share)	$ 106.57
Exchangeable senior notes	$ 569,513,000	$ 562,374,000
Series A Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Instruments to be settled in cash (at least)	$ 101,700,000
Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per common share (in shares)	0	36,075	45,286
2013 Notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Fixed interest rate					2.375%
Shares related to the Notes included in the computation for diluted earnings per share (in shares)	0		344,430
2015 Notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Exchangeable senior notes	$ 575,000,000
Fixed interest rate	3.125%			3.125%
Exchange price (in dollars per share)	$ 91.76
Shares related to the Notes included in the computation for diluted earnings per share (in shares)	993,114		0

Summary of Significant Accou_14

Summary of Significant Accounting Policies - Schedule of Antidilutive Shares Excluded from Computation of Earnings Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Equivalent Shares (if converted) (in shares)	1,474,558	1,795,632	910,309
Series B Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Equivalent Shares (if converted) (in shares)	393,189	464,033	533,174
Series C Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Equivalent Shares (if converted) (in shares)	0	312,075	377,135
Series D Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Equivalent Shares (if converted) (in shares)	1,081,369	1,019,524	0

Summary of Significant Accou_15

Summary of Significant Accounting Policies - Schedule of Computation of Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Net income attributable to common stockholders	$ 112,282	$ 108,087	$ 104,828	$ 94,770	$ 101,462	$ 130,418	$ 95,153	$ 88,256	$ 419,967	$ 415,289	$ 479,013
Earnings and dividends allocated to participating securities									(680)	(723)	(975)
Earnings for basic computations									419,287	414,566	478,038
Earnings and dividends allocated to participating securities									680	723	0
Income allocated to noncontrolling interest - Preferred Operating Partnership Units and Operating Partnership Units									23,727	22,831	30,088
Fixed component of income allocated to noncontrolling interest - Preferred Operating Partnership (Series A Units)									(2,288)	(2,288)	(3,119)
Net income for diluted computations									$ 441,406	$ 435,832	$ 505,007
Weighted average common shares outstanding:
Average number of common shares outstanding - basic (in shares)									128,203,568	126,087,487	125,967,831
OP Units (in shares)									6,006,114	5,675,547	5,590,831
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Unvested restricted stock awards included for treasury stock method (in shares)									212,402	244,215	0
Shares related to exchangeable senior notes and dilutive stock options (in shares)									1,136,205	276,304	640,068
Average number of common shares outstanding - diluted (in shares)									136,433,769	133,159,033	134,155,771
Earnings per common share
Basic (in dollars per share)	$ 0.87	$ 0.84	$ 0.82	$ 0.74	$ 0.80	$ 1.03	$ 0.75	$ 0.70	$ 3.27	$ 3.29	$ 3.79
Diluted (in dollars per share)	$ 0.86	$ 0.83	$ 0.81	$ 0.74	$ 0.80	$ 1.02	$ 0.75	$ 0.70	$ 3.24	$ 3.27	$ 3.76
Series A Units
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Series A&D Units (in shares)									875,480	875,480	875,480
Series D Units
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Series A&D Units (in shares)									0	0	1,081,561

Summary of Significant Accou_16

Summary of Significant Accounting Policies - Recently Issued Accounting Standards (Details) $ in Thousands	Dec. 31, 2019USD ($)	Jan. 01, 2019USD ($)lease
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Real estate assets - operating lease right-of-use assets	$ 264,643
Operating lease liabilities	$ 274,783
ASU 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Real estate assets - operating lease right-of-use assets		$ 104,863
Operating lease liabilities		$ 95,506
Operating ground leases
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of operating ground leases | lease		22
Corporate facility leases
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of operating ground leases | lease		2

Real Estate Assets - Schedule o

Real Estate Assets - Schedule of Components of Real Estate Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Real Estate [Abstract]
Land - operating	$ 1,935,551	$ 1,825,133
Land - development	3,372	7,359
Buildings, improvements and other intangibles	7,047,654	6,743,355
Right of use asset - finance lease	8,050
Intangible assets - tenant relationships	122,489	119,557
Intangible lease rights	12,443	12,443
Gross operating real estate assets	9,129,559	8,707,847
Less: accumulated depreciation and amortization	(1,473,852)	(1,262,438)
Net operating real estate assets	7,655,707	7,445,409
Real estate under development/redevelopment	41,157	46,422
Net real estate assets	7,696,864	7,491,831
Real estate assets held for sale included in net real estate assets	$ 2,947	$ 13,032

Real Estate Assets - Additional

Real Estate Assets - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)land_parcel	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Real Estate [Abstract]
Number of parcels of land classified as held for sale | land_parcel	1
Average period that a tenant is expected to utilize the facility	18 months
Amortization related to the tenant relationships and lease rights	$ 6,614	$ 9,050	$ 14,349
Real Estate Properties [Line Items]
Intangible assets, accumulated amortization	$ 127,712	$ 121,238
Minimum
Real Estate Properties [Line Items]
Remaining amortization period	9 years
Maximum
Real Estate Properties [Line Items]
Remaining amortization period	42 years

Property Acquisitions and Dis_3

Property Acquisitions and Dispositions - Acquisitions of Operating Stores (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019USD ($)storeshares	Sep. 30, 2019USD ($)storeshares	Jun. 30, 2019USD ($)storeshares	Mar. 31, 2019USD ($)storeshares	Dec. 31, 2018USD ($)storeshares	Sep. 30, 2018USD ($)storeshares	Jun. 30, 2018USD ($)storeshares	Mar. 31, 2018USD ($)storeshares	Dec. 31, 2019USD ($)storeshares	Dec. 31, 2018USD ($)storeshares	Dec. 31, 2017USD ($)
Real Estate [Abstract]
Number of Stores | store	5	1	1	14	6	6	17	5	21	34
Total Real Estate Assets Acquired	$ 51,278	$ 16,937	$ 8,424	$ 223,740	$ 74,852	$ 74,694	$ 237,284	$ 70,787	$ 300,379	$ 457,617
Cash Paid	51,058	16,941	8,424	202,890	74,868	71,989	148,650	70,171	279,313	365,678
Loan Assumed	0	0	0	17,157	0	0	87,500	0	17,157	87,500	$ 24,055
Investments in Real Estate Ventures	0	0	0	2,780	0	0	(1,024)	489	2,780	(535)	$ 12,957
Net Liabilities/ (Assets) Assumed	220	(4)	0	913	(16)	2,705	281	127	1,129	3,097
Value of OP Units Issued	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 1,877	$ 0	$ 0	$ 1,877
Number of OP Units Issued (in shares) | shares	0	0	0	0	0	0	21,768	0	0	21,768
Number of stores acquired, previously held noncontrolling interest | store									12	15

Property Acquisitions and Dis_4

Property Acquisitions and Dispositions - Additional Information (Details) $ in Thousands	Apr. 11, 2019USD ($)	Aug. 16, 2018USD ($)	Nov. 30, 2017USD ($)store	Sep. 13, 2017USD ($)	Jun. 30, 2017USD ($)	Dec. 31, 2019
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Disposal of New York Store
Property Acquisitions [Line Items]
Proceeds from sale of real estate assets, investments in real estate ventures and other assets	$ 11,272
Gain (loss) on disposition of assets	$ 1,205
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Disposal of California Store
Property Acquisitions [Line Items]
Proceeds from sale of real estate assets, investments in real estate ventures and other assets		$ 40,235
Gain (loss) on disposition of assets		$ 30,671
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Disposal of 36 Stores Located in Various States
Property Acquisitions [Line Items]
Proceeds from sale of real estate assets, investments in real estate ventures and other assets			$ 295,000
Gain (loss) on disposition of assets			$ 118,776
Number of stores sold | store			36
Percentage of gain received on disposition			90.00%
Percentage of gain deferred on disposition			10.00%
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Disposal of New York Land
Property Acquisitions [Line Items]
Proceeds from sale of real estate assets, investments in real estate ventures and other assets				$ 19,000
Gain (loss) on disposition of assets					$ (3,500)
Storage Portfolio II JV LLC
Property Acquisitions [Line Items]
Equity ownership %			10.00%			10.00%

