Iron Mountain (IRM) 10-Q 5 Aug 21 2021 Q2 Quarterly report Financial data

Cover Page

Cover Page - shares	6 Months Ended
	Jun. 30, 2021	Jul. 30, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 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		289,460,314
Entity Central Index Key	0001020569
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Amendment Flag	false

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current Assets:
Cash and cash equivalents	$ 315,928	$ 205,063
Accounts receivable (less allowances of $56,977 and $56,981 as of June 30, 2021 and December 31, 2020, respectively)	852,449	859,344
Prepaid expenses and other	222,231	205,380
Total Current Assets	1,390,608	1,269,787
Property, Plant and Equipment:
Property, plant and equipment	8,319,083	8,246,337
Less—Accumulated depreciation	(3,863,477)	(3,743,894)
Property, Plant and Equipment, Net	4,455,606	4,502,443
Other Assets, Net:
Goodwill	4,508,754	4,557,609
Customer relationships, customer inducements and data center lease-based intangibles	1,256,181	1,326,977
Operating lease right-of-use assets	2,342,197	2,196,502
Other	360,970	295,949
Total Other Assets, Net	8,468,102	8,377,037
Total Assets	14,314,316	14,149,267
Current Liabilities:
Current portion of long-term debt	106,274	193,759
Accounts payable	321,286	359,863
Accrued expenses and other current liabilities (includes current portion of operating lease liabilities)	1,064,397	1,146,288
Deferred revenue	256,245	295,785
Total Current Liabilities	1,748,202	1,995,695
Long-term Debt, net of current portion	8,760,728	8,509,555
Long-term Operating Lease Liabilities, net of current portion	2,186,625	2,044,598
Other Long-term Liabilities	169,548	204,508
Deferred Income Taxes	236,811	198,377
Commitments and Contingencies
Redeemable Noncontrolling Interests	64,660	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 289,458,768 and 288,273,049 shares as of June 30, 2021 and December 31, 2020, respectively)	2,895	2,883
Additional paid-in capital	4,392,396	4,340,078
(Distributions in excess of earnings) Earnings in excess of distributions	(2,988,896)	(2,950,339)
Accumulated other comprehensive items, net	(258,653)	(255,893)
Total Equity	1,147,742	1,136,729
Total Liabilities and Equity	$ 14,314,316	$ 14,149,267

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 56,977	$ 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)	289,458,768	288,273,049
Common stock, outstanding shares (in shares)	289,458,768	288,273,049

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenues:
Storage rental	$ 718,272	$ 676,956	$ 1,426,328	$ 1,360,503
Service	401,484	305,283	775,468	690,467
Total Revenues	1,119,756	982,239	2,201,796	2,050,970
Operating Expenses:
Cost of sales (excluding depreciation and amortization)	474,579	406,693	926,488	873,614
Selling, general and administrative	259,779	241,947	518,502	480,680
Depreciation and amortization	166,685	163,850	332,327	326,434
Acquisition and Integration Costs	2,277	0	2,277	0
Restructuring Charges	39,443	39,298	79,254	80,344
(Gain) Loss on disposal/write-down of property, plant and equipment, net	(128,935)	(1,275)	(133,386)	(2,330)
Total Operating Expenses	813,828	850,513	1,725,462	1,781,742
Operating Income (Loss)	305,928	131,726	476,334	269,228
Interest Expense, Net (includes Interest Income)	105,220	103,456	209,642	209,105
Other (Income) Expense, Net	(186,230)	25,700	(181,517)	(17,026)
Net Income (Loss) Before Provision (Benefit) for Income Taxes	386,938	2,570	448,209	77,149
Provision (Benefit) for Income Taxes	110,416	9,683	125,056	19,370
Net Income (Loss)	276,522	(7,113)	323,153	57,779
Less: Net Income (Loss) Attributable to Noncontrolling Interests	1,237	(27)	2,265	890
Net Income (Loss) Attributable to Iron Mountain Incorporated	$ 275,285	$ (7,086)	$ 320,888	$ 56,889
Net Income (Loss) Per Share Attributable to Iron Mountain Incorporated:
Income (Loss) from Continuing Operations, Basic (in dollars per share)	$ 0.95	$ (0.02)	$ 1.11	$ 0.20
Income (Loss) from Continuing Operations, Diluted (in dollars per share)	$ 0.95	$ (0.02)	$ 1.11	$ 0.20
Weighted Average Common Shares Outstanding-Basic (in shares)	289,247,000	288,071,000	289,001,000	287,955,000
Weighted Average Common Shares Outstanding-Diluted (in shares)	291,079,245	288,071,000	290,303,267	288,300,617

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Statement [Abstract]
Interest income	$ 1,127	$ 2,567	$ 3,698	$ 4,015

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 276,522	$ (7,113)	$ 323,153	$ 57,779
Other Comprehensive Income (Loss):
Foreign Currency Translation Adjustment	42,543	69,027	(23,812)	(154,625)
Change in Fair Value of Derivative Instruments	5,634	(2,961)	20,840	(11,323)
Total Other Comprehensive Income (Loss)	48,177	66,066	(2,972)	(165,948)
Comprehensive Income (Loss)	324,699	58,953	320,181	(108,169)
Comprehensive Income (Loss) Attributable to Noncontrolling Interests	1,156	314	2,053	(116)
Comprehensive Income (Loss) Attributable to Iron Mountain Incorporated	$ 323,543	$ 58,639	$ 318,128	$ (108,053)

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	24,642	$ 8	24,634
Issuance of shares under employee stock purchase plan and option plans and stock-based compensation (in shares)		843,058
Change in equity related to redeemable noncontrolling interests	2,603		2,603				$ (2,603)
Parent cash dividends declared	(358,854)			(358,854)
Foreign currency translation adjustment	(153,619)				(153,619)
Change in fair value of derivative instruments	(11,323)				(11,323)
Net income (loss)	56,655			56,889		(234)
End of period at Jun. 30, 2020	1,024,331	$ 2,881	4,325,803	(2,876,861)	(427,523)	31
Balance (in shares) at Jun. 30, 2020		288,142,703
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	2,603		2,603				(2,603)
Foreign currency translation adjustment							(1,006)
Net income (loss)							1,124
Noncontrolling interests dividends							(1,685)
Ending of redeemable noncontrolling interest at Jun. 30, 2020							63,512
Beginning 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
Increase (Decrease) in Stockholders' Equity
Issuance of shares under employee stock purchase plan and option plans and stock-based compensation	22,725	$ 2	22,723
Issuance of shares under employee stock purchase plan and option plans and stock-based compensation (in shares)		263,561
Change in equity related to redeemable noncontrolling interests	(1,397)		(1,397)				1,397
Parent cash dividends declared	(179,342)			(179,342)
Foreign currency translation adjustment	68,686				68,686
Change in fair value of derivative instruments	(2,961)				(2,961)
Net income (loss)	(7,221)			(7,086)		(135)
End of period at Jun. 30, 2020	1,024,331	$ 2,881	4,325,803	(2,876,861)	(427,523)	$ 31
Balance (in shares) at Jun. 30, 2020		288,142,703
Beginning of redeemable noncontrolling interest at Mar. 31, 2020							62,157
Increase (Decrease) in Temporary Equity [Roll Forward]
Change in equity related to redeemable noncontrolling interests	(1,397)		(1,397)				1,397
Foreign currency translation adjustment							341
Net income (loss)							108
Noncontrolling interests dividends							(491)
Ending of redeemable noncontrolling interest at Jun. 30, 2020							63,512
Beginning of Period at Dec. 31, 2020	$ 1,136,729	$ 2,883	4,340,078	(2,950,339)	(255,893)
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	$ 51,650	$ 12	51,638
Issuance of shares under employee stock purchase plan and option plans and stock-based compensation (in shares)		1,185,719
Change in equity related to redeemable noncontrolling interests	680		680				(680)
Parent cash dividends declared	(359,445)			(359,445)
Foreign currency translation adjustment	(23,600)				(23,600)
Change in fair value of derivative instruments	20,840				20,840
Net income (loss)	320,888			320,888
End of period at Jun. 30, 2021	$ 1,147,742	$ 2,895	4,392,396	(2,988,896)	(258,653)
Balance (in shares) at Jun. 30, 2021	289,458,768	289,458,768
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							(212)
Net income (loss)							2,265
Noncontrolling interests equity contributions							2,200
Noncontrolling interests dividends							(1,285)
Purchase of noncontrolling interests							2,567
Ending of redeemable noncontrolling interest at Jun. 30, 2021	64,660						64,660
Beginning of Period at Mar. 31, 2021	959,707	$ 2,888	4,347,151	(3,083,421)	(306,911)
Balance (in shares) at Mar. 31, 2021		288,727,747
Increase (Decrease) in Stockholders' Equity
Issuance of shares under employee stock purchase plan and option plans and stock-based compensation	45,252	$ 7	45,245
Issuance of shares under employee stock purchase plan and option plans and stock-based compensation (in shares)		731,021
Parent cash dividends declared	(180,760)			(180,760)
Foreign currency translation adjustment	42,624				42,624
Change in fair value of derivative instruments	5,634				5,634
Net income (loss)	275,285			275,285
End of period at Jun. 30, 2021	$ 1,147,742	$ 2,895	$ 4,392,396	$ (2,988,896)	$ (258,653)
Balance (in shares) at Jun. 30, 2021	289,458,768	289,458,768
Beginning of redeemable noncontrolling interest at Mar. 31, 2021							61,601
Increase (Decrease) in Temporary Equity [Roll Forward]
Foreign currency translation adjustment							(81)
Net income (loss)							1,237
Noncontrolling interests dividends							(664)
Purchase of noncontrolling interests							2,567
Ending of redeemable noncontrolling interest at Jun. 30, 2021	$ 64,660						$ 64,660

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash Flows from Operating Activities:
Net income (loss)	$ 323,153	$ 57,779
Adjustments to reconcile net income (loss) to cash flows from operating activities:
Depreciation	226,939	226,628
Amortization (includes amortization of deferred financing costs and discounts of $8,443 and $9,001 for the six months ended June 30, 2021 and 2020, respectively)	113,831	108,807
Intangible impairments	0	23,000
Revenue reduction associated with amortization of customer inducements and above- and below-market leases	4,327	5,248
Stock-based compensation expense	33,652	26,672
Provision (benefit) for deferred income taxes	30,899	(2,413)
Loss on early extinguishment of debt	0	17,040
Gain on IPM Divestment (as defined and described in Note 4)	(181,196)	0
(Gain) loss on disposal/write-down of property, plant and equipment, net	(133,386)	(2,330)
Foreign currency transactions and other, net	2,727	(30,555)
(Increase) decrease in assets	(83,975)	(10,794)
Increase (decrease) in liabilities	52,231	19,992
Cash Flows from Operating Activities	389,202	439,074
Cash Flows from Investing Activities:
Capital expenditures	(295,586)	(200,158)
Cash paid for acquisitions, net of cash acquired	(35,723)	(118,512)
Acquisition of customer relationships	(3,641)	(2,885)
Customer inducements	(3,818)	(6,970)
Contract fulfillment costs and third-party commissions	(29,023)	(18,738)
Investments in joint ventures and other investments	(63,135)	(6,850)
Net proceeds from IPM Divestment	213,878	0
Proceeds from sales of property and equipment and other, net	209,697	9,902
Cash Flows from Investing Activities	(7,351)	(344,211)
Cash Flows from Financing Activities:
Repayment of revolving credit facility, term loan facilities and other debt	(1,620,167)	(5,691,163)
Proceeds from revolving credit facility, term loan facilities and other debt	1,763,597	5,426,057
Early redemption of senior notes, including call premiums	0	(1,111,986)
Net proceeds from sales of senior notes	0	2,376,000
Debt repayment and equity distribution to noncontrolling interests	(1,285)	(1,685)
Repurchase of noncontrolling interest	(75,000)	0
Parent cash dividends	(359,824)	(359,461)
Net proceeds (payments) associated with employee stock-based awards	17,998	(2,030)
Other, net	3,742	(18,820)
Cash Flows from Financing Activities	(270,939)	616,912
Effect of Exchange Rates on Cash and Cash Equivalents	(47)	1,850
Increase (decrease) in Cash and Cash Equivalents	110,865	713,625
Cash and Cash Equivalents, including Restricted Cash, Beginning of Period	205,063	193,555
Cash and Cash Equivalents, including Restricted Cash, End of Period	315,928	907,180
Supplemental Information:
Cash Paid for Interest	217,687	225,676
Cash Paid for Income Taxes, Net	45,246	1,798
Non-Cash Investing and Financing Activities:
Financing Leases	13,775	26,546
Accrued Capital Expenditures	45,665	50,831
Fair Value of Investments Applied to Acquisitions	0	27,276
Dividends Payable	$ 187,488	$ 185,414

