Iron Mountain (IRM) 10-Q 6 May 21 2021 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2021	Apr. 30, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
Document Transition Report	false
Entity File Number	1-13045
Entity Registrant Name	IRON MOUNTAIN INC
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	23-2588479
Entity Address, Address Line One	One Federal Street
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02110
City Area Code	617
Local Phone Number	535-4766
Title of 12(b) Security	Common Stock, $.01 par value
Trading Symbol	IRM
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Emerging Growth Company	false
Small Business Entity	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		288,731,091
Entity Central Index Key	0001020569
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current Assets:
Cash and cash equivalents	$ 138,944	$ 205,063
Accounts receivable (less allowances of $60,743 and $56,981 as of March 31, 2021 and December 31, 2020, respectively)	814,983	859,344
Prepaid expenses and other	220,564	205,380
Total Current Assets	1,174,491	1,269,787
Property, Plant and Equipment:
Property, plant and equipment	8,254,410	8,246,337
Less—Accumulated depreciation	(3,787,770)	(3,743,894)
Property, Plant and Equipment, Net	4,466,640	4,502,443
Other Assets, Net:
Goodwill	4,520,775	4,557,609
Customer relationships, customer inducements and data center lease-based intangibles	1,271,604	1,326,977
Operating lease right-of-use assets	2,205,299	2,196,502
Other	305,640	295,949
Total Other Assets, Net	8,303,318	8,377,037
Total Assets	13,944,449	14,149,267
Current Liabilities:
Current portion of long-term debt	363,911	193,759
Accounts payable	327,060	359,863
Accrued expenses and other current liabilities (includes current portion of operating lease liabilities)	951,502	1,146,288
Deferred revenue	284,974	295,785
Total Current Liabilities	1,927,447	1,995,695
Long-term Debt, net of current portion	8,552,415	8,509,555
Long-term Operating Lease Liabilities, net of current portion	2,061,140	2,044,598
Other Long-term Liabilities	191,001	204,508
Deferred Income Taxes	191,138	198,377
Commitments and Contingencies
Redeemable Noncontrolling Interests	61,601	59,805
Equity:
Preferred stock (par value $0.01; authorized 10,000,000 shares; none issued and outstanding)	0	0
Common stock (par value $0.01; authorized 400,000,000 shares; issued and outstanding 288,727,747 and 288,273,049 shares as of March 31, 2021 and December 31, 2020, respectively)	2,888	2,883
Additional paid-in capital	4,347,151	4,340,078
(Distributions in excess of earnings) Earnings in excess of distributions	(3,083,421)	(2,950,339)
Accumulated other comprehensive items, net	(306,911)	(255,893)
Total Equity	959,707	1,136,729
Total Liabilities and Equity	$ 13,944,449	$ 14,149,267

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 60,743	$ 56,981
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, authorized shares (in shares)	10,000,000	10,000,000
Preferred stock, issued shares (in shares)	0	0
Preferred stock, outstanding shares (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized shares (in shares)	400,000,000	400,000,000
Common stock, issued shares (in shares)	288,727,747	288,273,049
Common stock, outstanding shares (in shares)	288,727,747	288,273,049

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenues:
Storage rental	$ 708,056	$ 683,547
Service	373,984	385,184
Total Revenues	1,082,040	1,068,731
Operating Expenses:
Cost of sales (excluding depreciation and amortization)	451,909	466,921
Selling, general and administrative	258,723	238,733
Depreciation and amortization	165,642	162,584
Restructuring Charges	39,811	41,046
Intangible impairments	0	23,000
(Gain) Loss on disposal/write-down of property, plant and equipment, net	(4,451)	(1,055)
Total Operating Expenses	911,634	931,229
Operating Income (Loss)	170,406	137,502
Interest Expense, Net (includes Interest Income of $2,571 and $1,448 for the three months ended March 31, 2021 and 2020, respectively)	104,422	105,649
Other Expense (Income), Net	4,713	(42,726)
Net Income (Loss) Before Provision (Benefit) for Income Taxes	61,271	74,579
Provision (Benefit) for Income Taxes	14,640	9,687
Net Income (Loss)	46,631	64,892
Less: Net Income (Loss) Attributable to Noncontrolling Interests	1,028	917
Net Income (Loss) Attributable to Iron Mountain Incorporated	$ 45,603	$ 63,975
Net Income (Loss) Per Share Attributable to Iron Mountain Incorporated:
Income (Loss) from Continuing Operations, Basic (in dollars per share)	$ 0.16	$ 0.22
Income (Loss) from Continuing Operations, Diluted (in dollars per share)	$ 0.16	$ 0.22
Weighted Average Common Shares Outstanding-Basic (in shares)	288,756,000	287,840,000
Weighted Average Common Shares Outstanding-Diluted (in shares)	289,528,287	288,359,133

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Interest income	$ 2,571	$ 1,448

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 46,631	$ 64,892
Other Comprehensive (Loss) Income:
Foreign Currency Translation Adjustment	(66,355)	(223,652)
Change in Fair Value of Derivative Instruments	15,206	(8,362)
Total Other Comprehensive (Loss) Income	(51,149)	(232,014)
Comprehensive (Loss) Income	(4,518)	(167,122)
Comprehensive Income (Loss) Attributable to Noncontrolling Interests	897	(430)
Comprehensive (Loss) Income Attributable to Iron Mountain Incorporated	$ (5,415)	$ (166,692)

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total	COMMON STOCK	ADDITIONAL PAID-IN CAPITAL	(DISTRIBUTIONS IN EXCESS OF EARNINGS) EARNINGS IN EXCESS OF DISTRIBUTIONS	ACCUMULATED OTHER COMPREHENSIVE ITEMS, NET	NONCONTROLLING INTERESTS	REDEEMABLE NONCONTROLLING INTERESTS
Beginning of Period at Dec. 31, 2019	$ 1,464,227	$ 2,873	$ 4,298,566	$ (2,574,896)	$ (262,581)	$ 265
Balance (in shares) at Dec. 31, 2019		287,299,645
Increase (Decrease) in Stockholders' Equity
Issuance of shares under employee stock purchase plan and option plans and stock-based compensation	1,917	$ 6	1,911
Issuance of shares under employee stock purchase plan and option plans and stock-based compensation (in shares)		579,497
Change in equity related to redeemable noncontrolling interests	4,000		4,000				$ (4,000)
Parent cash dividends declared	(179,512)			(179,512)
Foreign currency translation adjustment	(222,305)				(222,305)
Change in fair value of derivative instruments	(8,362)				(8,362)
Net income (loss)	63,876			63,975		(99)
End of period at Mar. 31, 2020	1,123,841	$ 2,879	4,304,477	(2,690,433)	(493,248)	166
Balance (in shares) at Mar. 31, 2020		287,879,142
Beginning of redeemable noncontrolling interest at Dec. 31, 2019							67,682
Increase (Decrease) in Temporary Equity [Roll Forward]
Change in equity related to redeemable noncontrolling interests	4,000		4,000				(4,000)
Foreign currency translation adjustment							(1,347)
Net income (loss)							1,016
Noncontrolling interests dividends							(1,194)
Ending of redeemable noncontrolling interest at Mar. 31, 2020							62,157
Beginning of Period at Dec. 31, 2020	$ 1,136,729	$ 2,883	4,340,078	(2,950,339)	(255,893)	0
Balance (in shares) at Dec. 31, 2020	288,273,049	288,273,049
Increase (Decrease) in Stockholders' Equity
Issuance of shares under employee stock purchase plan and option plans and stock-based compensation	$ 6,398	$ 5	6,393
Issuance of shares under employee stock purchase plan and option plans and stock-based compensation (in shares)		454,698
Change in equity related to redeemable noncontrolling interests	680		680				(680)
Parent cash dividends declared	(178,685)			(178,685)
Foreign currency translation adjustment	(66,224)				(66,224)
Change in fair value of derivative instruments	15,206				15,206
Net income (loss)	45,603			45,603
End of period at Mar. 31, 2021	$ 959,707	$ 2,888	4,347,151	$ (3,083,421)	$ (306,911)	$ 0
Balance (in shares) at Mar. 31, 2021	288,727,747	288,727,747
Beginning of redeemable noncontrolling interest at Dec. 31, 2020	$ 59,805						59,805
Increase (Decrease) in Temporary Equity [Roll Forward]
Change in equity related to redeemable noncontrolling interests	680		$ 680				(680)
Foreign currency translation adjustment							(131)
Net income (loss)							1,028
Noncontrolling interests equity contributions							2,200
Noncontrolling interests dividends							(621)
Ending of redeemable noncontrolling interest at Mar. 31, 2021	$ 61,601						$ 61,601

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash Flows from Operating Activities:
Net income (loss)	$ 46,631	$ 64,892
Adjustments to reconcile net income (loss) to cash flows from operating activities:
Depreciation	114,449	113,700
Amortization (includes amortization of deferred financing costs and discounts of $4,127 and $4,513 for the three months ended March 31, 2021 and 2020, respectively)	55,320	53,397
Intangible impairments	0	23,000
Revenue reduction associated with amortization of customer inducements and above- and below-market leases	2,263	2,682
Stock-based compensation expense	10,953	6,527
(Benefit) provision for deferred income taxes	(6,315)	(107)
(Gain) loss on disposal/write-down of property, plant and equipment, net	(4,451)	(1,055)
Foreign currency transactions and other, net	9,220	(44,849)
(Increase) decrease in assets	(22,154)	(45,594)
(Decrease) increase in liabilities	(137,087)	(47,178)
Cash Flows from Operating Activities	68,829	125,415
Cash Flows from Investing Activities:
Capital expenditures	(145,528)	(97,144)
Cash paid for acquisitions, net of cash acquired	0	(118,069)
Acquisition of customer relationships	(874)	(1,734)
Customer inducements	(1,457)	(4,328)
Contract fulfillment costs and third-party commissions	(16,719)	(11,142)
Investments in joint ventures and other investments	(6,500)	0
Proceeds from sales of property and equipment and other, net	12,448	1,246
Cash Flows from Investing Activities	(158,630)	(231,171)
Cash Flows from Financing Activities:
Repayment of revolving credit facility, term loan facilities and other debt	(415,030)	(2,581,771)
Proceeds from revolving credit facility, term loan facilities and other debt	625,689	2,850,451
Debt repayment and equity distribution to noncontrolling interests	(621)	(1,194)
Parent cash dividends	(180,992)	(181,302)
Net (payments) proceeds associated with employee stock-based awards	(4,556)	(4,610)
Net proceeds (payments) of debt financing costs and other	5,000	(7,816)
Cash Flows from Financing Activities	29,490	73,758
Effect of Exchange Rates on Cash and Cash Equivalents	(5,808)	(8,873)
(Decrease) increase in Cash and Cash Equivalents	(66,119)	(40,871)
Cash and Cash Equivalents, including Restricted Cash, Beginning of Period	205,063	193,555
Cash and Cash Equivalents, including Restricted Cash, End of Period	138,944	152,684
Supplemental Information:
Cash Paid for Interest	185,558	157,541
Cash Paid for Income Taxes, Net	20,847	14,004
Non-Cash Investing and Financing Activities:
Financing Leases	4,976	13,061
Accrued Capital Expenditures	59,490	60,761
Fair Value of Investments Applied to Acquisitions	0	27,276
Dividends Payable	$ 185,560	$ 184,231

CONDENSED CONSOLIDATED STATEM_6

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Cash Flows [Abstract]
Deferred financing costs and discount included in Amortization	$ 4,127	$ 4,513