Investments in Unconsolidated_3

Investments in Unconsolidated Real Estate Entities - Schedule of Investments in Unconsolidated Real Estate Ventures (Details) $ in Thousands	1 Months Ended		3 Months Ended								12 Months Ended
	Oct. 31, 2019USD ($)	Jan. 31, 2019USD ($)store	Dec. 31, 2019USD ($)storeproperty	Sep. 30, 2019USD ($)store	Jun. 30, 2019USD ($)store	Mar. 31, 2019USD ($)store	Dec. 31, 2018USD ($)store	Sep. 30, 2018USD ($)store	Jun. 30, 2018USD ($)store	Mar. 31, 2018USD ($)store	Dec. 31, 2019USD ($)storeproperty	Dec. 31, 2018USD ($)store	Dec. 31, 2017USD ($)	Nov. 30, 2017
Schedule of Equity Method Investments [Line Items]
Number of Stores | property			241								241
Investment balance			$ 292,790				$ 80,129				$ 292,790	$ 80,129
Amount invested											$ 197,759	$ 65,500	$ 17,944
Number of stores acquired | store			5	1	1	14	6	6	17	5	21	34
Cash paid to acquire properties			$ 51,058	$ 16,941	$ 8,424	$ 202,890	$ 74,868	$ 71,989	$ 148,650	$ 70,171	$ 279,313	$ 365,678
Minimum
Schedule of Equity Method Investments [Line Items]
Equity Ownership %			10.00%				10.00%				10.00%	10.00%	10.00%
Maximum
Schedule of Equity Method Investments [Line Items]
Equity Ownership %			50.00%				50.00%				50.00%	50.00%	25.00%
PRISA Self Storage LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property			85								85
Equity Ownership %			4.00%								4.00%
Excess Profit %			4.00%								4.00%
Investment balance			$ 9,133				$ 9,334				$ 9,133	$ 9,334
Storage Portfolio II JV LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property			36								36
Equity Ownership %			10.00%								10.00%			10.00%
Excess Profit %			30.00%								30.00%
Investment balance			$ (4,827)				(4,233)				$ (4,827)	(4,233)
Storage Portfolio I LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property			24								24
Equity Ownership %			34.00%								34.00%
Excess Profit %			49.00%								49.00%
Investment balance			$ (38,345)				(38,129)				$ (38,345)	(38,129)
VRS Self Storage, LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property			16								16
Equity Ownership %			45.00%								45.00%
Excess Profit %			54.00%								54.00%
Investment balance			$ 17,639				18,281				$ 17,639	18,281
ESS-NYFL JV LP
Schedule of Equity Method Investments [Line Items]
Number of Stores | property			11								11
Equity Ownership %			16.00%								16.00%
Excess Profit %			24.00%								24.00%
Investment balance			$ 13,320				0				$ 13,320	0
WICNN JV LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property			10								10
Equity Ownership %			10.00%								10.00%
Excess Profit %			25.00%								25.00%
Investment balance			$ 36,552				26,885				$ 36,552	26,885
Joint venture preferred equity investment			$ 31,500								$ 31,500
Joint venture preferred equity investment return percentage											8.00%
Extra Space Northern Properties Six LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property			10								10
Equity Ownership %			10.00%								10.00%
Excess Profit %			35.00%								35.00%
Investment balance			$ (2,091)				(1,700)				$ (2,091)	(1,700)
Alan Jathoo JV LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property			9								9
Equity Ownership %			10.00%								10.00%
Excess Profit %			10.00%								10.00%
Investment balance			$ 7,977				8,180				$ 7,977	8,180
PR EXR Self Storage, LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property			5								5
Equity Ownership %			25.00%								25.00%
Excess Profit %			40.00%								40.00%
Investment balance			$ 59,391				19,841				$ 59,391	19,841
ESS Bristol Investments LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property			8								8
Equity Ownership %			10.00%								10.00%
Excess Profit %			28.00%								28.00%
Investment balance			$ 3,046				2,331				$ 3,046	2,331
GFN JV, LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property			5								5
Equity Ownership %			10.00%								10.00%
Excess Profit %			30.00%								30.00%
Investment balance			$ 12,168				10,586				$ 12,168	10,586
Joint venture preferred equity investment			$ 10,335								$ 10,335
Joint venture preferred equity investment return percentage											8.00%
Extra Space West Two LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property			0								0
Equity Ownership %			5.00%								5.00%
Excess Profit %			40.00%								40.00%
Investment balance			$ 0				3,818				$ 0	3,818
Extra Space West One LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property			0								0
Equity Ownership %			5.00%								5.00%
Excess Profit %			40.00%								40.00%
Investment balance			$ 0				(1,038)				$ 0	(1,038)
Other minority owned stores
Schedule of Equity Method Investments [Line Items]
Number of Stores | property			22								22
Investment balance			$ 28,827				25,973				$ 28,827	25,973
Other minority owned stores | Minimum
Schedule of Equity Method Investments [Line Items]
Equity Ownership %			10.00%								10.00%
Excess Profit %			19.00%								19.00%
Other minority owned stores | Maximum
Schedule of Equity Method Investments [Line Items]
Equity Ownership %			50.00%								50.00%
Excess Profit %			50.00%								50.00%
SmartStop Self Storage REIT, Inc. Preferred Stock
Schedule of Equity Method Investments [Line Items]
Investment balance			$ 150,000				$ 0				$ 150,000	$ 0
Amount invested	$ 150,000
Investment commitment	$ 50,000
Investment commitment, period	12 months
Investment, preferred dividend rate	6.25%
Period after which preferred stock dividend is subject to increase	5 years
Period after which preferred stock dividend is redeemable	5 years
Extra Space West One and Two LLC
Schedule of Equity Method Investments [Line Items]
Equity Ownership %		100.00%
Number of stores acquired | store		12
Cash paid to acquire properties		$ 172,505

Investments in Unconsolidated_4

Investments in Unconsolidated Real Estate Entities - New Unconsolidated Joint Ventures (Details) $ in Thousands	Apr. 30, 2018USD ($)store	Dec. 31, 2019USD ($)store	Sep. 30, 2019USD ($)store	Jun. 30, 2019USD ($)store	Mar. 31, 2019USD ($)store	Dec. 31, 2018USD ($)store	Sep. 30, 2018USD ($)store	Jun. 30, 2018USD ($)store	Mar. 31, 2018USD ($)store	Dec. 31, 2019USD ($)store	Dec. 31, 2018USD ($)store	Dec. 31, 2017USD ($)store
Schedule of Equity Method Investments [Line Items]
Number of Stores | store		16				28				16	28	39
Total initial investment		$ 19,663				$ 63,723				$ 19,663	$ 63,723	$ 13,341
Contributions joint ventures										$ 104,338
Number of operating stores acquired | store										15
Number of stores acquired at certificate of occupancy | store										9
Cash paid to acquire properties		51,058	$ 16,941	$ 8,424	$ 202,890	74,868	$ 71,989	$ 148,650	$ 70,171	$ 279,313	365,678
Loan assumed		$ 0	$ 0	$ 0	$ 17,157	$ 0	$ 0	$ 87,500	$ 0	$ 17,157	$ 87,500	$ 24,055
Number of stores acquired | store		5	1	1	14	6	6	17	5	21	34
Minimum
Schedule of Equity Method Investments [Line Items]
Equity ownership %		10.00%				10.00%				10.00%	10.00%	10.00%
Maximum
Schedule of Equity Method Investments [Line Items]
Equity ownership %		50.00%				50.00%				50.00%	50.00%	25.00%
GFN JV, LLC
Schedule of Equity Method Investments [Line Items]
Equity ownership %		10.00%								10.00%
WCOT Self Storage LLC
Schedule of Equity Method Investments [Line Items]
Cash paid to acquire properties	$ 115,797
Loan assumed	$ 87,500
Number of stores acquired | store	14

Investments in Unconsolidated_5

Investments in Unconsolidated Real Estate Entities - Schedule of Equity in Earnings of Unconsolidated Real Estate Ventures (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Equity in earnings	$ 11,274	$ 14,452	$ 15,331
PRISA Self Storage LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings	2,327	2,338	2,430
Storage Portfolio II JV LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings	291	79	33
Storage Portfolio I LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings	1,809	1,886	2,684
VRS Self Storage, LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings	3,583	3,640	3,562
ESS-NYFL JV LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings	(96)	0	0
WICNN JV LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings	1,373	622	0
Extra Space Northern Properties Six LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings	1,091	1,014	918
Alan Jathoo JV LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings	(47)	(12)	0
ESS Bristol Investments LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings	(262)	(152)	0
GFN JV, LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings	450	22	0
PR EXR Self Storage, LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings	(443)	(75)	(105)
WCOT Self Storage LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings	0	359	1,033
Extra Space West Two LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings	0	1,042	1,210
Extra Space West One LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings	0	2,526	2,502
Other minority owned stores
Schedule of Equity Method Investments [Line Items]
Equity in earnings	$ 1,198	$ 1,163	$ 1,064

Investments in Unconsolidated_6

Investments in Unconsolidated Real Estate Entities - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Amortization amount of excess purchase price included in equity earnings	$ 27,867
Amortization period of excess purchase price included in equity earnings	40 years
Property Management Fee Revenue	$ 14,624	$ 14,123	$ 12,650

Notes Payable and Revolving L_3

Notes Payable and Revolving Lines of Credit - Schedule of Components of Notes Payable (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Total	$ 4,318,973	$ 4,137,213
Notes Payable
Debt Instrument [Line Items]
Total	4,343,502	4,167,249
Unamortized debt issuance costs	(24,529)	(29,936)
Total	4,318,973	4,137,313
Notes Payable | Secured notes payable
Debt Instrument [Line Items]
Fixed rate notes payable	1,365,408	2,032,414
Variable rate notes payable	$ 878,093	834,835
Notes Payable | Secured notes payable | Minimum
Debt Instrument [Line Items]
Fixed Rate	2.53%
Variable Rate	3.01%
Notes Payable | Secured notes payable | Maximum
Debt Instrument [Line Items]
Fixed Rate	6.00%
Variable Rate	3.31%
Notes Payable | Secured notes payable | LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	1.30%
Notes Payable | Secured notes payable | LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	1.60%
Notes Payable | Unsecured notes payable
Debt Instrument [Line Items]
Fixed rate notes payable	$ 2,052,521	990,000
Variable rate notes payable	$ 47,480	$ 310,000
Notes Payable | Unsecured notes payable | Minimum
Debt Instrument [Line Items]
Fixed Rate	2.80%
Variable Rate	2.76%
Notes Payable | Unsecured notes payable | Maximum
Debt Instrument [Line Items]
Fixed Rate	4.39%
Variable Rate	3.31%
Notes Payable | Unsecured notes payable | LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	1.00%
Notes Payable | Unsecured notes payable | LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	1.60%