CONDENSED CONSOLIDATED STATEM_6

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Statement of Cash Flows [Abstract]
Deferred financing costs and discount included in Amortization	$ 8,443	$ 9,001

General

General	6 Months Ended
	Jun. 30, 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	6 Months Ended
	Jun. 30, 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 six months ended June 30, 2021 is as follows: Balance as of December 31, 2020 $ 56,981 Credit memos charged to revenue 21,699 Allowance for bad debts charged to expense 13,442 Deductions and other (1) (35,145) Balance as of June 30, 2021 $ 56,977 (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 June 30, 2021 and December 31, 2020 are as follows: DESCRIPTION JUNE 30, 2021 DECEMBER 31, 2020 Assets: Operating lease right-of-use assets $ 2,342,197 $ 2,196,502 Financing lease right-of-use assets, net of accumulated depreciation (1) 297,052 310,534 Liabilities: Current Operating lease liabilities $ 263,784 $ 250,239 Financing lease liabilities (1) 43,728 43,149 Long-term Operating lease liabilities 2,186,625 2,044,598 Financing lease liabilities (1) 308,895 323,162 (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 and six months ended June 30, 2021 and 2020 are as follows: THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, DESCRIPTION 2021 2020 2021 2020 Operating lease cost (1) $ 135,086 $ 119,277 $ 267,761 $ 242,566 Financing lease cost: Depreciation of financing lease right-of-use assets $ 12,408 $ 12,567 $ 25,056 $ 25,522 Interest expense for financing lease liabilities 4,910 4,929 9,885 9,773 (1) Operating lease cost, the majority of which is included in Cost of sales, includes variable lease costs of $29,219 and $57,587 for the three and six months ended June 30, 2021, respectively, and $26,996 and $54,801 for the three and six months ended June 30, 2020, respectively. Other information: Supplemental cash flow information relating to our leases for the six months ended June 30, 2021 and 2020 is as follows: SIX MONTHS ENDED JUNE 30, CASH PAID FOR AMOUNTS INCLUDED IN MEASUREMENT OF LEASE LIABILITIES: 2021 2020 Operating cash flows used in operating leases $ 192,039 $ 178,011 Operating cash flows used in financing leases (interest) 9,885 9,773 Financing cash flows used in financing leases 23,656 23,953 NON-CASH ITEMS: Operating lease modifications and reassessments $ 63,047 $ 76,764 New operating leases (including acquisitions and sale-leaseback transactions) 210,881 123,860 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 six months ended June 30, 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 December 31, 2020 $ 4,024,182 $ 436,987 $ 96,440 $ 4,557,609 Non-tax deductible goodwill acquired during the period 6,108 — 8,807 14,915 Goodwill allocated to IPM Divestment (as defined and described in Note 4) — — (46,105) (46,105) Fair value and other adjustments (6,091) — (1,268) (7,359) Currency effects (5,598) (4,573) (135) (10,306) Goodwill balance, net accumulated amortization as of June 30, 2021 $ 4,018,601 $ 432,414 $ 57,739 $ 4,508,754 Accumulated goodwill impairment balance as of June 30, 2021 $ 132,409 $ — $ 26,011 $ 158,420 E. INVESTMENTS 2021 NEWLY FORMED JOINT VENTURE 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. Under the terms of the Web Werks JV shareholder agreement, we are required to make additional investments over a period ending May 2023 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). JOINT VENTURE SUMMARY The following joint ventures are accounted for as equity method investments and are presented as a component of Other within Other assets, net in our Condensed Consolidated Balance Sheets. The carrying values and equity interests in our joint ventures at June 30, 2021 and December 31, 2020 are as follows: JUNE 30, 2021 DECEMBER 31, 2020 CARRYING VALUE EQUITY INTEREST CARRYING VALUE EQUITY INTEREST Web Werks JV $ 50,135 38 % $ — — % Joint venture with AGC Equity Partners (the “Frankfurt JV”) 26,387 20 % 26,500 20 % Joint venture with MakeSpace Labs, Inc. (the “MakeSpace JV”) 24,069 45 % 16,924 39 % F. FAIR VALUE MEASUREMENTS The assets and liabilities carried at fair value measured on a recurring basis as of June 30, 2021 and December 31, 2020 are as follows: FAIR VALUE MEASUREMENTS AT JUNE 30, 2021 USING DESCRIPTION TOTAL CARRYING QUOTED PRICES IN SIGNIFICANT OTHER SIGNIFICANT Money Market Funds $ 160,100 $ — $ 160,100 $ — Time Deposits 3,130 — 3,130 — Trading Securities 12,672 12,431 241 — Derivative Liabilities 28,863 — 28,863 — 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 June 30, 2021 and December 31, 2020, other than (i) those disclosed in Note 2.o. to Notes to Consolidated Financial Statements included in our Annual Report, (ii) our investment in the Web Werks JV, as described in Note 2.e., and (iii) those acquired in acquisitions that occurred during the six months ended June 30, 2021, as described in Note 3, all of which are based on Level 3 inputs. G. REDEEMABLE NONCONTROLLING INTERESTS In 2018, one of the noncontrolling interest shareholders in one of our foreign consolidated subsidiaries exercised its option to put its ownership interest back to us. Upon the exercise of the put option, this noncontrolling interest became mandatorily redeemable by us, and, therefore, was accounted for as a liability rather than a component of redeemable noncontrolling interests. In May 2021, we agreed to final settlement terms and paid the put option price for the noncontrolling interest shares. We remain in dispute with this former shareholder with respect to whether interest from the date of the put and certain other costs should be reimbursable. We have vigorously defended that interest and costs are not owed, and are currently awaiting a ruling from an arbitration hearing. H. ACCUMULATED OTHER COMPREHENSIVE ITEMS, NET The changes in accumulated other comprehensive items, net for the three and six months ended June 30, 2021 and 2020 are as follows: THREE MONTHS ENDED JUNE 30, 2021 SIX MONTHS ENDED JUNE 30, 2021 FOREIGN CHANGE IN FAIR VALUE OF TOTAL FOREIGN CHANGE IN FAIR VALUE OF DERIVATIVE INSTRUMENTS TOTAL Beginning of Period $ (272,414) $ (34,497) $ (306,911) $ (206,190) $ (49,703) $ (255,893) Other comprehensive income (loss): Foreign currency translation and other adjustments 42,624 — 42,624 (23,600) — (23,600) Change in fair value of derivative instruments — 5,634 5,634 — 20,840 20,840 Total other comprehensive income (loss) 42,624 5,634 48,258 (23,600) 20,840 (2,760) End of Period $ (229,790) $ (28,863) $ (258,653) $ (229,790) $ (28,863) $ (258,653) THREE MONTHS ENDED JUNE 30, 2020 SIX MONTHS ENDED JUNE 30, 2020 FOREIGN CHANGE IN FAIR VALUE OF TOTAL FOREIGN CHANGE IN FAIR VALUE OF DERIVATIVE INSTRUMENTS TOTAL Beginning of Period $ (475,130) $ (18,118) $ (493,248) $ (252,825) $ (9,756) $ (262,581) Other comprehensive income (loss): Foreign currency translation and other adjustments 68,686 — 68,686 (153,619) — (153,619) Change in fair value of derivative instruments — (2,961) (2,961) — (11,323) (11,323) Total other comprehensive income (loss) 68,686 (2,961) 65,725 (153,619) (11,323) (164,942) End of Period $ (406,444) $ (21,079) $ (427,523) $ (406,444) $ (21,079) $ (427,523) I. 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 June 30, 2021 and December 31, 2020 are as follows: JUNE 30, 2021 DECEMBER 31, 2020 GROSS ACCUMULATED NET GROSS ACCUMULATED NET Intake Costs asset $ 70,263 $ (39,083) $ 31,180 $ 63,721 $ (33,352) $ 30,369 Commissions asset 104,184 (45,898) 58,286 91,069 (38,787) 52,282 Deferred revenue liabilities are reflected in our Condensed Consolidated Balance Sheets as follows: DESCRIPTION LOCATION IN BALANCE SHEET JUNE 30, 2021 DECEMBER 31, 2020 Deferred revenue - Current Deferred revenue $ 256,245 $ 295,785 Deferred revenue - Long-term Other Long-term Liabilities 34,502 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. Storage rental revenue, including revenue associated with power and connectivity, associated with our Global Data Center Business for the three and six months ended June 30, 2021 and 2020 are as follows: THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, 2021 2020 2021 2020 Storage rental revenue (1) $ 71,237 $ 63,812 $ 138,394 $ 128,407 (1) Revenue associated with power and connectivity included within storage rental revenue was $14,561 and $27,694 for the three and six months ended June 30, 2021, respectively, and $11,540 and $22,953 for the three and six months ended June 30, 2020, respectively. J. 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 and six months ended June 30, 2021 and 2020 is as follows: THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, 2021 2020 2021 2020 Stock-based compensation expense $ 22,699 $ 20,145 $ 33,652 $ 26,672 As of June 30, 2021, unrecognized compensation cost related to the unvested portion of our Employee Stock-Based Awards is $64,444. RESTRICTED STOCK UNITS AND PERFORMANCE UNITS The fair value of RSUs and earned PUs that vested during the three and six months ended June 30, 2021 and 2020 is as follows: THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, 2021 2020 2021 2020 Fair value of RSUs vested $ 3,118 $ 3,266 $ 22,979 $ 21,645 Fair value of earned PUs that vested 235 161 5,826 11,051 K. ACQUISITION AND INTEGRATION COSTS Acquisition and integration costs represent operating expenditures directly associated with the closing and integration activities of our business acquisitions that have closed, or are highly probable of closing, and include (i) advisory, legal and professional fees to complete business acquisitions and (ii) costs to integrate acquired businesses into our existing operations, including move, severance, facility upgrade and system integration costs (collectively, "Acquisition and Integration Costs"). Acquisition and Integration Costs do not include costs associated with the formation of joint ventures or costs associated with the acquisition of customer relationships. Total Acquisition and Integration Costs for the three and six months ended June 30, 2021 is $2,277. L. (GAIN) LOSS ON DISPOSAL/WRITE-DOWN OF PROPERTY, PLANT AND EQUIPMENT, NET Consolidated (gain) loss on disposal/write-down of property, plant and equipment, net for the three and six months ended June 30, 2021 and 2020 is as follows: THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, 2021 (1) 2020 2021 (1) 2020 (Gain) Loss on disposal/write-down of property, plant and equipment, net $ (128,935) $ (1,275) $ (133,386) $ (2,330) (1) The gains for the three and six months ended June 30, 2021 primarily consisted of gains of approximately $127,400 associated with the sale-leaseback transactions of five facilities in the United Kingdom, as part of our program to monetize a small portion of our industrial assets. The terms for these leases are consistent with the terms of our lease portfolio, which are disclosed in detail in Note 2.i. to Notes to Consolidated Financial Statements included in our Annual Report. M. OTHER (INCOME) EXPENSE, NET Consolidated other (income) expense, net for the three and six months ended June 30, 2021 and 2020 consists of the following: THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, DESCRIPTION 2021 2020 2021 2020 Foreign currency transaction losses (gains), net $ 4,729 $ 1,471 $ 7,043 $ (35,928) Debt extinguishment expense — 17,040 — 17,040 Other, net (1) (190,959) 7,189 (188,560) 1,862 Other (Income) Expense, Net $ (186,230) $ 25,700 $ (181,517) $ (17,026) N. 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 and six months ended June 30, 2021 and 2020 are as follows: THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, 2021 (1) 2020 (2) 2021 (1) 2020 (3) Effective Tax Rate 28.5 % — % 27.9 % 25.1 % (1) The primary reconciling items between the federal statutory tax rate of 21.0% and our overall effective tax rate for the three and six months ended June 30, 2021 were the impacts of differences in the tax rates at which our foreign earnings are subject and a discrete tax expense of approximately $12,000 primarily resulting from a tax law change in the United Kingdom, partially offset by the benefits derived from the dividends paid deduction. (2) For the three months ended June 30, 2020, we had a provision for income taxes of $9,683 and net income before provision for income taxes of $2,570; as such, our effective tax rate is not meaningful. (3) The primary reconciling items between the federal statutory tax rate of 21.0% and our overall effective tax rate for the six months ended June 30, 2020 were the impacts of differences in the tax rates at which our foreign earnings are subject, partially offset by the benefits derived from the dividends paid deduction. O. INCOME (LOSS) PER SHARE—BASIC AND DILUTED The calculation of basic and diluted income (loss) per share for the three and six months ended June 30, 2021 and 2020 are as follows: THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED 2021 2020 2021 2020 Net Income (Loss) $ 276,522 $ (7,113) $ 323,153 $ 57,779 Less: Net Income (Loss) Attributable to Noncontrolling Interests 1,237 (27) 2,265 890 Net Income (Loss) Attributable to Iron Mountain Incorporated (utilized in numerator of Earnings Per Share calculation) $ 275,285 $ (7,086) $ 320,888 $ 56,889 Weighted-average shares—basic 289,247,000 288,071,000 289,001,000 287,955,000 Effect of dilutive potential stock options 641,888 — 349,163 35,706 Effect of dilutive potential RSUs and PUs 1,190,357 — 953,104 309,911 Weighted-average shares—diluted 291,079,245 288,071,000 290,303,267 288,300,617 Net Income (Loss) Per Share Attributable to Iron Mountain Incorporated: Basic $ 0.95 $ (0.02) $ 1.11 $ 0.20 Diluted $ 0.95 $ (0.02) $ 1.11 $ 0.20 Antidilutive stock options, RSUs and PUs, excluded from the calculation 381,900 6,836,239 2,544,984 6,174,977 P. 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.