General

General	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
General	GENERAL The unaudited condensed consolidated financial statements of Iron Mountain Incorporated, a Delaware corporation (“IMI”), and its subsidiaries (“we” or “us”), have been prepared pursuant to the rules and regulations of the United States Securities and Exchange Commission (the “SEC”). Certain information and footnote disclosures normally included in the annual financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) have been omitted pursuant to those rules and regulations, but we believe that the disclosures included herein are adequate to make the information presented not misleading. The interim condensed consolidated financial statements are presented herein and, in the opinion of management, reflect all adjustments of a normal recurring nature necessary for a fair presentation. Interim results are not necessarily indicative of results for a full year. The Condensed Consolidated Financial Statements and Notes thereto, which are included herein, should be read in conjunction with the Consolidated Financial Statements and Notes thereto for the year ended December 31, 2020 included in our Annual Report on Form 10-K filed with the SEC on February 24, 2021 (our “Annual Report”). We have been organized and have operated as a real estate investment trust for United States federal income tax purposes (“REIT”) beginning with our taxable year ended December 31, 2014. In March 2020, the World Health Organization declared a novel strain of coronavirus (“COVID-19”) a pandemic. The preventative and protective actions that governments have ordered, or we or our customers have implemented, have resulted in a period of reduced service operations and business disruption for us, our customers and other third parties with which we do business. The broader impacts of the COVID-19 pandemic on our financial position, results of operations and cash flows, including impacts to the estimates we use in the preparation of our financial statements, remain uncertain and difficult to predict as information continues to evolve, and the severity and duration of the pandemic remains unknown, as is our visibility of its effect on the markets we serve and our customers within those markets.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	A. CASH, CASH EQUIVALENTS AND RESTRICTED CASH Cash and cash equivalents include cash on hand and cash invested in highly liquid short-term securities, which have remaining maturities at the date of purchase of less than 90 days. Cash and cash equivalents are carried at cost, which approximates fair value. B. ACCOUNTS RECEIVABLE We maintain an allowance for doubtful accounts and a credit memo reserve for estimated losses resulting from the potential inability of our customers to make required payments and potential disputes regarding billing and service issues. Rollforward of allowance for doubtful accounts and credit memo reserves for the three months ended March 31, 2021 is as follows: Balance as of December 31, 2020 $ 56,981 Credit memos charged to revenue 13,026 Allowance for bad debts charged to expense 9,850 Deductions and other (1) (19,114) Balance as of March 31, 2021 $ 60,743 (1) Primarily consists of the issuance of credit memos, the write-off of accounts receivable and the impact associated with currency translation adjustments. C. LEASES We lease facilities for certain warehouses, data centers and office space. We also have land leases, including those on which certain facilities are located. Operating and financing lease right-of-use assets and lease liabilities as of March 31, 2021 and December 31, 2020 are as follows: DESCRIPTION MARCH 31, 2021 DECEMBER 31, 2020 Assets: Operating lease right-of-use assets $ 2,205,299 $ 2,196,502 Financing lease right-of-use assets, net of accumulated depreciation (1) 300,399 310,534 Liabilities: Current Operating lease liabilities $ 248,319 $ 250,239 Financing lease liabilities (1) 42,692 43,149 Long-term Operating lease liabilities 2,061,140 2,044,598 Financing lease liabilities (1) 311,448 323,162 (1) Financing lease right-of-use assets, current financing lease liabilities and long-term financing lease liabilities are included within Property, Plant and Equipment, Net, Current portion of long-term debt and Long-term Debt, net of current portion, respectively, within our Condensed Consolidated Balance Sheets. The components of the lease expense for the three months ended March 31, 2021 and 2020 are as follows: THREE MONTHS ENDED MARCH 31, DESCRIPTION 2021 2020 Operating lease cost (1) $ 132,675 $ 123,289 Financing lease cost: Depreciation of financing lease right-of-use assets $ 12,648 $ 12,955 Interest expense for financing lease liabilities 4,975 4,844 (1) Operating lease cost, the majority of which is included in Cost of sales, includes variable lease costs of $28,368 and $27,805 for the three months ended March 31, 2021 and 2020, respectively. Other information: Supplemental cash flow information relating to our leases for the three months ended March 31, 2021 and 2020 is as follows: THREE MONTHS ENDED MARCH 31, CASH PAID FOR AMOUNTS INCLUDED IN MEASUREMENT OF LEASE LIABILITIES: 2021 2020 Operating cash flows used in operating leases $ 93,645 $ 86,418 Operating cash flows used in financing leases (interest) 4,975 4,844 Financing cash flows used in financing leases 12,441 12,739 NON-CASH ITEMS: Operating lease modifications and reassessments $ 31,994 $ 34,916 New operating leases (including acquisitions and sale-leaseback transactions) 48,200 110,609 D. GOODWILL Our reporting units as of December 31, 2020 are described in detail in Note 2.k. to Notes to Consolidated Financial Statements included in our Annual Report. The changes in the carrying value of goodwill attributable to each reportable operating segment for the three months ended March 31, 2021 are as follows: GLOBAL RIM BUSINESS GLOBAL DATA CENTER BUSINESS CORPORATE AND OTHER BUSINESS TOTAL CONSOLIDATED Goodwill balance, net of accumulated amortization as of $ 4,024,182 $ 436,987 $ 96,440 $ 4,557,609 Fair value and other adjustments (5,804) — — (5,804) Currency effects (24,298) (6,359) (373) (31,030) Goodwill balance, net accumulated amortization as of March 31, 2021 $ 3,994,080 $ 430,628 $ 96,067 $ 4,520,775 Accumulated goodwill impairment balance as of March 31, 2021 $ 132,409 $ — $ 26,011 $ 158,420 E. INVESTMENTS I. FRANKFURT DATA CENTER JOINT VENTURE In October 2020, we formed a joint venture with AGC Equity Partners (the “Frankfurt JV”). Our equity interest in the Frankfurt JV at both March 31, 2021 and December 31, 2020 was 20% , and the carrying value of our investment in the Frankfurt JV at March 31, 2021 and December 31, 2020 was $26,257 and $26,500, respectively, which is presented as a component of Other within Other assets, net in our Condensed Consolidated Balance Sheets. II. MAKESPACE JOINT VENTURE During 2019, we formed a joint venture with MakeSpace Labs, Inc. (the “MakeSpace JV”). Our equity interest in the MakeSpace JV at March 31, 2021 and December 31, 2020 was 42% and 39%, respectively, and the carrying value of our investment in the MakeSpace JV at March 31, 2021 and December 31, 2020 was $21,075 and $16,924, respectively, which is presented as a component of Other within Other assets, net in our Condensed Consolidated Balance Sheets. F. FAIR VALUE MEASUREMENTS The assets and liabilities carried at fair value measured on a recurring basis as of March 31, 2021 and December 31, 2020 are as follows: FAIR VALUE MEASUREMENTS AT MARCH 31, 2021 USING DESCRIPTION TOTAL CARRYING QUOTED PRICES IN SIGNIFICANT OTHER SIGNIFICANT Money Market Funds $ 7,673 $ — $ 7,673 $ — Time Deposits 1,291 — 1,291 — Trading Securities 11,323 11,067 256 — Derivative Liabilities 34,497 — 34,497 — FAIR VALUE MEASUREMENTS AT DECEMBER 31, 2020 USING DESCRIPTION TOTAL CARRYING QUOTED PRICES IN SIGNIFICANT OTHER SIGNIFICANT Money Market Funds $ 62,657 $ — $ 62,657 $ — Time Deposits 2,121 — 2,121 — Trading Securities 10,892 10,636 256 — Derivative Liabilities 49,703 — 49,703 — There were no material items that are measured at fair value on a non-recurring basis at March 31, 2021 and December 31, 2020, other than those disclosed in Note 2.o. to Notes to Consolidated Financial Statements included in our Annual Report which are based on Level 3 inputs. G. ACCUMULATED OTHER COMPREHENSIVE ITEMS, NET The changes in accumulated other comprehensive items, net for the three months ended March 31, 2021 and 2020 are as follows: THREE MONTHS ENDED MARCH 31, 2021 THREE MONTHS ENDED MARCH 31, 2020 FOREIGN CHANGE IN FAIR VALUE OF TOTAL FOREIGN CHANGE IN FAIR VALUE OF DERIVATIVE INSTRUMENTS TOTAL Beginning of Period $ (206,190) $ (49,703) $ (255,893) $ (252,825) $ (9,756) $ (262,581) Other comprehensive (loss) income: Foreign currency translation and other adjustments (66,224) — (66,224) (222,305) — (222,305) Change in fair value of derivative instruments — 15,206 15,206 — (8,362) (8,362) Total other comprehensive (loss) income (66,224) 15,206 (51,018) (222,305) (8,362) (230,667) End of Period $ (272,414) $ (34,497) $ (306,911) $ (475,130) $ (18,118) $ (493,248) H. REVENUES The costs associated with the initial movement of customer records into physical storage and certain commissions are considered costs to obtain or fulfill customer contracts (collectively, “Contract Fulfillment Costs”). Contract Fulfillment Costs as of March 31, 2021 and December 31, 2020, are as follows: MARCH 31, 2021 DECEMBER 31, 2020 GROSS ACCUMULATED NET GROSS ACCUMULATED NET Intake Costs asset $ 66,337 $ (35,904) $ 30,433 $ 63,721 $ (33,352) $ 30,369 Commissions asset 99,721 (43,125) 56,596 91,069 (38,787) 52,282 Deferred revenue liabilities are reflected in our Condensed Consolidated Balance Sheets as follows: DESCRIPTION LOCATION IN BALANCE SHEET MARCH 31, 2021 DECEMBER 31, 2020 Deferred revenue - Current Deferred revenue $ 284,974 $ 295,785 Deferred revenue - Long-term Other Long-term Liabilities 36,581 35,612 DATA CENTER LESSOR CONSIDERATIONS Our Global Data Center Business features storage rental provided to customers at contractually specified rates over a fixed contractual period, which are accounted for in accordance with Accounting Standards Update ("ASU") No. 2016-02, Leases (Topic 842) , as amended (“ASU 2016-02”). Storage rental revenue, including revenue associated with power and connectivity, associated with our Global Data Center Business for the three months ended March 31, 2021 and 2020 are as follows: THREE MONTHS ENDED MARCH 31, 2021 2020 Storage rental revenue (1) $ 67,157 $ 64,595 (1) Revenue associated with power and connectivity included within storage rental revenue was $13,133 and $11,413 for the three months ended March 31, 2021 and 2020, respectively. I. STOCK-BASED COMPENSATION Stock-based compensation expense for the cost of stock options, restricted stock units (“RSUs”), performance units (“PUs”) and shares of stock issued under our employee stock purchase plan (collectively, “Employee Stock-Based Awards”) for the three months ended March 31, 2021 and 2020 is as follows: THREE MONTHS ENDED MARCH 31, 2021 2020 Stock-based compensation expense $ 10,953 $ 6,527 As of March 31, 2021, unrecognized compensation cost related to the unvested portion of our Employee Stock-Based Awards was $80,625. RESTRICTED STOCK UNITS AND PERFORMANCE UNITS The fair value of RSUs and earned PUs that vested during the three months ended March 31, 2021 and 2020 is as follows: THREE MONTHS ENDED MARCH 31, 2021 2020 Fair value of RSUs vested $ 19,861 $ 18,379 Fair value of earned PUs that vested 5,591 10,890 J. OTHER EXPENSE (INCOME), NET Consolidated other expense (income), net for the three months ended March 31, 2021 and 2020 consists of the following: THREE MONTHS ENDED MARCH 31, DESCRIPTION 2021 2020 Foreign currency transaction losses (gains), net $ 2,314 $ (37,399) Other, net (1) 2,399 (5,327) Other Expense (Income), Net $ 4,713 $ (42,726) (1) Other, net for the three months ended March 31, 2021 is primarily comprised of losses on our equity method investments. Other, net for the three months ended March 31, 2020 is primarily comprised of a gain on our previously held 25% equity investment in OSG Records Management (Europe) Limited (“OSG”), which is partially offset by losses on our equity method investments. K. INCOME TAXES We provide for income taxes during interim periods based on our estimate of the effective tax rate for the year. Our effective tax rates for the three months ended March 31, 2021 and 2020 are as follows: THREE MONTHS ENDED MARCH 31, 2021 (1) 2020 (2) Effective Tax Rate 23.9 % 13.0 % (1) The primary reconciling items between the federal statutory tax rate of 21.0% and our overall effective tax rate for the three months ended March 31, 2021 were the benefits derived from the dividends paid deduction and the impacts of differences in the tax rates at which our foreign earnings are subject. (2) The primary reconciling items between the federal statutory tax rate of 21.0% and our overall effective tax rate for the three months ended March 31, 2020 were the benefits derived from the dividends paid deduction and foreign exchange losses in different jurisdictions with different tax rates as well as the impacts of differences in the tax rates at which our foreign earnings are subject. L. INCOME (LOSS) PER SHARE—BASIC AND DILUTED The calculation of basic and diluted income (loss) per share for the three months ended March 31, 2021 and 2020 are as follows: THREE MONTHS ENDED MARCH 31, 2021 2020 Net Income (Loss) $ 46,631 $ 64,892 Less: Net Income (Loss) Attributable to Noncontrolling Interests 1,028 917 Net Income (Loss) Attributable to Iron Mountain Incorporated (utilized in numerator of Earnings Per Share calculation) $ 45,603 $ 63,975 Weighted-average shares—basic 288,756,000 287,840,000 Effect of dilutive potential stock options 56,437 51,799 Effect of dilutive potential RSUs and PUs 715,850 467,334 Weighted-average shares—diluted 289,528,287 288,359,133 Net Income (Loss) Per Share Attributable to Iron Mountain Incorporated: Basic $ 0.16 $ 0.22 Diluted $ 0.16 $ 0.22 Antidilutive stock options, RSUs and PUs, excluded from the calculation 4,708,068 5,513,714 M. RECENT ACCOUNTING PRONOUNCEMENTS In December 2019, the Financial Accounting Standards Board issued ASU No. 2019-12, Income Taxes (Topic 740) (“ASU 2019-12”). ASU 2019-12 simplifies the accounting for income taxes by removing certain exceptions for recognizing deferred taxes for investments, performing intra-period allocation and calculating income taxes in interim periods. ASU 2019-12 also adds guidance to reduce complexity in certain areas, including recognizing deferred taxes for tax goodwill and allocating taxes to members of a consolidated group. We adopted ASU 2019-12 on January 1, 2021. ASU 2019-12 did not have a material impact on our consolidated financial statements.

