CyrusOne (CONE) 10-Q 28 Oct 21 2021 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2021	Oct. 22, 2021
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
Document Transition Report	false
Entity File Number	001-35789
Entity Registrant Name	CyrusOne Inc.
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	46-0691837
Entity Address, Address Line One	2850 N. Harwood Street
Entity Address, Address Line Two	Suite 2200
Entity Address, City or Town	Dallas
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	75201
City Area Code	972
Local Phone Number	350-0060
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		126,912,271
Entity Central Index Key	0001553023
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Amendment Flag	false
Common Stock, $0.01 par value
Document Information [Line Items]
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	CONE
Security Exchange Name	NASDAQ
1.450% Senior Notes due 2027
Document Information [Line Items]
Title of 12(b) Security	1.450% Senior Notes due 2027
Trading Symbol	CONE27
Security Exchange Name	NASDAQ

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Investment in real estate:
Land	$ 211.6	$ 208.8
Buildings and improvements	2,336.3	2,035.2
Equipment	4,064.7	3,538.9
Gross operating real estate	6,612.6	5,782.9
Less accumulated depreciation	(2,080.4)	(1,767.9)
Net operating real estate	4,532.2	4,015
Construction in progress, including land under development	729.8	982.2
Land held for future development	293	268.3
Total investment in real estate, net	5,555	5,265.5
Cash and cash equivalents	456.4	271.4
Rent and other receivables (net of allowance for doubtful accounts of $2.1 and $3.5 as of September 30, 2021 and December 31, 2020, respectively)	409.2	334.2
Restricted cash	24.3	1.5
Operating lease right-of-use assets, net	148.5	211.4
Equity investments	30.3	67.1
Goodwill	455.1	455.1
Intangible assets (net of accumulated amortization of $272.5 and $249.3 as of September 30, 2021 and December 31, 2020, respectively)	132.7	157.8
Other assets	128	133.4
Total assets	7,339.5	6,897.4
Liabilities and equity
Debt	3,515.1	3,409
Finance lease liabilities	157.2	29.1
Operating lease liabilities	183.9	249.1
Construction costs payable	104.6	133
Accounts payable and accrued expenses	192.1	151.3
Dividends payable	66.3	63.3
Deferred revenue and prepaid rents	227.9	174.1
Deferred tax liability	41.9	53
Other liabilities	45	77.3
Total liabilities	4,534	4,339.2
Commitments and contingencies
Stockholders' equity
Preferred stock, $0.01 par value, 100,000,000 authorized; no shares issued or outstanding	0	0
Common stock, $0.01 par value, 500,000,000 shares authorized and 126,913,710 and 120,442,521 shares issued and outstanding at September 30, 2021 and December 31, 2020, respectively	1.3	1.2
Additional paid in capital	3,952.7	3,537.3
Accumulated deficit	(1,125.3)	(966.6)
Accumulated other comprehensive loss	(23.2)	(13.7)
Total stockholders’ equity	2,805.5	2,558.2
Total liabilities and equity	$ 7,339.5	$ 6,897.4

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 2.1	$ 3.5
Accumulated amortization for intangible assets	$ 272.5	$ 249.3
Preferred stock par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock authorized (in shares)	100,000,000	100,000,000
Preferred stock issued (in shares)	0	0
Preferred stock outstanding (in shares)	0	0
Common stock par value (in dollars per share)	$ 0.01	$ 0.01
Common stock shares authorized (in shares)	500,000,000	500,000,000
Common stock issued (in shares)	126,913,710	120,442,521
Common stock outstanding (in shares)	126,913,710	120,442,521

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Revenue	$ 304.1	$ 262.8	$ 887.3	$ 765.1
Operating expenses:
Property operating expenses	133.4	109.7	391	301.3
Sales and marketing	3.6	4.5	11.1	13
General and administrative	30.8	29.7	70.4	76.9
Depreciation and amortization	127.5	113.1	372.6	330.9
Transaction, acquisition, integration and other related expenses	0.2	1.6	0.4	2.2
Impairment losses and loss on asset disposals	0.1	8.8	0.7	11.1
Total operating expenses	295.6	267.4	846.2	735.4
Operating income (loss)	8.5	(4.6)	41.1	29.7
Interest expense, net	(17.3)	(13.3)	(47.2)	(43.2)
Gain on marketable equity investment	0	4.7	2.4	69.8
Loss on early extinguishment of debt	0	(3.1)	0	(6.5)
Foreign currency and derivative gains (losses), net	14.4	(22.9)	31.2	(31.7)
Other expense (income)	0.1	0	(0.1)	0
Net income (loss) before income taxes	5.7	(39.2)	27.4	18.1
Income tax benefit	1	1.9	4.9	4.3
Net income (loss)	$ 6.7	$ (37.3)	$ 32.3	$ 22.4
Weighted average common shares outstanding - basic (in shares)	124.2	118.7	122.4	116.3
Weighted average common shares outstanding - diluted (in shares)	124.3	118.7	122.5	116.7
Net income (loss) per share - basic (in dollars per share)	$ 0.05	$ (0.32)	$ 0.26	$ 0.19
Net income (loss) per share - diluted (in dollars per share)	$ 0.05	$ (0.32)	$ 0.26	$ 0.19

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive (Loss) Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 6.7	$ (37.3)	$ 32.3	$ 22.4
Other comprehensive (loss) income:
Foreign currency translation adjustment	(27)	36.8	(42)	26.9
Net gain (loss) on cash flow hedging instruments	13.6	(20.9)	32.5	(31.5)
Comprehensive (loss) income	$ (6.7)	$ (21.4)	$ 22.8	$ 17.8

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Beginning Balance (in shares) at Dec. 31, 2019		114.8
Beginning Balance at Dec. 31, 2019	$ 2,434.6	$ 1.1	$ 3,202	$ (767.3)	$ (1.2)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	14.7			14.7
Issuance of common stock, net (in shares)		0.2
Issuance of common stock, net	0.6	$ 0.1	0.5
Stock-based compensation expense	3.7		3.7
Tax payment upon exercise of equity awards	(6.3)		(6.3)
Foreign currency translation adjustment	(24)				(24)
Net gain (loss) on cash flow hedging instruments	(1.1)				(1.1)
Dividends declared	(58.4)			(58.4)
Ending Balance (in shares) at Mar. 31, 2020		115
Ending Balance at Mar. 31, 2020	2,363.8	$ 1.2	3,199.9	(811)	(26.3)
Beginning Balance (in shares) at Dec. 31, 2019		114.8
Beginning Balance at Dec. 31, 2019	2,434.6	$ 1.1	3,202	(767.3)	(1.2)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	22.4
Foreign currency translation adjustment	26.9
Net gain (loss) on cash flow hedging instruments	(31.5)
Ending Balance (in shares) at Sep. 30, 2020		120.4
Ending Balance at Sep. 30, 2020	2,604.4	$ 1.2	3,532.9	(923.9)	(5.8)
Beginning Balance (in shares) at Mar. 31, 2020		115
Beginning Balance at Mar. 31, 2020	2,363.8	$ 1.2	3,199.9	(811)	(26.3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	45			45
Issuance of common stock, net (in shares)		1.9
Issuance of common stock, net	102.8	$ 0	102.8
Stock-based compensation expense	3.3		3.3
Tax payment upon exercise of equity awards	(0.1)		(0.1)
Foreign currency translation adjustment	14.1				14.1
Net gain (loss) on cash flow hedging instruments	(9.5)				(9.5)
Dividends declared	(58.7)			(58.7)
Ending Balance (in shares) at Jun. 30, 2020		116.9
Ending Balance at Jun. 30, 2020	2,460.7	$ 1.2	3,305.9	(824.7)	(21.7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(37.3)			(37.3)
Issuance of common stock, net (in shares)		3.5
Issuance of common stock, net	222.5	$ 0	222.5
Stock-based compensation expense	6.7		6.7
Tax payment upon exercise of equity awards	(2.2)		(2.2)
Foreign currency translation adjustment	36.8				36.8
Net gain (loss) on cash flow hedging instruments	(20.9)				(20.9)
Dividends declared	(61.9)			(61.9)
Ending Balance (in shares) at Sep. 30, 2020		120.4
Ending Balance at Sep. 30, 2020	2,604.4	$ 1.2	3,532.9	(923.9)	(5.8)
Beginning Balance (in shares) at Dec. 31, 2020		120.4
Beginning Balance at Dec. 31, 2020	2,558.2	$ 1.2	3,537.3	(966.6)	(13.7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	18.2			18.2
Issuance of common stock, net (in shares)		2.1
Issuance of common stock, net	95.8		95.8
Stock-based compensation expense	4.4		4.4
Tax payment upon exercise of equity awards	(8.9)		(8.9)
Foreign currency translation adjustment	(15)				(15)
Net gain (loss) on cash flow hedging instruments	23.9				23.9
Dividends declared	(61.8)			(61.8)
Ending Balance (in shares) at Mar. 31, 2021		122.5
Ending Balance at Mar. 31, 2021	2,614.8	$ 1.2	3,628.6	(1,010.2)	(4.8)
Beginning Balance (in shares) at Dec. 31, 2020		120.4
Beginning Balance at Dec. 31, 2020	2,558.2	$ 1.2	3,537.3	(966.6)	(13.7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	32.3
Foreign currency translation adjustment	(42)
Net gain (loss) on cash flow hedging instruments	32.5
Ending Balance (in shares) at Sep. 30, 2021		126.9
Ending Balance at Sep. 30, 2021	2,805.5	$ 1.3	3,952.7	(1,125.3)	(23.2)
Beginning Balance (in shares) at Mar. 31, 2021		122.5
Beginning Balance at Mar. 31, 2021	2,614.8	$ 1.2	3,628.6	(1,010.2)	(4.8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	7.4			7.4
Issuance of common stock, net (in shares)		1.5
Issuance of common stock, net	98.4	$ 0	98.4
Stock-based compensation expense	4.3		4.3
Net gain (loss) on cash flow hedging instruments	(5)				(5)
Dividends declared	(63.3)			(63.3)
Ending Balance (in shares) at Jun. 30, 2021		124
Ending Balance at Jun. 30, 2021	2,656.6	$ 1.2	3,731.3	(1,066.1)	(9.8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	6.7			6.7
Issuance of common stock, net (in shares)		2.9
Issuance of common stock, net	213.7	$ 0.1	213.6
Stock-based compensation expense	8.5		8.5
Tax payment upon exercise of equity awards	(0.7)		(0.7)
Foreign currency translation adjustment	(27)				(27)
Net gain (loss) on cash flow hedging instruments	13.6				13.6
Dividends declared	(65.9)			(65.9)
Ending Balance (in shares) at Sep. 30, 2021		126.9
Ending Balance at Sep. 30, 2021	$ 2,805.5	$ 1.3	$ 3,952.7	$ (1,125.3)	$ (23.2)

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Equity (Parenthetical) - $ / shares	3 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020
Statement of Stockholders' Equity [Abstract]
Dividends declared per share (in dollars per share)	$ 0.52	$ 0.51	$ 0.51	$ 0.51	$ 0.50	$ 0.50

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities:
Net income (loss)	$ 32.3	$ 22.4
Adjustments to reconcile Net income to Net cash provided by operating activities:
Depreciation and amortization	372.6	330.9
Provision for bad debt expense	(1)	0.3
Gain on marketable equity investment	(2.4)	(69.8)
Foreign currency and derivative (gains) losses, net	(31.2)	31.7
Proceeds from swap terminations	0	2.9
Impairment losses and loss on asset disposals	0.7	11.1
Loss on early extinguishment of debt	0	6.5
Interest expense amortization, net	5.7	5.2
Stock-based compensation expense	17.2	13.7
Deferred income tax benefit	(8)	(7.1)
Operating lease cost	15.3	15
Other (expense) income	(0.2)	0.6
Change in operating assets and liabilities:
Rent and other receivables, net and other assets	(90.6)	(29.1)
Accounts payable and accrued expenses	42.9	22
Deferred revenue and prepaid rents	54.3	2.3
Operating lease liabilities	(18.2)	(16.7)
Net cash provided by operating activities	389.4	341.9
Cash flows from investing activities:
Investments in real estate	(580.2)	(692.2)
Proceeds from sale of equity investments	46.6	31.8
Equity investments	(7.4)	(6.5)
Proceeds from the sale of real estate assets	4.4	0.3
Net cash used in investing activities	(536.6)	(666.6)
Cash flows from financing activities:
Issuance of common stock, net	407.9	325.9
Dividends paid	(187.9)	(174.7)
Proceeds from revolving credit facility	173.4	595.5
Repayments of revolving credit facility	(610.5)	(966.7)
Proceeds from Euro bond	603.1	561.2
Proceeds from unsecured term loan	0	1,100
Repayments of unsecured term loan	0	(1,400)
Proceeds from issuance of senior notes	0	395.2
Payment of deferred financing costs	(5)	(15.1)
Payments on finance lease liabilities	(3.5)	(2)
Tax payment upon exercise of equity awards	(9.6)	(8.6)
Net cash provided by financing activities	367.9	410.7
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(12.9)	(5.8)
Net increase in cash, cash equivalents and restricted cash	207.8	80.2
Cash, cash equivalents and restricted cash at beginning of period	272.9	77.7
Cash, cash equivalents and restricted cash at end of period	480.7	157.9
Supplemental disclosure of cash flow information:
Cash paid for interest, including amounts capitalized of $15.6 million and $17.0 million in 2021 and 2020, respectively	45.8	36.3
Cash paid for income taxes	4	3.2
Non-cash investing and financing activities:
Construction costs payable	104.6	168.2
Dividends payable	$ 66.3	$ 63.1

Condensed Consolidated Statem_6

Condensed Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Statement of Cash Flows [Abstract]
Cash paid for interest, capitalized amount	$ 15.6	$ 17

Description of Business

Description of Business	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Description of BusinessCyrusOne Inc., together with CyrusOne GP (the "General Partner"), a wholly-owned subsidiary of CyrusOne Inc., through which CyrusOne Inc. owns CyrusOne LP (the "Operating Partnership") and the subsidiaries of the Operating Partnership (collectively, "CyrusOne", "we", "us", "our", and the "Company") is an owner, operator and developer of enterprise-class, carrier-neutral, multi-tenant and single-tenant data center properties. As of September 30, 2021, all of the issued and outstanding operating partnership units of CyrusOne LP are owned, directly or indirectly, by the Company except for de minimis holdings by certain officers and employees of the Company of LTIP Units (as described below) in CyrusOne LP as a result of awards granted under the LTIP (as defined below). Our customers operate in a number of industries, including information technology, financial services, energy, oil and gas, mining, medical, research and consulting services, and consumer goods and services. We currently operate 57 data centers, including one recovery center, located in the United States, United Kingdom, Germany, The Netherlands, The Republic of Ireland, Singapore and France.On January 24, 2013, the Company completed its initial public offering (the "IPO") of common stock and its common stock currently trades on the NASDAQ Exchange under the ticker symbol "CONE".