Acquisitions

Acquisitions	6 Months Ended
	Jun. 30, 2021
Business Combination and Asset Acquisition [Abstract]
Acquisitions	, in order to enhance our existing operations in the United Kingdom and Indonesia and to expand our operations into Morocco, we completed the acquisition of two records management companies and one art storage company for total cash consideration of approximately $45,000. PURCHASE PRICE ALLOCATION A summary of the cumulative consideration paid and the preliminary allocation of the purchase price paid for all of our 2021 acquisitions through June 30, 2021 is as follows: SIX MONTHS ENDED JUNE 30, 2021 Cash Paid (gross of cash acquired) $ 44,760 Fair Value of Noncontrolling Interest 2,567 Purchase Price Holdbacks and Other 199 Total Consideration 47,526 Fair Value of Identifiable Assets Acquired and Liabilities Assumed: Cash 9,037 Accounts Receivable, Prepaid Expenses and Other Assets 8,487 Property, Plant and Equipment (1) 8,375 Customer Relationship Intangible Assets (2) 19,010 Operating Lease Right-of-Use Assets 40,057 Debt Assumed (1,367) Accounts Payable, Accrued Expenses and Other Liabilities (6,507) Operating Lease Liabilities (40,057) Deferred Income Taxes (4,424) Total Fair Value of Identifiable Net Assets Acquired 32,611 Goodwill Initially Recorded $ 14,915 (1) Consists primarily of leasehold improvements, racking structures, warehouse equipment and computer hardware and software. (2) The preliminary weighted average lives of customer relationship intangible assets associated with acquisitions is 12 years. The preliminary purchase price allocations that are not finalized as of June 30, 2021 relate to the final assessment of the fair values of intangible assets (primarily customer relationship intangible assets), property, plant and equipment (primarily racking structures) and income taxes (primarily deferred taxes) associated with the acquisitions we closed in 2021. Any adjustments to our estimates of purchase price allocation will be made in the periods in which the adjustments are determined, but no later than the one year measurement period, and the cumulative effect of such adjustments will be calculated as if the adjustments had been completed as of the acquisition dates. Adjustments recorded during the six months ended June 30, 2021 were not material to our results from operations.

Divestments

Divestments	6 Months Ended
	Jun. 30, 2021
Text Block [Abstract]
Divestments	On June 7, 2021, we sold our Intellectual Property Management ("IPM") business, also known as our technology escrow services business, which we predominantly operated in the United States, for total gross consideration of approximately $217,200 (the “IPM Divestment”). As a result of the IPM Divestment, we recorded a gain on sale of approximately $181,200 to Other (income) expense, net, in the second quarter of 2021, representing the excess of the fair value of the consideration received over the sum of the carrying value of the IPM business. We have concluded that the IPM Divestment does not meet the criteria to be reported as discontinued operations in our consolidated financial statements, as our decision to divest this business does not represent a strategic shift that will have a major effect on our operations and financial results. Accordingly, the revenues and expenses associated with this business are presented as a component of operating income (loss) in our Condensed Consolidated Statements of Operations for the three and six months ended June 30, 2021 and 2020 through the closing date of the IPM Divestment and the cash flows associated with this business is presented as a component of cash flows from operations in our Condensed Consolidated Statements of Cash Flows for the six months ended June 30, 2021 and 2020 through the closing date of the IPM Divestment.

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activities	6 Months Ended
	Jun. 30, 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 June 30, 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 a hedge of net investment 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. (Liabilities) assets recognized in our Condensed Consolidated Balance Sheets at June 30, 2021 and December 31, 2020, by derivative instrument, are as follows: DERIVATIVE INSTRUMENTS (1) JUNE 30, 2021 DECEMBER 31, 2020 Cash Flow Hedges (2) Interest Rate Swap Agreements $ (15,066) $ (21,062) Net Investment Hedges (3) August 2023 Cross-Currency Swap Agreements (4,951) (8,229) February 2026 Cross-Currency Swap Agreements (8,846) (20,412) (1) Our derivative liabilities are included either as a component of (i) Accrued expenses and other current liabilities or (ii) Other long-term liabilities in our Condensed Consolidated Balance Sheets. As of June 30, 2021, $6,413 is included within Accrued expenses and other current liabilities and $22,450 is included within Other long-term liabilities. As of December 31, 2020, $49,703 is included within Other long-term liabilities. (2) As of June 30, 2021, cumulative net losses of $15,066 are recorded within Accumulated other comprehensive items, net associated with these interest rate swap agreements. (3) As of June 30, 2021, cumulative net losses of $13,797 are recorded within Accumulated other comprehensive items, net associated with these cross-currency swap agreements. Unrealized gains (losses) recognized during the three and six months ended June 30, 2021 and 2020, by derivative instrument, are as follows: THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, DERIVATIVE INSTRUMENTS (1) 2021 2020 2021 2020 Cash Flow Hedges Interest Rate Swap Agreements $ 1,795 $ (898) $ 5,996 $ (15,630) Net Investment Hedges August 2023 Cross-Currency Swap Agreements (1,473) (2,062) 3,278 4,308 February 2026 Cross-Currency Swap Agreements 5,312 — 11,566 — (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 and six months ended June 30, 2021 and 2020 are as follows: THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED 2021 (1) 2020 2021 (1) 2020 Foreign exchange gains (losses) associated with net investment hedge $ — $ (6,854) $ — $ (401) (1) As there are no hedges of net investment outstanding during the three and six months ended June 30, 2021, no foreign exchange gains (losses) associated with hedges of net investment have been recognized. As of June 30, 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	6 Months Ended
	Jun. 30, 2021
Debt Disclosure [Abstract]
Debt	Long-term debt is as follows: JUNE 30, 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) $ — $ (6,896) $ (6,896) $ — $ — $ (8,620) $ (8,620) $ — Term Loan A (1) 209,375 — 209,375 209,375 215,625 — 215,625 215,625 Term Loan B 676,234 (5,620) 670,614 677,250 679,621 (6,244) 673,377 680,750 Australian Dollar Term Loan (the “AUD Term Loan”) 233,754 (1,130) 232,624 234,353 243,152 (1,624) 241,528 244,014 UK Bilateral Revolving Credit Facility (the “UK Bilateral Facility”) 193,701 (939) 192,762 193,701 191,101 (1,307) 189,794 191,101 3 7 / 8 % GBP Senior Notes due 2025 (the “GBP Notes”) 553,430 (4,441) 548,989 559,656 546,003 (4,983) 541,020 553,101 4 7 / 8 % Senior Notes due 2027 (the “4 7 / 8 % Notes due 2027”) (2) 1,000,000 (8,887) 991,113 1,036,250 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 (7,971) 817,029 862,125 825,000 (8,561) 816,439 868,313 5% Senior Notes due 2028 (the “5% Notes”) (2) 500,000 (5,125) 494,875 518,750 500,000 (5,486) 494,514 523,125 4 7 / 8 % Senior Notes due 2029 (the “4 7 / 8 % Notes due 2029”) (2) 1,000,000 (11,934) 988,066 1,033,750 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 (13,664) 1,286,336 1,373,125 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 (12,026) 1,087,974 1,112,375 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 (6,437) 593,563 645,000 600,000 (6,727) 593,273 660,000 Real Estate Mortgages, Financing Lease Liabilities and Other 485,244 (954) 484,290 485,244 511,922 (1,086) 510,836 511,922 Accounts Receivable Securitization Program 276,800 (512) 276,288 276,800 85,000 (152) 84,848 85,000 Total Long-term Debt 8,953,538 (86,536) 8,867,002 8,797,424 (94,110) 8,703,314 Less Current Portion (106,274) — (106,274) (193,759) — (193,759) Long-term Debt, Net of Current Portion $ 8,847,264 $ (86,536) $ 8,760,728 $ 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. In addition, we also had various outstanding letters of credit totaling $3,238. The remaining amount available for borrowing under the Revolving Credit Facility as of June 30, 2021 was $1,746,762 (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 June 30, 2021 and December 31, 2020. (2) Collectively, the “Parent Notes”. 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 June 30, 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). UK BILATERAL REVOLVING CREDIT FACILITY On May 25, 2021, Iron Mountain (UK) PLC and Iron Mountain (UK) Data Centre Limited entered into an amendment to the UK Bilateral Facility with Barclays Bank PLC to (i) modify the interest rate from LIBOR plus 2.25% to LIBOR plus 2.0% (with flexibility built in for the expected transition away from LIBOR) and (ii) add an additional option to extend the maturity date by one year. The UK Bilateral Facility now contains two one MAXIMUM AMOUNT £140,000 OPTIONAL ADDITIONAL COMMITMENTS £125,000 INTEREST RATE 2.3% As of June 30, 2021 ACCOUNTS RECEIVABLE SECURITIZATION PROGRAM On June 28, 2021, we entered into an amendment to the Accounts Receivable Securitization Program to extend the maturity date from July 30, 2021 to July 1, 2023, at which point all obligations become due. The interest rate under the amended Accounts Receivable Securitization Program is LIBOR plus 1.0%. The full amount outstanding under the Accounts Receivable Securitization Program is classified within long-term debt, net of current portion at June 30, 2021 and within current portion of long-term debt at December 31, 2020 in our Condensed Consolidated Balance Sheets. There were no other changes to the terms of the Accounts Receivable Securitization Program described in Note 6 to Notes to Consolidated Financial Statements included in our Annual Report. OUTSTANDING BORROWINGS $276,800 INTEREST RATE 1.1% As of June 30, 2021 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 our cash pools and the approximate amount of the gross position and outstanding debit balances for each of these pools as of June 30, 2021 and December 31, 2020 are as follows: JUNE 30, 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 $ 441,100 $ (435,200) $ 5,900 $ 448,700 $ (447,400) $ 1,300 TRS Cash Pool 575,900 (570,900) 5,000 555,500 (553,500) 2,000 The net cash position balances as of June 30, 2021 and December 31, 2020 are reflected as cash and cash equivalents in our Condensed Consolidated Balance Sheets. LETTERS OF CREDIT As of June 30, 2021, we had outstanding letters of credit totaling $36,679, of which $3,238 reduce our borrowing capacity under the Revolving Credit Facility (as described above). The letters of credit expire at various dates between September 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 EBITDAR- and EBITDA-based leverage calculations include our consolidated subsidiaries, other than those we have designated as “Unrestricted Subsidiaries” as defined in the Credit Agreement and 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 June 30, 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	6 Months Ended
	Jun. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	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. We have estimated a reasonably possible range for all loss contingencies and believe it is reasonably possible that we could incur aggregate losses in addition to amounts currently accrued for all matters up to an additional $23,000 over the next several years, of which certain amounts would be covered by insurance or indemnity arrangements.