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activities	3 Months Ended
	Mar. 31, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities	Derivative instruments we are party to include: (i) interest rate swap agreements (which are designated as cash flow hedges) and (ii) cross-currency swap agreements (which are designated as net investment hedges). INTEREST RATE SWAP AGREEMENTS DESIGNATED AS CASH FLOW HEDGES In March 2018, we entered into interest rate swap agreements to limit our exposure to changes in interest rates on a portion of our floating rate indebtedness. As of March 31, 2021 and December 31, 2020, we had $350,000 in notional value of interest rate swap agreements outstanding, which expire in March 2022. Under the interest rate swap agreements, we receive variable rate interest payments associated with the notional amount of each interest rate swap, based upon one-month LIBOR, in exchange for the payment of fixed interest rates as specified in the interest rate swap agreements. In July 2019, we entered into forward-starting interest rate swap agreements to limit our exposure to changes in interest rates on a portion of our floating rate indebtedness once our current interest rate swap agreements expire in March 2022. The forward-starting interest rate swap agreements have $350,000 in notional value, commence in March 2022 and expire in March 2024. Under the forward-starting interest rate swap agreements, we will receive variable rate interest payments based upon one-month LIBOR, in exchange for the payment of fixed interest rates as specified in the interest rate swap agreements. We have designated these interest rate swap agreements, including the forward-starting interest rate swap agreements, as cash flow hedges. Unrealized gains are recognized as assets, while unrealized losses are recognized as liabilities. CROSS-CURRENCY SWAP AGREEMENTS DESIGNATED AS A HEDGE OF NET INVESTMENT In August 2019, we entered into cross-currency swap agreements to hedge the variability of exchange rate impacts between the United States dollar and the Euro. Under the terms of the cross-currency swap agreements, we notionally exchanged approximately $110,000 at an interest rate of 6.0% for approximately 99,055 Euros at a weighted average interest rate of approximately 3.65%. These cross-currency swap agreements expire in August 2023 (“August 2023 Cross Currency Swap Agreements”). In September 2020, we entered into cross-currency swap agreements to hedge the variability of exchange rate impacts between the United States dollar and the Euro. Under the terms of the cross-currency swap agreements, we notionally exchanged approximately $359,200 at an interest rate of 4.5% for approximately 300,000 Euros at a weighted average interest rate of approximately 3.4%. These cross-currency swap agreements expire in February 2026 (“February 2026 Cross Currency Swap Agreements”). We have designated these cross-currency swap agreements as hedge of net investments against certain of our Euro denominated subsidiaries and they require an exchange of the notional amounts at maturity. These cross-currency swap agreements are marked to market at each reporting period, representing the fair values of the cross-currency swap agreements, and any changes in fair value are recognized as a component of Accumulated other comprehensive items, net. Unrealized gains are recognized as assets while unrealized losses are recognized as liabilities. These swaps are all deemed to be effective hedges and, therefore, all unrealized changes in fair value are included as a component of Accumulated other comprehensive items, net. (Liabilities) assets recognized in our Condensed Consolidated Balance Sheets at March 31, 2021 and December 31, 2020, by derivative instrument, are as follows: DERIVATIVE INSTRUMENTS (1) MARCH 31, 2021 DECEMBER 31, 2020 Cash Flow Hedges (2) Interest Rate Swap Agreements $ (16,861) $ (21,062) Net Investment Hedges (3) August 2023 Cross Currency Swap Agreements (3,478) (8,229) February 2026 Cross Currency Swap Agreements (14,158) (20,412) (1) Our derivative assets are included as a component of Other within Other assets, net and our derivative liabilities are included as a component of Other long-term liabilities in our Condensed Consolidated Balance Sheets. (2) As of March 31, 2021, cumulative net losses of $16,861 are recorded within Accumulated other comprehensive items, net associated with these interest rate swap agreements. (3) As of March 31, 2021, cumulative net losses of $17,636 are recorded within Accumulated other comprehensive items, net associated with these cross-currency swap agreements. Unrealized gains (losses) recognized during the three months ended March 31, 2021 and 2020, by derivative instrument, are as follows: THREE MONTHS ENDED MARCH 31, DERIVATIVE INSTRUMENTS (1) 2021 2020 Cash Flow Hedges Interest Rate Swap Agreements $ 4,201 $ (14,732) Net Investment Hedges August 2023 Cross Currency Swap Agreements 4,751 6,370 February 2026 Cross Currency Swap Agreements 6,254 — (1) These amounts are recognized as unrealized gains (losses), a component of Accumulated other comprehensive items, net. EURO NOTES DESIGNATED AS A HEDGE OF NET INVESTMENT Prior to their redemption in August 2020, we designated a portion of our previously outstanding 3% Euro Senior Notes due 2025 (the “Euro Notes”) as a hedge of net investment of certain of our Euro denominated subsidiaries. From January 1, 2020 through March 31, 2020, we designated 300,000 Euros of our Euro Notes as a hedge of net investment of certain of our Euro denominated subsidiaries. As a result, we recorded foreign exchange (gains) losses related to the change in fair value of such debt due to currency translation adjustments as a component of Accumulated other comprehensive items, net. Foreign exchange gains (losses) associated with this hedge of net investment for the three months ended March 31, 2021 and 2020 are as follows: THREE MONTHS ENDED MARCH 31, 2021 2020 Foreign exchange gains (losses) associated with net investment hedge $ — $ 6,453 As of March 31, 2021, cumulative net gains of $3,256, net of tax, are recorded in Accumulated other comprehensive items, net associated with this net investment hedge.

Debt

Debt	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Debt	Long-term debt is as follows: MARCH 31, 2021 DECEMBER 31, 2020 DEBT (INCLUSIVE OF DISCOUNT) UNAMORTIZED DEFERRED FINANCING COSTS CARRYING AMOUNT FAIR VALUE DEBT (INCLUSIVE OF DISCOUNT) UNAMORTIZED DEFERRED FINANCING COSTS CARRYING AMOUNT FAIR VALUE Revolving Credit Facility (1) $ 60,000 $ (7,758) $ 52,242 $ 60,000 $ — $ (8,620) $ (8,620) $ — Term Loan A (1) 212,500 — 212,500 212,500 215,625 — 215,625 215,625 Term Loan B 677,927 (5,932) 671,995 679,000 679,621 (6,244) 673,377 680,750 Australian Dollar Term Loan (the “AUD Term Loan”) 238,433 (1,374) 237,059 239,162 243,152 (1,624) 241,528 244,014 UK Bilateral Revolving Credit Facility (the “UK Bilateral Facility”) 192,732 (1,147) 191,585 192,732 191,101 (1,307) 189,794 191,101 3 7 / 8 % GBP Senior Notes due 2025 (the “GBP Notes”) 550,662 (4,765) 545,897 556,180 546,003 (4,983) 541,020 553,101 4 7 / 8 % Senior Notes due 2027 (the “4 7 / 8 % Notes due 2027”) (2) 1,000,000 (9,243) 990,757 1,025,000 1,000,000 (9,598) 990,402 1,046,250 5 1 / 4 % Senior Notes due 2028 (the “5 1 / 4 % Notes due 2028”) (2) 825,000 (8,266) 816,734 856,969 825,000 (8,561) 816,439 868,313 5% Senior Notes due 2028 (the “5% Notes”) (2) 500,000 (5,306) 494,694 511,250 500,000 (5,486) 494,514 523,125 4 7 / 8 % Senior Notes due 2029 (the “4 7 / 8 % Notes due 2029”) (2) 1,000,000 (12,296) 987,704 1,011,250 1,000,000 (12,658) 987,342 1,050,000 5 1 / 4 % Senior Notes due 2030 (the “5 1 / 4 Notes due 2030”) (2) 1,300,000 (14,040) 1,285,960 1,335,750 1,300,000 (14,416) 1,285,584 1,400,750 4 1 / 2 % Senior Notes due 2031 (the “4 1 / 2 % Notes”) (2) 1,100,000 (12,337) 1,087,663 1,080,750 1,100,000 (12,648) 1,087,352 1,138,500 5 5 / 8 % Senior Notes due 2032 (the “5 5 / 8 % Notes”) (2) 600,000 (6,582) 593,418 625,500 600,000 (6,727) 593,273 660,000 Real Estate Mortgages, Financing Lease Liabilities and Other 492,256 (1,003) 491,253 492,256 511,922 (1,086) 510,836 511,922 Accounts Receivable Securitization Program (3) 257,000 (135) 256,865 257,000 85,000 (152) 84,848 85,000 Total Long-term Debt 9,006,510 (90,184) 8,916,326 8,797,424 (94,110) 8,703,314 Less Current Portion (363,911) — (363,911) (193,759) — (193,759) Long-term Debt, Net of Current Portion $ 8,642,599 $ (90,184) $ 8,552,415 $ 8,603,665 $ (94,110) $ 8,509,555 (1) Collectively, the “Credit Agreement”. The Credit Agreement consists of a revolving credit facility (the “Revolving Credit Facility”) and a term loan (the “Term Loan A”). The Credit Agreement is scheduled to mature on June 3, 2023. All of the outstanding borrowings under the Revolving Credit Facility as of March 31, 2021 were denominated in United States dollars. In addition, we also had various outstanding letters of credit totaling $3,219. The remaining amount available for borrowing under the Revolving Credit Facility as of March 31, 2021 was $1,686,781 (which amount represents the maximum availability as of such date). The average interest rate in effect under the Credit Agreement was 1.9% as of March 31, 2021 and December 31, 2020. (2) Collectively, the “Parent Notes”. (3) The full amount outstanding under the Accounts Receivable Securitization Program is classified within the current portion of long-term debt in our Condensed Consolidated Balance Sheets as of March 31, 2021 and December 31, 2020. See Note 6 to Notes to Consolidated Financial Statements included in our Annual Report for additional information regarding the Credit Agreement and our other long-term debt, including the direct obligors of each of our debt instruments as well as information regarding the fair value of our debt instruments (including the levels of the fair value hierarchy used to determine the fair value of our debt instruments). The levels of the fair value hierarchy used to determine the fair value of our debt as of March 31, 2021 are consistent with the levels of the fair value hierarchy used to determine the fair value of our debt as of December 31, 2020 (which are disclosed in our Annual Report). CASH POOLING We currently utilize two separate cash pooling arrangements, one of which we utilize to manage global liquidity requirements for our qualified REIT subsidiaries (the “QRS Cash Pool”) and the other for our taxable REIT subsidiaries (the “TRS Cash Pool”). The approximate amount of the net cash position for the QRS Cash Pool and the TRS Cash Pool and the approximate amount of the gross position and outstanding debit balances for each of these pools as of March 31, 2021 and December 31, 2020 are as follows: MARCH 31, 2021 DECEMBER 31, 2020 GROSS CASH POSITION OUTSTANDING DEBIT BALANCES NET CASH POSITION GROSS CASH POSITION OUTSTANDING DEBIT BALANCES NET CASH POSITION QRS Cash Pool $ 567,300 $ (566,700) $ 600 $ 448,700 $ (447,400) $ 1,300 TRS Cash Pool 512,700 (510,200) 2,500 555,500 (553,500) 2,000 The net cash position balances as of March 31, 2021 and December 31, 2020 are reflected as cash and cash equivalents in our Condensed Consolidated Balance Sheets. LETTERS OF CREDIT As of March 31, 2021, we had outstanding letters of credit totaling $38,160, of which $3,219 reduce our borrowing capacity under the Revolving Credit Facility (as described above). The letters of credit expire at various dates between June 2021 and March 2025. DEBT COVENANTS The Credit Agreement, our bond indentures and other agreements governing our indebtedness contain certain restrictive financial and operating covenants, including covenants that restrict our ability to complete acquisitions, pay cash dividends, incur indebtedness, make investments, sell assets and take certain other corporate actions. The covenants do not contain a rating trigger. Therefore, a change in our debt rating would not trigger a default under the Credit Agreement, our bond indentures or other agreements governing our indebtedness. The Credit Agreement requires that we satisfy a fixed charge coverage ratio, a net total lease adjusted leverage ratio and a net secured debt lease adjusted leverage ratio on a quarterly basis and our bond indentures require that, among other things, we satisfy a leverage ratio (not lease adjusted) or a fixed charge coverage ratio (not lease adjusted), as a condition to taking actions such as paying dividends and incurring indebtedness. The Credit Agreement uses EBITDAR-based calculations and the bond indentures use EBITDA-based calculations as the primary measures of financial performance for purposes of calculating leverage and fixed charge coverage ratios. The bond indenture EBITDA-based calculations include our consolidated subsidiaries, other than those we have designated as “Unrestricted Subsidiaries” as defined in the bond indentures. Generally, the Credit Agreement and the bond indentures use a trailing four fiscal quarter basis for purposes of the relevant calculations and require certain adjustments and exclusions for purposes of those calculations, which make the calculation of financial performance for purposes of those calculations under the Credit Agreement and bond indentures not directly comparable to Adjusted EBITDA as presented herein. We are in compliance with our leverage and fixed charge coverage ratios under the Credit Agreement, our bond indentures and other agreements governing our indebtedness as of March 31, 2021 and December 31, 2020. Noncompliance with these leverage and fixed charge coverage ratios would have a material adverse effect on our financial condition.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIESWe are involved in litigation from time to time in the ordinary course of business, including litigation arising from damage to customer assets in our facilities caused by fires and other natural disasters. While the outcome of such litigation is inherently uncertain, we do not believe any current litigation will have a material adverse effect on our consolidated financial condition, results of operations or cash flows.