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Risks and Uncertainties The novel strain of the coronavirus (COVID-19) identified in China in late 2019 has spread globally and has resulted in authorities implementing numerous measures to attempt to contain the virus. This has included travel bans, shelter in place regulations and other restrictions and shutdowns. We continue to monitor the global outbreak and to take steps to mitigate the potential risks to us posed by the pandemic. We have continued to implement restrictions on physical participation in meetings and limit business travel, which have disrupted how we operate our business. The duration and extent of the impact from the COVID-19 pandemic continues to depend on future developments that cannot be accurately predicted at this time, such as the severity and transmission rate of the virus, including variants such as Delta, the extent and effectiveness of containment actions, the rate and effectiveness of vaccinations and the impact of these and other factors on our employees, customers, suppliers and vendors. The effect of the pandemic and measures implemented by authorities could disrupt our supply chain, which currently remains fully functional, including the provision of services to us by our vendors and could result in restrictions on construction activities. These factors and the continuing uncertainty around them could adversely impact our employees, customers, vendors and suppliers resulting in a material adverse effect on our business, financial condition, results of operations, cash flows and ability to pay dividends as well as the market price of our common stock. Interim Unaudited Financial Information The accompanying condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") and should be read in conjunction with the financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2020, which was filed with the Securities and Exchange Commission ("SEC") on February 19, 2021. Certain information and footnote disclosures normally included in the consolidated financial statements prepared in accordance with GAAP have been omitted from this report on Form 10-Q pursuant to the rules and regulations of the SEC. Results for the interim periods in this report are not necessarily indicative of future financial results and have not been audited by our independent registered public accounting firm. In the opinion of management, the accompanying unaudited condensed consolidated financial statements include all adjustments necessary to present fairly our condensed consolidated financial statements as of September 30, 2021 and December 31, 2020, and for the three and nine months ended September 30, 2021 and 2020. These adjustments are of a normal recurring nature and consistent with the adjustments recorded to prepare the annual audited consolidated financial statements as of December 31, 2020. All amounts reflected are in millions except share and per share data. Basis of Presentation The accompanying condensed consolidated financial statements include the accounts of the Company, as well as all wholly-owned subsidiaries and any consolidated variable interest entities. All intercompany balances and transactions have been eliminated in consolidation. Investment in Real Estate Acquisition of Properties Investment in real estate consists of land, buildings, improvements and integral equipment utilized in our data center operations. We expect most acquisitions to be an acquisition of assets rather than a business combination as our typical acquisitions consist of properties whereby substantially all the fair value of gross assets acquired is concentrated in a single asset set (land, building and in-place leases), which are treated as asset acquisitions. Impairment Losses When events or circumstances indicate that the carrying amount of a real estate investment may not be recoverable, we review the carrying value of the asset. When such impairment indicators exist, we review an estimate of the undiscounted future cash flows expected to result from the use of the real estate investment and proceeds from its eventual disposition and compare such amount to the carrying value of the real estate investment. If our undiscounted cash flows indicate that we are unable to recover the carrying value of the real estate investment, an impairment loss is recognized. An impairment loss is measured as the amount by which the real estate investment's carrying value exceeds its estimated fair value. We did not record any impairment losses for the three or nine months ended September 30, 2021. For the three and nine months ended September 30, 2020, we recognized an impairment loss of $8.8 million and $11.2 million, respectively, which includes an $8.8 million impairment loss in both periods based on our estimate of the decrease in the fair value of the equipment held for use in inventory at our U.S. data centers and a $2.4 million impairment loss in the nine months ended September 30, 2020 based on the estimated fair value for our investment in land held in Atlanta for future development as the Company entered into a non-binding contract to sell this land to a third-party. These fair values were based on unobservable inputs and the determination of fair value of real estate assets to be held for use is derived using the discounted cash flow method and involves a number of management assumptions relating to future economic events that could materially affect the determination of the ultimate fair value. Such assumptions are Level 3 inputs and include, but are not limited to, projected vacancy rates, rental rates, property operating expenses and required capital expenditures. These factors require management's judgment of factors such as market knowledge, historical experience, lease terms, tenant financial strength, economy, demographics, environment, property location, age, physical condition and expected return requirements, among other things. The aforementioned factors are taken as a whole by management in the determination of fair value. See Fair Value Measurements below for further information on fair value. Cash and Cash Equivalents and Restricted Cash Cash and cash equivalents include all non-restricted cash held in financial institutions and other non-restricted highly liquid short-term investments with original maturities of three months or less. Restricted cash includes cash equivalents restricted by contract or regulation, including letters of credit. Equity Investments We hold investments in various joint ventures where the Company evaluates its ability to influence the operating or financial decisions of the investee in applying the appropriate method of accounting for such investments. Influence tends to be more effective as the investor's percent of ownership in the voting rights of the investee increases. Our equity investments represent less than 20% of the voting rights of the investees and we do not exercise influence over the investee's operating and financial decisions. Accordingly, we do not account for our equity investments using the equity method of accounting. For further information about our equity investments, see Note 7, Equity Investments. Our equity investments are carried at cost because we do not exercise influence over the operating and financial decisions of the ventures and there is no readily determinable fair value and our investments are recorded at cost less impairment, if any. Dividends paid from operating profits are reported as a component of net income, while other dividends are reported as a return of capital. Revenue Recognition Our revenue consists of lease revenue and revenue from contracts with customers. Lease Revenue: Our leasing revenue primarily consists of colocation rent, metered power reimbursements and interconnection revenue and is accounted for under Accounting Standards Codification (“ASC”) 842, Leases (“ASC 842”). We generally are not entitled to reimbursements for rental expenses including real estate taxes, insurance or other common area operating expenses. a. Colocation Rent Revenue Colocation rent revenues, including interconnection revenue, are fixed minimum lease payments generally billed monthly in advance based on the contracted power or leased space. Some contracts may provide initial free rent periods and rents that escalate over the term of the contract. If rents escalate without the lessee gaining access to or control over additional leased power or space at the beginning of the lease term, the rental payments are recognized as revenue on a straight-line basis over the term of the lease. If rents escalate because the lessee gains access to and control over additional power and or leased space, revenue is recognized in proportion to the additional power or space in the periods that the lessee has control over the use of the additional power or space. The excess of revenue recognized over amounts contractually due is recognized as a straight-line receivable, which is included in Rent and other receivables in our Condensed Consolidated Balance Sheets. Some of our leases are structured on a gross basis in which the customer pays a fixed amount for colocation space and power. The revenue for these types of leases is recorded in colocation rent revenue. b. Metered Power Reimbursements Revenue Some of our leases provide that the customer is separately billed for power based upon actual or estimated metered usage generally at rates then in effect. Metered power reimbursement revenue is variable lease payments generally billed one month in arrears, and an estimate of this revenue is accrued in the month that the associated power is provided and recorded in metered power reimbursements revenue. Revenue from Contracts with Customers Revenue from our managed services, equipment sales, installations and other services are recognized under ASC 606, Revenue from Contracts with Customers ("ASC 606"). Equipment sold by us generally consists of servers, switches, networking equipment, cable infrastructure and cabinets. Revenue is recognized at a point-in-time when control of the equipment transfers to the customer from the Company, which generally occurs upon delivery to the customer. Managed services include providing a full-service managed data center, monitoring customer computer equipment, managing backups and storage, utilization reporting and other related ancillary information technology services. Management service contracts generally range from one Installation services include mounting, wiring, and testing of customer owned equipment. The installation period is typically short term in duration, and accordingly, revenue from the installation of customer equipment is recognized at a point-in-time once the installation is complete and the performance obligation is satisfied. Other services generally include installation of customer equipment, performing customer system re-boots, server cabinet and cage management, power monitoring, shipping and receiving, resolving technical issues, and other services requested by the customer. Other service revenue is measured based on the consideration specified in the contract and recognized over time as we satisfy the performance obligation. We adopted the practical expedient in ASC 606 that allows the Company to not disclose information about remaining performance obligations that have original expected durations of one year or less, the amount of the transaction price allocated to the remaining performance obligations and when we expect to recognize that amount as revenue for the year. We have also adopted the “as invoiced” practical expedient, whereby the Company recognizes revenue in the amount that directly corresponds to the amount of value transferred to the customer. Contract assets were $0.7 million and $0.4 million as of September 30, 2021 and December 31, 2020, respectively. Contract liabilities w ere not material as of both September 30, 2021 and December 31, 2020. Rent and Other Receivables Receivables consist principally of rent receivables including straight-line rent receivables. A general reserve may be recognized as an allowance for doubtful accounts when collectibility is not probable, after applying the overall collectibility constraint under ASC 842. Straight-line rent receivable, net was $175.8 million and $172.6 million at September 30, 2021 and December 31, 2020, respectively. The allowance for doubtful accounts is estimated based upon historic patterns of credit losses for aged receivables as well as specific provisions for certain identifiable, potentially uncollectible balances. Foreign Currency Translation and Transactions The financial position of foreign subsidiaries is translated at the exchange rates in effect at the end of the period, while revenues and expenses are translated at average exchange rates during the period. Gains or losses from translation of foreign operations where the local currency is the functional currency are included as components of Other comprehensive income (loss). Gains or losses from foreign currency transactions are included in determining net income. Stock-Based Compensation We have a stock-based incentive award plan for our employees and directors. Stock-based compensation expense associated with these awards is recognized in General and administrative expenses, Property operating expenses, and Sales and marketing expenses in our Condensed Consolidated Statements of Operations. We measure stock-based compensation at the estimated fair value on the grant date and recognize the amortization of stock-based compensation expense over the requisite service period. Fair value is determined based on assumptions related to stock volatility, risk-free rate of return and estimates of market and company performance. Fair Value Measurements Fair value measurements are utilized in accounting for business combinations, asset acquisitions, testing of goodwill and other long-lived assets for impairment, recording unrealized gain on available-for-sale securities, derivatives and related disclosures. Fair value of financial and non-financial assets and liabilities is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. The three-tier hierarchy that prioritizes certain inputs used in the methodologies of measuring fair value for asset and liabilities, is as follows: Level 1—Observable inputs for identical instruments such as quoted market prices; Level 2—Inputs include quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (i.e., interest rates, yield curves, etc.), and inputs that are derived principally from or corroborated by observable market data by correlation or other means (market corroborated inputs); and Level 3—Unobservable inputs that reflect our determination of assumptions that market participants would use in pricing the asset or liability. These inputs are developed based on the best information available, including our own data. Derivative Instruments We primarily hedge our foreign currency risk by borrowing in the currencies in which we invest. We may use derivative financial instruments, such as cross-currency swaps to manage foreign currency exchange rate risk related to both our foreign investments and the related earnings. In addition, we occasionally use interest rate swap contracts to manage interest rate risk and limit the impact of future interest rate changes on earnings and cash flows, primarily related to variable-rate debt. Derivative instruments are measured at fair value and recorded in Other assets and Other liabilities, depending on our rights or obligations under the applicable derivative contract. Derivatives that are not designated as hedges must be adjusted to fair value through earnings. Designated Derivatives . We may choose to designate our derivative financial instruments, generally cross-currency swaps as net investment hedges in foreign operations. At inception of the transaction, we designate the derivative financial instrument as a hedge of a specific underlying exposure, including the risk management objective and the strategy for undertaking the hedge transaction. We formally assess both at inception and at least quarterly thereafter, the effectiveness of our hedging transactions. Due to the high degree of effectiveness between the hedging instruments and the underlying exposures hedged, fluctuations in the value of the derivative financial instruments will generally be offset by changes in the cash flows or fair values of the underlying exposures being hedged. In addition to the net investment hedges described above, we may issue debt in a currency that is not the same functional currency of the borrowing entity to hedge our international investments. We designate the debt and related accrued interest as a net investment hedge to offset the translation and economic exposures related to our international investments. If the debt and related accrued interest exceeds the designated amount of our international investment, the foreign currency remeasurement on the unhedged portion of the debt during the period is recognized in Foreign currency and derivative gains (losses), net. For cash flow hedges, such as interest rate swaps, we report the effective portion of the gain or loss as a component of Other comprehensive (loss) income and reclassify it to the applicable line item in the Condensed Consolidated Statements of Operations, generally Interest expense, net over the corresponding period of the underlying hedged item. The ineffective portion of a derivative financial instrument’s change in fair value is recognized in earnings, generally Interest expense, net at the time the ineffectiveness occurred. To the extent the hedged debt related to our interest rate swaps and forwards is paid off early, we write off the remaining balance in Other comprehensive (loss) income and recognize the amount in Interest expense, net in the Condensed Consolidated Statements of Operations. Undesignated Derivatives . Derivative instruments, such as cross-currency swaps, for which hedge accounting is not applied are recorded at fair value in Other assets and Other liabilities and gains and losses resulting from changes in the fair value are reported in Foreign currency and derivative gains (losses), net in the Condensed Consolidated Statements of Operations. In addition, we may choose to not designate our interest rate swap and forward contracts. If a swap or forward contract is not designated as a hedge, the changes in fair value of these instruments is immediately recognized in earnings in Interest expense, net in the Condensed Consolidated Statements of Operations.