Notes Payable and Revolving L_4

Notes Payable and Revolving Lines of Credit - Additional Information (Details)	12 Months Ended
	Dec. 31, 2019USD ($)extension	Dec. 20, 2019USD ($)	Jul. 01, 2019USD ($)	Dec. 31, 2018USD ($)
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 790,000,000
Line of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 1,850,000,000
Increase limit		$ 2,500,000,000		$ 2,000,000,000
Number of extension options | extension	2
Extension term	6 months
Line of Credit | Base rate
Debt Instrument [Line Items]
Basis spread on variable rate	0.00%
Line of Credit | Base rate | If Company elects to use alternative rates based on specified investment grade rating | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	0.00%
Line of Credit | Base rate | If Company elects to use alternative rates based on specified investment grade rating | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	1.30%
Line of Credit | Federal funds rate
Debt Instrument [Line Items]
Basis spread on variable rate	0.50%
Line of Credit | Eurodollar
Debt Instrument [Line Items]
Basis spread on variable rate	1.00%
Line of Credit | Eurodollar | If Company elects to use alternative rates based on specified investment grade rating | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	0.75%
Line of Credit | Eurodollar | If Company elects to use alternative rates based on specified investment grade rating | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	2.25%
Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 650,000,000
Term	4 years
Line of Credit | Tranche 1 Term Loan Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 480,000,000
Line of Credit | Tranche 2 Term Loan Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	220,000,000
Line of Credit | Tranche 3 Term Loan Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	245,000,000		$ 245,000,000
Line of Credit | Tranche 4 Term Loan Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	255,000,000		$ 255,000,000
Notes Payable
Debt Instrument [Line Items]
Notes payable	4,343,502,000			$ 4,167,249,000
Notes payable subject to recourse	$ 2,012,791,000

Notes Payable and Revolving L_5

Notes Payable and Revolving Lines of Credit - Schedule of Maturities of Notes Payable (Details) - Notes Payable - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
2020	$ 568,431
2021	252,053
2022	150,796
2023	767,405
2024	712,972
Thereafter	1,891,845
Total	$ 4,343,502	$ 4,167,249

Notes Payable and Revolving L_6

Notes Payable and Revolving Lines of Credit - Schedule of Information on Lines of Credit (Details)	12 Months Ended
	Dec. 31, 2019USD ($)extension	Dec. 31, 2018USD ($)
Debt Instrument [Line Items]
Amount Drawn	$ 158,000,000	$ 81,000,000
Capacity	790,000,000
Credit Line 1
Debt Instrument [Line Items]
Amount Drawn	38,000,000
Capacity	$ 140,000,000
Interest Rate	3.20%
Number of extensions available | extension	1
Extension term	2 years
Credit Line 2
Debt Instrument [Line Items]
Amount Drawn	$ 120,000,000
Capacity	$ 650,000,000
Interest Rate	2.70%
Number of extensions available | extension	2
Extension term	6 months
LIBOR | Credit Line 1
Debt Instrument [Line Items]
Basis spread on variable rate	1.45%
LIBOR | Credit Line 2
Debt Instrument [Line Items]
Basis spread on variable rate	0.90%

Derivatives - Additional Inform

Derivatives - Additional Information (Details) $ in Thousands	Dec. 31, 2019USD ($)derivative
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Estimated amount of unrealized gains (losses) expected to be reclassified as interest expense in next fiscal year	$ 4,374
Number of derivative financial instruments | derivative	24
Combined notional amount	$ 2,354,609
Derivatives with contingent features, net liability position	30,269
Derivatives with contingent features, contingent cash settlement value	$ 32,245

Derivatives - Schedule Summariz

Derivatives - Schedule Summarizing Terms of Entity's Derivative Financial Instruments (Details) $ in Thousands	Dec. 31, 2019USD ($)
Derivative [Line Items]
Notional amounts	$ 2,354,609
Cash flow hedging | Swap Agreements | Minimum
Derivative [Line Items]
Notional amounts	$ 30,943
Strike rate	1.13%
Cash flow hedging | Swap Agreements | Maximum
Derivative [Line Items]
Notional amounts	$ 267,431
Strike rate	4.60%

Derivatives - Schedule of Balan

Derivatives - Schedule of Balance Sheet Classification and Fair Value of Entity's Derivative Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Other assets
Derivative [Line Items]
Asset Derivatives	$ 6,214	$ 42,324
Other liabilities
Derivative [Line Items]
Liability Derivatives	$ 31,400	$ 2,131

Derivatives - Schedule of Infor

Derivatives - Schedule of Information Relating to Gain (Loss) Recognized on Swap Agreements (Details) - Swap Agreements - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain (loss) recognized in OCI	$ (54,680)	$ 9,889
Gain (loss) reclassified from OCI	$ 12,322	$ 8,258	$ (8,853)

Notes Payable to Trusts (Detail

Notes Payable to Trusts (Details) $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2019USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2005subsidiary
Variable Interest Entity [Line Items]
Variable interest entity interest in trust number | subsidiary					3
Principal payments on notes payable to trusts		$ 30,928	$ 88,662	$ 0
Variable Interest Entity, Not Primary Beneficiary | Notes payable to Trusts
Variable Interest Entity [Line Items]
Principal payments on notes payable to trusts	$ 30,928		88,662
Notes payable to Trusts			$ 30,928

Exchangeable Senior Notes - Add

Exchangeable Senior Notes - Additional Information (Details)	Dec. 31, 2019	Jun. 21, 2013USD ($)	Sep. 30, 2015USD ($)	Dec. 31, 2019USD ($)day	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Debt Instrument [Line Items]
Cash paid for repurchase of debt				$ 1,977,805,000	$ 1,109,854,000	$ 1,088,679,000
2015 Notes
Debt Instrument [Line Items]
Principal amount of notes issued			$ 575,000,000
Fixed interest rate	3.125%		3.125%	3.125%
Related debt issuance costs			$ 11,992,000
Underwriting fee percentage			2.00%
Amortization period			5 years
Conversion ratio	0.01090
Redemption price as percentage of principal amount of notes plus accrued and unpaid interest			100.00%
Redemption price as percentage of principal amount of notes at request of debt holders and upon occurrence of designated event			100.00%
Notes exchange, threshold percentage				130.00%
Notes exchange, threshold trading days | day				20
Notes exchange, threshold consecutive trading days | day				30
Effective interest rate	4.00%			4.00%
2015 Notes | Minimum
Debt Instrument [Line Items]
Number of days of written notice to holders of notes required for redemption			30 days
2015 Notes | Maximum
Debt Instrument [Line Items]
Number of days of written notice to holders of notes required for redemption			60 days
2013 Notes
Debt Instrument [Line Items]
Principal amount of notes issued		$ 250,000,000
Fixed interest rate		2.375%
Related debt issuance costs		$ 1,672,000			10,000	35,000
Debt, measurement input		1.50%
Unamortized cash discount		$ 3,750,000			230,000	184,000
Amortization period		5 years
Principal amount repurchased					49,259,000	13,911,000
Cash paid for repurchase of debt					$ 80,270,000	$ 20,042,000

Exchangeable Senior Notes - Equ

Exchangeable Senior Notes - Equity and Liability Components (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Sep. 30, 2015
Debt Instrument [Line Items]
Principal amount of liability component	$ 569,513	$ 562,374
2015 Notes
Debt Instrument [Line Items]
Principal amount of liability component	575,000
Unamortized debt issuance costs			$ (11,992)
Senior Notes | 2015 Notes
Debt Instrument [Line Items]
Carrying amount of equity component	22,597	22,597
Principal amount of liability component	575,000	575,000
Unamortized discount - equity component	(3,675)	(8,417)
Unamortized debt issuance costs	(1,812)	(4,209)
Net carrying amount of liability component	$ 569,513	$ 562,374

Exchangeable Senior Notes - Int

Exchangeable Senior Notes - Interest Cost Recognized (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt Disclosure [Abstract]
Contractual interest	$ 17,968	$ 18,106	$ 19,303
Amortization of discount	4,742	4,687	5,103
Total interest expense recognized	$ 22,710	$ 22,793	$ 24,406