Stockholders' Equity Matters

Stockholders' Equity Matters	3 Months Ended
	Mar. 31, 2021
Equity [Abstract]
Stockholders' Equity Matters	In fiscal year 2020 and the first three months of 2021, our board of directors declared the following dividends: DECLARATION DATE DIVIDEND RECORD DATE TOTAL PAYMENT DATE February 13, 2020 $ 0.6185 March 16, 2020 $ 178,047 April 6, 2020 May 5, 2020 0.6185 June 15, 2020 178,212 July 2, 2020 August 5, 2020 0.6185 September 15, 2020 178,224 October 2, 2020 November 4, 2020 0.6185 December 15, 2020 178,290 January 6, 2021 February 24, 2021 0.6185 March 15, 2021 178,569 April 6, 2021 On May 6, 2021, we declared a dividend to our stockholders of record as of June 15, 2021 of $0.6185 per share, payable on July 6, 2021.

Segment Information

Segment Information	3 Months Ended
	Mar. 31, 2021
Segment Reporting [Abstract]
Segment Information	SEGMENT INFORMATION Our three reportable operating segments as of December 31, 2020 are described in Note 10 to Notes to Consolidated Financial Statements included in our Annual Report and are as follows: • Global Records and Information Management (“Global RIM”) Business • Global Data Center Business • Corporate and Other Business There have been no changes to these reportable operating segments during the first three months of 2021. An analysis of our business segment information and reconciliation to the accompanying Condensed Consolidated Financial Statements is as follows: THREE MONTHS ENDED 2021 2020 Global RIM Business Total Revenues $ 967,294 $ 956,419 Adjusted EBITDA 408,562 391,972 Global Data Center Business Total Revenues $ 71,108 $ 67,357 Adjusted EBITDA 30,432 30,895 Corporate and Other Business Total Revenues $ 43,638 $ 44,955 Adjusted EBITDA (58,429) (56,868) Total Consolidated Total Revenues $ 1,082,040 $ 1,068,731 Adjusted EBITDA 380,565 365,999 During the fourth quarter of 2020, we changed our definition of Adjusted EBITDA to (a) exclude stock-based compensation expense and (b) include our share of Adjusted EBITDA from our unconsolidated joint ventures. All prior periods have been recast to conform to these changes. We now define Adjusted EBITDA for each segment as net income (loss) before interest expense, net, provision (benefit) for income taxes, depreciation and amortization (inclusive of our share of Adjusted EBITDA from our unconsolidated joint ventures), and excluding certain items we do not believe to be indicative of our core operating results, specifically: EXCLUDED • Restructuring Charges • Other expense (income), net • Intangible impairments • Stock-based compensation expense • (Gain) loss on disposal/write-down of property, plant and equipment, net (including real estate) • COVID-19 Costs (1) (1) Costs that are incremental and directly attributable to the COVID-19 pandemic which are not expected to recur once the pandemic ends ("COVID-19 Costs"). These costs include the purchase of personal protective equipment for our employees and incremental cleaning costs of our facilities, among other direct costs. Internally, we use Adjusted EBITDA as the basis for evaluating the performance of, and allocated resources to, our operating segments. A reconciliation of Net Income (Loss) to Adjusted EBITDA on a consolidated basis for the three months ended March 31, 2021 and 2020 is as follows: THREE MONTHS ENDED MARCH 31, 2021 2020 Net Income (Loss) $ 46,631 $ 64,892 Add/(Deduct): Interest expense, net 104,422 105,649 Provision (benefit) for income taxes 14,640 9,687 Depreciation and amortization 165,642 162,584 Restructuring Charges 39,811 41,046 Intangible impairments — 23,000 (Gain) loss on disposal/write-down of property, plant and equipment, net (including real estate) (4,451) (1,055) Other expense (income), net, excluding our share of losses (gains) from our unconsolidated joint ventures 2,121 (45,031) Stock-based compensation expense 10,733 5,111 Our share of Adjusted EBITDA reconciling items from our unconsolidated joint ventures 1,016 116 Adjusted EBITDA $ 380,565 $ 365,999 Information as to our revenues by product and service lines by segment for the three months ended March 31, 2021 and 2020 are as follows: THREE MONTHS ENDED MARCH 31, 2021 2020 Global RIM Business Records Management (1) $ 752,123 $ 727,616 Data Management (1) 118,414 125,898 Information Destruction (1)(2) 96,757 102,905 Data Center — — Global Data Center Business Records Management (1) $ — $ — Data Management (1) — — Information Destruction (1)(2) — — Data Center 71,108 67,357 Corporate and Other Business Records Management (1) $ 26,967 $ 28,876 Data Management (1) 16,671 16,079 Information Destruction (1)(2) — — Data Center — — Total Consolidated Records Management (1) $ 779,090 $ 756,492 Data Management (1) 135,085 141,977 Information Destruction (1)(2) 96,757 102,905 Data Center 71,108 67,357 (1) Each of the offerings within our product and service lines has a component of revenue that is storage rental related and a component that is service revenues, except for information destruction, which does not have a storage rental component. (2) Includes secure shredding services.

Related Parties

Related Parties	3 Months Ended
	Mar. 31, 2021
Related Party Transactions [Abstract]
Related Parties	RELATED PARTIES In October 2020, in connection with the formation of the Frankfurt JV, we entered into agreements whereby we will earn various fees, including property management and construction and development fees, for services we are providing to the Frankfurt JV (the “Frankfurt JV Agreements”). Revenues and expenses associated with the Frankfurt JV Agreements are presented as a component of our Global Data Business segment. During the three months ended March 31, 2021, we recognized revenue of approximately $1,060 associated with the Frankfurt JV Agreements. In March 2019, in connection with the formation of the MakeSpace JV, we entered into a storage and service agreement with the MakeSpace JV to provide certain storage and related services to the MakeSpace JV (the “MakeSpace Agreement”). Revenues and expenses associated with the MakeSpace Agreement are presented as a component of our Global RIM Business segment. We recognized revenue of approximately $7,500 and $6,800 for the three months ended March 31, 2021 and 2020, respectively, associated with the MakeSpace Agreement.

Project Summit

Project Summit	3 Months Ended
	Mar. 31, 2021
Restructuring and Related Activities [Abstract]
Project Summit	In October 2019, we announced our global program designed to better position us for future growth and achievement of our strategic objectives (“Project Summit”). As a result of the program, we expect to reduce the number of positions at vice president and above by approximately 45%. The total program is expected to reduce our total managerial and administrative workforce by approximately 700 positions by the end of 2021. We have also reduced our services and operations workforce. As of March 31, 2021, we have completed approximately 80% of our planned workforce reductions. The activities associated with Project Summit began in the fourth quarter of 2019 and are expected to be substantially complete by the end of 2021. We estimate that the implementation of Project Summit will result in total operating expenditures (“Restructuring Charges”) of approximately $450,000 that primarily consist of: (1) employee severance costs; (2) internal costs associated with the development and implementation of Project Summit initiatives; (3) professional fees, primarily related to third party consultants who are assisting with the design and execution of various initiatives as well as project management activities and (4) system implementation and data conversion costs. Restructuring Charges included in the accompanying Condensed Consolidated Statements of Operations for the three months ended March 31, 2021 and 2020, and from the inception of Project Summit through March 31, 2021, are as follows: THREE MONTHS ENDED MARCH 31, 2021 THREE MONTHS ENDED MARCH 31, 2020 FROM THE INCEPTION Employee severance costs $ 3,808 $ 6,108 $ 72,007 Professional fees and other costs 36,003 34,938 210,797 Restructuring Charges $ 39,811 $ 41,046 $ 282,804 Restructuring Charges by segment for the three months ended March 31, 2021 and 2020, and from the inception of Project Summit through March 31, 2021, are as follows: THREE MONTHS ENDED MARCH 31, 2021 THREE MONTHS ENDED MARCH 31, 2020 FROM THE INCEPTION Global RIM Business $ 8,224 $ 8,288 $ 97,264 Global Data Center Business 454 187 2,392 Corporate and Other Business 31,133 32,571 183,148 Restructuring Charges $ 39,811 $ 41,046 $ 282,804 A rollforward of the accrued Restructuring Charges, which is included as a component of Accrued expenses and other current liabilities in our Condensed Consolidated Balance Sheets, from December 31, 2019 through March 31, 2021, is as follows: EMPLOYEE SEVERANCE COSTS PROFESSIONAL FEES AND OTHER TOTAL ACCRUED RESTRUCTURING CHARGES Balance as of December 31, 2019 $ 4,823 $ 12,954 $ 17,777 Amounts accrued 47,349 147,047 194,396 Payments (32,455) (136,222) (168,677) Other, including currency translation adjustments (3,439) (4) (3,443) Balance as of December 31, 2020 16,278 23,775 40,053 Amounts accrued 3,808 36,003 39,811 Payments (17,087) (13,849) (30,936) Other, including currency translation adjustments (220) — (220) Balance as of March 31, 2021 $ 2,779 $ 45,929 $ 48,708