Recently Issued Accounting Stan

Recently Issued Accounting Standards	9 Months Ended
	Sep. 30, 2021
Accounting Changes and Error Corrections [Abstract]
Recently Issued Accounting Standards	Recently Issued Accounting Standards Recently Adopted Accounting Pronouncements Reference Rate Reform On March 12, 2020, the FASB issued Accounting Standards Update ("ASU") 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting ("ASU 2020-04"). ASU 2020-04 contains practical expedients for reference rate reform related activities that impact debt, leases, derivatives and other contracts. The guidance in ASU 2020-04 is optional and may be elected over time as reference rate reform activities occur. During the first quarter of 2021, we elected to apply the hedge accounting expedients related to probability and the assessments of effectiveness for future LIBOR-indexed cash flows to assume that the index upon which future hedged transactions will be based matches the index on the corresponding derivatives. Application of these expedients preserves the presentation of derivatives in our financial statements consistent with past presentation. We continue to evaluate the impact of the guidance and may apply other elections as applicable as additional changes in the market occur. Income Taxes On January 1, 2021, we adopted ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, which simplifies various aspects related to the accounting for income taxes, eliminates certain exceptions within ASC 740, Income Taxes, and clarifies certain aspects of the current guidance to promote consistency among reporting entities. The adoption did not have a significant impact on the Company. Financial Instruments - Credit Losses On January 1, 2020, we adopted ASU 2016-13, Financial Instruments-Credit Losses (CECL), which requires certain financial assets to be presented at the net amount expected to be collected. CECL and its related amendments apply to our customer contract trade receivables, notes receivable and net investments in leases. Our Rent and other receivables are primarily comprised of rent receivables, which are not within the scope of this sub-topic. The adoption did not have a significant impact on the Company because of our limited exposure to financial instruments subject to this standard. New Accounting Pronouncements Not Yet Adopted In August 2020, the FASB issued ASU 2020-06, Debt - Debt with Conversion and Other Options (Topic 470) and Derivatives and Hedging – Contracts in Entity’s Own Equity (Topic 815). This ASU reduces the number of accounting models for

Revenue Recognition

Revenue Recognition	9 Months Ended
	Sep. 30, 2021
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Revenue Recognition Lease Revenue Lease revenue primarily consists of colocation rent and metered power reimbursements from the lease of our data centers. Colocation leases may include all or portions of a data center, where customers may also lease office space to support their colocation operations. Revenue is primarily based on power usage as well as square footage. Customer lease arrangements customarily contain provisions that allow for renewal or continuation on a month-to-month arrangement, and certain leases contain early termination rights. We do not include any of these extension or termination options in a customer’s lease term for lease classification purposes or for recognizing lease revenue unless we are reasonably certain the customer will exercise these extension or termination options at lease commencement. At lease commencement, early termination is generally not deemed probable due to the significant economic penalty incurred by the lessee to exercise its early termination right and to relocate their equipment installed in our facilities. Generally, our customer lease arrangements do not provide any option to purchase and are classified as operating leases. We have substantial revenue primarily related to lease revenue from one customer that represented approximately 19% of our total revenue for both of the nine months ended September 30, 2021 and 2020. At September 30, 2021, the future minimum lease payments to be received under non-cancellable operating leases, excluding month-to-month arrangements and metered power reimbursements are shown below (in millions): As of September 30, 2021 Minimum Lease Payments 2021 $ 219.8 2022 802.7 2023 659.5 2024 526.6 2025 442.4 2026 344.3 Thereafter 971.5 Total $ 3,966.8 At September 30, 2020, the future minimum lease payments to be received under non-cancellable operating leases, excluding month-to-month arrangements and metered power reimbursements are shown below (in millions): As of September 30, 2020 Minimum Lease Payments 2020 $ 198.9 2021 721.9 2022 614.5 2023 493.7 2024 377.7 2025 307.8 Thereafter 837.3 Total $ 3,551.8 Revenue from Contracts with Customers Revenue from equipment sales and the installation of customer equipment is recognized at a point-in-time. Title to such assets are transferred to the customer, and the benefits of the installation service are typically consumed at the completion of the service. Disaggregation of Revenue For the three and nine months ended September 30, 2021 and 2020 lease revenue disaggregated by primary revenue stream is as follows (in millions): Three Months Ended September 30, Nine Months Ended September 30, Lease revenue 2021 2020 2021 2020 Colocation (Minimum lease payments) $ 236.4 $ 212.5 $ 681.5 $ 624.0 Metered power reimbursements (Variable lease payments) 62.5 44.6 188.6 116.5 Total lease revenue $ 298.9 $ 257.1 $ 870.1 $ 740.5 For the three and nine months ended September 30, 2021 and 2020, revenue from contracts with customers disaggregated by primary revenue stream is as follows (in millions): Three Months Ended September 30, Nine Months Ended September 30, Revenue from contracts with customers 2021 2020 2021 2020 Equipment sales and services $ 0.8 $ 0.6 $ 3.4 $ 10.0 Other revenue 4.4 5.1 13.8 14.6 Total revenue from contracts with customers $ 5.2 $ 5.7 $ 17.2 $ 24.6 Other revenue related to contracts with customers in the table above includes managed services and other services revenue of $3.6 million and $11.4 million for the three and nine months ended September 30, 2021, respectively, and $4.0 million and $11.9 million for the three and nine months ended September 30, 2020, respectively. Total revenues from contracts with customers generated from operations outside of the United States were insignificant for the three and nine months ended September 30, 2021 and $0.2 million and $4.4 million for the three and nine months ended September 30, 2020. Accounts receivable associated with revenue from contracts with customers were $0.3 million and $2.3 million as of September 30, 2021 and December 31, 2020, respectively.

Leases - As a Lessee

Leases - As a Lessee	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Leases - As a Lessee	Leases - As a Lessee Right-of-use ("ROU") assets represent our right to use an underlying asset for the lease term and lease liabilities represent our obligation to make lease payments arising from the lease. ROU assets and lease liabilities are recognized at the lease commencement date based on the estimated present value of lease payments over the lease term. Variable lease payments consisting of non-lease components and services are excluded from the ROU assets and lease liabilities and are recognized in the period in which the obligation is incurred. ASC 842 defines initial direct costs as only the incremental costs of signing a lease. Initial direct costs related to leasing that are not incremental are expensed as general and administrative expense in our Condensed Consolidated Statements of Operations. As a result of electing the package of practical expedients, initial direct costs incurred prior to January 1, 2019 (the effective date for ASC 842) have not been reassessed. Our operating lease agreements primarily consist of leased real estate and are included within Operating lease ROU assets and Operating lease liabilities on the Condensed Consolidated Balance Sheets. Many of our lease agreements include options to extend the lease, which are not included in our minimum lease payments unless they are reasonably certain to be exercised at lease commencement. Rental expense related to operating leases is recognized on a straight-line basis over the lease term. We operate seven data center facilities and have a data center under development subject to finance leases. The remaining terms of our data center finance leases range from one twenty-three The components of lease expense are as follows (in millions): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Operating lease cost $ 5.0 $ 5.1 $ 15.3 $ 15.0 Finance lease cost: Amortization of assets 0.4 0.7 1.5 1.5 Interest on lease liabilities 1.1 0.4 2.3 1.1 Total net lease cost $ 6.5 $ 6.2 $ 19.1 $ 17.6 Supplemental balance sheet information related to leases is as follows (in millions, except lease term and discount rate): September 30, 2021 December 31, 2020 Operating leases: Operating lease right-of-use assets $ 148.5 $ 211.4 Operating lease liabilities $ 183.9 $ 249.1 Finance leases: Property and equipment, at cost $ 163.1 $ 34.7 Accumulated amortization (8.6) (7.1) Property and equipment, net $ 154.5 $ 27.6 Finance lease liabilities $ 157.2 $ 29.1 Weighted average remaining lease term (in years): Operating leases 16.5 14.3 Finance leases (a) 27.5 18.2 Weighted average discount rate: Operating leases 4.0 % 3.7 % Finance leases (a) 2.6 % 4.7 % (a) Excludes a 999-year ground lease in Dublin, The Republic of Ireland entered into during the third quarter of 2019. The Dublin property is under active development and the finance lease is included in Construction in progress, including land under development on the Condensed Consolidated Balance Sheets. Supplemental cash flow and other information related to leases is as follows (in millions): Nine Months Ended September 30, 2021 Nine Months Ended September 30, 2020 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 18.2 $ 16.7 Operating cash flows from finance leases 2.3 1.1 Financing cash flows from finance leases 3.5 2.0 Non-cash right-of-use assets obtained in exchange for lease liabilities: Operating leases $ — $ 56.9 Finance leases $ 128.4 $ — Maturities of lease liabilities were as follows as of September 30, 2021 (in millions): Operating Leases Finance Leases 2021 $ 6.6 $ 2.0 2022 24.7 7.7 2023 20.8 6.6 2024 16.2 6.4 2025 14.4 6.5 2026 9.4 6.9 Thereafter 159.7 187.1 Total lease payments $ 251.8 $ 223.2 Less: Imputed interest (67.9) (66.0) Total lease obligations $ 183.9 $ 157.2 Maturities of lease liabilities were as follows as of December 31, 2020 (in millions): Operating Leases Finance Leases 2021 $ 27.8 $ 4.2 2022 27.9 3.0 2023 23.9 2.0 2024 19.4 1.4 2025 17.8 1.5 Thereafter 221.6 30.5 Total lease payments $ 338.4 $ 42.6 Less: Imputed interest (89.3) (13.5) Total lease obligations $ 249.1 $ 29.1
Leases - As a Lessee	Leases - As a Lessee Right-of-use ("ROU") assets represent our right to use an underlying asset for the lease term and lease liabilities represent our obligation to make lease payments arising from the lease. ROU assets and lease liabilities are recognized at the lease commencement date based on the estimated present value of lease payments over the lease term. Variable lease payments consisting of non-lease components and services are excluded from the ROU assets and lease liabilities and are recognized in the period in which the obligation is incurred. ASC 842 defines initial direct costs as only the incremental costs of signing a lease. Initial direct costs related to leasing that are not incremental are expensed as general and administrative expense in our Condensed Consolidated Statements of Operations. As a result of electing the package of practical expedients, initial direct costs incurred prior to January 1, 2019 (the effective date for ASC 842) have not been reassessed. Our operating lease agreements primarily consist of leased real estate and are included within Operating lease ROU assets and Operating lease liabilities on the Condensed Consolidated Balance Sheets. Many of our lease agreements include options to extend the lease, which are not included in our minimum lease payments unless they are reasonably certain to be exercised at lease commencement. Rental expense related to operating leases is recognized on a straight-line basis over the lease term. We operate seven data center facilities and have a data center under development subject to finance leases. The remaining terms of our data center finance leases range from one twenty-three The components of lease expense are as follows (in millions): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Operating lease cost $ 5.0 $ 5.1 $ 15.3 $ 15.0 Finance lease cost: Amortization of assets 0.4 0.7 1.5 1.5 Interest on lease liabilities 1.1 0.4 2.3 1.1 Total net lease cost $ 6.5 $ 6.2 $ 19.1 $ 17.6 Supplemental balance sheet information related to leases is as follows (in millions, except lease term and discount rate): September 30, 2021 December 31, 2020 Operating leases: Operating lease right-of-use assets $ 148.5 $ 211.4 Operating lease liabilities $ 183.9 $ 249.1 Finance leases: Property and equipment, at cost $ 163.1 $ 34.7 Accumulated amortization (8.6) (7.1) Property and equipment, net $ 154.5 $ 27.6 Finance lease liabilities $ 157.2 $ 29.1 Weighted average remaining lease term (in years): Operating leases 16.5 14.3 Finance leases (a) 27.5 18.2 Weighted average discount rate: Operating leases 4.0 % 3.7 % Finance leases (a) 2.6 % 4.7 % (a) Excludes a 999-year ground lease in Dublin, The Republic of Ireland entered into during the third quarter of 2019. The Dublin property is under active development and the finance lease is included in Construction in progress, including land under development on the Condensed Consolidated Balance Sheets. Supplemental cash flow and other information related to leases is as follows (in millions): Nine Months Ended September 30, 2021 Nine Months Ended September 30, 2020 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 18.2 $ 16.7 Operating cash flows from finance leases 2.3 1.1 Financing cash flows from finance leases 3.5 2.0 Non-cash right-of-use assets obtained in exchange for lease liabilities: Operating leases $ — $ 56.9 Finance leases $ 128.4 $ — Maturities of lease liabilities were as follows as of September 30, 2021 (in millions): Operating Leases Finance Leases 2021 $ 6.6 $ 2.0 2022 24.7 7.7 2023 20.8 6.6 2024 16.2 6.4 2025 14.4 6.5 2026 9.4 6.9 Thereafter 159.7 187.1 Total lease payments $ 251.8 $ 223.2 Less: Imputed interest (67.9) (66.0) Total lease obligations $ 183.9 $ 157.2 Maturities of lease liabilities were as follows as of December 31, 2020 (in millions): Operating Leases Finance Leases 2021 $ 27.8 $ 4.2 2022 27.9 3.0 2023 23.9 2.0 2024 19.4 1.4 2025 17.8 1.5 Thereafter 221.6 30.5 Total lease payments $ 338.4 $ 42.6 Less: Imputed interest (89.3) (13.5) Total lease obligations $ 249.1 $ 29.1