Stockholders' Equity Matters

Stockholders' Equity Matters	6 Months Ended
	Jun. 30, 2021
Equity [Abstract]
Stockholders' Equity Matters	STOCKHOLDERS' EQUITY MATTERS In fiscal year 2020 and the first six 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 May 6, 2021 0.6185 June 15, 2021 179,026 July 6, 2021 On August 5, 2021, we declared a dividend to our stockholders of record as of September 15, 2021 of $0.6185 per share, payable on October 6, 2021.

Segment Information

Segment Information	6 Months Ended
	Jun. 30, 2021
Segment Reporting [Abstract]
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 The operations associated with acquisitions completed during the first six months of 2021 have been incorporated into our existing reportable operating segments. An analysis of our business segment information and reconciliation to the accompanying Condensed Consolidated Financial Statements for the three and six months ended June 30, 2021 and 2020 is as follows: THREE MONTHS ENDED SIX MONTHS ENDED 2021 2020 2021 2020 Global RIM Business Total Revenues $ 992,932 $ 877,102 $ 1,960,226 $ 1,833,521 Adjusted EBITDA 430,308 383,816 838,870 775,787 Global Data Center Business Total Revenues $ 76,977 $ 66,768 $ 148,085 $ 134,125 Adjusted EBITDA 33,432 30,558 63,864 61,454 Corporate and Other Business Total Revenues $ 49,847 $ 38,369 $ 93,485 $ 83,324 Adjusted EBITDA (58,109) (54,912) (116,538) (111,780) Total Consolidated Total Revenues $ 1,119,756 $ 982,239 $ 2,201,796 $ 2,050,970 Adjusted EBITDA 405,631 359,462 786,196 725,461 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 • Acquisition and Integration Costs • Other (income) expense, net • Restructuring Charges • Stock-based compensation expense • Intangible impairments • COVID-19 Costs (as defined below) • (Gain) loss on disposal/write-down of property, plant and equipment, net (including real estate) 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 and six months ended June 30, 2021 and 2020 is as follows: THREE MONTHS ENDED SIX MONTHS ENDED 2021 2020 2021 2020 Net Income (Loss) $ 276,522 $ (7,113) $ 323,153 $ 57,779 Add/(Deduct): Interest expense, net 105,220 103,456 209,642 209,105 Provision (benefit) for income taxes 110,416 9,683 125,056 19,370 Depreciation and amortization 166,685 163,850 332,327 326,434 Acquisition and Integration Costs 2,277 — 2,277 — Restructuring Charges 39,443 39,298 79,254 80,344 Intangible impairments — — — 23,000 (Gain) loss on disposal/write-down of property, plant and equipment, net (including real estate) (128,935) (1,275) (133,386) (2,330) Other (income) expense, net, excluding our share of losses (gains) from our unconsolidated joint ventures (189,605) 23,239 (187,484) (21,792) Stock-based compensation expense (1) 22,536 18,880 33,269 23,991 COVID-19 Costs (2) — 9,285 — 9,285 Our share of Adjusted EBITDA reconciling items from our unconsolidated joint ventures 1,072 159 2,088 275 Adjusted EBITDA $ 405,631 $ 359,462 $ 786,196 $ 725,461 (1) Stock-based compensation expense related to Project Summit is included within Restructuring Charges for the three and six months ended June 30, 2021 and 2020. (2) 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. Information as to our revenues by product and service lines by segment for the three and six months ended June 30, 2021 and 2020 are as follows: THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, 2021 2020 2021 2020 Global RIM Business Records Management (1) $ 765,818 $ 678,969 $ 1,517,941 $ 1,406,585 Data Management (1) 118,239 119,259 236,653 245,157 Information Destruction (1)(2) 108,875 78,874 205,632 181,779 Data Center (1) — — — — Global Data Center Business Records Management (1) $ — $ — $ — $ — Data Management (1) — — — — Information Destruction (1)(2) — — — — Data Center (1) 76,977 66,768 148,085 134,125 Corporate and Other Business Records Management (1) $ 34,041 $ 21,079 $ 61,008 $ 49,955 Data Management (1) 15,806 17,290 32,477 33,369 Information Destruction (1)(2) — — — — Data Center (1) — — — — Total Consolidated Records Management (1) $ 799,859 $ 700,048 $ 1,578,949 $ 1,456,540 Data Management (1) 134,045 136,549 269,130 278,526 Information Destruction (1)(2) 108,875 78,874 205,632 181,779 Data Center (1) 76,977 66,768 148,085 134,125 (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	6 Months Ended
	Jun. 30, 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 Center Business segment. During the three and six months ended June 30, 2021, we recognized revenue of approximately $800 and $1,900, respectively, 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 $8,100 and $15,600 for the three and six months ended June 30, 2021, respectively, and $7,100 and $13,900 for the three and six months ended June 30, 2020, respectively, associated with the MakeSpace Agreement.

Project Summit

Project Summit	6 Months Ended
	Jun. 30, 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 June 30, 2021, we have completed approximately 95% 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 and six months ended June 30, 2021 and 2020, and from the inception of Project Summit through June 30, 2021, are as follows: THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, FROM THE INCEPTION 2021 2020 2021 2020 Employee severance costs $ 3,921 $ 11,542 $ 7,729 $ 17,650 $ 75,928 Professional fees and other costs 35,522 27,756 71,525 62,694 246,319 Restructuring Charges $ 39,443 $ 39,298 $ 79,254 $ 80,344 $ 322,247 Restructuring Charges by segment for the three and six months ended June 30, 2021 and 2020, and from the inception of Project Summit through June 30, 2021, are as follows: THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, FROM THE INCEPTION 2021 2020 2021 2020 Global RIM Business $ 7,942 $ 12,774 $ 16,166 $ 21,062 $ 105,206 Global Data Center Business 1,183 503 1,637 690 3,575 Corporate and Other Business 30,318 26,021 61,451 58,592 213,466 Restructuring Charges $ 39,443 $ 39,298 $ 79,254 $ 80,344 $ 322,247 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 June 30, 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 7,729 71,525 79,254 Payments (16,474) (69,380) (85,854) Other, including currency translation adjustments (384) — (384) Balance as of June 30, 2021 $ 7,149 $ 25,920 $ 33,069

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2021
Subsequent Events [Abstract]
Subsequent Events	[Placeholder]