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2021
Subsequent Events [Abstract]
Subsequent Events	In April 2021, we closed on an agreement to form a joint venture (the "Web Werks JV") with the shareholders of Web Werks India Private Limited ("Web Werks"), a colocation data center provider in India. In connection with the formation of the Web Werks JV, we made an initial investment of approximately 3,750,000 Indian rupees (or approximately $50,100, based upon the exchange rate between the United States dollar and Indian rupee as of the closing date of the initial investment) in exchange for a noncontrolling interest in the form of convertible preference shares in the Web Werks JV (the “Initial Web Werks JV Investment”). These shares are convertible into a to-be-determined amount of common shares based upon the achievement of EBITDA targets for the Web Werks JV's fiscal year ending March 31, 2022. We currently estimate our noncontrolling interest to be 39%. We will account for the Initial Web Werks JV Investment as an equity method investment and the carrying value of such investment will be presented as a component of Other within Other Assets, net in our Condensed Consolidated Balance Sheet beginning in the second quarter of 2021. Under the terms of the Web Werks JV shareholders agreement, we are required to make additional investments over the next two years, if certain conditions are met, totaling approximately 7,500,000 Indian rupees (or approximately $100,000, based upon the current exchange rate between the United States dollar and Indian rupee), and, over time, we expect to acquire a majority interest in the Web Werks JV.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Cash, Cash Equivalents and Restricted Cash	Cash and cash equivalents include cash on hand and cash invested in highly liquid short-term securities, which have remaining maturities at the date of purchase of less than 90 days. Cash and cash equivalents are carried at cost, which approximates fair value.
Accounts Receivable	We maintain an allowance for doubtful accounts and a credit memo reserve for estimated losses resulting from the potential inability of our customers to make required payments and potential disputes regarding billing and service issues
Revenues	DATA CENTER LESSOR CONSIDERATIONS Our Global Data Center Business features storage rental provided to customers at contractually specified rates over a fixed contractual period, which are accounted for in accordance with Accounting Standards Update ("ASU") No. 2016-02, Leases (Topic 842)
Leases	LEASES We lease facilities for certain warehouses, data centers and office space. We also have land leases, including those on which certain facilities are located.
Income Taxes	We provide for income taxes during interim periods based on our estimate of the effective tax rate for the year.
Recent Accounting Pronouncements	In December 2019, the Financial Accounting Standards Board issued ASU No. 2019-12, Income Taxes (Topic 740) (“ASU 2019-12”). ASU 2019-12 simplifies the accounting for income taxes by removing certain exceptions for recognizing deferred taxes for investments, performing intra-period allocation and calculating income taxes in interim periods. ASU 2019-12 also adds guidance to reduce complexity in certain areas, including recognizing deferred taxes for tax goodwill and allocating taxes to members of a consolidated group. We adopted ASU 2019-12 on January 1, 2021. ASU 2019-12 did not have a material impact on our consolidated financial statements.
Segment Information	During the fourth quarter of 2020, we changed our definition of Adjusted EBITDA to (a) exclude stock-based compensation expense and (b) include our share of Adjusted EBITDA from our unconsolidated joint ventures. All prior periods have been recast to conform to these changes. We now define Adjusted EBITDA for each segment as net income (loss) before interest expense, net, provision (benefit) for income taxes, depreciation and amortization (inclusive of our share of Adjusted EBITDA from our unconsolidated joint ventures), and excluding certain items we do not believe to be indicative of our core operating results, specifically: EXCLUDED • Restructuring Charges • Other expense (income), net • Intangible impairments • Stock-based compensation expense • (Gain) loss on disposal/write-down of property, plant and equipment, net (including real estate) • COVID-19 Costs (1) (1) Costs that are incremental and directly attributable to the COVID-19 pandemic which are not expected to recur once the pandemic ends ("COVID-19 Costs"). These costs include the purchase of personal protective equipment for our employees and incremental cleaning costs of our facilities, among other direct costs. Internally, we use Adjusted EBITDA as the basis for evaluating the performance of, and allocated resources to, our operating segments.
Commitments and Contingencies	We are involved in litigation from time to time in the ordinary course of business, including litigation arising from damage to customer assets in our facilities caused by fires and other natural disasters. While the outcome of such litigation is inherently uncertain, we do not believe any current litigation will have a material adverse effect on our consolidated financial condition, results of operations or cash flows.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Schedule of allowance for credit loss	Rollforward of allowance for doubtful accounts and credit memo reserves for the three months ended March 31, 2021 is as follows: Balance as of December 31, 2020 $ 56,981 Credit memos charged to revenue 13,026 Allowance for bad debts charged to expense 9,850 Deductions and other (1) (19,114) Balance as of March 31, 2021 $ 60,743 (1) Primarily consists of the issuance of credit memos, the write-off of accounts receivable and the impact associated with currency translation adjustments.
Schedule of operating and financing lease right-of-use assets and lease liabilities	Operating and financing lease right-of-use assets and lease liabilities as of March 31, 2021 and December 31, 2020 are as follows: DESCRIPTION MARCH 31, 2021 DECEMBER 31, 2020 Assets: Operating lease right-of-use assets $ 2,205,299 $ 2,196,502 Financing lease right-of-use assets, net of accumulated depreciation (1) 300,399 310,534 Liabilities: Current Operating lease liabilities $ 248,319 $ 250,239 Financing lease liabilities (1) 42,692 43,149 Long-term Operating lease liabilities 2,061,140 2,044,598 Financing lease liabilities (1) 311,448 323,162 (1) Financing lease right-of-use assets, current financing lease liabilities and long-term financing lease liabilities are included within Property, Plant and Equipment, Net, Current portion of long-term debt and Long-term Debt, net of current portion, respectively, within our Condensed Consolidated Balance Sheets.
Schedule of lease, cost	The components of the lease expense for the three months ended March 31, 2021 and 2020 are as follows: THREE MONTHS ENDED MARCH 31, DESCRIPTION 2021 2020 Operating lease cost (1) $ 132,675 $ 123,289 Financing lease cost: Depreciation of financing lease right-of-use assets $ 12,648 $ 12,955 Interest expense for financing lease liabilities 4,975 4,844 (1) Operating lease cost, the majority of which is included in Cost of sales, includes variable lease costs of $28,368 and $27,805 for the three months ended March 31, 2021 and 2020, respectively. THREE MONTHS ENDED MARCH 31, CASH PAID FOR AMOUNTS INCLUDED IN MEASUREMENT OF LEASE LIABILITIES: 2021 2020 Operating cash flows used in operating leases $ 93,645 $ 86,418 Operating cash flows used in financing leases (interest) 4,975 4,844 Financing cash flows used in financing leases 12,441 12,739 NON-CASH ITEMS: Operating lease modifications and reassessments $ 31,994 $ 34,916 New operating leases (including acquisitions and sale-leaseback transactions) 48,200 110,609
Schedule of changes in the carrying value of goodwill attributable to each reportable operating segment	The changes in the carrying value of goodwill attributable to each reportable operating segment for the three months ended March 31, 2021 are as follows: GLOBAL RIM BUSINESS GLOBAL DATA CENTER BUSINESS CORPORATE AND OTHER BUSINESS TOTAL CONSOLIDATED Goodwill balance, net of accumulated amortization as of $ 4,024,182 $ 436,987 $ 96,440 $ 4,557,609 Fair value and other adjustments (5,804) — — (5,804) Currency effects (24,298) (6,359) (373) (31,030) Goodwill balance, net accumulated amortization as of March 31, 2021 $ 3,994,080 $ 430,628 $ 96,067 $ 4,520,775 Accumulated goodwill impairment balance as of March 31, 2021 $ 132,409 $ — $ 26,011 $ 158,420
Schedule of assets and liabilities carried at fair value measured on a recurring basis	The assets and liabilities carried at fair value measured on a recurring basis as of March 31, 2021 and December 31, 2020 are as follows: FAIR VALUE MEASUREMENTS AT MARCH 31, 2021 USING DESCRIPTION TOTAL CARRYING QUOTED PRICES IN SIGNIFICANT OTHER SIGNIFICANT Money Market Funds $ 7,673 $ — $ 7,673 $ — Time Deposits 1,291 — 1,291 — Trading Securities 11,323 11,067 256 — Derivative Liabilities 34,497 — 34,497 — FAIR VALUE MEASUREMENTS AT DECEMBER 31, 2020 USING DESCRIPTION TOTAL CARRYING QUOTED PRICES IN SIGNIFICANT OTHER SIGNIFICANT Money Market Funds $ 62,657 $ — $ 62,657 $ — Time Deposits 2,121 — 2,121 — Trading Securities 10,892 10,636 256 — Derivative Liabilities 49,703 — 49,703 —
Schedule of changes in accumulated other comprehensive items, net	The changes in accumulated other comprehensive items, net for the three months ended March 31, 2021 and 2020 are as follows: THREE MONTHS ENDED MARCH 31, 2021 THREE MONTHS ENDED MARCH 31, 2020 FOREIGN CHANGE IN FAIR VALUE OF TOTAL FOREIGN CHANGE IN FAIR VALUE OF DERIVATIVE INSTRUMENTS TOTAL Beginning of Period $ (206,190) $ (49,703) $ (255,893) $ (252,825) $ (9,756) $ (262,581) Other comprehensive (loss) income: Foreign currency translation and other adjustments (66,224) — (66,224) (222,305) — (222,305) Change in fair value of derivative instruments — 15,206 15,206 — (8,362) (8,362) Total other comprehensive (loss) income (66,224) 15,206 (51,018) (222,305) (8,362) (230,667) End of Period $ (272,414) $ (34,497) $ (306,911) $ (475,130) $ (18,118) $ (493,248)
Schedule of amortization expense associated with commissions asset and Intake Costs	The costs associated with the initial movement of customer records into physical storage and certain commissions are considered costs to obtain or fulfill customer contracts (collectively, “Contract Fulfillment Costs”). Contract Fulfillment Costs as of March 31, 2021 and December 31, 2020, are as follows: MARCH 31, 2021 DECEMBER 31, 2020 GROSS ACCUMULATED NET GROSS ACCUMULATED NET Intake Costs asset $ 66,337 $ (35,904) $ 30,433 $ 63,721 $ (33,352) $ 30,369 Commissions asset 99,721 (43,125) 56,596 91,069 (38,787) 52,282
Schedule of deferred revenue liabilities	Deferred revenue liabilities are reflected in our Condensed Consolidated Balance Sheets as follows: DESCRIPTION LOCATION IN BALANCE SHEET MARCH 31, 2021 DECEMBER 31, 2020 Deferred revenue - Current Deferred revenue $ 284,974 $ 295,785 Deferred revenue - Long-term Other Long-term Liabilities 36,581 35,612
Schedule of revenue	Our Global Data Center Business features storage rental provided to customers at contractually specified rates over a fixed contractual period, which are accounted for in accordance with Accounting Standards Update ("ASU") No. 2016-02, Leases (Topic 842) , as amended (“ASU 2016-02”). Storage rental revenue, including revenue associated with power and connectivity, associated with our Global Data Center Business for the three months ended March 31, 2021 and 2020 are as follows: THREE MONTHS ENDED MARCH 31, 2021 2020 Storage rental revenue (1) $ 67,157 $ 64,595 (1) Revenue associated with power and connectivity included within storage rental revenue was $13,133 and $11,413 for the three months ended March 31, 2021 and 2020, respectively.
Schedule of stock-based compensation expense	Stock-based compensation expense for the cost of stock options, restricted stock units (“RSUs”), performance units (“PUs”) and shares of stock issued under our employee stock purchase plan (collectively, “Employee Stock-Based Awards”) for the three months ended March 31, 2021 and 2020 is as follows: THREE MONTHS ENDED MARCH 31, 2021 2020 Stock-based compensation expense $ 10,953 $ 6,527
Schedule of vested and expected to vest	The fair value of RSUs and earned PUs that vested during the three months ended March 31, 2021 and 2020 is as follows: THREE MONTHS ENDED MARCH 31, 2021 2020 Fair value of RSUs vested $ 19,861 $ 18,379 Fair value of earned PUs that vested 5,591 10,890
Schedule of other expense (income), net	Consolidated other expense (income), net for the three months ended March 31, 2021 and 2020 consists of the following: THREE MONTHS ENDED MARCH 31, DESCRIPTION 2021 2020 Foreign currency transaction losses (gains), net $ 2,314 $ (37,399) Other, net (1) 2,399 (5,327) Other Expense (Income), Net $ 4,713 $ (42,726) (1) Other, net for the three months ended March 31, 2021 is primarily comprised of losses on our equity method investments. Other, net for the three months ended March 31, 2020 is primarily comprised of a gain on our previously held 25% equity investment in OSG Records Management (Europe) Limited (“OSG”), which is partially offset by losses on our equity method investments.
Schedule of income taxes	Our effective tax rates for the three months ended March 31, 2021 and 2020 are as follows: THREE MONTHS ENDED MARCH 31, 2021 (1) 2020 (2) Effective Tax Rate 23.9 % 13.0 % (1) The primary reconciling items between the federal statutory tax rate of 21.0% and our overall effective tax rate for the three months ended March 31, 2021 were the benefits derived from the dividends paid deduction and the impacts of differences in the tax rates at which our foreign earnings are subject. (2) The primary reconciling items between the federal statutory tax rate of 21.0% and our overall effective tax rate for the three months ended March 31, 2020 were the benefits derived from the dividends paid deduction and foreign exchange losses in different jurisdictions with different tax rates as well as the impacts of differences in the tax rates at which our foreign earnings are subject.
Schedule of calculation of basic and diluted net income (loss) per share attributable to the entity	The calculation of basic and diluted income (loss) per share for the three months ended March 31, 2021 and 2020 are as follows: THREE MONTHS ENDED MARCH 31, 2021 2020 Net Income (Loss) $ 46,631 $ 64,892 Less: Net Income (Loss) Attributable to Noncontrolling Interests 1,028 917 Net Income (Loss) Attributable to Iron Mountain Incorporated (utilized in numerator of Earnings Per Share calculation) $ 45,603 $ 63,975 Weighted-average shares—basic 288,756,000 287,840,000 Effect of dilutive potential stock options 56,437 51,799 Effect of dilutive potential RSUs and PUs 715,850 467,334 Weighted-average shares—diluted 289,528,287 288,359,133 Net Income (Loss) Per Share Attributable to Iron Mountain Incorporated: Basic $ 0.16 $ 0.22 Diluted $ 0.16 $ 0.22 Antidilutive stock options, RSUs and PUs, excluded from the calculation 4,708,068 5,513,714

Derivative Instruments and He_2

Derivative Instruments and Hedging Activities (Tables)	3 Months Ended
	Mar. 31, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments	(Liabilities) assets recognized in our Condensed Consolidated Balance Sheets at March 31, 2021 and December 31, 2020, by derivative instrument, are as follows: DERIVATIVE INSTRUMENTS (1) MARCH 31, 2021 DECEMBER 31, 2020 Cash Flow Hedges (2) Interest Rate Swap Agreements $ (16,861) $ (21,062) Net Investment Hedges (3) August 2023 Cross Currency Swap Agreements (3,478) (8,229) February 2026 Cross Currency Swap Agreements (14,158) (20,412) (1) Our derivative assets are included as a component of Other within Other assets, net and our derivative liabilities are included as a component of Other long-term liabilities in our Condensed Consolidated Balance Sheets. (2) As of March 31, 2021, cumulative net losses of $16,861 are recorded within Accumulated other comprehensive items, net associated with these interest rate swap agreements. (3) As of March 31, 2021, cumulative net losses of $17,636 are recorded within Accumulated other comprehensive items, net associated with these cross-currency swap agreements.
Schedule of (Gains) Losses For Derivative Instruments	Unrealized gains (losses) recognized during the three months ended March 31, 2021 and 2020, by derivative instrument, are as follows: THREE MONTHS ENDED MARCH 31, DERIVATIVE INSTRUMENTS (1) 2021 2020 Cash Flow Hedges Interest Rate Swap Agreements $ 4,201 $ (14,732) Net Investment Hedges August 2023 Cross Currency Swap Agreements 4,751 6,370 February 2026 Cross Currency Swap Agreements 6,254 —
Schedule of Net Investment Hedges in AOCI	Foreign exchange gains (losses) associated with this hedge of net investment for the three months ended March 31, 2021 and 2020 are as follows: THREE MONTHS ENDED MARCH 31, 2021 2020 Foreign exchange gains (losses) associated with net investment hedge $ — $ 6,453