Investment in Real Estate

Investment in Real Estate	9 Months Ended
	Sep. 30, 2021
Real Estate [Abstract]
Investment in Real Estate	Investment in Real Estate Land for future development During the nine months ended September 30, 2021, the Company purchased land for future development in Madrid, Spain; Amsterdam, The Netherlands; San Antonio, Texas and Frankfurt, Germany totaling 22 acres for $39.8 million. During the nine months ended September 30, 2020, the Company purchased land for future development in Frankfurt, Germany and London, United Kingdom totaling 35 acres for $58.7 million. Leases of real estate In February 2021, the Company entered into a 20-year lease comprising a 130,000 square feet building and commenced development of a 18 megawatt ("MW") data center in London, United Kingdom. We have three renewal options for 15 years each which were not reasonably certain at commencement and the lease was classified as an operating lease. In June 2021, the Company entered into lease amendments for the two data center leases located in London, United Kingdom to extend the lease terms. Per lease modification accounting rules under ASC 842, these leases were classified as finance leases on the modification effective date. Previously these leases were accounted as operating leases. The finance lease asset and liability are presented in Buildings and improvements and Finance lease liabilities in the Condensed Consolidated Balance sheets, respectively. In March 2020, the Company entered into a 25-year lease comprising a 45,000 square feet building and commenced development of a 27 MW data center in Paris, France, which was preleased to a customer. We have one renewal option for 25 years which was not reasonably certain at commencement and the lease was classified as an operating lease. Real estate related capital expenditures Construction in progress was $729.8 million and $982.2 million, including land which was under active development of $12.9 million and $5.1 million as of September 30, 2021 and December 31, 2020, respectively. For the nine months ended September 30, 2021, our capital expenditures were $580.2 million, and substantially all of our investing activity related to our development activities. Our capital expenditures for the nine months ended September 30, 2021 primarily related to the acquisition of land for future development and continued development in key markets, primarily in Northern Virginia, Phoenix, Frankfurt, Dublin, London, Somerset, Paris, San Antonio and Madrid. For the nine months ended September 30, 2020, our capital expenditures were $692.2 million, primarily related to the continued development in key markets, primarily in Dublin, Iowa, Frankfurt, London, the New York Metro area, Northern Virginia, Phoenix, San Antonio, Santa Clara and Dallas. In addition, included in capital expenditures were land purchases of $58.7 million in Frankfurt and London for future development. Real Estate Investments and Intangible Assets and Related Depreciation and Amortization As of September 30, 2021 and December 31, 2020, major components of our real estate investments and intangibles and related accumulated depreciation and amortization are as follows (in millions): As of: September 30, 2021 December 31, 2020 Cost Accumulated Depreciation and Amortization Net book value Cost Accumulated Depreciation and Amortization Net book value Investment in real estate Building and improvements $ 2,336.3 $ (714.1) $ 1,622.2 $ 2,035.2 $ (639.4) $ 1,395.8 Equipment 4,064.7 (1,366.3) 2,698.4 3,538.9 (1,128.5) 2,410.4 Intangible assets Customer relationships $ 247.1 $ (171.4) $ 75.7 $ 247.1 $ (163.1) $ 84.0 In-place leases 138.6 (88.3) 50.3 140.4 (74.6) 65.8 Other contractual 19.5 (12.8) 6.7 19.6 (11.6) 8.0 Total intangible assets $ 405.2 $ (272.5) $ 132.7 $ 407.1 $ (249.3) $ 157.8 Depreciation and amortization are calculated using the straight-line method over the useful lives of the assets. The typical life of owned assets are as follows: Buildings 30 years Building improvements 30 years Equipment 20 years Leased real estate and leasehold improvements are depreciated over the shorter of the asset's useful life or the remaining lease term. Depreciation expense was $115.4 million and $335.8 million for the three and nine months ended September 30, 2021, respectively, and $99.7 million and $291.2 million for the three and nine months ended September 30, 2020, respectively. Other contract intangible assets include tradenames, favorable leasehold interests and above market leases. Amortization expense related to intangibles was $12.1 million and $36.8 million for the three and nine months ended September 30, 2021, respectively, and $13.4 million and $39.7 million for the three and nine months ended September 30, 2020, respectively.

Equity Investments

Equity Investments	9 Months Ended
	Sep. 30, 2021
Investments, Debt and Equity Securities [Abstract]
Equity Investments	Equity Investments The Company has the following equity investments where it has a noncontrolling interest in the investees (in millions). Equity Investments as of: Investees Equity Method September 30, 2021 December 31, 2020 GDS, Class A share equivalent Fair value $ — $ 44.2 ODATA investments Cost method 30.3 22.9 Equity investments $ 30.3 $ 67.1 During January 2021, we disposed of our remaining investment of approximately 0.5 million GDS Holdings Limited ("GDS") American depositary shares ("ADSs") for net proceeds of approximately $46.6 million. The Company recognized gains on marketable equity investment in GDS ADSs held and sold as follows: Three Months Ended September 30, Nine Months Ended September 30, IN MILLIONS 2021 2020 2021 2020 Net gain on marketable equity investments $ — $ 4.7 $ 2.4 $ 69.8 Less: Net gain recognized on marketable equity investments sold — 0.6 2.4 12.4 Unrealized gain on marketable equity investments held $ — $ 4.1 $ — $ 57.4 The gain on investment was recognized in the Condensed Consolidated Statements of Operations in Gain on marketable equity investment.

Other Assets

Other Assets	9 Months Ended
	Sep. 30, 2021
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Other Assets	Other Assets As of September 30, 2021 and December 31, 2020, the components of Other assets are as follows (in millions): September 30, 2021 December 31, 2020 Deferred leasing and other contract costs $ 63.7 $ 62.4 Prepaid expenses 22.8 19.1 Non-real estate assets, net 9.9 13.8 Other assets 31.6 38.1 Total $ 128.0 $ 133.4