Exchangeable Senior Notes - Rep

Exchangeable Senior Notes - Repurchase of Debt (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jun. 21, 2013
Debt Instrument [Line Items]
Total consideration paid for repurchase	$ 1,977,805	$ 1,109,854	$ 1,088,679
2013 Notes
Debt Instrument [Line Items]
Principal amount repurchased		49,259	13,911
Extinguishment of liability component		49,019	13,692
Reacquisition of equity component		31,251	6,350
Total consideration paid for repurchase		80,270	20,042
Extinguishment of liability component		(49,019)	(13,692)
Discount on exchangeable senior notes		(230)	(184)	$ (3,750)
Related debt issuance costs		(10)	(35)	$ (1,672)
Gain/(loss) on repurchase		$ 0	$ 0

Stockholders' Equity (Details)

Stockholders' Equity (Details) $ / shares in Units, $ in Thousands	May 15, 2019USD ($)sales_agent	Dec. 31, 2019USD ($)item$ / sharesshares	Dec. 31, 2018USD ($)$ / sharesshares
Changes In Equity And Comprehensive Income Line Items [Line Items]
Common stock, shares authorized (in shares)		500,000,000	500,000,000
Common stock, par value (in dollars per share) | $ / shares		$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)		50,000,000	50,000,000
Preferred stock, par value (in dollars per share) | $ / shares		$ 0.01	$ 0.01
Common stock, shares issued (in shares)		129,534,407	127,103,750
Common stock, shares outstanding (in shares)		129,534,407	127,103,750
Preferred stock, shares issued (in shares)		0	0
Preferred stock, shares outstanding (in shares)		0	0
Number of votes, common stockholder rights | item		1
Number of sales agents | sales_agent	9
Average share price (in dollars per share) | $ / shares		$ 106.57
“At the market” equity program
Changes In Equity And Comprehensive Income Line Items [Line Items]
Aggregate offering price | $	$ 500,000
Common stock sold (in shares)		1,779,200	933,789
Average share price (in dollars per share) | $ / shares		$ 113.19	$ 97.93
Net proceeds from sale of stock | $		$ 198,827	$ 90,531
Available for issuance | $		$ 298,621

Noncontrolling Interest Repre_2

Noncontrolling Interest Represented By Preferred Operating Partnership Units (Details) - USD ($) $ / shares in Units, $ in Thousands	Apr. 25, 2019	Apr. 17, 2019	Dec. 01, 2018	Apr. 18, 2017	Jun. 25, 2007	Dec. 31, 2014	Oct. 31, 2014	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jun. 30, 2007
Noncontrolling Interest [Line Items]
Loan to holders of preferred OP units								$ 100,000				$ 108,644				$ 100,000	$ 108,644
Number of units issued (in shares)								0	0	0	0	0	0	21,768	0	0	21,768
Value of units issued								$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 1,877	$ 0	$ 0	$ 1,877
Operating Partnership
Noncontrolling Interest [Line Items]
Conversion of units, units issued upon conversion (in shares)	270,709		373,113
Reduction of noncontrolling interest for note receivable								$ 18,524				11,091				$ 18,524	11,091
Series A Units
Noncontrolling Interest [Line Items]
Fixed priority return on preferred OP units, amount							$ 101,700
Fixed priority return on preferred OP units, stated return rate		5.00%		2.30%												2.30%
Fixed priority return on preferred OP units, liquidation value																			$ 115,000
Preferred units outstanding (in shares)							875,480
Series A Units | Holders Of Series A Preferred Operating Partnership Units
Noncontrolling Interest [Line Items]
Loan to holders of preferred OP units					$ 100,000
Maximum number of preferred OP units converted prior to the maturity date of the loan (in shares)							114,500
Note receivable interest rate				2.10%	4.90%
Additional units redeemed (in shares)					0
Series B Units
Noncontrolling Interest [Line Items]
Preferred units outstanding (in shares)								1,676,087								1,676,087
Liquidation value (in dollars per share)								$ 25								$ 25
Fixed liquidation value								$ 41,902								$ 41,902
Annual rate of return percent																6.00%
Series C Units
Noncontrolling Interest [Line Items]
Loan to holders of preferred OP units												19,735					19,735
Note receivable interest rate						5.00%
Liquidation value (in dollars per share)								$ 42.10								$ 42.10
Quarterly distribution per preferred OP unit payable above quarterly distribution for common OP Unit (in dollars per share)																$ 0.18
Period from date of issuance after which preferred OP units will become redeemable at the option of the holder																1 year
Period from date of issuance after which preferred OP units will become convertible into common OP units at the option of the holder																1 year
Preferred OP units conversion ratio (in units)																0.9145
Origination of Notes Receivable from Related Parties						$ 20,230
Conversion of units, units converted (in shares)	296,020		407,996
Reduction of noncontrolling interest for note receivable												$ 8,644					$ 8,644
Series D Units
Noncontrolling Interest [Line Items]
Preferred units outstanding (in shares)								4,803,445								4,803,445
Liquidation value (in dollars per share)								$ 25								$ 25
Fixed liquidation value								$ 120,086								$ 120,086
Number of units issued (in shares)																1,120,924		446,420
Value of units issued																$ 28,023		$ 11,161
Series D Units | Minimum
Noncontrolling Interest [Line Items]
Annual rate of return percent																3.00%
Series D Units | Maximum
Noncontrolling Interest [Line Items]
Annual rate of return percent																5.00%

Noncontrolling Interests In O_3

Noncontrolling Interests In Operating Partnership and Other Noncontrolling Interests - Additional Information (Details) $ / shares in Units, $ in Thousands	Apr. 25, 2019shares	Dec. 01, 2018shares	Dec. 31, 2019USD ($)storejoint_venture$ / sharesshares	Dec. 31, 2018USD ($)store	Dec. 31, 2017store
Noncontrolling Interest [Line Items]
Period used as a denomination to determine the average closing price of common stock			10 days
Ten day average closing stock price (in dollars per share) | $ / shares			$ 104.18
OP units outstanding (in units) | shares			5,924,778
Consideration to be paid on redemption of common OP units | $			$ 617,243
Number of owned stores | store			16	28	39
Joint venture one | TX
Noncontrolling Interest [Line Items]
Number of owned stores | store			2
Joint venture one | CO
Noncontrolling Interest [Line Items]
Number of owned stores | store			2
Operating Partnership
Noncontrolling Interest [Line Items]
Ownership interest held by entity (as a percent)			90.70%
Voting interests of third-party owners			9.30%
Series C Units
Noncontrolling Interest [Line Items]
Conversion of units, units converted (in shares) | shares	296,020	407,996
Reduction of noncontrolling interest for note receivable | $				$ 8,644
Operating Partnership
Noncontrolling Interest [Line Items]
Conversion of units, units issued upon conversion (in shares) | shares	270,709	373,113
Reduction of noncontrolling interest for note receivable | $			$ 18,524	$ 11,091
Common Stock
Noncontrolling Interest [Line Items]
Unit conversion ratio			1
Other
Noncontrolling Interest [Line Items]
Number of consolidated joint ventures | joint_venture			2
Other | Joint venture one | Minimum
Noncontrolling Interest [Line Items]
Voting interests of third-party owners			5.00%
Other | Joint venture one | Maximum
Noncontrolling Interest [Line Items]
Voting interests of third-party owners			20.00%

Noncontrolling Interests In O_4

Noncontrolling Interests In Operating Partnership and Other Noncontrolling Interests - Schedule of OP Unit Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Noncontrolling Interest [Abstract]
OP Units redeemed for common stock (in shares)	340,182	35,000	0
OP Units redeemed for cash (in shares)	0	30,000	33,896
Cash paid for OP Units redeemed	$ 0	$ 2,558	$ 2,510
OP Units issued in conjunction with acquisitions (in shares)	0	21,768	90,228
Value of OP Units issued in conjunction with acquisitions	$ 0	$ 1,877	$ 7,618
OP Units issued upon redemption of Series C Units (in shares)	270,709	373,113	0

Leases - Additional Information

Leases - Additional Information (Details) $ in Thousands	1 Months Ended		12 Months Ended
	Aug. 31, 2019USD ($)store	Jun. 30, 2019USD ($)store	Dec. 31, 2019USD ($)leaseextension	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Jan. 01, 2019USD ($)
Lessee, Lease, Description [Line Items]
Operating lease liabilities			$ 274,783
Operating lease right-of-use assets			$ 264,643
Number of stores added under operating lease | store	5	22
Operating lease, term			25 years
Operating lease, termination option, term			10 years
increase in right-of-use assets under new operating leases	$ 52,224	$ 127,532
Lease expense related to operating leases				$ 8,229	$ 6,898
Store Lease
Lessee, Lease, Description [Line Items]
Number of leases | lease			49
Store Lease | Minimum
Lessee, Lease, Description [Line Items]
Operating and finance lease, original lease term			10 years
Operating and finance lease, extension term			5 years
Store Lease | Maximum
Lessee, Lease, Description [Line Items]
Operating and finance lease, original lease term			67 years
Operating and finance lease, extension term			35 years
Corporate Office And Call Center Lease | Minimum
Lessee, Lease, Description [Line Items]
Operating lease, original lease term			5 years 3 months 18 days
Corporate Office And Call Center Lease | Maximum
Lessee, Lease, Description [Line Items]
Operating lease, original lease term			12 years 1 month 6 days
Regional Office Lease
Lessee, Lease, Description [Line Items]
Number of leases | lease			13
Operating lease, number of option to extend | extension			5
Operating lease, renewal term			3 years
Regional Office Lease | Minimum
Lessee, Lease, Description [Line Items]
Operating lease, original lease term			3 years
Regional Office Lease | Maximum
Lessee, Lease, Description [Line Items]
Operating lease, original lease term			5 years
District Office Lease
Lessee, Lease, Description [Line Items]
Operating lease, original lease term			12 months
New Jersey Store Lease
Lessee, Lease, Description [Line Items]
Lease not yet commenced, term			75 years
Lease not yet commenced, number of extension options | extension			3
Lease not yet commenced, term of extension options			10 years
California Store Lease
Lessee, Lease, Description [Line Items]
Lease not yet commenced, term			15 years
California Store Lease | Lease Option One
Lessee, Lease, Description [Line Items]
Lease not yet commenced, number of extension options | extension			3
Lease not yet commenced, term of extension options			10 years
California Store Lease | Lease Option Two
Lessee, Lease, Description [Line Items]
Lease not yet commenced, number of extension options | extension			1
Lease not yet commenced, term of extension options			5 years
ASU 2016-02
Lessee, Lease, Description [Line Items]
Operating lease liabilities						$ 95,506
Operating lease right-of-use assets						$ 104,863