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Schedule of Carrying Amount and Fair Value of Long-Term Debt Instruments	Long-term debt is as follows: MARCH 31, 2021 DECEMBER 31, 2020 DEBT (INCLUSIVE OF DISCOUNT) UNAMORTIZED DEFERRED FINANCING COSTS CARRYING AMOUNT FAIR VALUE DEBT (INCLUSIVE OF DISCOUNT) UNAMORTIZED DEFERRED FINANCING COSTS CARRYING AMOUNT FAIR VALUE Revolving Credit Facility (1) $ 60,000 $ (7,758) $ 52,242 $ 60,000 $ — $ (8,620) $ (8,620) $ — Term Loan A (1) 212,500 — 212,500 212,500 215,625 — 215,625 215,625 Term Loan B 677,927 (5,932) 671,995 679,000 679,621 (6,244) 673,377 680,750 Australian Dollar Term Loan (the “AUD Term Loan”) 238,433 (1,374) 237,059 239,162 243,152 (1,624) 241,528 244,014 UK Bilateral Revolving Credit Facility (the “UK Bilateral Facility”) 192,732 (1,147) 191,585 192,732 191,101 (1,307) 189,794 191,101 3 7 / 8 % GBP Senior Notes due 2025 (the “GBP Notes”) 550,662 (4,765) 545,897 556,180 546,003 (4,983) 541,020 553,101 4 7 / 8 % Senior Notes due 2027 (the “4 7 / 8 % Notes due 2027”) (2) 1,000,000 (9,243) 990,757 1,025,000 1,000,000 (9,598) 990,402 1,046,250 5 1 / 4 % Senior Notes due 2028 (the “5 1 / 4 % Notes due 2028”) (2) 825,000 (8,266) 816,734 856,969 825,000 (8,561) 816,439 868,313 5% Senior Notes due 2028 (the “5% Notes”) (2) 500,000 (5,306) 494,694 511,250 500,000 (5,486) 494,514 523,125 4 7 / 8 % Senior Notes due 2029 (the “4 7 / 8 % Notes due 2029”) (2) 1,000,000 (12,296) 987,704 1,011,250 1,000,000 (12,658) 987,342 1,050,000 5 1 / 4 % Senior Notes due 2030 (the “5 1 / 4 Notes due 2030”) (2) 1,300,000 (14,040) 1,285,960 1,335,750 1,300,000 (14,416) 1,285,584 1,400,750 4 1 / 2 % Senior Notes due 2031 (the “4 1 / 2 % Notes”) (2) 1,100,000 (12,337) 1,087,663 1,080,750 1,100,000 (12,648) 1,087,352 1,138,500 5 5 / 8 % Senior Notes due 2032 (the “5 5 / 8 % Notes”) (2) 600,000 (6,582) 593,418 625,500 600,000 (6,727) 593,273 660,000 Real Estate Mortgages, Financing Lease Liabilities and Other 492,256 (1,003) 491,253 492,256 511,922 (1,086) 510,836 511,922 Accounts Receivable Securitization Program (3) 257,000 (135) 256,865 257,000 85,000 (152) 84,848 85,000 Total Long-term Debt 9,006,510 (90,184) 8,916,326 8,797,424 (94,110) 8,703,314 Less Current Portion (363,911) — (363,911) (193,759) — (193,759) Long-term Debt, Net of Current Portion $ 8,642,599 $ (90,184) $ 8,552,415 $ 8,603,665 $ (94,110) $ 8,509,555 (1) Collectively, the “Credit Agreement”. The Credit Agreement consists of a revolving credit facility (the “Revolving Credit Facility”) and a term loan (the “Term Loan A”). The Credit Agreement is scheduled to mature on June 3, 2023. All of the outstanding borrowings under the Revolving Credit Facility as of March 31, 2021 were denominated in United States dollars. In addition, we also had various outstanding letters of credit totaling $3,219. The remaining amount available for borrowing under the Revolving Credit Facility as of March 31, 2021 was $1,686,781 (which amount represents the maximum availability as of such date). The average interest rate in effect under the Credit Agreement was 1.9% as of March 31, 2021 and December 31, 2020. (2) Collectively, the “Parent Notes”. (3) The full amount outstanding under the Accounts Receivable Securitization Program is classified within the current portion of long-term debt in our Condensed Consolidated Balance Sheets as of March 31, 2021 and December 31, 2020.
Schedule of Net Cash Position in Cash Pool Agreements	The approximate amount of the net cash position for the QRS Cash Pool and the TRS Cash Pool and the approximate amount of the gross position and outstanding debit balances for each of these pools as of March 31, 2021 and December 31, 2020 are as follows: MARCH 31, 2021 DECEMBER 31, 2020 GROSS CASH POSITION OUTSTANDING DEBIT BALANCES NET CASH POSITION GROSS CASH POSITION OUTSTANDING DEBIT BALANCES NET CASH POSITION QRS Cash Pool $ 567,300 $ (566,700) $ 600 $ 448,700 $ (447,400) $ 1,300 TRS Cash Pool 512,700 (510,200) 2,500 555,500 (553,500) 2,000

Stockholders' Equity Matters (T

Stockholders' Equity Matters (Tables)	3 Months Ended
	Mar. 31, 2021
Equity [Abstract]
Schedule of dividend declared and payments	In fiscal year 2020 and the first three months of 2021, our board of directors declared the following dividends: DECLARATION DATE DIVIDEND RECORD DATE TOTAL PAYMENT DATE February 13, 2020 $ 0.6185 March 16, 2020 $ 178,047 April 6, 2020 May 5, 2020 0.6185 June 15, 2020 178,212 July 2, 2020 August 5, 2020 0.6185 September 15, 2020 178,224 October 2, 2020 November 4, 2020 0.6185 December 15, 2020 178,290 January 6, 2021 February 24, 2021 0.6185 March 15, 2021 178,569 April 6, 2021

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2021
Segment Reporting [Abstract]
Schedule of analysis of business segment information	An analysis of our business segment information and reconciliation to the accompanying Condensed Consolidated Financial Statements is as follows: THREE MONTHS ENDED 2021 2020 Global RIM Business Total Revenues $ 967,294 $ 956,419 Adjusted EBITDA 408,562 391,972 Global Data Center Business Total Revenues $ 71,108 $ 67,357 Adjusted EBITDA 30,432 30,895 Corporate and Other Business Total Revenues $ 43,638 $ 44,955 Adjusted EBITDA (58,429) (56,868) Total Consolidated Total Revenues $ 1,082,040 $ 1,068,731 Adjusted EBITDA 380,565 365,999
Schedule of Reconciliation Of Profit (loss) To Adjusted EBITDA	A reconciliation of Net Income (Loss) to Adjusted EBITDA on a consolidated basis for the three months ended March 31, 2021 and 2020 is as follows: THREE MONTHS ENDED MARCH 31, 2021 2020 Net Income (Loss) $ 46,631 $ 64,892 Add/(Deduct): Interest expense, net 104,422 105,649 Provision (benefit) for income taxes 14,640 9,687 Depreciation and amortization 165,642 162,584 Restructuring Charges 39,811 41,046 Intangible impairments — 23,000 (Gain) loss on disposal/write-down of property, plant and equipment, net (including real estate) (4,451) (1,055) Other expense (income), net, excluding our share of losses (gains) from our unconsolidated joint ventures 2,121 (45,031) Stock-based compensation expense 10,733 5,111 Our share of Adjusted EBITDA reconciling items from our unconsolidated joint ventures 1,016 116 Adjusted EBITDA $ 380,565 $ 365,999
Schedule of revenues by product and service lines by segment	Information as to our revenues by product and service lines by segment for the three months ended March 31, 2021 and 2020 are as follows: THREE MONTHS ENDED MARCH 31, 2021 2020 Global RIM Business Records Management (1) $ 752,123 $ 727,616 Data Management (1) 118,414 125,898 Information Destruction (1)(2) 96,757 102,905 Data Center — — Global Data Center Business Records Management (1) $ — $ — Data Management (1) — — Information Destruction (1)(2) — — Data Center 71,108 67,357 Corporate and Other Business Records Management (1) $ 26,967 $ 28,876 Data Management (1) 16,671 16,079 Information Destruction (1)(2) — — Data Center — — Total Consolidated Records Management (1) $ 779,090 $ 756,492 Data Management (1) 135,085 141,977 Information Destruction (1)(2) 96,757 102,905 Data Center 71,108 67,357 (1) Each of the offerings within our product and service lines has a component of revenue that is storage rental related and a component that is service revenues, except for information destruction, which does not have a storage rental component. (2) Includes secure shredding services.

Project Summit (Tables)

Project Summit (Tables)	3 Months Ended
	Mar. 31, 2021
Restructuring and Related Activities [Abstract]
Schedule of restructuring charges and restructuring liability rollforward	Restructuring Charges included in the accompanying Condensed Consolidated Statements of Operations for the three months ended March 31, 2021 and 2020, and from the inception of Project Summit through March 31, 2021, are as follows: THREE MONTHS ENDED MARCH 31, 2021 THREE MONTHS ENDED MARCH 31, 2020 FROM THE INCEPTION Employee severance costs $ 3,808 $ 6,108 $ 72,007 Professional fees and other costs 36,003 34,938 210,797 Restructuring Charges $ 39,811 $ 41,046 $ 282,804 Restructuring Charges by segment for the three months ended March 31, 2021 and 2020, and from the inception of Project Summit through March 31, 2021, are as follows: THREE MONTHS ENDED MARCH 31, 2021 THREE MONTHS ENDED MARCH 31, 2020 FROM THE INCEPTION Global RIM Business $ 8,224 $ 8,288 $ 97,264 Global Data Center Business 454 187 2,392 Corporate and Other Business 31,133 32,571 183,148 Restructuring Charges $ 39,811 $ 41,046 $ 282,804 A rollforward of the accrued Restructuring Charges, which is included as a component of Accrued expenses and other current liabilities in our Condensed Consolidated Balance Sheets, from December 31, 2019 through March 31, 2021, is as follows: EMPLOYEE SEVERANCE COSTS PROFESSIONAL FEES AND OTHER TOTAL ACCRUED RESTRUCTURING CHARGES Balance as of December 31, 2019 $ 4,823 $ 12,954 $ 17,777 Amounts accrued 47,349 147,047 194,396 Payments (32,455) (136,222) (168,677) Other, including currency translation adjustments (3,439) (4) (3,443) Balance as of December 31, 2020 16,278 23,775 40,053 Amounts accrued 3,808 36,003 39,811 Payments (17,087) (13,849) (30,936) Other, including currency translation adjustments (220) — (220) Balance as of March 31, 2021 $ 2,779 $ 45,929 $ 48,708

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Allowance for Doubtful Accounts and Credit Memo Reserves (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance as of December 31, 2020	$ 56,981
Credit memos charged to revenue	13,026
Allowance for bad debts charged to expense	9,850
Deductions and other	(19,114)
Balance as of March 31, 2021	$ 60,743

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Supplemental Balance Sheet (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Operating lease right-of-use assets	$ 2,205,299	$ 2,196,502
Financing lease right-of-use assets, net of accumulated depreciation	300,399	310,534
Current
Operating lease liabilities	248,319	250,239
Finance lease liabilities	42,692	43,149
Long-term
Operating lease liabilities	2,061,140	2,044,598
Finance lease liabilities	$ 311,448	$ 323,162
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization	us-gaap:PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accrued expenses and other current liabilities (includes current portion of operating lease liabilities)	Accrued expenses and other current liabilities (includes current portion of operating lease liabilities)
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Current portion of long-term debt	Current portion of long-term debt
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Long-term Debt, net of current portion	Long-term Debt, net of current portion

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Leases Costs (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Accounting Policies [Abstract]
Operating lease cost	$ 132,675	$ 123,289
Depreciation of financing lease right-of-use assets	12,648	12,955
Interest expense for financing lease liabilities	4,975	4,844
Variable lease costs	$ 28,368	$ 27,805

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Supplemental Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Accounting Policies [Abstract]
Operating cash flows used in operating leases	$ 93,645	$ 86,418
Operating cash flows used in financing leases (interest)	4,975	4,844
Financing cash flows used in financing leases	12,441	12,739
Operating lease modifications and reassessments	31,994	34,916
New operating leases (including acquisitions and sale-leaseback transactions)	$ 48,200	$ 110,609