Debt

Debt	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Debt	Debt As of September 30, 2021 and December 31, 2020, the components of Debt are as follows (unless otherwise noted, interest rate and maturity date information are as of September 30, 2021) (in millions): September 30, 2021 December 31, 2020 Interest Rate Maturity Date Amended Credit Agreement: Revolving Credit Facility: March 2024 (b) EUR Revolver $ — $ 275.9 Monthly EURIBOR + 1.00% GBP Revolver — 157.0 Monthly LIBOR + 1.00% 2023 Term Loan Facility (a) 100.0 100.0 Monthly LIBOR + 1.20% March 2023 (c) 2025 Term Loan Facility (a) 700.0 700.0 Monthly LIBOR + 1.20% March 2025 2024 Notes, including bond discount of $0.6 million and $0.7 million, respectively 599.4 599.3 2.900 % November 2024 2027 Notes, including bond discount of $0.6 million and $0.6 million, respectively (d) 578.9 612.6 1.450 % January 2027 2028 Notes, including bond discount of $7.4 million (e) 572.1 — 1.125 % May 2028 2029 Notes, including bond discount of $1.4 million and $1.6 million, respectively 598.6 598.4 3.450 % November 2029 2030 Notes, including bond discount of $4.3 million and $4.7 million, respectively 395.7 395.3 2.150 % November 2030 Deferred financing costs (29.6) (29.5) — — Total $ 3,515.1 $ 3,409.0 (a) - Monthly USD LIBOR as of September 30, 2021 was 0.09%. (b) - The Company has an option to exercise a one-year extension option, subject to certain conditions. (c) - The Company has an option to exercise two 1-year extension options, subject to certain conditions. (d) - The 2027 Notes represent €495.3 million, including bond discount of €0.7 million, of Euro bonds. (e) - The 2028 Notes represent €489.2 million, including bond discount of €6.7 million, of Euro bonds. Credit facilities On March 31, 2020, CyrusOne LP, a Maryland limited partnership and subsidiary of CyrusOne Inc., entered into an amendment to its credit agreement, dated as of March 29, 2018 (as so amended, the “Amended Credit Agreement”), among the Operating Partnership, as borrower, the lenders party thereto (the “Lenders”) and JPMorgan Chase Bank, N.A., as administrative agent for the Lenders. Proceeds from the Amended Credit Agreement were used, among other things, to refinance and replace the credit facilities under the $3.0 Billion Credit Facility (as defined below). The Amended Credit Agreement provides for (i) a $1.4 billion senior unsecured multi-currency revolving credit facility (the “Revolving Credit Facility”), (ii) senior unsecured term loans due 2023 in a dollar equivalent principal amount of $400.0 million (the “2023 Term Loan Facility”), and (iii) senior unsecured term loans due 2025 in a principal amount of $700.0 million (the “2025 Term Loan Facility”). The Amended Credit Agreement also includes an accordion feature pursuant to which the Operating Partnership is permitted to obtain additional revolving or term loan commitments so long as the aggregate principal amount of commitments and/or term loans under the Amended Credit Agreement does not exceed $4.0 billion. The Revolving Credit Facility provides for borrowings in U.S. Dollars, Euros, Pounds Sterling, Canadian Dollars, Australian Dollars, Japanese Yen, Hong Kong Dollars, Singapore Dollars and Swiss Francs (subject to a sublimit of $750.0 million on borrowings in currencies other than U.S. Dollars). The Revolving Credit Facility matures on March 29, 2024 with one 12-month extension option. The 2023 Term Loan Facility matures on March 29, 2023 with two 1-year extension options, and the 2025 Term Loan Facility matures on March 28, 2025. The interest rates for borrowings under the Amended Credit Agreement are, at the option of the borrower, based on a floating rate or base rate, plus a margin determined by reference to a pricing grid based on the lower of (i) the rate corresponding to the then applicable credit rating for the Operating Partnership’s senior unsecured debt or (ii) the rate corresponding to the then applicable ratio of the Company’s consolidated total indebtedness to its gross asset value. The Amended Credit Agreement includes certain restricted covenants, requirements to maintain certain financial ratios, including with respect to unencumbered assets, and events of default. On March 31, 2020, borrowings of $1.3 billion under the Amended Credit Agreement were used to repay the $3.0 Billion Credit Facility, which consisted of a $1.7 billion revolving credit facility ("$1.7 Billion Revolving Credit Facility"), which included a $750.0 million multicurrency borrowing sublimit, a 5-year term loan with commitments totaling $1.0 billion and a $300.0 million 7-year term loan (collectively, the "$3.0 Billion Credit Facility"). The aggregate outstanding principal balance under the Amended Credit Agreement as of March 31, 2020, was $1.3 billion, and the Company recognized a loss on early extinguishment of debt of $3.4 million in connection with the repayment of the $3.0 Billion Credit Facility. The current administrator of LIBOR will cease to publish one-month EUR LIBOR and GBP LIBOR after December 31, 2021, and USD LIBOR after June 30, 2023. There is a risk that the LIBOR transition could increase our interest and other costs relative to our outstanding subordinated debt. We may not be able to refinance those instruments on terms that reduce those costs to the level we would have expected if the administrator of LIBOR were to continue publishing indefinitely. Also, the transition from LIBOR could impact or change our hedge accounting practices. We pay a facility fee calculated based on the aggregate revolving commitments. The facility fee rate varies based on ratings-based pricing levels, and is currently equal to 0.25% per annum of the aggregate revolving commitments. The facility fee was $0.7 million and $2.1 million for the three and nine months ended September 30, 2021, respectively and $0.6 million and $2.4 million for the three and nine months ended September 30, 2020, respectively. As of September 30, 2021, we had $100.0 million and $700.0 million outstanding under the 2023 Term Loan Facility and the 2025 Term Loan Facility, respectively, and additional borrowing capacity under the Amended Credit Agreement was approximately $1.4 billion, net of $8.4 million of outstanding letters of credit. We had no borrowings outstanding under the Revolving Credit Facility as of September 30, 2021. Senior notes Euro bonds On May 26, 2021, CyrusOne Europe Finance DAC, a designated activity company organized under the laws of Ireland (the "Issuer"), and an indirect subsidiary of the Company and wholly owned by the Operating Partnership, closed its offering of €500.0 million aggregate principal amount of 1.125% senior notes due May 2028 (the “2028 Notes”). The Company received proceeds of €490.8 million, net of discount, underwriting costs and other deferred financing costs. The Company used the proceeds to repay floating rate Euro and GBP denominated obligations and fund continued development in Europe. The Notes were issued in a private offering exempt from the registration requirements of the Securities Act of 1933, as amended (the “Securities Act”), to persons outside of the United States pursuant to Regulation S under the Securities Act. The Notes have not been and will not be registered under the Securities Act and may not be offered or sold within the United States or to United States persons (within the meaning of Regulation S under the Securities Act) absent registration or an applicable exemption from the registration requirements. The 2028 Notes are senior unsecured obligations of the Issuer guaranteed by CyrusOne LP and CyrusOne Inc., which rank equally in right of payment with all existing and future unsecured senior indebtedness of the Issuer. The 2028 Notes are effectively subordinated in right of payment to any future secured indebtedness, if any, to the extent of the value of the assets securing such indebtedness. The 2028 Notes may be redeemed at our option prior to their scheduled maturity dates at the prices and premiums and on the terms set forth in the respective indentures governing the notes. On January 22, 2020, the Operating Partnership and CyrusOne Finance Corp., a single-purpose finance subsidiary, both wholly-owned subsidiaries of the Company (together, the "Issuers"), completed a public offering of €500.0 million aggregate principal amount of 1.450% senior notes due January 2027 (the “2027 Notes”). The Company received proceeds of €495.3 million, net of discount, underwriting costs and other deferred financing costs. The Company used the proceeds to repay floating rate Euro denominated obligations and fund continued development in Europe. The 2027 Notes are senior unsecured obligations of the Issuers guaranteed by CyrusOne Inc., which rank equally in right of payment with all existing and future unsecured senior indebtedness of the Issuers. The 2027 Notes are effectively subordinated in right of payment to any future secured indebtedness, if any, to the extent of the value of the assets securing such indebtedness. The 2027 Notes may be redeemed at our option prior to their scheduled maturity dates at the prices and premiums and on the terms set forth in the respective indentures governing the notes. US bonds On September 21, 2020, the Issuers completed a public offering of $400.0 million aggregate principal amount of 2.150% senior notes due November 2030 (the "2030 Notes"). The Company received proceeds of $392.6 million, net of discount, underwriting costs and other deferred financing costs. The Company used the proceeds to repay $300.0 million of the outstanding indebtedness under the Operating Partnership's 2023 Term Loan Facility, to repay the then outstanding balance of $20.0 million on the US Revolver balance under the Revolving Credit Facility and the remainder for general corporate purposes. In connection with the repayment of outstanding indebtedness of the senior unsecured term loans due March 2023, the Company recognized a loss on early extinguishment of debt of $3.1 million in the three months ended September 30, 2020. On December 5, 2019, the Issuers completed a public offering of $600.0 million aggregate principal amount of 2.900% senior notes due November 2024 (the "2024 Notes") and $600.0 million aggregate principal amount of 3.450% senior notes due November 2029 (the “2029 Notes”). The Company received proceeds of $1,197.4 million, net of discounts, underwriting costs and other deferred financing costs. The Company used the proceeds to finance the repurchase of all of its 5.000% senior notes due 2024 (the “Old 2024 Notes”) and all of its 5.375% senior notes due 2027 (together with the Old 2024 Notes, the "Existing Notes"), including the payment of consent payments, for the redemption and discharge of Existing Notes that remained outstanding after the completion of the tender offers and consent solicitations, for the payment of related premiums, fees, discounts and expenses and for general corporate purposes. In connection with the repurchase of the Existing Notes, the Company recognized a loss on early extinguishment of debt of $71.8 million in the three months ended December 31, 2019. The 2024 Notes, 2029 Notes and 2030 Notes are senior unsecured obligations of the Issuers guaranteed by CyrusOne Inc., which rank equally in right of payment with all existing and future unsecured senior indebtedness of the Issuers. The 2024 Notes, 2029 Notes and 2030 Notes are effectively subordinated in right of payment to any future secured indebtedness of the Issuers, if any, to the extent of the value of the assets securing such indebtedness. The 2024 Notes, 2029 Notes and 2030 Notes may be redeemed at our option prior to their scheduled maturity dates at the prices and premiums and on the terms set forth in the respective indentures governing the notes. Financial debt covenants Our debt agreements contain customary provisions with respect to events of default, affirmative and negative covenants and borrowing conditions. The most restrictive covenants are generally included in the Amended Credit Agreement. The Amended Credit Agreement requires us to maintain certain financial covenants including the following, in each case on a consolidated basis, a minimum fixed charge ratio, maximum total and secured leverage ratios, maximum net operating income to debt service ratio and a maximum ratio of unsecured indebtedness to unencumbered asset value. In order to continue to have access to amounts available under the Amended Credit Agreement, the Company must remain in compliance with all of that agreement's covenants. As of September 30, 2021, we are in compliance with the financial covenants of our debt agreements.