Leases - Lease Costs (Details)

Leases - Lease Costs (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Finance lease cost:
Amortization of finance lease right-of-use assets	$ 168
Interest expense related to finance lease liabilities	290
Operating lease cost	20,268
Variable lease cost	5,068
Short-term lease cost	164
Total lease cost	25,958
Cash paid for amounts included in the measurement of lease liabilities
Operating cash outflows for finance lease payments	231
Operating cash outflows for operating lease payments	19,226
Total cash flows for lease liability measurement	19,457
Right-of-use assets obtained in exchange for new operating lease liabilities	277,557
Right-of-use assets obtained in exchange for new finance lease liabilities	$ 8,050
Weighted average remaining lease term - finance leases (years)	46 years 10 months 24 days
Weighted average remaining lease term - operating leases (years)	14 years 8 months 12 days
Weighted average discount rate - finance leases	6.07%
Weighted average discount rate - operating leases	3.65%

Leases - Undiscounted Cash Flow

Leases - Undiscounted Cash Flows on an Annual Basis (Details) $ in Thousands	Dec. 31, 2019USD ($)
Operating
2020	$ 28,369
2021	28,628
2022	28,651
2023	28,707
2024	29,198
Thereafter	223,823
Total	367,376
Present value adjustments	(92,593)
Lease liabilities	274,783
Finance
2020	232
2021	237
2022	255
2023	255
2024	255
Thereafter	16,522
Total	17,756
Present value adjustments	(12,918)
Lease liabilities	4,838
Total
2020	28,601
2021	28,865
2022	28,906
2023	28,962
2024	29,453
Thereafter	240,345
Total	385,132
Present value adjustments	(105,511)
Lease liabilities	$ 279,621

Leases - Future Minimum Lease P

Leases - Future Minimum Lease Payments Under Operating Leases (Details) $ in Thousands	Dec. 31, 2018USD ($)
Leases [Abstract]
2019	$ 8,203
2020	8,307
2021	8,137
2022	7,837
2023	7,021
Thereafter	111,653
Future minimum lease payments	$ 151,158

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuance under plans (in shares)	1,438,073
Intrinsic value of options exercised	$ 18,089	$ 3,693	$ 1,786
Options granted (in shares)	0	0	0
Weighted average forfeiture rate	7.40%
Net proceeds from exercise of stock options	$ 3,063	$ 1,169	$ 1,266
Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Expiration period	10 years
Compensation cost	$ 364	570	649
Net proceeds from exercise of stock options	3,063	1,169	1,266
Unrecognized compensation cost	$ 0
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Weighted average forfeiture rate	9.70%
Compensation cost	$ 9,173	8,733	7,232
Unrecognized compensation cost	$ 11,712
Unrecognized compensation cost, period of recognition	2 years 2 months 1 day
Performance-Based Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Compensation cost	$ 3,514	1,873	840
Unrecognized compensation cost	$ 4,315	$ 2,739	$ 1,681
Unrecognized compensation cost, period of recognition	3 years	3 years	3 years
Performance component weight percentage	50.00%
Minimum shares issued for each PSU (in shares)	0
Maximum shares issued for each PSU (in shares)	2
Dividend yield	0.00%	0.00%	0.00%

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock option activity
Balance at the beginning of the period (in shares)	417,581	472,156	510,574
Exercised (in shares)	(211,057)	(54,575)	(38,418)
Balance at the end of the period (in shares)	206,524	417,581	472,156
Vested and Expected to Vest (in shares)	206,460
Exercisable at the end of the period (in shares)	197,576
Weighted average exercise price
Balance at the beginning of the period (in dollars per share)	$ 31.58	$ 30.41	$ 30.60
Exercised (in dollars per share)	14.65	21.45	32.94
Balance at the end of the period (in dollars per share)	48.88	$ 31.58	$ 30.41
Vested and Expected to Vest (in dollars per share)	48.87
Exercisable at the end of the period (in dollars per share)	$ 47.20
Weighted average remaining contractual life
Outstanding at the beginning of period	3 years 5 months 4 days
Vested and Expected to Vest	3 years 5 months 4 days
Exercisable at the end of period	3 years 3 months 18 days
Aggregate intrinsic value
Outstanding at the end of the period	$ 11,719
Vested and Expected to Vest	11,717
Exercisable at the end of the period	$ 11,543

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary Stock Options Outstanding and Exercisable (Details)	12 Months Ended
	Dec. 31, 2019$ / sharesshares
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Options outstanding (in shares) | shares	206,524
Options outstanding, weighted average remaining contractual life	3 years 5 months 1 day
Weighted average exercise price (in dollars per share)	$ 48.88
Options exercisable (in shares) | shares	197,576
Options exercisable, weighted average exercise price (in dollars per share)	$ 47.20
$12.21 - $12.21
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise price range, lower limit (in dollars per share)	12.21
Exercise price range, upper limit (in dollars per share)	$ 12.21
Options outstanding (in shares) | shares	77,400
Options outstanding, weighted average remaining contractual life	5 days
Weighted average exercise price (in dollars per share)	$ 12.21
Options exercisable (in shares) | shares	77,400
Options exercisable, weighted average exercise price (in dollars per share)	$ 12.21
$38.40 - $38.40
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise price range, lower limit (in dollars per share)	38.40
Exercise price range, upper limit (in dollars per share)	$ 38.40
Options outstanding (in shares) | shares	8,085
Options outstanding, weighted average remaining contractual life	3 years 1 month 20 days
Weighted average exercise price (in dollars per share)	$ 38.40
Options exercisable (in shares) | shares	8,085
Options exercisable, weighted average exercise price (in dollars per share)	$ 38.40
$47.50 - $47.50
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise price range, lower limit (in dollars per share)	47.50
Exercise price range, upper limit (in dollars per share)	$ 47.50
Options outstanding (in shares) | shares	9,800
Options outstanding, weighted average remaining contractual life	4 years 1 month 17 days
Weighted average exercise price (in dollars per share)	$ 47.50
Options exercisable (in shares) | shares	9,800
Options exercisable, weighted average exercise price (in dollars per share)	$ 47.50
$65.36 - $65.36
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise price range, lower limit (in dollars per share)	65.36
Exercise price range, upper limit (in dollars per share)	$ 65.36
Options outstanding (in shares) | shares	15,647
Options outstanding, weighted average remaining contractual life	5 years 1 month 24 days
Weighted average exercise price (in dollars per share)	$ 65.36
Options exercisable (in shares) | shares	15,647
Options exercisable, weighted average exercise price (in dollars per share)	$ 65.36
$65.45 - $65.45
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise price range, lower limit (in dollars per share)	65.45
Exercise price range, upper limit (in dollars per share)	$ 65.45
Options outstanding (in shares) | shares	11,960
Options outstanding, weighted average remaining contractual life	5 years 1 month 17 days
Weighted average exercise price (in dollars per share)	$ 65.45
Options exercisable (in shares) | shares	11,960
Options exercisable, weighted average exercise price (in dollars per share)	$ 64.45
$73.52 - $73.52
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise price range, lower limit (in dollars per share)	73.52
Exercise price range, upper limit (in dollars per share)	$ 73.52
Options outstanding (in shares) | shares	50,000
Options outstanding, weighted average remaining contractual life	5 years 6 months 29 days
Weighted average exercise price (in dollars per share)	$ 73.52
Options exercisable (in shares) | shares	50,000
Options exercisable, weighted average exercise price (in dollars per share)	$ 73.52
$85.99 - $85.99
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise price range, lower limit (in dollars per share)	85.99
Exercise price range, upper limit (in dollars per share)	$ 85.99
Options outstanding (in shares) | shares	33,632
Options outstanding, weighted average remaining contractual life	6 years 1 month 24 days
Weighted average exercise price (in dollars per share)	$ 85.99
Options exercisable (in shares) | shares	24,684
Options exercisable, weighted average exercise price (in dollars per share)	$ 85.99