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Schedule of Changes in Carrying Value of Goodwill (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)
Gross amount of goodwill [Roll Forward]
Goodwill beginning balance	$ 4,557,609
Fair value and other adjustments	(5,804)
Currency effects	(31,030)
Goodwill ending balance	4,520,775
Accumulated goodwill impairment	158,420
GLOBAL RIM BUSINESS
Gross amount of goodwill [Roll Forward]
Goodwill beginning balance	4,024,182
Fair value and other adjustments	(5,804)
Currency effects	(24,298)
Goodwill ending balance	3,994,080
Accumulated goodwill impairment	132,409
GLOBAL DATA CENTER BUSINESS
Gross amount of goodwill [Roll Forward]
Goodwill beginning balance	436,987
Fair value and other adjustments	0
Currency effects	(6,359)
Goodwill ending balance	430,628
Accumulated goodwill impairment	0
CORPORATE AND OTHER BUSINESS
Gross amount of goodwill [Roll Forward]
Goodwill beginning balance	96,440
Fair value and other adjustments	0
Currency effects	(373)
Goodwill ending balance	96,067
Accumulated goodwill impairment	$ 26,011

Summary of Significant Accoun_9

Summary of Significant Accounting Policies - Investments Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Frankfurt JV
Schedule of Equity Method Investments [Line Items]
Equity investments	$ 26,257	$ 26,500
Ownership percentage	20.00%	20.00%
Makespace
Schedule of Equity Method Investments [Line Items]
Equity investments	$ 21,075	$ 16,924
Ownership percentage	42.00%	39.00%

Summary of Significant Accou_10

Summary of Significant Accounting Policies - Fair Value Measurements (Details) - Fair value measured on recurring basis - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
QUOTED PRICES IN ACTIVE MARKETS (LEVEL 1)
Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis [Line Items]
Trading securities	$ 11,067	$ 10,636
Derivative Liabilities	0	0
SIGNIFICANT OTHER OBSERVABLE INPUTS (LEVEL 2)
Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis [Line Items]
Trading securities	256	256
Derivative Liabilities	34,497	49,703
SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3)
Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis [Line Items]
Trading securities	0	0
Derivative Liabilities	0	0
Estimate of Fair Value Measurement
Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis [Line Items]
Trading securities	11,323	10,892
Derivative Liabilities	34,497	49,703
Money Market Funds | QUOTED PRICES IN ACTIVE MARKETS (LEVEL 1)
Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis [Line Items]
Money market funds	0	0
Money Market Funds | SIGNIFICANT OTHER OBSERVABLE INPUTS (LEVEL 2)
Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis [Line Items]
Money market funds	7,673	62,657
Money Market Funds | SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3)
Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis [Line Items]
Money market funds	0	0
Money Market Funds | Estimate of Fair Value Measurement
Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis [Line Items]
Money market funds	7,673	62,657
Bank Time Deposits | QUOTED PRICES IN ACTIVE MARKETS (LEVEL 1)
Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis [Line Items]
Money market funds	0	0
Bank Time Deposits | SIGNIFICANT OTHER OBSERVABLE INPUTS (LEVEL 2)
Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis [Line Items]
Money market funds	1,291	2,121
Bank Time Deposits | SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3)
Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis [Line Items]
Money market funds	0	0
Bank Time Deposits | Estimate of Fair Value Measurement
Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis [Line Items]
Money market funds	$ 1,291	$ 2,121

Summary of Significant Accou_11

Summary of Significant Accounting Policies - Accumulated Other Comprehensive Income and Other Expenses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
AOCI Rollforward
Beginning of Period	$ 1,136,729	$ 1,464,227
Other comprehensive (loss) income:
Foreign currency translation and other adjustments	(66,224)	(222,305)
Change in fair value of derivative instruments	15,206	(8,362)
Total other comprehensive (loss) income	(51,018)	(230,667)
End of period	959,707	1,123,841
FOREIGN CURRENCY TRANSLATION AND OTHER ADJUSTMENTS
AOCI Rollforward
Beginning of Period	(206,190)	(252,825)
Other comprehensive (loss) income:
Foreign currency translation and other adjustments	(66,224)	(222,305)
Change in fair value of derivative instruments	0	0
Total other comprehensive (loss) income	(66,224)	(222,305)
End of period	(272,414)	(475,130)
CHANGE IN FAIR VALUE OF DERIVATIVE INSTRUMENTS
AOCI Rollforward
Beginning of Period	(49,703)	(9,756)
Other comprehensive (loss) income:
Foreign currency translation and other adjustments	0	0
Change in fair value of derivative instruments	15,206	(8,362)
Total other comprehensive (loss) income	15,206	(8,362)
End of period	(34,497)	(18,118)
TOTAL
AOCI Rollforward
Beginning of Period	(255,893)	(262,581)
Other comprehensive (loss) income:
End of period	$ (306,911)	$ (493,248)

Summary of Significant Accou_12

Summary of Significant Accounting Policies - Contract Fulfillment Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Intake Costs
Contract With Customer, Asset And Liabilities [Line Items]
GROSS CARRYING AMOUNT	$ 66,337	$ 63,721
ACCUMULATED AMORTIZATION	(35,904)	(33,352)
NET CARRYING AMOUNT	30,433	30,369
Commissions
Contract With Customer, Asset And Liabilities [Line Items]
GROSS CARRYING AMOUNT	99,721	91,069
ACCUMULATED AMORTIZATION	(43,125)	(38,787)
NET CARRYING AMOUNT	$ 56,596	$ 52,282

Summary of Significant Accou_13

Summary of Significant Accounting Policies - Summary of Deferred Revenue Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Deferred revenue - Current	$ 284,974	$ 295,785
Deferred revenue - Long-term	$ 36,581	$ 35,612

Summary of Significant Accou_14

Summary of Significant Accounting Policies - Storage Rental (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Lessor, Lease, Description [Line Items]
Storage rental	$ 708,056	$ 683,547
GLOBAL DATA CENTER BUSINESS
Lessor, Lease, Description [Line Items]
Storage rental	67,157	64,595
Storage Rental, Power and Connectivity | GLOBAL DATA CENTER BUSINESS
Lessor, Lease, Description [Line Items]
Storage rental	$ 13,133	$ 11,413

Summary of Significant Accou_15

Summary of Significant Accounting Policies - Stock-Based Compensation Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 10,953	$ 6,527
Unrecognized compensation cost	$ 80,625
Two Thousand Twenty One
Performance Units Disclosure
Percentage of achievement of the predefined revenue and ROIC targets	100.00%
Two Thousand Twenty
Performance Units Disclosure
Percentage of achievement of the predefined revenue and ROIC targets	100.00%
Two Thousand Nineteen
Performance Units Disclosure
Percentage of achievement of the predefined revenue and ROIC targets	100.00%
Restricted Stock Units
Summary of Option Activity
Total fair value of shares or units vested	$ 19,861	18,379
Performance units
Summary of Option Activity
Total fair value of shares or units vested	$ 5,591	$ 10,890

Summary of Significant Accou_16

Summary of Significant Accounting Policies - Other Expense (Income), Net / Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Accounting Policies [Abstract]
Foreign currency transaction losses (gains), net	$ 2,314	$ (37,399)
Other, net	2,399	(5,327)
Other Expense (Income), Net	$ 4,713	$ (42,726)
Effective Tax Rate	23.90%	13.00%
OSG Investment
Schedule of Equity Method Investments [Line Items]
Ownership percentage	25.00%

Summary of Significant Accou_17

Summary of Significant Accounting Policies - Income Per Share, Allowance for Doubtful Accounts, Income Taxes, and Concentration of Credit Risk (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income (Loss) Per Share-Basic and Diluted
Net Income (Loss)	$ 46,631	$ 64,892
Less: Net Income (Loss) Attributable to Noncontrolling Interests	1,028	917
Net Income (Loss) Attributable to Iron Mountain Incorporated	$ 45,603	$ 63,975
Weighted-average shares—basic (in shares)	288,756,000	287,840,000
Effect of dilutive potential stock options (in shares)	56,437	51,799
Effect of dilutive potential restricted stock, RSUs and PUs (in shares)	715,850	467,334
Weighted-average shares—diluted (in shares)	289,528,287	288,359,133
Income (Loss) from Continuing Operations, Basic (in dollars per share)	$ 0.16	$ 0.22
Income (Loss) from Continuing Operations, Diluted (in dollars per share)	$ 0.16	$ 0.22
Antidilutive stock options, RSUs and PUs, excluded from the calculation (in shares)	4,708,068	5,513,714

Derivative Instruments and He_3

Derivative Instruments and Hedging Activities - Additional Information (Details)	Mar. 31, 2021USD ($)	Dec. 31, 2020USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2020EUR (€)	Aug. 31, 2020EUR (€)	Aug. 31, 2019USD ($)	Aug. 31, 2019EUR (€)	Jul. 31, 2019USD ($)
Net Investment Hedges
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cumulative net gains	$ (17,636,000)
Net Investment Hedges | Designated as Hedging Instrument | Euro Notes
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged notes | €					€ 300,000,000
Cumulative net gains	3,256,000
Interest Rate Swap Agreements
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional amount	$ 350,000,000	$ 350,000,000						$ 350,000,000
Cross-currency Swap Agreements | Net Investment Hedges
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional amount			$ 359,200,000	€ 300,000,000		$ 110,000,000	€ 99,055,000
Interest rate			4.50%	4.50%		6.00%	6.00%
Weighted average interest rate			3.40%	3.40%		3.65%	3.65%

Derivative Instruments and He_4

Derivative Instruments and Hedging Activities - Net Investment Hedges (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Net Investment Hedges
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cumulative net losses in cross-currency swaps	$ 17,636
Interest Rate Swap Agreements
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cumulative net losses in AOCI	16,861
Interest Rate Swap Agreements | Cash Flow Hedging
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative liabilities	(16,861)		$ (21,062)
Interest Rate Swap Agreements | Designated as Hedging Instrument | Cash Flow Hedging
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Unrealized gains (losses) associated with interest rate swap agreements	4,201	$ (14,732)
August 2023 Cross Currency Swap Agreements | Net Investment Hedges
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative liabilities	(3,478)		(8,229)
August 2023 Cross Currency Swap Agreements | Designated as Hedging Instrument | Net Investment Hedges
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Unrealized gains (losses) associated with cross-currency swaps	4,751	6,370
February 2026 Cross Currency Swap Agreements | Net Investment Hedges
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative liabilities	(14,158)		$ (20,412)
February 2026 Cross Currency Swap Agreements | Designated as Hedging Instrument | Net Investment Hedges
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Unrealized gains (losses) associated with cross-currency swaps	$ 6,254	$ 0

Derivative Instruments and He_5

Derivative Instruments and Hedging Activities - Hedge of Net Investment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Foreign exchange gains (losses) associated with net investment hedge	$ 0	$ 6,453