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 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	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”).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 • Acquisition and Integration Costs • Other (income) expense, net • Restructuring Charges • Stock-based compensation expense • Intangible impairments • COVID-19 Costs (as defined below) • (Gain) loss on disposal/write-down of property, plant and equipment, net (including real estate) 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)	6 Months Ended
	Jun. 30, 2021
Accounting Policies [Abstract]
Schedule of allowance for credit loss	Rollforward of allowance for doubtful accounts and credit memo reserves for the six months ended June 30, 2021 is as follows: Balance as of December 31, 2020 $ 56,981 Credit memos charged to revenue 21,699 Allowance for bad debts charged to expense 13,442 Deductions and other (1) (35,145) Balance as of June 30, 2021 $ 56,977 (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 June 30, 2021 and December 31, 2020 are as follows: DESCRIPTION JUNE 30, 2021 DECEMBER 31, 2020 Assets: Operating lease right-of-use assets $ 2,342,197 $ 2,196,502 Financing lease right-of-use assets, net of accumulated depreciation (1) 297,052 310,534 Liabilities: Current Operating lease liabilities $ 263,784 $ 250,239 Financing lease liabilities (1) 43,728 43,149 Long-term Operating lease liabilities 2,186,625 2,044,598 Financing lease liabilities (1) 308,895 323,162 (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 and six months ended June 30, 2021 and 2020 are as follows: THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, DESCRIPTION 2021 2020 2021 2020 Operating lease cost (1) $ 135,086 $ 119,277 $ 267,761 $ 242,566 Financing lease cost: Depreciation of financing lease right-of-use assets $ 12,408 $ 12,567 $ 25,056 $ 25,522 Interest expense for financing lease liabilities 4,910 4,929 9,885 9,773 (1) Operating lease cost, the majority of which is included in Cost of sales, includes variable lease costs of $29,219 and $57,587 for the three and six months ended June 30, 2021, respectively, and $26,996 and $54,801 for the three and six months ended June 30, 2020, respectively. SIX MONTHS ENDED JUNE 30, CASH PAID FOR AMOUNTS INCLUDED IN MEASUREMENT OF LEASE LIABILITIES: 2021 2020 Operating cash flows used in operating leases $ 192,039 $ 178,011 Operating cash flows used in financing leases (interest) 9,885 9,773 Financing cash flows used in financing leases 23,656 23,953 NON-CASH ITEMS: Operating lease modifications and reassessments $ 63,047 $ 76,764 New operating leases (including acquisitions and sale-leaseback transactions) 210,881 123,860
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 six months ended June 30, 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 December 31, 2020 $ 4,024,182 $ 436,987 $ 96,440 $ 4,557,609 Non-tax deductible goodwill acquired during the period 6,108 — 8,807 14,915 Goodwill allocated to IPM Divestment (as defined and described in Note 4) — — (46,105) (46,105) Fair value and other adjustments (6,091) — (1,268) (7,359) Currency effects (5,598) (4,573) (135) (10,306) Goodwill balance, net accumulated amortization as of June 30, 2021 $ 4,018,601 $ 432,414 $ 57,739 $ 4,508,754 Accumulated goodwill impairment balance as of June 30, 2021 $ 132,409 $ — $ 26,011 $ 158,420
Schedule of equity method investments	The carrying values and equity interests in our joint ventures at June 30, 2021 and December 31, 2020 are as follows: JUNE 30, 2021 DECEMBER 31, 2020 CARRYING VALUE EQUITY INTEREST CARRYING VALUE EQUITY INTEREST Web Werks JV $ 50,135 38 % $ — — % Joint venture with AGC Equity Partners (the “Frankfurt JV”) 26,387 20 % 26,500 20 % Joint venture with MakeSpace Labs, Inc. (the “MakeSpace JV”) 24,069 45 % 16,924 39 %
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 June 30, 2021 and December 31, 2020 are as follows: FAIR VALUE MEASUREMENTS AT JUNE 30, 2021 USING DESCRIPTION TOTAL CARRYING QUOTED PRICES IN SIGNIFICANT OTHER SIGNIFICANT Money Market Funds $ 160,100 $ — $ 160,100 $ — Time Deposits 3,130 — 3,130 — Trading Securities 12,672 12,431 241 — Derivative Liabilities 28,863 — 28,863 — 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 and six months ended June 30, 2021 and 2020 are as follows: THREE MONTHS ENDED JUNE 30, 2021 SIX MONTHS ENDED JUNE 30, 2021 FOREIGN CHANGE IN FAIR VALUE OF TOTAL FOREIGN CHANGE IN FAIR VALUE OF DERIVATIVE INSTRUMENTS TOTAL Beginning of Period $ (272,414) $ (34,497) $ (306,911) $ (206,190) $ (49,703) $ (255,893) Other comprehensive income (loss): Foreign currency translation and other adjustments 42,624 — 42,624 (23,600) — (23,600) Change in fair value of derivative instruments — 5,634 5,634 — 20,840 20,840 Total other comprehensive income (loss) 42,624 5,634 48,258 (23,600) 20,840 (2,760) End of Period $ (229,790) $ (28,863) $ (258,653) $ (229,790) $ (28,863) $ (258,653) THREE MONTHS ENDED JUNE 30, 2020 SIX MONTHS ENDED JUNE 30, 2020 FOREIGN CHANGE IN FAIR VALUE OF TOTAL FOREIGN CHANGE IN FAIR VALUE OF DERIVATIVE INSTRUMENTS TOTAL Beginning of Period $ (475,130) $ (18,118) $ (493,248) $ (252,825) $ (9,756) $ (262,581) Other comprehensive income (loss): Foreign currency translation and other adjustments 68,686 — 68,686 (153,619) — (153,619) Change in fair value of derivative instruments — (2,961) (2,961) — (11,323) (11,323) Total other comprehensive income (loss) 68,686 (2,961) 65,725 (153,619) (11,323) (164,942) End of Period $ (406,444) $ (21,079) $ (427,523) $ (406,444) $ (21,079) $ (427,523)
Schedule of cost and accumulated amortization associated with contract fulfillment 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 June 30, 2021 and December 31, 2020 are as follows: JUNE 30, 2021 DECEMBER 31, 2020 GROSS ACCUMULATED NET GROSS ACCUMULATED NET Intake Costs asset $ 70,263 $ (39,083) $ 31,180 $ 63,721 $ (33,352) $ 30,369 Commissions asset 104,184 (45,898) 58,286 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 JUNE 30, 2021 DECEMBER 31, 2020 Deferred revenue - Current Deferred revenue $ 256,245 $ 295,785 Deferred revenue - Long-term Other Long-term Liabilities 34,502 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. Storage rental revenue, including revenue associated with power and connectivity, associated with our Global Data Center Business for the three and six months ended June 30, 2021 and 2020 are as follows: THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, 2021 2020 2021 2020 Storage rental revenue (1) $ 71,237 $ 63,812 $ 138,394 $ 128,407 (1) Revenue associated with power and connectivity included within storage rental revenue was $14,561 and $27,694 for the three and six months ended June 30, 2021, respectively, and $11,540 and $22,953 for the three and six months ended June 30, 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 and six months ended June 30, 2021 and 2020 is as follows: THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, 2021 2020 2021 2020 Stock-based compensation expense $ 22,699 $ 20,145 $ 33,652 $ 26,672
Schedule of vested and expected to vest	The fair value of RSUs and earned PUs that vested during the three and six months ended June 30, 2021 and 2020 is as follows: THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, 2021 2020 2021 2020 Fair value of RSUs vested $ 3,118 $ 3,266 $ 22,979 $ 21,645 Fair value of earned PUs that vested 235 161 5,826 11,051
Schedule of components of gain/loss on sale/disposal of property, plant and equipment	THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, 2021 (1) 2020 2021 (1) 2020 (Gain) Loss on disposal/write-down of property, plant and equipment, net $ (128,935) $ (1,275) $ (133,386) $ (2,330)
Schedule of other (income) expense, net	Consolidated other (income) expense, net for the three and six months ended June 30, 2021 and 2020 consists of the following: THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, DESCRIPTION 2021 2020 2021 2020 Foreign currency transaction losses (gains), net $ 4,729 $ 1,471 $ 7,043 $ (35,928) Debt extinguishment expense — 17,040 — 17,040 Other, net (1) (190,959) 7,189 (188,560) 1,862 Other (Income) Expense, Net $ (186,230) $ 25,700 $ (181,517) $ (17,026) (1) Other, net for the three and six months ended June 30, 2021 is primarily comprised of (a) a gain of approximately $181,200 associated with our IPM Divestment (as defined in Note 4) and (b) a gain of approximately $20,300 associated with the loss of control and related deconsolidation, as of May 18, 2021, of one of our wholly owned Netherlands subsidiaries, for which we had value-added tax liability exposure that was recorded in 2019.
Schedule of income taxes	Our effective tax rates for the three and six months ended June 30, 2021 and 2020 are as follows: THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, 2021 (1) 2020 (2) 2021 (1) 2020 (3) Effective Tax Rate 28.5 % — % 27.9 % 25.1 % (1) The primary reconciling items between the federal statutory tax rate of 21.0% and our overall effective tax rate for the three and six months ended June 30, 2021 were the impacts of differences in the tax rates at which our foreign earnings are subject and a discrete tax expense of approximately $12,000 primarily resulting from a tax law change in the United Kingdom, partially offset by the benefits derived from the dividends paid deduction. (2) For the three months ended June 30, 2020, we had a provision for income taxes of $9,683 and net income before provision for income taxes of $2,570; as such, our effective tax rate is not meaningful. (3) The primary reconciling items between the federal statutory tax rate of 21.0% and our overall effective tax rate for the six months ended June 30, 2020 were the impacts of differences in the tax rates at which our foreign earnings are subject, partially offset by the benefits derived from the dividends paid deduction.
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 and six months ended June 30, 2021 and 2020 are as follows: THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED 2021 2020 2021 2020 Net Income (Loss) $ 276,522 $ (7,113) $ 323,153 $ 57,779 Less: Net Income (Loss) Attributable to Noncontrolling Interests 1,237 (27) 2,265 890 Net Income (Loss) Attributable to Iron Mountain Incorporated (utilized in numerator of Earnings Per Share calculation) $ 275,285 $ (7,086) $ 320,888 $ 56,889 Weighted-average shares—basic 289,247,000 288,071,000 289,001,000 287,955,000 Effect of dilutive potential stock options 641,888 — 349,163 35,706 Effect of dilutive potential RSUs and PUs 1,190,357 — 953,104 309,911 Weighted-average shares—diluted 291,079,245 288,071,000 290,303,267 288,300,617 Net Income (Loss) Per Share Attributable to Iron Mountain Incorporated: Basic $ 0.95 $ (0.02) $ 1.11 $ 0.20 Diluted $ 0.95 $ (0.02) $ 1.11 $ 0.20 Antidilutive stock options, RSUs and PUs, excluded from the calculation 381,900 6,836,239 2,544,984 6,174,977

Acquisitions (Tables)

Acquisitions (Tables)	6 Months Ended
	Jun. 30, 2021
Business Combination and Asset Acquisition [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	A summary of the cumulative consideration paid and the preliminary allocation of the purchase price paid for all of our 2021 acquisitions through June 30, 2021 is as follows: SIX MONTHS ENDED JUNE 30, 2021 Cash Paid (gross of cash acquired) $ 44,760 Fair Value of Noncontrolling Interest 2,567 Purchase Price Holdbacks and Other 199 Total Consideration 47,526 Fair Value of Identifiable Assets Acquired and Liabilities Assumed: Cash 9,037 Accounts Receivable, Prepaid Expenses and Other Assets 8,487 Property, Plant and Equipment (1) 8,375 Customer Relationship Intangible Assets (2) 19,010 Operating Lease Right-of-Use Assets 40,057 Debt Assumed (1,367) Accounts Payable, Accrued Expenses and Other Liabilities (6,507) Operating Lease Liabilities (40,057) Deferred Income Taxes (4,424) Total Fair Value of Identifiable Net Assets Acquired 32,611 Goodwill Initially Recorded $ 14,915 (1) Consists primarily of leasehold improvements, racking structures, warehouse equipment and computer hardware and software. (2) The preliminary weighted average lives of customer relationship intangible assets associated with acquisitions is 12 years.

Derivative Instruments and He_2

Derivative Instruments and Hedging Activities (Tables)	6 Months Ended
	Jun. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments	(Liabilities) assets recognized in our Condensed Consolidated Balance Sheets at June 30, 2021 and December 31, 2020, by derivative instrument, are as follows: DERIVATIVE INSTRUMENTS (1) JUNE 30, 2021 DECEMBER 31, 2020 Cash Flow Hedges (2) Interest Rate Swap Agreements $ (15,066) $ (21,062) Net Investment Hedges (3) August 2023 Cross-Currency Swap Agreements (4,951) (8,229) February 2026 Cross-Currency Swap Agreements (8,846) (20,412) (1) Our derivative liabilities are included either as a component of (i) Accrued expenses and other current liabilities or (ii) Other long-term liabilities in our Condensed Consolidated Balance Sheets. As of June 30, 2021, $6,413 is included within Accrued expenses and other current liabilities and $22,450 is included within Other long-term liabilities. As of December 31, 2020, $49,703 is included within Other long-term liabilities. (2) As of June 30, 2021, cumulative net losses of $15,066 are recorded within Accumulated other comprehensive items, net associated with these interest rate swap agreements. (3) As of June 30, 2021, cumulative net losses of $13,797 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 and six months ended June 30, 2021 and 2020, by derivative instrument, are as follows: THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, DERIVATIVE INSTRUMENTS (1) 2021 2020 2021 2020 Cash Flow Hedges Interest Rate Swap Agreements $ 1,795 $ (898) $ 5,996 $ (15,630) Net Investment Hedges August 2023 Cross-Currency Swap Agreements (1,473) (2,062) 3,278 4,308 February 2026 Cross-Currency Swap Agreements 5,312 — 11,566 —
Schedule of Net Investment Hedges in AOCI	Foreign exchange gains (losses) associated with this hedge of net investment for the three and six months ended June 30, 2021 and 2020 are as follows: THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED 2021 (1) 2020 2021 (1) 2020 Foreign exchange gains (losses) associated with net investment hedge $ — $ (6,854) $ — $ (401) (1) As there are no hedges of net investment outstanding during the three and six months ended June 30, 2021, no foreign exchange gains (losses) associated with hedges of net investment have been recognized.

Debt (Tables)

Debt (Tables)	6 Months Ended
	Jun. 30, 2021
Debt Disclosure [Abstract]
Schedule of Carrying Amount and Fair Value of Long-Term Debt Instruments	Long-term debt is as follows: JUNE 30, 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) $ — $ (6,896) $ (6,896) $ — $ — $ (8,620) $ (8,620) $ — Term Loan A (1) 209,375 — 209,375 209,375 215,625 — 215,625 215,625 Term Loan B 676,234 (5,620) 670,614 677,250 679,621 (6,244) 673,377 680,750 Australian Dollar Term Loan (the “AUD Term Loan”) 233,754 (1,130) 232,624 234,353 243,152 (1,624) 241,528 244,014 UK Bilateral Revolving Credit Facility (the “UK Bilateral Facility”) 193,701 (939) 192,762 193,701 191,101 (1,307) 189,794 191,101 3 7 / 8 % GBP Senior Notes due 2025 (the “GBP Notes”) 553,430 (4,441) 548,989 559,656 546,003 (4,983) 541,020 553,101 4 7 / 8 % Senior Notes due 2027 (the “4 7 / 8 % Notes due 2027”) (2) 1,000,000 (8,887) 991,113 1,036,250 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 (7,971) 817,029 862,125 825,000 (8,561) 816,439 868,313 5% Senior Notes due 2028 (the “5% Notes”) (2) 500,000 (5,125) 494,875 518,750 500,000 (5,486) 494,514 523,125 4 7 / 8 % Senior Notes due 2029 (the “4 7 / 8 % Notes due 2029”) (2) 1,000,000 (11,934) 988,066 1,033,750 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 (13,664) 1,286,336 1,373,125 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 (12,026) 1,087,974 1,112,375 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 (6,437) 593,563 645,000 600,000 (6,727) 593,273 660,000 Real Estate Mortgages, Financing Lease Liabilities and Other 485,244 (954) 484,290 485,244 511,922 (1,086) 510,836 511,922 Accounts Receivable Securitization Program 276,800 (512) 276,288 276,800 85,000 (152) 84,848 85,000 Total Long-term Debt 8,953,538 (86,536) 8,867,002 8,797,424 (94,110) 8,703,314 Less Current Portion (106,274) — (106,274) (193,759) — (193,759) Long-term Debt, Net of Current Portion $ 8,847,264 $ (86,536) $ 8,760,728 $ 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. In addition, we also had various outstanding letters of credit totaling $3,238. The remaining amount available for borrowing under the Revolving Credit Facility as of June 30, 2021 was $1,746,762 (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 June 30, 2021 and December 31, 2020. (2) Collectively, the “Parent Notes”.
Schedule of Net Cash Position in Cash Pool Agreements	The approximate amount of the net cash position for our cash pools and the approximate amount of the gross position and outstanding debit balances for each of these pools as of June 30, 2021 and December 31, 2020 are as follows: JUNE 30, 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 $ 441,100 $ (435,200) $ 5,900 $ 448,700 $ (447,400) $ 1,300 TRS Cash Pool 575,900 (570,900) 5,000 555,500 (553,500) 2,000