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Employee and Director Share Grant Activity (Details) - Restricted Stock - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restricted Stock Grants
Balance at the beginning of the period (in shares)	223,114	266,475	299,585
Granted (in shares)	109,081	85,066	95,392
Released (in shares)	(110,724)	(116,656)	(120,323)
Cancelled (in shares)	(8,863)	(11,771)	(8,179)
Balance at the end of the period (in shares)	212,608	223,114	266,475
Weighted-Average Grant-Date Fair Value
Balance at the beginning of the period (in dollars per share)	$ 80.02	$ 74.76	$ 70.57
Granted (in dollars per share)	101.52	86.14	74.49
Released (in dollars per share)	79.58	72.38	63.95
Cancelled (in dollars per share)	90.11	80.96	77.25
Balance at the end of the period (in dollars per share)	$ 90.85	$ 80.02	$ 74.76

Stock-Based Compensation - Su_4

Stock-Based Compensation - Summary of PSU Activity (Details) - Performance-Based Stock Units - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Units
Balance at the beginning of the period (in shares)	58,806	30,071	0
Granted (in shares)	49,334	28,735	30,071
Balance at the end of the period (in shares)	108,140	58,806	30,071
Weighted-Average Grant-Date Fair Value
Balance at the beginning of the period (in dollars per share)	$ 89.87	$ 83.84	$ 0
Granted (in dollars per share)	103.18	96.19	83.84
Balance at the end of the period (in dollars per share)	$ 95.94	$ 89.87	$ 83.84

Stock-Based Compensation - Assu

Stock-Based Compensation - Assumptions Used to Calculate Fair Value of Awards (Details) - Performance-Based Stock Units - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value	$ 6,211	$ 5,321	$ 2,630
Risk-free rate	2.53%	2.37%	1.62%
Volatility	20.70%	22.60%	21.40%
Expected term	2 years 9 months 18 days	2 years 10 months 24 days	2 years 9 months 18 days
Dividend yield	0.00%	0.00%	0.00%
Unrecognized compensation cost	$ 4,315	$ 2,739	$ 1,681
Term over which compensation cost recognized	3 years	3 years	3 years

Employee Benefit Plan (Details)

Employee Benefit Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Retirement Benefits [Abstract]
Employee contribution to retirement saving plan as a percentage of annual salary, maximum	60.00%
Matching contributions made by the entity during the period	$ 3,355	$ 2,833	$ 2,212
Percentage of company's matching contributions of first 3 percent of employee's compensation	100.00%
Percentage of employee's compensation that qualifies for 100 percent matching contribution by the company	3.00%
Maximum percentage of the company's matching contributions of next 2 percent of employee's compensation	50.00%
Percentage of employee's compensation that qualifies for 50 percent matching contribution by the company	2.00%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details)	Dec. 31, 2019subsidiary
Extra Space Management, Inc
Income Tax [Line Items]
Number of taxable REIT subsidiaries	1

Income Taxes - Income Tax Provi

Income Taxes - Income Tax Provision (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Federal
Current expense, federal	$ 10,164	$ 9,136	$ 5,677
Tax credits/true-up, federal	(3,633)	(5,841)	(5,573)
Change in deferred expense/(benefit), federal	1,787	3,730	1,700
Income tax expense, federal	8,318	7,025	1,804
State
Current expense, state	2,936	2,426	1,662
Tax credits/true-up, state	(30)	(175)	(383)
Change in deferred expense/(benefit), state	84	(32)	542
Income tax expense, state	2,990	2,219	1,821
Current expense, total	13,100	11,562	7,339
Tax credits/true-up, total	(3,663)	(6,016)	(5,956)
Change in deferred expense/(benefit), total	1,871	3,698	2,242
Total provision	$ 11,308	$ 9,244	$ 3,625

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Statutory Income Tax Provision (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Expected tax at statutory rate	$ 97,110	$ 95,828	$ 186,274
Non-taxable REIT income	(82,717)	(83,022)	(170,811)
State and local tax expense - net of federal benefit	2,837	2,385	2,306
Change in valuation allowance	(207)	(1,052)	159
Tax credits/true-up	(3,663)	(6,016)	(5,956)
Remeasurement of deferred balances	0	0	(8,460)
Miscellaneous	(2,052)	1,121	113
Total provision	$ 11,308	$ 9,244	$ 3,625
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Expected tax at statutory rate	21.00%	21.00%	35.00%
Non-taxable REIT income	(17.90%)	(18.20%)	(32.10%)
State and local tax expense - net of federal benefit	0.60%	0.50%	0.40%
Change in valuation allowance	0.00%	(0.20%)	0.00%
Tax credits/true-up	(0.80%)	(1.30%)	(1.10%)
Remeasurement of deferred balances	0.00%	0.00%	(1.60%)
Miscellaneous	(0.40%)	0.20%	0.00%
Total provision	2.50%	2.00%	0.60%

Income Taxes - Sources of Tempo

Income Taxes - Sources of Temporary Differences (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax liabilities:
Fixed assets	$ (23,805)	$ (20,907)
Operating lease right-of-use assets	(2,475)	0
Other	(84)	(96)
State deferred taxes	(3,405)	(3,076)
Total deferred tax liabilities	(29,769)	(24,079)
Deferred tax assets:
Captive insurance subsidiary	312	324
Accrued liabilities	2,006	1,772
Stock compensation	2,118	1,604
Operating lease liabilities	2,478	0
SmartStop TRS	219	219
Other	50	53
State deferred taxes	7,250	7,196
Total deferred tax assets	14,433	11,168
Valuation allowance	(3,665)	(3,872)
Net deferred income tax liabilities	$ (19,001)	$ (16,783)

Segment Information - Additiona

Segment Information - Additional Information (Details)	12 Months Ended
	Dec. 31, 2019segment
Segment Reporting [Abstract]
Number of reportable segments	2

Segment Information - Schedule

Segment Information - Schedule of Financial Information of Business Segments (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Revenues	$ 335,801	$ 337,505	$ 323,602	$ 311,546	$ 307,353	$ 306,953	$ 296,813	$ 285,485	$ 1,308,454	$ 1,196,604	$ 1,105,009
Operating expenses	171,156	174,867	165,609	163,069	150,676	153,362	152,097	151,573	674,701	607,708	563,404
Net operating income	164,645	162,638	157,993	148,477	156,677	153,591	144,716	133,912	634,958	619,703	654,394
Property management fees and other income									49,890	41,757	39,379
General and administrative expense									(89,418)	(81,256)	(78,961)
Depreciation and amortization expense									(219,857)	(209,050)	(193,296)
Gain on real estate transactions and impairment of real estate									1,205	30,807	112,789
Interest expense									(186,526)	(178,436)	(153,511)
Non-cash interest expense related to amortization of discount on equity component of exchangeable senior notes									(4,742)	(4,687)	(5,103)
Interest income									7,467	5,292	6,736
Equity in earnings of unconsolidated real estate entities									11,274	14,452	15,331
Income tax expense									(11,308)	(9,244)	(3,625)
Net income	$ 120,279	$ 115,995	$ 112,689	$ 102,160	$ 109,250	$ 139,687	$ 102,713	$ 95,430	451,123	447,080	514,222
Operating Segments
Segment Reporting Information [Line Items]
Revenues									1,258,564	1,154,847	1,065,630
Operating expenses									365,426	317,402	291,147
Net operating income									893,138	837,445	774,483
Operating Segments | Self-Storage Operations
Segment Reporting Information [Line Items]
Revenues									1,130,177	1,039,340	967,229
Operating expenses									336,050	291,695	271,974
Net operating income									794,127	747,645	695,255
Operating Segments | Tenant Reinsurance
Segment Reporting Information [Line Items]
Revenues									128,387	115,507	98,401
Operating expenses									29,376	25,707	19,173
Net operating income									$ 99,011	$ 89,800	$ 79,228

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Thousands	Dec. 31, 2019USD ($)store
Commitment to acquire stores
Other Commitments [Line Items]
Number of properties to be acquired | store	3
Other commitment | $	$ 27,400
Commitment to acquire stores, 2020
Other Commitments [Line Items]
Other commitment | $	$ 16,000
Number of store acquisitions expected to close | store	2
Commitment to acquire stores, 2021
Other Commitments [Line Items]
Other commitment | $	$ 11,400
Number of store acquisitions expected to close | store	1
Commitment to acquire stores with joint venture partners
Other Commitments [Line Items]
Number of properties to be acquired | store	7
Other commitment | $	$ 25,095