Debt - Schedule of Long Term De

Debt - Schedule of Long Term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020
Debt Instrument [Line Items]
DEBT (INCLUSIVE OF DISCOUNT)	$ 9,006,510	$ 8,797,424
UNAMORTIZED DEFERRED FINANCING COSTS	(90,184)	(94,110)
CARRYING AMOUNT	8,916,326	8,703,314
Long-term debt, gross, current maturities	(363,911)	(193,759)
Long term debt, gross, net of current portion	8,642,599	8,603,665
Unamortized debt issuance expense, net of current portion	0	0
Unamortized debt issuance expense, net	(90,184)	(94,110)
Carrying amount, current maturities	(363,911)	(193,759)
Carrying amount, excluding current maturities	8,552,415	8,509,555
Australian Dollar Term Loan (the AUD Term Loan)
Debt Instrument [Line Items]
DEBT (INCLUSIVE OF DISCOUNT)	238,433	243,152
UNAMORTIZED DEFERRED FINANCING COSTS	(1,374)	(1,624)
CARRYING AMOUNT	237,059	241,528
FAIR VALUE	239,162	244,014
Real Estate Mortgages, Financing Lease Liabilities and Other
Debt Instrument [Line Items]
DEBT (INCLUSIVE OF DISCOUNT)	492,256	511,922
UNAMORTIZED DEFERRED FINANCING COSTS	(1,003)	(1,086)
CARRYING AMOUNT	491,253	510,836
FAIR VALUE	492,256	511,922
Accounts Receivable Securitization Program
Debt Instrument [Line Items]
DEBT (INCLUSIVE OF DISCOUNT)	257,000	85,000
UNAMORTIZED DEFERRED FINANCING COSTS	(135)	(152)
CARRYING AMOUNT	256,865	84,848
FAIR VALUE	257,000	$ 85,000
Credit Agreement
Debt Instrument [Line Items]
Letters of credit outstanding	38,160
Revolving Credit Facility | Credit Agreement
Debt Instrument [Line Items]
Letters of credit outstanding	3,219
Remaining capacity	1,686,781
Weighted average interest rate		1.90%	1.90%
New Credit Agreement | Revolving Credit Facility
Debt Instrument [Line Items]
DEBT (INCLUSIVE OF DISCOUNT)	60,000	$ 0
UNAMORTIZED DEFERRED FINANCING COSTS	(7,758)	(8,620)
CARRYING AMOUNT	52,242	(8,620)
FAIR VALUE	60,000	0
Term Loan A | Term Loan Facility
Debt Instrument [Line Items]
DEBT (INCLUSIVE OF DISCOUNT)	212,500	215,625
UNAMORTIZED DEFERRED FINANCING COSTS	0	0
CARRYING AMOUNT	212,500	215,625
FAIR VALUE	212,500	215,625
Term Loan B | Term Loan Facility
Debt Instrument [Line Items]
DEBT (INCLUSIVE OF DISCOUNT)	677,927	679,621
UNAMORTIZED DEFERRED FINANCING COSTS	(5,932)	(6,244)
CARRYING AMOUNT	671,995	673,377
FAIR VALUE	679,000	680,750
UK Bilateral Revolving Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
DEBT (INCLUSIVE OF DISCOUNT)	192,732	191,101
UNAMORTIZED DEFERRED FINANCING COSTS	(1,147)	(1,307)
CARRYING AMOUNT	191,585	189,794
FAIR VALUE	$ 192,732	191,101
GBP Senior Notes due 2025 3.875 Percent | Senior Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)	3.875%
DEBT (INCLUSIVE OF DISCOUNT)	$ 550,662	546,003
UNAMORTIZED DEFERRED FINANCING COSTS	(4,765)	(4,983)
CARRYING AMOUNT	545,897	541,020
FAIR VALUE	$ 556,180	553,101
Senior Notes 4.875 Percent due 2027 | Senior Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)	4.875%
DEBT (INCLUSIVE OF DISCOUNT)	$ 1,000,000	1,000,000
UNAMORTIZED DEFERRED FINANCING COSTS	(9,243)	(9,598)
CARRYING AMOUNT	990,757	990,402
FAIR VALUE	$ 1,025,000	1,046,250
Senior Notes 5.25 Percent due 2028 | Senior Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)	5.25%
DEBT (INCLUSIVE OF DISCOUNT)	$ 825,000	825,000
UNAMORTIZED DEFERRED FINANCING COSTS	(8,266)	(8,561)
CARRYING AMOUNT	816,734	816,439
FAIR VALUE	$ 856,969	868,313
Senior Notes 5 Percent Due 2028 Member | Senior Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)	5.00%
DEBT (INCLUSIVE OF DISCOUNT)	$ 500,000	500,000
UNAMORTIZED DEFERRED FINANCING COSTS	(5,306)	(5,486)
CARRYING AMOUNT	494,694	494,514
FAIR VALUE	$ 511,250	523,125
Senior Notes 4.875 Percent due 2029 | Senior Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)	4.875%
DEBT (INCLUSIVE OF DISCOUNT)	$ 1,000,000	1,000,000
UNAMORTIZED DEFERRED FINANCING COSTS	(12,296)	(12,658)
CARRYING AMOUNT	987,704	987,342
FAIR VALUE	$ 1,011,250	1,050,000
Senior Notes 5.25 Percent Due 2030 | Senior Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)	5.25%
DEBT (INCLUSIVE OF DISCOUNT)	$ 1,300,000	1,300,000
UNAMORTIZED DEFERRED FINANCING COSTS	(14,040)	(14,416)
CARRYING AMOUNT	1,285,960	1,285,584
FAIR VALUE	$ 1,335,750	1,400,750
Senior Notes 4.5 Percent Due 2031 | Senior Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)	4.50%
DEBT (INCLUSIVE OF DISCOUNT)	$ 1,100,000	1,100,000
UNAMORTIZED DEFERRED FINANCING COSTS	(12,337)	(12,648)
CARRYING AMOUNT	1,087,663	1,087,352
FAIR VALUE	$ 1,080,750	1,138,500
Senior Notes 5.625 Percent Due 2032 | Senior Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)	5.625%
DEBT (INCLUSIVE OF DISCOUNT)	$ 600,000	600,000
UNAMORTIZED DEFERRED FINANCING COSTS	(6,582)	(6,727)
CARRYING AMOUNT	593,418	593,273
FAIR VALUE	$ 625,500	$ 660,000

Debt - Cash Pool (Details)

Debt - Cash Pool (Details) $ in Thousands	Mar. 31, 2021USD ($)cash_pool	Dec. 31, 2020USD ($)
Debt Instrument [Line Items]
Number of cash pools | cash_pool	2
QRS Cash Pool
Debt Instrument [Line Items]
Number of cash pools | cash_pool	1
GROSS CASH POSITION	$ 567,300	$ 448,700
OUTSTANDING DEBIT BALANCES	(566,700)	(447,400)
NET CASH POSITION	$ 600	1,300
TRS Cash Pool
Debt Instrument [Line Items]
Number of cash pools | cash_pool	1
GROSS CASH POSITION	$ 512,700	555,500
OUTSTANDING DEBIT BALANCES	(510,200)	(553,500)
NET CASH POSITION	$ 2,500	$ 2,000

Debt - Letters of Credit (Detai

Debt - Letters of Credit (Details) - Credit Agreement $ in Thousands	Mar. 31, 2021USD ($)
Debt Instrument [Line Items]
Letters of credit outstanding	$ 38,160
Revolving Credit Facility
Debt Instrument [Line Items]
Letters of credit outstanding	$ 3,219

Stockholders' Equity Matters -

Stockholders' Equity Matters - Dividends Declared (Details) - USD ($) $ / shares in Units, $ in Thousands

May 06, 2021

Mar. 15, 2021

Feb. 24, 2021

Dec. 15, 2020

Nov. 04, 2020

Sep. 15, 2020

Aug. 05, 2020

Jun. 15, 2020

May 05, 2020

Mar. 16, 2020

Feb. 13, 2020

Mar. 31, 2021

Mar. 31, 2020

Class of Stock [Line Items]

DIVIDEND PER SHARE (in dollars per share)

$ 0.6185

$ 0.6185

$ 0.6185

$ 0.6185

$ 0.6185

TOTAL AMOUNT

$ 178,569

$ 178,290

$ 178,224

$ 178,212

$ 178,047

$ 178,685

$ 179,512

Subsequent Event

Class of Stock [Line Items]

DIVIDEND PER SHARE (in dollars per share)

$ 0.6185

Segment Information - Additiona

Segment Information - Additional Information (Details)	12 Months Ended
	Dec. 31, 2020segment
Segment Reporting [Abstract]
Number of operating segments	3

Segment Information - Segment R

Segment Information - Segment Reporting Information by Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting Information [Line Items]
Total Revenues	$ 1,082,040	$ 1,068,731
Adjusted EBITDA	380,565	365,999
GLOBAL RIM BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	967,294	956,419
Adjusted EBITDA	408,562	391,972
GLOBAL DATA CENTER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	71,108	67,357
Adjusted EBITDA	30,432	30,895
CORPORATE AND OTHER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	43,638	44,955
Adjusted EBITDA	$ (58,429)	$ (56,868)

Segment Information - Reconcili

Segment Information - Reconciliation to Income from Continuing Operations (Details) - USD ($) $ in Thousands	3 Months Ended		18 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021
Reconciliation of Adjusted EBITDA to income from continuing operations
Net Income (Loss)	$ 46,631	$ 64,892
Interest expense, net	104,422	105,649
Provision (benefit) for income taxes	14,640	9,687
Depreciation and amortization	165,642	162,584
Restructuring Charges	39,811	41,046	$ 282,804
Intangible impairments	0	23,000
(Gain) loss on disposal/write-down of property, plant and equipment, net (including real estate)	(4,451)	(1,055)
Other expense (income), net, excluding our share of losses (gains) from our unconsolidated joint ventures	2,121	(45,031)
Stock-based compensation expense	10,733	5,111
Our share of Adjusted EBITDA reconciling items from our unconsolidated joint ventures	1,016	116
Adjusted EBITDA	$ 380,565	$ 365,999

Segment Information - Revenues

Segment Information - Revenues by Product and Service Lines by Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting Information [Line Items]
Total Revenues	$ 1,082,040	$ 1,068,731
GLOBAL RIM BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	967,294	956,419
GLOBAL DATA CENTER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	71,108	67,357
CORPORATE AND OTHER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	43,638	44,955
Records management
Segment Reporting Information [Line Items]
Total Revenues	779,090	756,492
Records management | GLOBAL RIM BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	752,123	727,616
Records management | GLOBAL DATA CENTER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	0	0
Records management | CORPORATE AND OTHER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	26,967	28,876
Data management
Segment Reporting Information [Line Items]
Total Revenues	135,085	141,977
Data management | GLOBAL RIM BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	118,414	125,898
Data management | GLOBAL DATA CENTER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	0	0
Data management | CORPORATE AND OTHER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	16,671	16,079
Information destruction
Segment Reporting Information [Line Items]
Total Revenues	96,757	102,905
Information destruction | GLOBAL RIM BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	96,757	102,905
Information destruction | GLOBAL DATA CENTER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	0	0
Information destruction | CORPORATE AND OTHER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	0	0
Data Center
Segment Reporting Information [Line Items]
Total Revenues	71,108	67,357
Data Center | GLOBAL RIM BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	0	0
Data Center | GLOBAL DATA CENTER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	71,108	67,357
Data Center | CORPORATE AND OTHER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	$ 0	$ 0

Related Parties - (Details)

Related Parties - (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Frankfurt JV
Related Party Transaction [Line Items]
Revenue	$ 1,060
Makespace
Related Party Transaction [Line Items]
Revenue	$ 7,500	$ 6,800

Project Summit - Additional Inf

Project Summit - Additional Information (Details) $ in Thousands	3 Months Ended		12 Months Ended	18 Months Ended	27 Months Ended
	Mar. 31, 2021USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2020USD ($)	Mar. 31, 2021USD ($)	Dec. 31, 2021USD ($)employee
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 39,811	$ 41,046		$ 282,804
Project Summit costs
Restructuring Cost and Reserve [Line Items]
Planned workforce reductions	80.00%			80.00%
Restructuring Charges	$ 39,811		$ 194,396
Forecast | Project Summit costs
Restructuring Cost and Reserve [Line Items]
Percentage of positions eliminated					45.00%
Managerial and administrative workforce | employee					700
Restructuring Charges					$ 450,000

Project Summit - Restructuring

Project Summit - Restructuring Charges (Details) - USD ($) $ in Thousands	3 Months Ended		18 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 39,811	$ 41,046	$ 282,804
GLOBAL RIM BUSINESS
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	8,224	8,288	97,264
GLOBAL DATA CENTER BUSINESS
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	454	187	2,392
Corporate and Other Business
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	31,133	32,571	183,148
Employee severance costs
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	3,808	6,108	72,007
Professional fees and other costs
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 36,003	$ 34,938	$ 210,797

Project Summit - Restructurin_2

Project Summit - Restructuring Rollforward (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended	18 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Mar. 31, 2021
Restructuring Reserve [Roll Forward]
Amounts accrued	$ 39,811	$ 41,046		$ 282,804
Project Summit costs
Restructuring Reserve [Roll Forward]
Beginning balance	40,053	17,777	$ 17,777
Amounts accrued	39,811		194,396
Payments	(30,936)		(168,677)
Other, including currency translation adjustments	(220)		(3,443)
Ending balance	48,708		40,053	48,708
Employee severance costs
Restructuring Reserve [Roll Forward]
Amounts accrued	3,808	6,108		72,007
Employee severance costs | Project Summit costs
Restructuring Reserve [Roll Forward]
Beginning balance	16,278	4,823	4,823
Amounts accrued	3,808		47,349
Payments	(17,087)		(32,455)
Other, including currency translation adjustments	(220)		(3,439)
Ending balance	2,779		16,278	2,779
Professional fees and other costs
Restructuring Reserve [Roll Forward]
Amounts accrued	36,003	34,938		210,797
Professional fees and other costs | Project Summit costs
Restructuring Reserve [Roll Forward]
Beginning balance	23,775	$ 12,954	12,954
Amounts accrued	36,003		147,047
Payments	(13,849)		(136,222)
Other, including currency translation adjustments	0		(4)
Ending balance	$ 45,929		$ 23,775	$ 45,929

Subsequent Events (Details)

Subsequent Events (Details) - Web Werks JV ₨ in Thousands, $ in Thousands	1 Months Ended		25 Months Ended
	Apr. 30, 2021INR (₨)	Apr. 30, 2021USD ($)	Apr. 30, 2023INR (₨)	Apr. 30, 2023USD ($)
Forecast
Subsequent Event [Line Items]
Investment period			2 years	2 years
Additional investments			₨ 7,500,000	$ 100,000
Subsequent Event
Subsequent Event [Line Items]
Payments to acquire equity investments	₨ 3,750,000	$ 50,100
Ownership percentage	39.00%	39.00%