Fair Value of Financial Instrum

Fair Value of Financial Instruments and Hedging Activities	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments and Hedging Activities	Fair Value of Financial Instruments and Hedging Activities Fair value measurements are based on the assumptions that market participants would use in pricing the asset or liability. As a basis for considering assumptions in fair value measurements, a fair value hierarchy that distinguishes between market participant assumptions based on market data obtained from sources independent of the reporting entity (observable inputs that are classified within Levels 1 and 2 of the hierarchy) and the reporting entity's own assumptions about market participant assumptions (unobservable inputs classified within Level 3 of the hierarchy) has been established. Level 1 inputs utilize quoted prices (unadjusted) in active markets for identical assets and liabilities that we have the ability to access. Level 2 inputs are inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. Level 2 inputs may include quoted prices for similar assets and liabilities in active markets, as well as inputs that are observable for the asset or liability (other than quoted prices), such as interest rates and yield curves that are observable at commonly quoted intervals. Level 3 inputs are unobservable inputs for the asset or liability that are typically based on an entity's own assumptions, as there is little, if any, related market activity. In instances where the determination of the fair value measurement is based on inputs from different levels of the fair value hierarchy, the level in the fair value hierarchy within which the fair value measurement falls is based on the lowest level input that is significant to the fair value measurement in its entirety. Our assessment of the significance of a particular input to the fair value measurement requires judgment and considers factors specific to the asset or liability. The fair value of Cash and cash equivalents, Rent and other receivables, Construction costs payable, Dividends payable and Accounts payable and accrued expenses approximate their carrying value because of the short-term nature of these financial instruments. The carrying value, exclusive of deferred financing costs, for the revolving credit facilities and the floating rate term loans approximate estimated fair value as of September 30, 2021 and December 31, 2020, due to the floating rate nature of the interest rates and the stability of our credit ratings. We determine the fair value of our derivative financial instruments using widely accepted valuation techniques including discounted cash flow analysis on the expected cash flows of each derivative. This analysis reflects the contractual terms of the derivatives, including the period to maturity, and uses observable market-based inputs, including interest rate curves, foreign exchange rates and implied volatilities. We determine the fair values of our interest rate swaps using the market standard methodology of netting the discounted future fixed cash receipts or payments and the discounted expected variable cash payments. We base the variable cash payments on an expectation of future interest rates, or forward curves, derived from observable market interest rate curves. We base the fair values of our net investment hedges on the change in the spot rate at the end of the period as compared with the strike price at inception. We incorporate credit valuation adjustments to appropriately reflect nonperformance risk for us and the respective counterparty in the fair value measurements. In adjusting the fair value of our derivative contracts for the effect of nonperformance risk, we consider the impact of netting and any applicable credit enhancements, such as collateral postings, thresholds, mutual puts and guarantees. We have determined that the majority of the inputs used to value our derivatives fall within Level 2 of the fair value hierarchy. Although the credit valuation adjustments associated with our derivatives utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default by us and our counterparties, we assess the significance of the impact of the credit valuation adjustments on the overall valuation of our derivative positions and have determined that the credit valuation adjustments are not significant to the overall valuation of our derivatives. The carrying value and fair value of other financial instruments are as follows (in millions): September 30, 2021 December 31, 2020 Carrying Value Fair Value Carrying Value Fair Value Debt: Variable Rate Debt: Revolving Credit Facility $ — $ — $ 432.9 $ 432.9 2023 Term Loan Facility 100.0 100.0 100.0 100.0 2025 Term Loan Facility 700.0 700.0 700.0 700.0 Fixed Rate Debt: 2024 Notes - 2.900% (1) 599.4 629.8 599.3 640.7 2027 Notes - 1.450% (1) 578.9 581.8 612.6 619.9 2028 Notes - 1.125% (1) 572.1 568.3 — — 2029 Notes - 3.450% (1) 598.6 623.0 598.4 644.1 2030 Notes - 2.150% (1) 395.7 370.1 395.3 388.6 Derivative Contracts: Cross Currency Swaps Liability (2) 22.3 22.3 52.2 52.2 Interest Rate Swap Liability (2) 4.4 4.4 7.0 7.0 Equity Investments carried at Fair Value: GDS equity investment (3) — — 44.2 44.2 (1) - The fair value of notes are based on quoted market prices for these notes, which is considered Level 1 of the fair value hierarchy. (2) - The fair values of our cross currency and interest rate swaps are determined using the market standard methodology of netting the discounted future fixed cash flows and the discounted expected variable cash flows based on an expectation of future interest rates derived from Level 2 observable market interest rate curves. (3) - The fair value is based on quoted market prices for the GDS ADSs, which is considered Level 1 of the fair value hierarchy. Hedging Activities When we use derivative instruments, it is generally to reduce our exposure to fluctuations in interest rates and foreign currency exchange rate movements. We have not entered into, and do not plan to enter into, financial instruments for trading or speculative purposes. To manage foreign currency exposure, we have entered into Euro denominated debt and cross-currency swaps to hedge the Company's net investment in its Euro functional currency consolidated subsidiaries and the variability in EUR-USD exchange rate. Accounting for changes in the fair value of derivatives depends on the intended use of the derivative and the designation of the derivative, including whether we have elected to designate a derivative in a hedging relationship and apply hedge accounting and whether the hedging relationship has satisfied the criteria necessary to apply hedge accounting. Derivatives designated and qualifying as a hedge of the exposure to changes in the fair value of an asset, liability, or firm commitment attributable to a particular risk, such as foreign currency risk or interest rate risk, are considered fair value hedges. Derivatives designated and qualifying as a hedge of the exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. Hedge accounting generally provides for the matching of the timing of gain or loss recognition on the hedging instrument with the recognition of the changes in the fair value of the hedged asset or liability that are attributable to the hedged risk in a fair value hedge or the earnings effect of the hedged forecasted transactions in a cash flow hedge. For derivatives designated as "cash flow" hedges, the change in the fair value of the derivative is initially reported in Other comprehensive (loss) income ("OCI") in our Condensed Consolidated Statements of Comprehensive (Loss) Income and subsequently reclassified into Gain (loss) when the hedged transaction affects earnings, or the hedging relationship is no longer highly effective. We assess the effectiveness of each hedging relationship whenever financial statements are issued, or earnings are reported and at least every three months. We also use derivatives, such as foreign currency swaps, that are not designated as hedges to manage foreign currency exchange rate risks. The changes in fair values of these derivatives that were not designated or did not qualify as hedging instruments are immediately, recognized in earnings within the line item Foreign currency and derivative gains (losses), net in the Condensed Consolidated Statements of Operations. The following table summarizes the Company's derivative positions as of September 30, 2021 and December 31, 2020, (in millions): September 30, 2021 December 31, 2020 Maturity Date Notional Amount Hedged Risk Asset Liability Asset Liability Designated derivatives Cross Currency Swaps EUR - USD 3/29/2023 $ 250.0 Net investment hedge $ — $ 11.1 $ — $ 26.0 EUR - USD 3/29/2023 250.0 Net investment hedge — 11.2 — 26.2 Interest Rate Swaps USD Libor 3/29/2023 300.0 Interest rate hedge - Float to fixed — 4.4 — 7.0 Total $ — $ 26.7 $ — $ 59.2 Cross-Currency Swaps The Company has entered into cross-currency swaps whereby the Company pays floating interest rate and receives floating interest rate to hedge the variability of future cash flows attributable to changes in the 1-month USD LIBOR versus EUR LIBOR rates (a pay-floating, receive-floating interest rate swap). The pay-floating, receive-floating interest rate swap payments are recognized in Interest expense, net in the Condensed Consolidated Statements of Operations. As of September 30, 2021, the Company has two cross-currency EUR/USD contracts to sell $500.0 million and purchase €450.7 million maturing in March 2023 representing a fair value liability of $22.3 million reported in Other liabilities. As of December 31, 2020, our cross-currency swaps were designated as net investment hedges with a fair value liability of $52.2 million reported in Other liabilities. The Company recognized gains of $4.5 million for the nine months ended September 30, 2020 on undesignated cross-currency contracts which were recognized in Foreign currency and derivative gains (losses), net in the Condensed Consolidated Statements of Operations. Interest Rate Swaps On September 3, 2019, the Company entered into a floating-fixed interest rate swap agreement to convert $300.0 million of variable interest rate debt of the 2023 Term Loan Facility to 1.19% fixed rate debt to hedge the risk of changes in cash flows attributable to USD-LIBOR interest payments. On September 21, 2020, the Company paid down $300.0 million of term loans under the 2023 Term Loan Facility. The $300.0 million floating-fixed interest rate swap remains in place and continues to provide an effective hedge of the risk of changes in cash flows attributable to USD-LIBOR term loans through March 2023. For the three and nine months ended September 30, 2021 and 2020, the Company recognized changes in fair value of the interest rate swap in OCI. As of September 30, 2021, the interest rate swap was a liability of $4.4 million reported in Other liabilities. As of December 31, 2020, the interest rate swap was a liability of $7.0 million reported in Other liabilities. Net Investment Hedges Exchange rate variations impact our financial results because the financial results of our foreign subsidiaries are translated to U.S. dollars each period, with the effect of exchange rate variations being recorded in OCI as part of the cumulative foreign currency translation adjustment. As a result, changes in the value of our borrowings under the foreign currency denominated revolver under our Revolving Credit Facility, 2027 Notes and synthetically swapped debt will be reported in the same manner as foreign currency translation adjustments, which are recorded in OCI as part of the cumulative foreign currency translation adjustment. The following table presents the effect of our derivative financial instruments on our accompanying condensed consolidated financial statements (in millions): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2021 2020 2021 2020 Derivatives in Cash Flow Hedging Relationships Cross-Currency and Interest Rate Swaps: Amount of gain (loss) recognized in OCI for derivatives $ 13.6 $ (20.9) $ 32.5 $ (31.5) Amount of gain (loss) reclassified from Accumulated OCI for derivatives (1) $ (0.8) $ (0.8) $ (2.5) $ (0.9) (1) - Gains and (losses) are recognized in Interest expense, net. During the next 12 months, we estimate that based on current prevailing interest rates that losses of approximately $3.3 million will be reclassified from "Accumulated OCI" to Net income.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Stockholders' Equity	Stockholders' Equity During the fourth quarter of 2018, the Company entered into sales agreements pursuant to which the Company may issue and sell from time to time shares of its common stock having an aggregate sales price of up to $750.0 million (the "New 2018 ATM Stock Offering Program"). During the second quarter of 2020, the Company entered into sales agreements pursuant to which the Company may issue and sell from time to time shares of its common stock having an aggregate sales price of up to $750.0 million (the “2020 ATM Stock Offering Program”). The 2020 ATM Stock Offering Program replaced the New 2018 ATM Stock Offering Program. During the second quarter of 2021, the Company entered into sales agreements pursuant to which the Company may issue and sell from time to time shares of its common stock having an aggregate sales price of up to $750.0 million (the "2021 ATM Stock Offering Program" and, together with the New 2018 ATM Stock Offering Program and 2020 ATM Stock Offering Program, the “ATM stock offering program”). The 2021 ATM Stock Offering Program replaced the 2020 ATM Stock Offering Program. The Company did not enter into any forward agreements under its ATM stock offering program for the three months ended September 30, 2021. During the three months ended September 30, 2020, the Company entered into forward agreements for 3.0 million common shares under its ATM stock offering program for estimated net proceeds of approximately $218.7 million, subject to adjustment for a floating interest rate factor and scheduled dividends. During the nine months ended September 30, 2021, the Company settled forward agreements under its ATM stock offering program entered into in May 2020 and September 2020 totaling 5.7 million common shares at an average price of $69.91 for proceeds of $403.8 million, net of expenses. During the nine months ended September 30, 2020, the Company settled forward agreements under its ATM stock offering program totaling 5.0 million common shares at an average price of $63.61 for proceeds of $315.6 million, net of expenses. As of September 30, 2021, there was approximately $513.4 million under the 2021 ATM Stock Offering Program available for future offerings. At September 30, 2021, the Company had approximately 126.9 million shares of common stock outstanding. Forward Sales The Company currently expects to fully physically settle the remaining forward equity sale agreements by June 2022 and receive cash proceeds upon one or more settlement dates at the Company’s discretion, prior to the final settlement dates under the forward equity sale agreements, in which case we expect to receive aggregate net cash proceeds at settlement equal to the number of shares specified in such forward equity sale agreements multiplied by the relevant forward price per share. The weighted average forward sale price that we expect to receive upon physical settlement of the agreements will be subject to adjustment for (i) a floating interest rate factor equal to a specified daily rate less a spread and (ii) scheduled dividends during the terms of the agreements. The following table represents a summary of forward sale of equity of our common stock for the nine months ended September 30, 2021 (in millions): Offering Program Forward Shares Sold/(Settled) Net Proceeds Received Remaining Proceeds Available (1) Total at December 31, 2020 6.8 $ — $ 484.7 Forward adjustments — — (7.6) May 2020 Forward Offering settlement (1.4) 95.3 (95.3) May 2020 Forward Offering settlement (1.3) 95.5 (95.5) May 2021 Forward Offering - Sales 0.3 22.5 June 2021 Forward Offering - Sales 1.6 116.7 June 2021 Forward Offering - Sales 1.1 91.0 September 2020 Forward Offering settlement (1.4) 100.5 (100.5) September 2020 Forward Offering settlement (1.6) 112.5 (112.5) Total at September 30, 2021 4.1 $ 403.8 $ 303.5 (1) As of September 30, 2021, the total estimated proceeds, net of adjustments for (i) a floating interest rate factor equal to a specified daily rate less a spread and (ii) scheduled dividends adjustments is $303.5 million subject to further adjustment when the forward offerings are settled as described above. Dividends During the nine months ended September 30, 2021 and 2020, regular dividends were paid to our stockholders of $1.54 and $1.51 per common share, respectively, totaling $187.9 million and $174.7 million, respectively. On October 27, 2021, the Company announced a cash dividend of $0.52 per common share payable on January 7, 2022, to stockholders of record at the close of business on January 3, 2022.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation Stock Plans The board of directors of CyrusOne Inc. adopted the 2012 Long-Term Incentive Plan ("LTIP"), prior to the IPO, which was amended and restated on May 2, 2016 and February 18, 2019. The LTIP is administered by the compensation committee of the board of directors. Awards issuable under the LTIP include common stock, restricted stock, restricted stock units, stock options, LTIP Units (as described below) and other incentive awards. CyrusOne Inc. has reserved a total of 8.9 million shares of CyrusOne Inc. common stock for issuance pursuant to the LTIP, which may be adjusted for changes in capitalization and certain corporate transactions. To the extent that an award, if forfeitable, expires, terminates or lapses, or an award is otherwise settled in cash without the delivery of shares of common stock to the participant, then any unpaid shares subject to the award will be available for future grant or issuance under the LTIP. The payment of dividend equivalents in cash in conjunction with any outstanding awards will not be counted against the shares available for issuance under the LTIP. The related stock compensation expense incurred by CyrusOne Inc. is allocated to the operating partnership. Shares available under the LTIP as of September 30, 2021 were approximately 4.2 million. Shares vest according to each agreement and as long as the employee remains employed with the Company. The Company has granted awards with time-based vesting and market-based vesting features. The company began awarding LTIP Units as grants in February 2021. Pursuant to the LTIP plan, the Company may grant partnership common units in CyrusOne LP called LTIP Units. Vested LTIP Units may be redeemed by the Company in cash or CyrusOne common stock, at the discretion of the Company, on a one-for-one basis with common shares, subject to certain restrictions of the Second Amendment to the Amended and Restated Agreement of Limited Partnership of CyrusOne LP. Time-based LTIP Units receive distributions equally along with common shares. Market-based LTIP Units receive distribution equally along with common shares, however payments are deferred if and until vesting has lapsed, subject to de minimis distributions for federal tax purposes. Restricted stock, restricted stock units and LTIP Units are issued as either time-based where the award vests over the service period of the grant or market-based where the fair value at the time of the award is recognized as expense over the service period. Vesting of market-based awards, if any, is based on achieving certain financial targets, currently based on total stockholder return ("TSR"). The restricted stock units have the right to receive dividend equivalents in cash and holders of restricted stock have the right to receive dividends. The market-based awards accrue dividends equivalents that are payable in cash upon the vesting, if any, of the awards. Compensation expense is measured based on the estimated grant-date fair value. Expense for time-based grants is recognized under a straight-line method. For market-based grants, expense is recognized under a graded expense attribution method. Total stock-based compensation expense was $8.5 million and $17.2 million for the three and nine months ended September 30, 2021, respectively, and $6.7 million and $13.7 million for the three and nine months ended September 30, 2020, respectively. The following tables summarize the unvested restricted stock, restricted stock units, stock options and LTIP Units activity and the weighted average fair value of these shares at the date of grant for the nine months ended September 30, 2021 and 2020 (market-based awards are reflected at the target amount of the grant): Restricted Stock ("RS") 2021 2020 Restricted Stock Weighted Average Grant Date Fair Value Restricted Stock Weighted Average Grant Date Fair Value Outstanding January 1, 118,233 $ 74.12 16,681 $ 52.46 Granted 119,323 74.10 100,649 74.64 Exercised (96,410) 74.61 (16,681) 52.46 Forfeited (8,586) 72.44 — — Outstanding September 30, 132,560 $ 73.85 100,649 $ 74.64 Time-based RS outstanding 120,275 $ 71.53 100,649 $ 74.64 Market-based RS outstanding 12,285 $ 96.60 — $ — Restricted Stock Units ("RSUs") 2021 2020 Restricted Stock Units Weighted Average Grant Date Fair Value Restricted Stock Units Weighted Average Grant Date Fair Value Outstanding January 1, 484,890 $ 66.66 646,619 $ 55.80 Granted 20,222 69.92 220,176 97.49 TSR and other adjustments (a) 106,628 92.67 164,071 91.32 Exercised (387,815) 61.74 (371,186) 81.23 Forfeited (34,823) 131.32 (155,466) 58.68 Outstanding September 30, 189,102 $ 79.86 504,214 $ 67.87 Time-based RSUs outstanding 115,316 $ 61.96 230,951 $ 60.32 Market-based RSUs outstanding 73,786 $ 107.83 273,263 $ 74.24 (a) TSR adjustments represent the incremental shares earned for the TSR performance metric exceeding target and resulting in 200% payout for the 2018 LTIP Performance Awards. Stock Options 2021 2020 Options Weighted Average Exercise Price Options Weighted Average Exercise Price Outstanding January 1, 97,801 $ 30.87 375,086 $ 31.64 Granted — — — — Exercised (95,196) 31.07 (277,285) 31.92 Forfeited — — — — Outstanding September 30, 2,605 $ 23.58 97,801 $ 30.87 Time-based stock options outstanding — $ — 80,871 $ 32.40 Market-based stock options outstanding 1,881 $ 23.58 12,754 $ 23.58 Performance-based stock options outstanding 724 $ 23.58 4,176 $ 23.58 LTIP Units 2021 2020 LTIP Units Weighted Average Grant Date Fair Value LTIP Units Weighted Average Grant Date Fair Value Outstanding January 1, — $ — — $ — Granted 149,061 83.15 — — Exercised — — — — Forfeited (52,331) 87.70 — — Outstanding September 30, 96,730 $ 80.69 — $ — Time-based LTIP Units outstanding 47,291 $ 65.62 — $ — Market-based LTIP Units outstanding 49,439 $ 95.10 — $ —

Income (Loss) per Share

Income (Loss) per Share	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Income (Loss) per Share	Income (Loss) per Share Basic income per share is calculated using the weighted average number of shares of common stock outstanding during the period. In addition, Net income (loss) applicable to participating securities and the participating securities are both excluded from the computation of basic income per share. Diluted income per share is calculated using the weighted average number of shares of common stock outstanding during the period, including restricted stock outstanding. If there is Net income (loss) during the period, the dilutive impact of common stock equivalents outstanding are also reflected. For the three and nine months ended September 30, 2021, 4.2 million shares and 4.1 million shares, respectively, were excluded from the calculation of diluted net income per share because the effect was anti-dilutive. For the three and nine months ended September 30, 2020, 5.5 million shares and 5.7 million shares, respectively, were excluded from the calculation of diluted net income per share because the effect was anti-dilutive. The following table reflects the computation of basic and diluted Net income (loss) per share for the three and nine months ended September 30, 2021 and 2020: IN MILLIONS, except per share amounts Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Basic Diluted Basic Diluted Basic Diluted Basic Diluted Numerator: Net income (loss) $ 6.7 $ 6.7 $ (37.3) $ (37.3) $ 32.3 $ 32.3 $ 22.4 $ 22.4 Less: Restricted stock dividends (0.2) (0.2) (0.1) (0.1) (0.4) (0.4) (0.4) (0.4) Net income (loss) available to stockholders $ 6.5 $ 6.5 $ (37.4) $ (37.4) $ 31.9 $ 31.9 $ 22.0 $ 22.0 Denominator: Weighted average common outstanding - basic 124.2 124.2 118.7 118.7 122.4 122.4 116.3 116.3 Performance-based restricted stock and units — — 0.1 0.4 Dilutive forward shares 0.1 — — — Weighted average shares outstanding - diluted 124.3 118.7 122.5 116.7 EPS: Net income (loss) per share - basic $ 0.05 $ (0.32) $ 0.26 $ 0.19 Effect of dilutive shares: Net income (loss) per share - diluted $ 0.05 $ (0.32) $ 0.26 $ 0.19