Stockholders' Equity Matters (T

Stockholders' Equity Matters (Tables)	6 Months Ended
	Jun. 30, 2021
Equity [Abstract]
Schedule of dividend declared and payments	In fiscal year 2020 and the first six 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 May 6, 2021 0.6185 June 15, 2021 179,026 July 6, 2021

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
	Jun. 30, 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 for the three and six months ended June 30, 2021 and 2020 is as follows: THREE MONTHS ENDED SIX MONTHS ENDED 2021 2020 2021 2020 Global RIM Business Total Revenues $ 992,932 $ 877,102 $ 1,960,226 $ 1,833,521 Adjusted EBITDA 430,308 383,816 838,870 775,787 Global Data Center Business Total Revenues $ 76,977 $ 66,768 $ 148,085 $ 134,125 Adjusted EBITDA 33,432 30,558 63,864 61,454 Corporate and Other Business Total Revenues $ 49,847 $ 38,369 $ 93,485 $ 83,324 Adjusted EBITDA (58,109) (54,912) (116,538) (111,780) Total Consolidated Total Revenues $ 1,119,756 $ 982,239 $ 2,201,796 $ 2,050,970 Adjusted EBITDA 405,631 359,462 786,196 725,461
Schedule of reconciliation of net income	A reconciliation of Net Income (Loss) to Adjusted EBITDA on a consolidated basis for the three and six months ended June 30, 2021 and 2020 is as follows: THREE MONTHS ENDED SIX MONTHS ENDED 2021 2020 2021 2020 Net Income (Loss) $ 276,522 $ (7,113) $ 323,153 $ 57,779 Add/(Deduct): Interest expense, net 105,220 103,456 209,642 209,105 Provision (benefit) for income taxes 110,416 9,683 125,056 19,370 Depreciation and amortization 166,685 163,850 332,327 326,434 Acquisition and Integration Costs 2,277 — 2,277 — Restructuring Charges 39,443 39,298 79,254 80,344 Intangible impairments — — — 23,000 (Gain) loss on disposal/write-down of property, plant and equipment, net (including real estate) (128,935) (1,275) (133,386) (2,330) Other (income) expense, net, excluding our share of losses (gains) from our unconsolidated joint ventures (189,605) 23,239 (187,484) (21,792) Stock-based compensation expense (1) 22,536 18,880 33,269 23,991 COVID-19 Costs (2) — 9,285 — 9,285 Our share of Adjusted EBITDA reconciling items from our unconsolidated joint ventures 1,072 159 2,088 275 Adjusted EBITDA $ 405,631 $ 359,462 $ 786,196 $ 725,461 (1) Stock-based compensation expense related to Project Summit is included within Restructuring Charges for the three and six months ended June 30, 2021 and 2020. (2) 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.
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 and six months ended June 30, 2021 and 2020 are as follows: THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, 2021 2020 2021 2020 Global RIM Business Records Management (1) $ 765,818 $ 678,969 $ 1,517,941 $ 1,406,585 Data Management (1) 118,239 119,259 236,653 245,157 Information Destruction (1)(2) 108,875 78,874 205,632 181,779 Data Center (1) — — — — Global Data Center Business Records Management (1) $ — $ — $ — $ — Data Management (1) — — — — Information Destruction (1)(2) — — — — Data Center (1) 76,977 66,768 148,085 134,125 Corporate and Other Business Records Management (1) $ 34,041 $ 21,079 $ 61,008 $ 49,955 Data Management (1) 15,806 17,290 32,477 33,369 Information Destruction (1)(2) — — — — Data Center (1) — — — — Total Consolidated Records Management (1) $ 799,859 $ 700,048 $ 1,578,949 $ 1,456,540 Data Management (1) 134,045 136,549 269,130 278,526 Information Destruction (1)(2) 108,875 78,874 205,632 181,779 Data Center (1) 76,977 66,768 148,085 134,125 (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)	6 Months Ended
	Jun. 30, 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 and six months ended June 30, 2021 and 2020, and from the inception of Project Summit through June 30, 2021, are as follows: THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, FROM THE INCEPTION 2021 2020 2021 2020 Employee severance costs $ 3,921 $ 11,542 $ 7,729 $ 17,650 $ 75,928 Professional fees and other costs 35,522 27,756 71,525 62,694 246,319 Restructuring Charges $ 39,443 $ 39,298 $ 79,254 $ 80,344 $ 322,247 Restructuring Charges by segment for the three and six months ended June 30, 2021 and 2020, and from the inception of Project Summit through June 30, 2021, are as follows: THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, FROM THE INCEPTION 2021 2020 2021 2020 Global RIM Business $ 7,942 $ 12,774 $ 16,166 $ 21,062 $ 105,206 Global Data Center Business 1,183 503 1,637 690 3,575 Corporate and Other Business 30,318 26,021 61,451 58,592 213,466 Restructuring Charges $ 39,443 $ 39,298 $ 79,254 $ 80,344 $ 322,247 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 June 30, 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 7,729 71,525 79,254 Payments (16,474) (69,380) (85,854) Other, including currency translation adjustments (384) — (384) Balance as of June 30, 2021 $ 7,149 $ 25,920 $ 33,069

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Allowance for Doubtful Accounts and Credit Memo Reserves (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2021USD ($)
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance as of December 31, 2020	$ 56,981
Credit memos charged to revenue	21,699
Allowance for bad debts charged to expense	13,442
Deductions and other	(35,145)
Balance as of June 30, 2021	$ 56,977

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Supplemental Balance Sheet (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Operating lease right-of-use assets	$ 2,342,197	$ 2,196,502
Financing lease right-of-use assets, net of accumulated depreciation	297,052	310,534
Current
Operating lease liabilities	263,784	250,239
Finance lease liabilities	43,728	43,149
Long-term
Operating lease liabilities	2,186,625	2,044,598
Finance lease liabilities	$ 308,895	$ 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		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Accounting Policies [Abstract]
Operating lease cost	$ 135,086	$ 119,277	$ 267,761	$ 242,566
Depreciation of financing lease right-of-use assets	12,408	12,567	25,056	25,522
Interest expense for financing lease liabilities	4,910	4,929	9,885	9,773
Variable lease costs	$ 29,219	$ 26,996	$ 57,587	$ 54,801

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Supplemental Cash Flows (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Accounting Policies [Abstract]
Operating cash flows used in operating leases	$ 192,039	$ 178,011
Operating cash flows used in financing leases (interest)	9,885	9,773
Financing cash flows used in financing leases	23,656	23,953
Operating lease modifications and reassessments	63,047	76,764
New operating leases (including acquisitions and sale-leaseback transactions)	$ 210,881	$ 123,860

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Schedule of Changes in Carrying Value of Goodwill (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2021USD ($)
Gross amount of goodwill [Roll Forward]
Goodwill beginning balance	$ 4,557,609
Non-tax deductible goodwill acquired during the period	14,915
Goodwill allocated to IPM Divestment (as defined and described in Note 4)	(46,105)
Fair value and other adjustments	(7,359)
Currency effects	(10,306)
Goodwill ending balance	4,508,754
Accumulated goodwill impairment	158,420
GLOBAL RIM BUSINESS
Gross amount of goodwill [Roll Forward]
Goodwill beginning balance	4,024,182
Non-tax deductible goodwill acquired during the period	6,108
Goodwill allocated to IPM Divestment (as defined and described in Note 4)	0
Fair value and other adjustments	(6,091)
Currency effects	(5,598)
Goodwill ending balance	4,018,601
Accumulated goodwill impairment	132,409
GLOBAL DATA CENTER BUSINESS
Gross amount of goodwill [Roll Forward]
Goodwill beginning balance	436,987
Non-tax deductible goodwill acquired during the period	0
Goodwill allocated to IPM Divestment (as defined and described in Note 4)	0
Fair value and other adjustments	0
Currency effects	(4,573)
Goodwill ending balance	432,414
Accumulated goodwill impairment	0
CORPORATE AND OTHER BUSINESS
Gross amount of goodwill [Roll Forward]
Goodwill beginning balance	96,440
Non-tax deductible goodwill acquired during the period	8,807
Goodwill allocated to IPM Divestment (as defined and described in Note 4)	(46,105)
Fair value and other adjustments	(1,268)
Currency effects	(135)
Goodwill ending balance	57,739
Accumulated goodwill impairment	$ 26,011

Summary of Significant Accoun_9

Summary of Significant Accounting Policies - Investments Narrative (Details) ₨ in Thousands, $ in Thousands	Jun. 30, 2021USD ($)	Apr. 30, 2021INR (₨)	Apr. 30, 2021USD ($)	Dec. 31, 2020USD ($)
Web Werks JV
Schedule of Equity Method Investments [Line Items]
Equity method investments, fair value disclosure		₨ 3,750,000	$ 50,100
Additional equity method investments, fair value disclosure		₨ 7,500,000	$ 100
Equity investments	$ 50,135			$ 0
Ownership percentage	38.00%			0.00%
Frankfurt JV
Schedule of Equity Method Investments [Line Items]
Equity investments	$ 26,387			$ 26,500
Ownership percentage	20.00%			20.00%
MakeSpace JV
Schedule of Equity Method Investments [Line Items]
Equity investments	$ 24,069			$ 16,924
Ownership percentage	45.00%			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	Jun. 30, 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	$ 12,431	$ 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	241	256
Derivative Liabilities	28,863	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	12,672	10,892
Derivative Liabilities	28,863	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	160,100	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	160,100	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	3,130	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	$ 3,130	$ 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		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
AOCI Rollforward
Beginning of Period	$ 959,707	$ 1,123,841	$ 1,136,729	$ 1,464,227
Other comprehensive income (loss):
Foreign currency translation and other adjustments	42,624	68,686	(23,600)	(153,619)
Change in fair value of derivative instruments	5,634	(2,961)	20,840	(11,323)
Total other comprehensive income (loss)	48,258	65,725	(2,760)	(164,942)
End of period	1,147,742	1,024,331	1,147,742	1,024,331
FOREIGN CURRENCY TRANSLATION AND OTHER ADJUSTMENTS
AOCI Rollforward
Beginning of Period	(272,414)	(475,130)	(206,190)	(252,825)
Other comprehensive income (loss):
Foreign currency translation and other adjustments	42,624	68,686	(23,600)	(153,619)
Change in fair value of derivative instruments	0	0	0	0
Total other comprehensive income (loss)	42,624	68,686	(23,600)	(153,619)
End of period	(229,790)	(406,444)	(229,790)	(406,444)
CHANGE IN FAIR VALUE OF DERIVATIVE INSTRUMENTS
AOCI Rollforward
Beginning of Period	(34,497)	(18,118)	(49,703)	(9,756)
Other comprehensive income (loss):
Foreign currency translation and other adjustments	0	0	0	0
Change in fair value of derivative instruments	5,634	(2,961)	20,840	(11,323)
Total other comprehensive income (loss)	5,634	(2,961)	20,840	(11,323)
End of period	(28,863)	(21,079)	(28,863)	(21,079)
TOTAL
AOCI Rollforward
Beginning of Period	(306,911)	(493,248)	(255,893)	(262,581)
Other comprehensive income (loss):
End of period	$ (258,653)	$ (427,523)	$ (258,653)	$ (427,523)