Supplementary Quarterly Finan_3

Supplementary Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 335,801	$ 337,505	$ 323,602	$ 311,546	$ 307,353	$ 306,953	$ 296,813	$ 285,485	$ 1,308,454	$ 1,196,604	$ 1,105,009
Cost of operations	171,156	174,867	165,609	163,069	150,676	153,362	152,097	151,573	674,701	607,708	563,404
Income from operations	164,645	162,638	157,993	148,477	156,677	153,591	144,716	133,912	634,958	619,703	654,394
Net income	120,279	115,995	112,689	102,160	109,250	139,687	102,713	95,430	451,123	447,080	514,222
Net income attributable to common stockholders	$ 112,282	$ 108,087	$ 104,828	$ 94,770	$ 101,462	$ 130,418	$ 95,153	$ 88,256	$ 419,967	$ 415,289	$ 479,013
Earnings per common share-basic (in dollars per share)	$ 0.87	$ 0.84	$ 0.82	$ 0.74	$ 0.80	$ 1.03	$ 0.75	$ 0.70	$ 3.27	$ 3.29	$ 3.79
Earnings per common share-diluted (in dollars per share)	$ 0.86	$ 0.83	$ 0.81	$ 0.74	$ 0.80	$ 1.02	$ 0.75	$ 0.70	$ 3.24	$ 3.27	$ 3.76

Schedule III - Real Estate an_2

Schedule III - Real Estate and Accumulated Depreciation - Property Summary (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)store
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	930
Debt	$ 2,249,685
Land Initial Cost	1,938,111
Building and Improvements Initial Cost	6,462,425
Adjustments and Costs to Land and Building Subsequent to Acquisition	770,180
Gross carrying amount - Land	1,938,923
Gross carrying amount - Building and improvements	7,231,793
Gross carrying amount - Total	9,170,716
Accumulated Depreciation	1,473,852
Right of use asset - finance lease	$ 8,050
Self storage facilities | AL
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	8
Debt	$ 29,567
Land Initial Cost	7,690
Building and Improvements Initial Cost	42,770
Adjustments and Costs to Land and Building Subsequent to Acquisition	3,693
Gross carrying amount - Land	7,691
Gross carrying amount - Building and improvements	46,462
Gross carrying amount - Total	54,153
Accumulated Depreciation	$ 8,277
Self storage facilities | AZ
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	23
Debt	$ 21,845
Land Initial Cost	27,535
Building and Improvements Initial Cost	117,304
Adjustments and Costs to Land and Building Subsequent to Acquisition	9,574
Gross carrying amount - Land	27,533
Gross carrying amount - Building and improvements	126,880
Gross carrying amount - Total	154,413
Accumulated Depreciation	$ 24,239
Self storage facilities | CA
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	165
Debt	$ 531,406
Land Initial Cost	539,355
Building and Improvements Initial Cost	1,166,591
Adjustments and Costs to Land and Building Subsequent to Acquisition	109,246
Gross carrying amount - Land	540,043
Gross carrying amount - Building and improvements	1,275,149
Gross carrying amount - Total	1,815,192
Accumulated Depreciation	$ 264,874
Self storage facilities | CO
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	16
Debt	$ 30,432
Land Initial Cost	16,809
Building and Improvements Initial Cost	71,894
Adjustments and Costs to Land and Building Subsequent to Acquisition	16,652
Gross carrying amount - Land	17,527
Gross carrying amount - Building and improvements	87,828
Gross carrying amount - Total	105,355
Accumulated Depreciation	$ 19,546
Self storage facilities | CT
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	7
Debt	$ 23,557
Land Initial Cost	9,875
Building and Improvements Initial Cost	50,966
Adjustments and Costs to Land and Building Subsequent to Acquisition	4,766
Gross carrying amount - Land	9,874
Gross carrying amount - Building and improvements	55,733
Gross carrying amount - Total	65,607
Accumulated Depreciation	$ 9,934
Self storage facilities | FL
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	91
Debt	$ 263,634
Land Initial Cost	163,455
Building and Improvements Initial Cost	588,353
Adjustments and Costs to Land and Building Subsequent to Acquisition	56,727
Gross carrying amount - Land	163,919
Gross carrying amount - Building and improvements	644,616
Gross carrying amount - Total	808,535
Accumulated Depreciation	$ 134,121
Self storage facilities | GA
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	63
Debt	$ 85,820
Land Initial Cost	83,742
Building and Improvements Initial Cost	406,477
Adjustments and Costs to Land and Building Subsequent to Acquisition	27,502
Gross carrying amount - Land	83,726
Gross carrying amount - Building and improvements	433,995
Gross carrying amount - Total	517,721
Accumulated Depreciation	$ 60,262
Self storage facilities | HI
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	13
Debt	$ 31,029
Land Initial Cost	17,663
Building and Improvements Initial Cost	133,870
Adjustments and Costs to Land and Building Subsequent to Acquisition	6,025
Gross carrying amount - Land	17,663
Gross carrying amount - Building and improvements	139,895
Gross carrying amount - Total	157,558
Accumulated Depreciation	$ 25,676
Self storage facilities | IL
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	37
Debt	$ 50,669
Land Initial Cost	45,435
Building and Improvements Initial Cost	234,396
Adjustments and Costs to Land and Building Subsequent to Acquisition	25,785
Gross carrying amount - Land	44,888
Gross carrying amount - Building and improvements	260,728
Gross carrying amount - Total	305,616
Accumulated Depreciation	$ 43,160
Self storage facilities | IN
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	15
Debt	$ 10,987
Land Initial Cost	12,447
Building and Improvements Initial Cost	58,247
Adjustments and Costs to Land and Building Subsequent to Acquisition	5,850
Gross carrying amount - Land	12,447
Gross carrying amount - Building and improvements	64,097
Gross carrying amount - Total	76,544
Accumulated Depreciation	$ 11,698
Self storage facilities | KS
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	1
Debt	$ 0
Land Initial Cost	366
Building and Improvements Initial Cost	1,897
Adjustments and Costs to Land and Building Subsequent to Acquisition	866
Gross carrying amount - Land	366
Gross carrying amount - Building and improvements	2,763
Gross carrying amount - Total	3,129
Accumulated Depreciation	$ 1,087
Self storage facilities | KY
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	11
Debt	$ 34,066
Land Initial Cost	8,640
Building and Improvements Initial Cost	68,679
Adjustments and Costs to Land and Building Subsequent to Acquisition	18,260
Gross carrying amount - Land	9,412
Gross carrying amount - Building and improvements	86,167
Gross carrying amount - Total	95,579
Accumulated Depreciation	$ 12,296
Self storage facilities | LA
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	2
Debt	$ 0
Land Initial Cost	6,114
Building and Improvements Initial Cost	8,541
Adjustments and Costs to Land and Building Subsequent to Acquisition	1,312
Gross carrying amount - Land	6,115
Gross carrying amount - Building and improvements	9,852
Gross carrying amount - Total	15,967
Accumulated Depreciation	$ 4,221
Self storage facilities | MA
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	46
Debt	$ 105,046
Land Initial Cost	73,544
Building and Improvements Initial Cost	270,243
Adjustments and Costs to Land and Building Subsequent to Acquisition	50,778
Gross carrying amount - Land	73,725
Gross carrying amount - Building and improvements	320,840
Gross carrying amount - Total	394,565
Accumulated Depreciation	$ 80,863
Self storage facilities | MD
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	32
Debt	$ 118,007
Land Initial Cost	99,147
Building and Improvements Initial Cost	284,253
Adjustments and Costs to Land and Building Subsequent to Acquisition	16,756
Gross carrying amount - Land	97,180
Gross carrying amount - Building and improvements	302,976
Gross carrying amount - Total	400,156
Accumulated Depreciation	$ 70,387
Self storage facilities | MI
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	7
Debt	$ 5,792
Land Initial Cost	9,583
Building and Improvements Initial Cost	51,359
Adjustments and Costs to Land and Building Subsequent to Acquisition	3,239
Gross carrying amount - Land	9,583
Gross carrying amount - Building and improvements	54,598
Gross carrying amount - Total	64,181
Accumulated Depreciation	$ 5,740
Self storage facilities | MN
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	5
Debt	$ 0
Land Initial Cost	7,377
Building and Improvements Initial Cost	50,057
Adjustments and Costs to Land and Building Subsequent to Acquisition	514
Gross carrying amount - Land	7,377
Gross carrying amount - Building and improvements	50,571
Gross carrying amount - Total	57,948
Accumulated Depreciation	$ 2,585
Self storage facilities | MO
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	5
Debt	$ 0
Land Initial Cost	4,129
Building and Improvements Initial Cost	15,444
Adjustments and Costs to Land and Building Subsequent to Acquisition	4,107
Gross carrying amount - Land	4,086
Gross carrying amount - Building and improvements	19,594
Gross carrying amount - Total	23,680
Accumulated Depreciation	$ 7,392
Self storage facilities | MS
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	3
Debt	$ 0
Land Initial Cost	2,420
Building and Improvements Initial Cost	20,849
Adjustments and Costs to Land and Building Subsequent to Acquisition	1,450
Gross carrying amount - Land	2,420
Gross carrying amount - Building and improvements	22,299
Gross carrying amount - Total	24,719
Accumulated Depreciation	$ 2,635
Self storage facilities | NC
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	19
Debt	$ 28,221
Land Initial Cost	31,969
Building and Improvements Initial Cost	104,104
Adjustments and Costs to Land and Building Subsequent to Acquisition	7,379
Gross carrying amount - Land	31,967
Gross carrying amount - Building and improvements	111,485
Gross carrying amount - Total	143,452
Accumulated Depreciation	$ 11,241
Self storage facilities | NH
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	2
Debt	$ 5,938
Land Initial Cost	754
Building and Improvements Initial Cost	4,054
Adjustments and Costs to Land and Building Subsequent to Acquisition	1,278
Gross carrying amount - Land	817
Gross carrying amount - Building and improvements	5,269
Gross carrying amount - Total	6,086
Accumulated Depreciation	$ 2,388
Self storage facilities | NJ
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	59
Debt	$ 155,754
Land Initial Cost	134,032
Building and Improvements Initial Cost	560,512
Adjustments and Costs to Land and Building Subsequent to Acquisition	41,422
Gross carrying amount - Land	137,258
Gross carrying amount - Building and improvements	598,708
Gross carrying amount - Total	735,966
Accumulated Depreciation	$ 129,970
Self storage facilities | NM
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	11
Debt	$ 17,689
Land Initial Cost	32,252
Building and Improvements Initial Cost	71,142
Adjustments and Costs to Land and Building Subsequent to Acquisition	5,049
Gross carrying amount - Land	32,252
Gross carrying amount - Building and improvements	76,191
Gross carrying amount - Total	108,443
Accumulated Depreciation	$ 9,373
Self storage facilities | NV
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	14
Debt	$ 37,557
Land Initial Cost	15,252
Building and Improvements Initial Cost	74,376
Adjustments and Costs to Land and Building Subsequent to Acquisition	4,671
Gross carrying amount - Land	15,252
Gross carrying amount - Building and improvements	79,047
Gross carrying amount - Total	94,299
Accumulated Depreciation	$ 10,422
Self storage facilities | NY
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	27
Debt	$ 43,218
Land Initial Cost	121,945
Building and Improvements Initial Cost	230,875
Adjustments and Costs to Land and Building Subsequent to Acquisition	34,801
Gross carrying amount - Land	122,680
Gross carrying amount - Building and improvements	264,941
Gross carrying amount - Total	387,621
Accumulated Depreciation	$ 59,450
Self storage facilities | OH
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	17
Debt	$ 34,470
Land Initial Cost	17,788
Building and Improvements Initial Cost	50,493
Adjustments and Costs to Land and Building Subsequent to Acquisition	6,733
Gross carrying amount - Land	17,787
Gross carrying amount - Building and improvements	57,227
Gross carrying amount - Total	75,014
Accumulated Depreciation	$ 13,318
Self storage facilities | OR
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	6
Debt	$ 30,267
Land Initial Cost	7,906
Building and Improvements Initial Cost	39,576
Adjustments and Costs to Land and Building Subsequent to Acquisition	2,042
Gross carrying amount - Land	7,906
Gross carrying amount - Building and improvements	41,618
Gross carrying amount - Total	49,524
Accumulated Depreciation	$ 7,545
Self storage facilities | PA
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	18
Debt	$ 34,475
Land Initial Cost	24,297
Building and Improvements Initial Cost	149,144
Adjustments and Costs to Land and Building Subsequent to Acquisition	12,297
Gross carrying amount - Land	23,589
Gross carrying amount - Building and improvements	162,149
Gross carrying amount - Total	185,738
Accumulated Depreciation	$ 24,480
Self storage facilities | RI
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	2
Debt	$ 11,841
Land Initial Cost	3,191
Building and Improvements Initial Cost	6,926
Adjustments and Costs to Land and Building Subsequent to Acquisition	1,253
Gross carrying amount - Land	3,191
Gross carrying amount - Building and improvements	8,179
Gross carrying amount - Total	11,370
Accumulated Depreciation	$ 2,939
Self storage facilities | SC
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	23
Debt	$ 43,543
Land Initial Cost	37,075
Building and Improvements Initial Cost	135,760
Adjustments and Costs to Land and Building Subsequent to Acquisition	10,029
Gross carrying amount - Land	37,076
Gross carrying amount - Building and improvements	145,788
Gross carrying amount - Total	182,864
Accumulated Depreciation	$ 22,598
Self storage facilities | TN
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	17
Debt	$ 45,601
Land Initial Cost	25,938
Building and Improvements Initial Cost	91,497
Adjustments and Costs to Land and Building Subsequent to Acquisition	8,750
Gross carrying amount - Land	25,938
Gross carrying amount - Building and improvements	100,247
Gross carrying amount - Total	126,185
Accumulated Depreciation	$ 18,046
Self storage facilities | TX
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	100
Debt	$ 213,291
Land Initial Cost	169,160
Building and Improvements Initial Cost	648,128
Adjustments and Costs to Land and Building Subsequent to Acquisition	57,365
Gross carrying amount - Land	169,012
Gross carrying amount - Building and improvements	705,641
Gross carrying amount - Total	874,653
Accumulated Depreciation	$ 112,790
Self storage facilities | UT
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	10
Debt	$ 13,181
Land Initial Cost	9,008
Building and Improvements Initial Cost	39,295
Adjustments and Costs to Land and Building Subsequent to Acquisition	2,247
Gross carrying amount - Land	9,008
Gross carrying amount - Building and improvements	41,542
Gross carrying amount - Total	50,550
Accumulated Depreciation	$ 9,854
Self storage facilities | VA
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	46
Debt	$ 163,675
Land Initial Cost	139,318
Building and Improvements Initial Cost	414,335
Adjustments and Costs to Land and Building Subsequent to Acquisition	19,385
Gross carrying amount - Land	139,319
Gross carrying amount - Building and improvements	433,719
Gross carrying amount - Total	573,038
Accumulated Depreciation	$ 69,063
Self storage facilities | DC
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	8
Debt	$ 20,345
Land Initial Cost	12,528
Building and Improvements Initial Cost	47,645
Adjustments and Costs to Land and Building Subsequent to Acquisition	2,694
Gross carrying amount - Land	12,530
Gross carrying amount - Building and improvements	50,337
Gross carrying amount - Total	62,867
Accumulated Depreciation	$ 11,380
Self storage facilities | DC
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Store Count | store	1
Debt	$ 8,762
Land Initial Cost	14,394
Building and Improvements Initial Cost	18,172
Adjustments and Costs to Land and Building Subsequent to Acquisition	429
Gross carrying amount - Land	14,394
Gross carrying amount - Building and improvements	18,601
Gross carrying amount - Total	32,995
Accumulated Depreciation	1,824
Other corporate assets
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Debt	0
Land Initial Cost	0
Building and Improvements Initial Cost	2,202
Adjustments and Costs to Land and Building Subsequent to Acquisition	138,483
Gross carrying amount - Land	0
Gross carrying amount - Building and improvements	140,685
Gross carrying amount - Total	140,685
Accumulated Depreciation	40,298
Intangible tenant relationships and lease rights
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Debt	0
Land Initial Cost	0
Building and Improvements Initial Cost	132,000
Adjustments and Costs to Land and Building Subsequent to Acquisition	2,932
Gross carrying amount - Land	0
Gross carrying amount - Building and improvements	134,932
Gross carrying amount - Total	134,932
Accumulated Depreciation	127,712
Construction in Progress/Undeveloped Land
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Debt	0
Land Initial Cost	5,978
Building and Improvements Initial Cost	0
Adjustments and Costs to Land and Building Subsequent to Acquisition	39,788
Gross carrying amount - Land	3,372
Gross carrying amount - Building and improvements	42,394
Gross carrying amount - Total	45,766
Accumulated Depreciation	0
Right of use asset - finance lease
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Debt	0
Land Initial Cost	0
Building and Improvements Initial Cost	0
Adjustments and Costs to Land and Building Subsequent to Acquisition	8,050
Gross carrying amount - Land	0
Gross carrying amount - Building and improvements	8,050
Gross carrying amount - Total	8,050
Accumulated Depreciation	$ 168