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes CyrusOne Inc. elected to be taxed as a REIT under the Internal Revenue Code of 1986, as amended (the "Code"), commencing with its taxable year ended December 31, 2013. To remain qualified as a REIT, the Company is required to distribute at least 90% of its taxable income to its stockholders and meet various other requirements imposed by the Code relating to such matters as operating results, asset holdings, distribution levels and diversity of stock ownership. Provided the Company continues to qualify for taxation as a REIT, the Company is generally not subject to corporate level federal income tax on the earnings distributed currently to its stockholders. It is the Company's policy and intent, subject to change, to distribute 100% of its taxable income and therefore no provision is required in the accompanying financial statements for federal income taxes with regards to activities of CyrusOne Inc. and its subsidiary pass-through entities. CyrusOne Inc. and certain of its subsidiaries are subject to state and local income taxes, franchise taxes, and gross receipts taxes. The Company has elected to treat certain of its subsidiaries as taxable REIT subsidiaries ("TRSs"). The Company's TRSs are subject to U.S. federal, state and local corporate income taxes. The Company's foreign subsidiaries are subject to corporate income taxes in the jurisdictions in which they operate.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Operating Leases The Company leases certain data center facilities and equipment from third parties. Certain of these leases provide for renewal options with fixed rent escalations beyond the initial lease term. Standby Letters of Credit As of September 30, 2021, the Company had outstanding letters of credit of $8.4 million as security for obligations under the terms of its lessee agreements. Performance Guarantees Customer contracts generally require specified levels of performance related to uninterrupted service and cooling temperatures and delivery of data center spaces at specified dates. If these performance standards are not met, the Company could be obligated to issue billing credits to the customer. Management assesses the probability that a performance standard will not be achieved. We recognized contingent losses of $0.8 million and $0.3 million for performance guarantees for the nine months ended September 30, 2021 and 2020, respectively. Purchase Commitments The Company has entered into non-cancellable contracted commitments for construction of data center facilities and acquisition of equipment. As of September 30, 2021, these commitments were approximately $176.3 million and are expected to be incurred over the next one one Indemnifications During the normal course of business, we make certain indemnities, commitments and guarantees under which we may be required to make payments in relation to certain transactions. These include (i) intellectual property indemnities to customers in connection with the use, sale and/or license of products and services, (ii) indemnities to vendors and service providers pertaining to claims based on our negligence or willful misconduct and (iii) indemnities involving the representations and warranties in certain contracts. In addition, we have made contractual commitments to several employees providing for payments upon the occurrence of certain prescribed events. The majority of these indemnities, commitments and guarantees do not provide for any limitation on the maximum potential for future payments that we could be obligated to make. Management assesses the probability that these performance standards, credits, claims or indemnities have been incurred and liabilities or asset reserves are established for loss contingencies when the losses associated are deemed to be probable and the loss can be reasonably estimated. Based on information currently available, the Company believes that the outcome of such matters will not, individually or in the aggregate, have a material effect on its condensed consolidated financial statements. Contingencies CyrusOne is involved in legal, tax and regulatory proceedings arising from the conduct of its business activities. Liabilities are established for loss contingencies when losses associated with such claims are deemed to be probable, and the loss can be reasonably estimated. Based on information currently available and consultation with legal counsel, we believe that the outcome of all claims will not, individually or in the aggregate, have a material effect on our financial statements.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Risks and Uncertainties	Risks and Uncertainties The novel strain of the coronavirus (COVID-19) identified in China in late 2019 has spread globally and has resulted in authorities implementing numerous measures to attempt to contain the virus. This has included travel bans, shelter in place regulations and other restrictions and shutdowns. We continue to monitor the global outbreak and to take steps to mitigate the potential risks to us posed by the pandemic. We have continued to implement restrictions on physical participation in meetings and limit business travel, which have disrupted how we operate our business. The duration and extent of the impact from the COVID-19 pandemic continues to depend on future developments that cannot be accurately predicted at this time, such as the severity and transmission rate of the virus, including variants such as Delta, the extent and effectiveness of containment actions, the rate and effectiveness of vaccinations and the impact of these and other factors on our employees, customers, suppliers and vendors. The effect of the pandemic and measures implemented by authorities could disrupt our supply chain, which currently remains fully functional, including the provision of services to us by our vendors and could result in restrictions on construction activities. These factors and the continuing uncertainty around them could adversely impact our employees, customers, vendors and suppliers resulting in a material adverse effect on our business, financial condition, results of operations, cash flows and ability to pay dividends as well as the market price of our common stock.
Basis of Presentation	Basis of Presentation The accompanying condensed consolidated financial statements include the accounts of the Company, as well as all wholly-owned subsidiaries and any consolidated variable interest entities. All intercompany balances and transactions have been eliminated in consolidation.
Investment in Real Estate	Investment in Real Estate Acquisition of Properties Investment in real estate consists of land, buildings, improvements and integral equipment utilized in our data center operations. We expect most acquisitions to be an acquisition of assets rather than a business combination as our typical acquisitions consist of properties whereby substantially all the fair value of gross assets acquired is concentrated in a single asset set (land, building and in-place leases), which are treated as asset acquisitions.
Impairment Losses	Impairment LossesWhen events or circumstances indicate that the carrying amount of a real estate investment may not be recoverable, we review the carrying value of the asset. When such impairment indicators exist, we review an estimate of the undiscounted future cash flows expected to result from the use of the real estate investment and proceeds from its eventual disposition and compare such amount to the carrying value of the real estate investment. If our undiscounted cash flows indicate that we are unable to recover the carrying value of the real estate investment, an impairment loss is recognized. An impairment loss is measured as the amount by which the real estate investment's carrying value exceeds its estimated fair value
Cash and Cash Equivalents and Restricted Cash	Cash and Cash Equivalents and Restricted Cash Cash and cash equivalents include all non-restricted cash held in financial institutions and other non-restricted highly liquid short-term investments with original maturities of three months or less. Restricted cash includes cash equivalents restricted by contract or regulation, including letters of credit.
Equity Investments	Equity Investments We hold investments in various joint ventures where the Company evaluates its ability to influence the operating or financial decisions of the investee in applying the appropriate method of accounting for such investments. Influence tends to be more effective as the investor's percent of ownership in the voting rights of the investee increases. Our equity investments represent less than 20% of the voting rights of the investees and we do not exercise influence over the investee's operating and financial decisions. Accordingly, we do not account for our equity investments using the equity method of accounting. For further information about our equity investments, see Note 7, Equity Investments. Our equity investments are carried at cost because we do not exercise influence over the operating and financial decisions of the ventures and there is no readily determinable fair value and our investments are recorded at cost less impairment, if any. Dividends paid from operating profits are reported as a component of net income, while other dividends are reported as a return of capital.
Revenue Recognition	Revenue Recognition Our revenue consists of lease revenue and revenue from contracts with customers. Lease Revenue: Our leasing revenue primarily consists of colocation rent, metered power reimbursements and interconnection revenue and is accounted for under Accounting Standards Codification (“ASC”) 842, Leases (“ASC 842”). We generally are not entitled to reimbursements for rental expenses including real estate taxes, insurance or other common area operating expenses. a. Colocation Rent Revenue Colocation rent revenues, including interconnection revenue, are fixed minimum lease payments generally billed monthly in advance based on the contracted power or leased space. Some contracts may provide initial free rent periods and rents that escalate over the term of the contract. If rents escalate without the lessee gaining access to or control over additional leased power or space at the beginning of the lease term, the rental payments are recognized as revenue on a straight-line basis over the term of the lease. If rents escalate because the lessee gains access to and control over additional power and or leased space, revenue is recognized in proportion to the additional power or space in the periods that the lessee has control over the use of the additional power or space. The excess of revenue recognized over amounts contractually due is recognized as a straight-line receivable, which is included in Rent and other receivables in our Condensed Consolidated Balance Sheets. Some of our leases are structured on a gross basis in which the customer pays a fixed amount for colocation space and power. The revenue for these types of leases is recorded in colocation rent revenue. b. Metered Power Reimbursements Revenue Some of our leases provide that the customer is separately billed for power based upon actual or estimated metered usage generally at rates then in effect. Metered power reimbursement revenue is variable lease payments generally billed one month in arrears, and an estimate of this revenue is accrued in the month that the associated power is provided and recorded in metered power reimbursements revenue. Revenue from Contracts with Customers Revenue from our managed services, equipment sales, installations and other services are recognized under ASC 606, Revenue from Contracts with Customers ("ASC 606"). Equipment sold by us generally consists of servers, switches, networking equipment, cable infrastructure and cabinets. Revenue is recognized at a point-in-time when control of the equipment transfers to the customer from the Company, which generally occurs upon delivery to the customer. Managed services include providing a full-service managed data center, monitoring customer computer equipment, managing backups and storage, utilization reporting and other related ancillary information technology services. Management service contracts generally range from one Installation services include mounting, wiring, and testing of customer owned equipment. The installation period is typically short term in duration, and accordingly, revenue from the installation of customer equipment is recognized at a point-in-time once the installation is complete and the performance obligation is satisfied. Other services generally include installation of customer equipment, performing customer system re-boots, server cabinet and cage management, power monitoring, shipping and receiving, resolving technical issues, and other services requested by the customer. Other service revenue is measured based on the consideration specified in the contract and recognized over time as we satisfy the performance obligation. We adopted the practical expedient in ASC 606 that allows the Company to not disclose information about remaining performance obligations that have original expected durations of one year or less, the amount of the transaction price allocated to the remaining performance obligations and when we expect to recognize that amount as revenue for the year. We have also adopted the “as invoiced” practical expedient, whereby the Company recognizes revenue in the amount that directly corresponds to the amount of value transferred to the customer.
Rent and Other Receivables	Rent and Other Receivables Receivables consist principally of rent receivables including straight-line rent receivables. A general reserve may be recognized as an allowance for doubtful accounts when collectibility is not probable, after applying the overall collectibility constraint under ASC 842. Straight-line rent receivable, net was $175.8 million and $172.6 million at September 30, 2021 and December 31, 2020, respectively. The allowance for doubtful accounts is estimated based upon historic patterns of credit losses for aged receivables as well as specific provisions for certain identifiable, potentially uncollectible balances.
Foreign Currency Translation and Transactions	Foreign Currency Translation and Transactions The financial position of foreign subsidiaries is translated at the exchange rates in effect at the end of the period, while revenues and expenses are translated at average exchange rates during the period. Gains or losses from translation of foreign operations where the local currency is the functional currency are included as components of Other comprehensive income (loss). Gains or losses from foreign currency transactions are included in determining net income.
Stock-Based Compensation	Stock-Based Compensation We have a stock-based incentive award plan for our employees and directors. Stock-based compensation expense associated with these awards is recognized in General and administrative expenses, Property operating expenses, and Sales and marketing expenses in our Condensed Consolidated Statements of Operations. We measure stock-based compensation at the estimated fair value on the grant date and recognize the amortization of stock-based compensation expense over the requisite service period. Fair value is determined based on assumptions related to stock volatility, risk-free rate of return and estimates of market and company performance.
Fair Value Measurements	Fair Value Measurements Fair value measurements are utilized in accounting for business combinations, asset acquisitions, testing of goodwill and other long-lived assets for impairment, recording unrealized gain on available-for-sale securities, derivatives and related disclosures. Fair value of financial and non-financial assets and liabilities is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. The three-tier hierarchy that prioritizes certain inputs used in the methodologies of measuring fair value for asset and liabilities, is as follows: Level 1—Observable inputs for identical instruments such as quoted market prices; Level 2—Inputs include quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (i.e., interest rates, yield curves, etc.), and inputs that are derived principally from or corroborated by observable market data by correlation or other means (market corroborated inputs); and Level 3—Unobservable inputs that reflect our determination of assumptions that market participants would use in pricing the asset or liability. These inputs are developed based on the best information available, including our own data.
Derivative Instruments	Derivative Instruments We primarily hedge our foreign currency risk by borrowing in the currencies in which we invest. We may use derivative financial instruments, such as cross-currency swaps to manage foreign currency exchange rate risk related to both our foreign investments and the related earnings. In addition, we occasionally use interest rate swap contracts to manage interest rate risk and limit the impact of future interest rate changes on earnings and cash flows, primarily related to variable-rate debt. Derivative instruments are measured at fair value and recorded in Other assets and Other liabilities, depending on our rights or obligations under the applicable derivative contract. Derivatives that are not designated as hedges must be adjusted to fair value through earnings. Designated Derivatives . We may choose to designate our derivative financial instruments, generally cross-currency swaps as net investment hedges in foreign operations. At inception of the transaction, we designate the derivative financial instrument as a hedge of a specific underlying exposure, including the risk management objective and the strategy for undertaking the hedge transaction. We formally assess both at inception and at least quarterly thereafter, the effectiveness of our hedging transactions. Due to the high degree of effectiveness between the hedging instruments and the underlying exposures hedged, fluctuations in the value of the derivative financial instruments will generally be offset by changes in the cash flows or fair values of the underlying exposures being hedged. In addition to the net investment hedges described above, we may issue debt in a currency that is not the same functional currency of the borrowing entity to hedge our international investments. We designate the debt and related accrued interest as a net investment hedge to offset the translation and economic exposures related to our international investments. If the debt and related accrued interest exceeds the designated amount of our international investment, the foreign currency remeasurement on the unhedged portion of the debt during the period is recognized in Foreign currency and derivative gains (losses), net. For cash flow hedges, such as interest rate swaps, we report the effective portion of the gain or loss as a component of Other comprehensive (loss) income and reclassify it to the applicable line item in the Condensed Consolidated Statements of Operations, generally Interest expense, net over the corresponding period of the underlying hedged item. The ineffective portion of a derivative financial instrument’s change in fair value is recognized in earnings, generally Interest expense, net at the time the ineffectiveness occurred. To the extent the hedged debt related to our interest rate swaps and forwards is paid off early, we write off the remaining balance in Other comprehensive (loss) income and recognize the amount in Interest expense, net in the Condensed Consolidated Statements of Operations. Undesignated Derivatives . Derivative instruments, such as cross-currency swaps, for which hedge accounting is not applied are recorded at fair value in Other assets and Other liabilities and gains and losses resulting from changes in the fair value are reported in Foreign currency and derivative gains (losses), net in the Condensed Consolidated Statements of Operations. In addition, we may choose to not designate our interest rate swap and forward contracts. If a swap or forward contract is not designated as a hedge, the changes in fair value of these instruments is immediately recognized in earnings in Interest expense, net in the Condensed Consolidated Statements of Operations.
Recently Adopted Accounting Pronouncements and New Accounting Pronouncements Not Yet Adopted	Recently Issued Accounting Standards Recently Adopted Accounting Pronouncements Reference Rate Reform On March 12, 2020, the FASB issued Accounting Standards Update ("ASU") 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting ("ASU 2020-04"). ASU 2020-04 contains practical expedients for reference rate reform related activities that impact debt, leases, derivatives and other contracts. The guidance in ASU 2020-04 is optional and may be elected over time as reference rate reform activities occur. During the first quarter of 2021, we elected to apply the hedge accounting expedients related to probability and the assessments of effectiveness for future LIBOR-indexed cash flows to assume that the index upon which future hedged transactions will be based matches the index on the corresponding derivatives. Application of these expedients preserves the presentation of derivatives in our financial statements consistent with past presentation. We continue to evaluate the impact of the guidance and may apply other elections as applicable as additional changes in the market occur. Income Taxes On January 1, 2021, we adopted ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, which simplifies various aspects related to the accounting for income taxes, eliminates certain exceptions within ASC 740, Income Taxes, and clarifies certain aspects of the current guidance to promote consistency among reporting entities. The adoption did not have a significant impact on the Company. Financial Instruments - Credit Losses On January 1, 2020, we adopted ASU 2016-13, Financial Instruments-Credit Losses (CECL), which requires certain financial assets to be presented at the net amount expected to be collected. CECL and its related amendments apply to our customer contract trade receivables, notes receivable and net investments in leases. Our Rent and other receivables are primarily comprised of rent receivables, which are not within the scope of this sub-topic. The adoption did not have a significant impact on the Company because of our limited exposure to financial instruments subject to this standard. New Accounting Pronouncements Not Yet Adopted In August 2020, the FASB issued ASU 2020-06, Debt - Debt with Conversion and Other Options (Topic 470) and Derivatives and Hedging – Contracts in Entity’s Own Equity (Topic 815). This ASU reduces the number of accounting models for