Summary of Significant Accou_12

Summary of Significant Accounting Policies - Contract Fulfillment Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Intake Costs
Contract With Customer, Asset And Liabilities [Line Items]
GROSS CARRYING AMOUNT	$ 70,263	$ 63,721
ACCUMULATED AMORTIZATION	(39,083)	(33,352)
NET CARRYING AMOUNT	31,180	30,369
Commissions
Contract With Customer, Asset And Liabilities [Line Items]
GROSS CARRYING AMOUNT	104,184	91,069
ACCUMULATED AMORTIZATION	(45,898)	(38,787)
NET CARRYING AMOUNT	$ 58,286	$ 52,282

Summary of Significant Accou_13

Summary of Significant Accounting Policies - Summary of Deferred Revenue Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Deferred revenue - Current	$ 256,245	$ 295,785
Deferred revenue - Long-term	$ 34,502	$ 35,612

Summary of Significant Accou_14

Summary of Significant Accounting Policies - Storage Rental (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Lessor, Lease, Description [Line Items]
Storage rental	$ 718,272	$ 676,956	$ 1,426,328	$ 1,360,503
GLOBAL DATA CENTER BUSINESS
Lessor, Lease, Description [Line Items]
Storage rental	71,237	63,812	138,394	128,407
Storage Rental, Power and Connectivity | GLOBAL DATA CENTER BUSINESS
Lessor, Lease, Description [Line Items]
Storage rental	$ 14,561	$ 11,540	$ 27,694	$ 22,953

Summary of Significant Accou_15

Summary of Significant Accounting Policies - Stock-Based Compensation Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 22,699	$ 20,145	$ 33,652	$ 26,672
Unrecognized compensation cost	$ 64,444		$ 64,444
Two Thousand Twenty One
Performance Units Disclosure
Percentage of achievement of the predefined revenue and ROIC targets	133.00%		133.00%
Two Thousand Twenty
Performance Units Disclosure
Percentage of achievement of the predefined revenue and ROIC targets	114.00%		114.00%
Two Thousand Nineteen
Performance Units Disclosure
Percentage of achievement of the predefined revenue and ROIC targets	103.00%		103.00%
Restricted Stock Units
Summary of Option Activity
Total fair value of shares or units vested	$ 3,118	3,266	$ 22,979	21,645
Performance units
Summary of Option Activity
Total fair value of shares or units vested	$ 235	$ 161	$ 5,826	$ 11,051

Summary of Significant Accou_16

Summary of Significant Accounting Policies - Acquisition and Integration costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Accounting Policies [Abstract]
Acquisition and Integration Costs	$ 2,277	$ 0	$ 2,277	$ 0

Summary of Significant Accou_17

Summary of Significant Accounting Policies - (Gain) Loss on Disposal/Write-Down of Property, Plant and Equipment, Net (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
(Gain) loss on disposal/write-down of property, plant and equipment, net	$ (128,935,000)	$ (1,275,000)	$ (133,386,000)	$ (2,330,000)
Facilities In The United Kingdom
Accumulated Other Comprehensive Income (Loss) [Line Items]
Sale and sale-leaseback transactions	$ 127,400,000		$ 127,400,000
Number Of Sale Lease back Properties			5

Summary of Significant Accou_18

Summary of Significant Accounting Policies - Other Expense (Income), Net (Details) - USD ($) $ in Thousands	May 18, 2021	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Accounting Policies [Abstract]
Foreign currency transaction losses (gains), net		$ 4,729	$ 1,471	$ 7,043	$ (35,928)
Debt extinguishment expense		0	17,040	0	17,040
Other, net		(190,959)	7,189	(188,560)	1,862
Other (Income) Expense, Net		(186,230)	$ 25,700	(181,517)	(17,026)
Gain on divestment	$ 20,300	$ 181,200		$ 181,196	$ 0

Summary of Significant Accou_19

Summary of Significant Accounting Policies - Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Accounting Policies [Abstract]
Effective Tax Rate	28.50%	0.00%	27.90%	25.10%
Expense related to change in enacted tax law	$ 12,000		$ 12,000
Provision (benefit) for income taxes	110,416	$ 9,683	125,056	$ 19,370
Net income before provision for income taxes	$ 386,938	$ 2,570	$ 448,209	$ 77,149

Summary of Significant Accou_20

Summary of Significant Accounting Policies - Income (Loss) Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income (Loss) Per Share-Basic and Diluted
Net Income (Loss)	$ 276,522	$ (7,113)	$ 323,153	$ 57,779
Less: Net Income (Loss) Attributable to Noncontrolling Interests	1,237	(27)	2,265	890
Net Income (Loss) Attributable to Iron Mountain Incorporated	$ 275,285	$ (7,086)	$ 320,888	$ 56,889
Weighted-average shares—basic (in shares)	289,247,000	288,071,000	289,001,000	287,955,000
Effect of dilutive potential stock options (in shares)	641,888	0	349,163	35,706
Effect of dilutive potential restricted stock, RSUs and PUs (in shares)	1,190,357	0	953,104	309,911
Weighted-average shares—diluted (in shares)	291,079,245	288,071,000	290,303,267	288,300,617
Income (Loss) from Continuing Operations, Basic (in dollars per share)	$ 0.95	$ (0.02)	$ 1.11	$ 0.20
Income (Loss) from Continuing Operations, Diluted (in dollars per share)	$ 0.95	$ (0.02)	$ 1.11	$ 0.20
Antidilutive stock options, RSUs and PUs, excluded from the calculation (in shares)	381,900	6,836,239	2,544,984	6,174,977

Acquisitions - Additional Infor

Acquisitions - Additional Information (Details) $ in Thousands	3 Months Ended
	Jun. 30, 2021USD ($)company
Business Acquisition [Line Items]
Cash consideration | $	$ 45,000
Records Management Company
Business Acquisition [Line Items]
Number of businesses acquired	2
Art Storage Company
Business Acquisition [Line Items]
Number of businesses acquired	1

Acquisitions - Schedule of Purc

Acquisitions - Schedule of Purchase Price Allocation (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2021	Dec. 31, 2020
Business Acquisition [Line Items]
Cash Paid (gross of cash acquired)	$ 45,000
Fair Value of Identifiable Assets Acquired and Liabilities Assumed:
Operating Lease Right-of-Use Assets	2,342,197	$ 2,342,197	$ 2,196,502
Operating Lease Liabilities	(2,186,625)	(2,186,625)	(2,044,598)
Goodwill Initially Recorded	4,508,754	$ 4,508,754	$ 4,557,609
Customer Relationships
Fair Value of Identifiable Assets Acquired and Liabilities Assumed:
Acquired finite-lived intangible assets, weighted average useful life		12 years
2020 Acquisitions
Business Acquisition [Line Items]
Cash Paid (gross of cash acquired)		$ 44,760
Fair Value of Noncontrolling Interest	2,567	2,567
Purchase Price Holdbacks and Other		199
Total Consideration		47,526
Fair Value of Identifiable Assets Acquired and Liabilities Assumed:
Cash	9,037	9,037
Accounts Receivable, Prepaid Expenses and Other Assets	8,487	8,487
Property, Plant and Equipment	8,375	8,375
Customer Relationship Intangible Assets	19,010	19,010
Operating Lease Right-of-Use Assets	40,057	40,057
Debt Assumed	(1,367)	(1,367)
Accounts Payable, Accrued Expenses and Other Liabilities	(6,507)	(6,507)
Operating Lease Liabilities	(40,057)	(40,057)
Deferred Income Taxes	(4,424)	(4,424)
Total Fair Value of Identifiable Net Assets Acquired	32,611	32,611
Goodwill Initially Recorded	$ 14,915	$ 14,915

Divestments (Details)

Divestments (Details) - USD ($) $ in Thousands	May 18, 2021	Jun. 30, 2021	Jun. 30, 2021	Jun. 30, 2020	Jun. 07, 2021
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on IPM Divestment	$ 20,300	$ 181,200	$ 181,196	$ 0
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Iron Mountain Intellectual Property Divestiture
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total gross consideration					$ 217,200
Gain on IPM Divestment		$ 181,200

Derivative Instruments and He_3

Derivative Instruments and Hedging Activities - Additional Information (Details) € in Thousands	Jun. 30, 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	$ (13,797,000)
Net Investment Hedges | Designated as Hedging Instrument | Euro Notes
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged notes | €					€ 300,000
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		$ 110,000,000	€ 99,055
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		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Accrued Expenses And Other Current Liabilities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative liabilities	$ (6,413)		$ (6,413)
Other Long-Term Liabilities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative liabilities	(22,450)		(22,450)		$ (49,703)
Net Investment Hedges
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cumulative net losses in cross-currency swaps	13,797		13,797
Interest Rate Swap Agreements
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cumulative net losses in AOCI	15,066		15,066
Interest Rate Swap Agreements | Cash Flow Hedging
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative liabilities	(15,066)		(15,066)		(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	1,795	$ (898)	5,996	$ (15,630)
August 2023 Cross Currency Swap Agreements | Net Investment Hedges
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative liabilities	(4,951)		(4,951)		(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	(1,473)	(2,062)	3,278	4,308
February 2026 Cross Currency Swap Agreements | Net Investment Hedges
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative liabilities	(8,846)		(8,846)		$ (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	$ 5,312	$ 0	$ 11,566	$ 0

Derivative Instruments and He_5

Derivative Instruments and Hedging Activities - Hedge of Net Investment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Foreign exchange gains (losses) associated with net investment hedge	$ 0	$ (6,854)	$ 0	$ (401)