Schedule III - Real Estate an_3

Schedule III - Real Estate and Accumulated Depreciation - Activity in Real Estate Facilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Real estate, gross:
Balance at end of year	$ 9,170,716
Accumulated depreciation:
Balance at end of year	1,473,852
Net real estate assets:
Net non-lease real estate assets	7,696,864	$ 7,491,831	$ 7,132,431
Right of use asset - finance lease	8,050
Aggregate cost of real estate for U.S. federal income tax purposes	7,721,422
Operating facilities
Real estate, gross:
Balance at beginning of year	8,709,315	8,158,741	7,649,448
Acquisitions	303,588	459,223	628,391
Improvements	68,459	64,336	71,090
Transfers from construction in progress (to operating facilities)	59,614	49,449	19,079
Dispositions and other	(11,418)	(22,434)	(209,267)
Balance at end of year	9,129,558	8,709,315	8,158,741
Accumulated depreciation:
Balance at beginning of year	1,262,438	1,060,060	900,861
Depreciation expense	212,202	203,030	185,903
Dispositions and other	(789)	(652)	(26,704)
Balance at end of year	1,473,851	1,262,438	1,060,060
Real estate under development/redevelopment
Real estate, gross:
Balance at beginning of year	44,954	33,750	21,860
Current development	55,817	60,677	33,484
Transfers from construction in progress (to operating facilities)	(59,614)	(49,449)	(19,079)
Dispositions and other	0	(24)	(2,515)
Balance at end of year	$ 41,157	$ 44,954	$ 33,750