Debt - Schedule of Long Term De

Debt - Schedule of Long Term Debt (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020
Debt Instrument [Line Items]
DEBT (INCLUSIVE OF DISCOUNT)	$ 8,953,538	$ 8,797,424
UNAMORTIZED DEFERRED FINANCING COSTS	(86,536)	(94,110)
CARRYING AMOUNT	8,867,002	8,703,314
Long-term debt, gross, current maturities	(106,274)	(193,759)
Long term debt, gross, net of current portion	8,847,264	8,603,665
Unamortized debt issuance expense, net of current portion	0	0
Unamortized debt issuance expense, net	(86,536)	(94,110)
Carrying amount, current maturities	(106,274)	(193,759)
Carrying amount, excluding current maturities	8,760,728	8,509,555
Australian Dollar Term Loan (the AUD Term Loan)
Debt Instrument [Line Items]
DEBT (INCLUSIVE OF DISCOUNT)	233,754	243,152
UNAMORTIZED DEFERRED FINANCING COSTS	(1,130)	(1,624)
CARRYING AMOUNT	232,624	241,528
FAIR VALUE	234,353	244,014
Real Estate Mortgages, Financing Lease Liabilities and Other
Debt Instrument [Line Items]
DEBT (INCLUSIVE OF DISCOUNT)	485,244	511,922
UNAMORTIZED DEFERRED FINANCING COSTS	(954)	(1,086)
CARRYING AMOUNT	484,290	510,836
FAIR VALUE	485,244	511,922
Accounts Receivable Securitization Program
Debt Instrument [Line Items]
DEBT (INCLUSIVE OF DISCOUNT)	276,800	85,000
UNAMORTIZED DEFERRED FINANCING COSTS	(512)	(152)
CARRYING AMOUNT	276,288	84,848
FAIR VALUE	276,800	$ 85,000
Credit Agreement
Debt Instrument [Line Items]
Letters of credit outstanding	36,679
Revolving Credit Facility | Credit Agreement
Debt Instrument [Line Items]
Letters of credit outstanding	3,238
Remaining capacity	1,746,762
Weighted average interest rate		1.90%	1.90%
New Credit Agreement | Revolving Credit Facility
Debt Instrument [Line Items]
DEBT (INCLUSIVE OF DISCOUNT)	0	$ 0
UNAMORTIZED DEFERRED FINANCING COSTS	(6,896)	(8,620)
CARRYING AMOUNT	(6,896)	(8,620)
FAIR VALUE	0	0
Term Loan A | Term Loan Facility
Debt Instrument [Line Items]
DEBT (INCLUSIVE OF DISCOUNT)	209,375	215,625
UNAMORTIZED DEFERRED FINANCING COSTS	0	0
CARRYING AMOUNT	209,375	215,625
FAIR VALUE	209,375	215,625
Term Loan B | Term Loan Facility
Debt Instrument [Line Items]
DEBT (INCLUSIVE OF DISCOUNT)	676,234	679,621
UNAMORTIZED DEFERRED FINANCING COSTS	(5,620)	(6,244)
CARRYING AMOUNT	670,614	673,377
FAIR VALUE	677,250	680,750
UK Bilateral Revolving Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
DEBT (INCLUSIVE OF DISCOUNT)	193,701	191,101
UNAMORTIZED DEFERRED FINANCING COSTS	(939)	(1,307)
CARRYING AMOUNT	192,762	189,794
FAIR VALUE	$ 193,701	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)	$ 553,430	546,003
UNAMORTIZED DEFERRED FINANCING COSTS	(4,441)	(4,983)
CARRYING AMOUNT	548,989	541,020
FAIR VALUE	$ 559,656	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	(8,887)	(9,598)
CARRYING AMOUNT	991,113	990,402
FAIR VALUE	$ 1,036,250	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	(7,971)	(8,561)
CARRYING AMOUNT	817,029	816,439
FAIR VALUE	$ 862,125	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	(5,125)	(5,486)
CARRYING AMOUNT	494,875	494,514
FAIR VALUE	$ 518,750	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	(11,934)	(12,658)
CARRYING AMOUNT	988,066	987,342
FAIR VALUE	$ 1,033,750	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	(13,664)	(14,416)
CARRYING AMOUNT	1,286,336	1,285,584
FAIR VALUE	$ 1,373,125	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	(12,026)	(12,648)
CARRYING AMOUNT	1,087,974	1,087,352
FAIR VALUE	$ 1,112,375	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	(6,437)	(6,727)
CARRYING AMOUNT	593,563	593,273
FAIR VALUE	$ 645,000	$ 660,000

Debt - UK Bilateral Revolving C

Debt - UK Bilateral Revolving Credit Facility (Details) - Revolving Credit Facility - UK Bilateral Revolving Credit Facility £ in Thousands	May 25, 2021extension	May 24, 2021	Jun. 30, 2021GBP (£)
Debt Instrument [Line Items]
Period of extension	1 year
Number of extensions | extension	2
Maximum borrowing capacity			£ 140,000
Additional borrowing capacity			£ 125,000
Interest rate at period end			2.30%
London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	2.00%	2.25%

Debt - Accounts Receivable Secu

Debt - Accounts Receivable Securitization Program (Details) - USD ($) $ in Thousands	Jun. 28, 2021	Jun. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Outstanding borrowings		$ 8,867,002	$ 8,703,314
Effective interest rate (as a percent)		1.10%
Accounts Receivable Securitization Program
Debt Instrument [Line Items]
Outstanding borrowings		$ 276,800
Accounts Receivable Securitization Program | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	1.00%

Debt - Cash Pool (Details)

Debt - Cash Pool (Details) $ in Thousands	Jun. 30, 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	$ 441,100	$ 448,700
OUTSTANDING DEBIT BALANCES	(435,200)	(447,400)
NET CASH POSITION	$ 5,900	1,300
TRS Cash Pool
Debt Instrument [Line Items]
Number of cash pools | cash_pool	1
GROSS CASH POSITION	$ 575,900	555,500
OUTSTANDING DEBIT BALANCES	(570,900)	(553,500)
NET CASH POSITION	$ 5,000	$ 2,000

Debt - Letters of Credit (Detai

Debt - Letters of Credit (Details) - Credit Agreement $ in Thousands	Jun. 30, 2021USD ($)
Debt Instrument [Line Items]
Letters of credit outstanding	$ 36,679
Revolving Credit Facility
Debt Instrument [Line Items]
Letters of credit outstanding	$ 3,238

Commitments and Contingencies -

Commitments and Contingencies - (Details) $ in Thousands	Jun. 30, 2021USD ($)
Insurance settlement
Commitments and Contingencies
Reasonably possible additional losses	$ 23,000

Stockholders' Equity Matters -

Stockholders' Equity Matters - Dividends Declared (Details) - USD ($) $ / shares in Units, $ in Thousands	Jun. 15, 2021	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	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Aug. 05, 2021
Equity [Abstract]
DIVIDEND PER SHARE (in dollars per share)		$ 0.6185		$ 0.6185		$ 0.6185		$ 0.6185		$ 0.6185		$ 0.6185
TOTAL AMOUNT	$ 179,026		$ 178,569		$ 178,290		$ 178,224		$ 178,212		$ 178,047		$ 180,760	$ 179,342	$ 359,445	$ 358,854
Subsequent Event
Dividends Payable [Line Items]
Dividends declared (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		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting Information [Line Items]
Total Revenues	$ 1,119,756	$ 982,239	$ 2,201,796	$ 2,050,970
Adjusted EBITDA	405,631	359,462	786,196	725,461
GLOBAL RIM BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	992,932	877,102	1,960,226	1,833,521
Adjusted EBITDA	430,308	383,816	838,870	775,787
GLOBAL DATA CENTER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	76,977	66,768	148,085	134,125
Adjusted EBITDA	33,432	30,558	63,864	61,454
CORPORATE AND OTHER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	49,847	38,369	93,485	83,324
Adjusted EBITDA	$ (58,109)	$ (54,912)	$ (116,538)	$ (111,780)

Segment Information - Reconcili

Segment Information - Reconciliation to Income from Continuing Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		21 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021
Reconciliation of Adjusted EBITDA to income from continuing operations
Net Income (Loss)	$ 276,522	$ (7,113)	$ 323,153	$ 57,779
Interest expense, net	105,220	103,456	209,642	209,105
Provision (benefit) for income taxes	110,416	9,683	125,056	19,370
Depreciation and amortization	166,685	163,850	332,327	326,434
Acquisition and Integration Costs	2,277	0	2,277	0
Restructuring Charges	39,443	39,298	79,254	80,344	$ 322,247
Intangible impairments	0	0	0	23,000
(Gain) loss on disposal/write-down of property, plant and equipment, net (including real estate)	(128,935)	(1,275)	(133,386)	(2,330)
Other (income) expense, net, excluding our share of losses (gains) from our unconsolidated joint ventures	(189,605)	23,239	(187,484)	(21,792)
Stock-based compensation expense(1)	22,536	18,880	33,269	23,991
COVID-19 Costs	0	9,285	0	9,285
Our share of Adjusted EBITDA reconciling items from our unconsolidated joint ventures	1,072	159	2,088	275
Adjusted EBITDA	$ 405,631	$ 359,462	$ 786,196	$ 725,461

Segment Information - Revenues

Segment Information - Revenues by Product and Service Lines by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting Information [Line Items]
Total Revenues	$ 1,119,756	$ 982,239	$ 2,201,796	$ 2,050,970
GLOBAL RIM BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	992,932	877,102	1,960,226	1,833,521
GLOBAL DATA CENTER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	76,977	66,768	148,085	134,125
CORPORATE AND OTHER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	49,847	38,369	93,485	83,324
Records management
Segment Reporting Information [Line Items]
Total Revenues	799,859	700,048	1,578,949	1,456,540
Records management | GLOBAL RIM BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	765,818	678,969	1,517,941	1,406,585
Records management | GLOBAL DATA CENTER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	0	0	0	0
Records management | CORPORATE AND OTHER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	34,041	21,079	61,008	49,955
Data management
Segment Reporting Information [Line Items]
Total Revenues	134,045	136,549	269,130	278,526
Data management | GLOBAL RIM BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	118,239	119,259	236,653	245,157
Data management | GLOBAL DATA CENTER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	0	0	0	0
Data management | CORPORATE AND OTHER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	15,806	17,290	32,477	33,369
Information destruction
Segment Reporting Information [Line Items]
Total Revenues	108,875	78,874	205,632	181,779
Information destruction | GLOBAL RIM BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	108,875	78,874	205,632	181,779
Information destruction | GLOBAL DATA CENTER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	0	0	0	0
Information destruction | CORPORATE AND OTHER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	0	0	0	0
Data Center(1)
Segment Reporting Information [Line Items]
Total Revenues	76,977	66,768	148,085	134,125
Data Center(1) | GLOBAL RIM BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	0	0	0	0
Data Center(1) | GLOBAL DATA CENTER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	76,977	66,768	148,085	134,125
Data Center(1) | CORPORATE AND OTHER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	$ 0	$ 0	$ 0	$ 0

Related Parties - (Details)

Related Parties - (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Frankfurt JV
Related Party Transaction [Line Items]
Revenue	$ 800		$ 1,900
Makespace
Related Party Transaction [Line Items]
Revenue	$ 8,100	$ 7,100	$ 15,600	$ 13,900

Project Summit - Additional Inf

Project Summit - Additional Information (Details) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended	21 Months Ended	27 Months Ended
	Jun. 30, 2021USD ($)	Jun. 30, 2020USD ($)	Jun. 30, 2021USD ($)	Jun. 30, 2020USD ($)	Dec. 31, 2020USD ($)	Jun. 30, 2021USD ($)	Dec. 31, 2021USD ($)employee
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 39,443	$ 39,298	$ 79,254	$ 80,344		$ 322,247
Project Summit costs
Restructuring Cost and Reserve [Line Items]
Planned workforce reductions	95.00%		95.00%			95.00%
Restructuring Charges			$ 79,254		$ 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		6 Months Ended		21 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 39,443	$ 39,298	$ 79,254	$ 80,344	$ 322,247
GLOBAL RIM BUSINESS
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	7,942	12,774	16,166	21,062	105,206
GLOBAL DATA CENTER BUSINESS
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	1,183	503	1,637	690	3,575
Corporate and Other Business
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	30,318	26,021	61,451	58,592	213,466
Employee severance costs
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	3,921	11,542	7,729	17,650	75,928
Professional fees and other costs
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 35,522	$ 27,756	$ 71,525	$ 62,694	$ 246,319

Project Summit - Restructurin_2

Project Summit - Restructuring Rollforward (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended	21 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Jun. 30, 2021
Restructuring Reserve [Roll Forward]
Amounts accrued	$ 39,443	$ 39,298	$ 79,254	$ 80,344		$ 322,247
Project Summit costs
Restructuring Reserve [Roll Forward]
Beginning balance			40,053	17,777	$ 17,777
Amounts accrued			79,254		194,396
Payments			(85,854)		(168,677)
Other, including currency translation adjustments			(384)		(3,443)
Ending balance	33,069		33,069		40,053	33,069
Employee severance costs
Restructuring Reserve [Roll Forward]
Amounts accrued	3,921	11,542	7,729	17,650		75,928
Employee severance costs | Project Summit costs
Restructuring Reserve [Roll Forward]
Beginning balance			16,278	4,823	4,823
Amounts accrued			7,729		47,349
Payments			(16,474)		(32,455)
Other, including currency translation adjustments			(384)		(3,439)
Ending balance	7,149		7,149		16,278	7,149
Professional fees and other costs
Restructuring Reserve [Roll Forward]
Amounts accrued	35,522	$ 27,756	71,525	62,694		246,319
Professional fees and other costs | Project Summit costs
Restructuring Reserve [Roll Forward]
Beginning balance			23,775	$ 12,954	12,954
Amounts accrued			71,525		147,047
Payments			(69,380)		(136,222)
Other, including currency translation adjustments			0		(4)
Ending balance	$ 25,920		$ 25,920		$ 23,775	$ 25,920