Revenue Recognition (Tables)

Revenue Recognition (Tables)	9 Months Ended
	Sep. 30, 2021
Revenue from Contract with Customer [Abstract]
Lessor, Operating Lease, Payments to be Received, Maturity	At September 30, 2021, the future minimum lease payments to be received under non-cancellable operating leases, excluding month-to-month arrangements and metered power reimbursements are shown below (in millions): As of September 30, 2021 Minimum Lease Payments 2021 $ 219.8 2022 802.7 2023 659.5 2024 526.6 2025 442.4 2026 344.3 Thereafter 971.5 Total $ 3,966.8 At September 30, 2020, the future minimum lease payments to be received under non-cancellable operating leases, excluding month-to-month arrangements and metered power reimbursements are shown below (in millions): As of September 30, 2020 Minimum Lease Payments 2020 $ 198.9 2021 721.9 2022 614.5 2023 493.7 2024 377.7 2025 307.8 Thereafter 837.3 Total $ 3,551.8
Disaggregation of Revenue	For the three and nine months ended September 30, 2021 and 2020 lease revenue disaggregated by primary revenue stream is as follows (in millions): Three Months Ended September 30, Nine Months Ended September 30, Lease revenue 2021 2020 2021 2020 Colocation (Minimum lease payments) $ 236.4 $ 212.5 $ 681.5 $ 624.0 Metered power reimbursements (Variable lease payments) 62.5 44.6 188.6 116.5 Total lease revenue $ 298.9 $ 257.1 $ 870.1 $ 740.5 For the three and nine months ended September 30, 2021 and 2020, revenue from contracts with customers disaggregated by primary revenue stream is as follows (in millions): Three Months Ended September 30, Nine Months Ended September 30, Revenue from contracts with customers 2021 2020 2021 2020 Equipment sales and services $ 0.8 $ 0.6 $ 3.4 $ 10.0 Other revenue 4.4 5.1 13.8 14.6 Total revenue from contracts with customers $ 5.2 $ 5.7 $ 17.2 $ 24.6

Leases - As a Lessee (Tables)

Leases - As a Lessee (Tables)	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Lease, Cost	The components of lease expense are as follows (in millions): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Operating lease cost $ 5.0 $ 5.1 $ 15.3 $ 15.0 Finance lease cost: Amortization of assets 0.4 0.7 1.5 1.5 Interest on lease liabilities 1.1 0.4 2.3 1.1 Total net lease cost $ 6.5 $ 6.2 $ 19.1 $ 17.6 Supplemental cash flow and other information related to leases is as follows (in millions): Nine Months Ended September 30, 2021 Nine Months Ended September 30, 2020 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 18.2 $ 16.7 Operating cash flows from finance leases 2.3 1.1 Financing cash flows from finance leases 3.5 2.0 Non-cash right-of-use assets obtained in exchange for lease liabilities: Operating leases $ — $ 56.9 Finance leases $ 128.4 $ —
Assets and Liabilities, Lessee	Supplemental balance sheet information related to leases is as follows (in millions, except lease term and discount rate): September 30, 2021 December 31, 2020 Operating leases: Operating lease right-of-use assets $ 148.5 $ 211.4 Operating lease liabilities $ 183.9 $ 249.1 Finance leases: Property and equipment, at cost $ 163.1 $ 34.7 Accumulated amortization (8.6) (7.1) Property and equipment, net $ 154.5 $ 27.6 Finance lease liabilities $ 157.2 $ 29.1 Weighted average remaining lease term (in years): Operating leases 16.5 14.3 Finance leases (a) 27.5 18.2 Weighted average discount rate: Operating leases 4.0 % 3.7 % Finance leases (a) 2.6 % 4.7 % (a) Excludes a 999-year ground lease in Dublin, The Republic of Ireland entered into during the third quarter of 2019. The Dublin property is under active development and the finance lease is included in Construction in progress, including land under development on the Condensed Consolidated Balance Sheets.
Lessee, Operating Lease, Liability, Maturity	Maturities of lease liabilities were as follows as of September 30, 2021 (in millions): Operating Leases Finance Leases 2021 $ 6.6 $ 2.0 2022 24.7 7.7 2023 20.8 6.6 2024 16.2 6.4 2025 14.4 6.5 2026 9.4 6.9 Thereafter 159.7 187.1 Total lease payments $ 251.8 $ 223.2 Less: Imputed interest (67.9) (66.0) Total lease obligations $ 183.9 $ 157.2 Maturities of lease liabilities were as follows as of December 31, 2020 (in millions): Operating Leases Finance Leases 2021 $ 27.8 $ 4.2 2022 27.9 3.0 2023 23.9 2.0 2024 19.4 1.4 2025 17.8 1.5 Thereafter 221.6 30.5 Total lease payments $ 338.4 $ 42.6 Less: Imputed interest (89.3) (13.5) Total lease obligations $ 249.1 $ 29.1
Finance Lease, Liability, Maturity	Maturities of lease liabilities were as follows as of September 30, 2021 (in millions): Operating Leases Finance Leases 2021 $ 6.6 $ 2.0 2022 24.7 7.7 2023 20.8 6.6 2024 16.2 6.4 2025 14.4 6.5 2026 9.4 6.9 Thereafter 159.7 187.1 Total lease payments $ 251.8 $ 223.2 Less: Imputed interest (67.9) (66.0) Total lease obligations $ 183.9 $ 157.2 Maturities of lease liabilities were as follows as of December 31, 2020 (in millions): Operating Leases Finance Leases 2021 $ 27.8 $ 4.2 2022 27.9 3.0 2023 23.9 2.0 2024 19.4 1.4 2025 17.8 1.5 Thereafter 221.6 30.5 Total lease payments $ 338.4 $ 42.6 Less: Imputed interest (89.3) (13.5) Total lease obligations $ 249.1 $ 29.1

Investment in Real Estate (Tabl

Investment in Real Estate (Tables)	9 Months Ended
	Sep. 30, 2021
Real Estate [Abstract]
Schedule of Major Components of Real Estate Investments and Intangibles	As of September 30, 2021 and December 31, 2020, major components of our real estate investments and intangibles and related accumulated depreciation and amortization are as follows (in millions): As of: September 30, 2021 December 31, 2020 Cost Accumulated Depreciation and Amortization Net book value Cost Accumulated Depreciation and Amortization Net book value Investment in real estate Building and improvements $ 2,336.3 $ (714.1) $ 1,622.2 $ 2,035.2 $ (639.4) $ 1,395.8 Equipment 4,064.7 (1,366.3) 2,698.4 3,538.9 (1,128.5) 2,410.4 Intangible assets Customer relationships $ 247.1 $ (171.4) $ 75.7 $ 247.1 $ (163.1) $ 84.0 In-place leases 138.6 (88.3) 50.3 140.4 (74.6) 65.8 Other contractual 19.5 (12.8) 6.7 19.6 (11.6) 8.0 Total intangible assets $ 405.2 $ (272.5) $ 132.7 $ 407.1 $ (249.3) $ 157.8
Schedule of Useful Lives	Depreciation and amortization are calculated using the straight-line method over the useful lives of the assets. The typical life of owned assets are as follows: Buildings 30 years Building improvements 30 years Equipment 20 years

Equity Investments (Tables)

Equity Investments (Tables)	9 Months Ended
	Sep. 30, 2021
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	The Company has the following equity investments where it has a noncontrolling interest in the investees (in millions). Equity Investments as of: Investees Equity Method September 30, 2021 December 31, 2020 GDS, Class A share equivalent Fair value $ — $ 44.2 ODATA investments Cost method 30.3 22.9 Equity investments $ 30.3 $ 67.1
Schedule of Unrealized Loss on Investments	The Company recognized gains on marketable equity investment in GDS ADSs held and sold as follows: Three Months Ended September 30, Nine Months Ended September 30, IN MILLIONS 2021 2020 2021 2020 Net gain on marketable equity investments $ — $ 4.7 $ 2.4 $ 69.8 Less: Net gain recognized on marketable equity investments sold — 0.6 2.4 12.4 Unrealized gain on marketable equity investments held $ — $ 4.1 $ — $ 57.4

Other Assets (Tables)

Other Assets (Tables)	9 Months Ended
	Sep. 30, 2021
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of Other Assets	As of September 30, 2021 and December 31, 2020, the components of Other assets are as follows (in millions): September 30, 2021 December 31, 2020 Deferred leasing and other contract costs $ 63.7 $ 62.4 Prepaid expenses 22.8 19.1 Non-real estate assets, net 9.9 13.8 Other assets 31.6 38.1 Total $ 128.0 $ 133.4

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Debt	As of September 30, 2021 and December 31, 2020, the components of Debt are as follows (unless otherwise noted, interest rate and maturity date information are as of September 30, 2021) (in millions): September 30, 2021 December 31, 2020 Interest Rate Maturity Date Amended Credit Agreement: Revolving Credit Facility: March 2024 (b) EUR Revolver $ — $ 275.9 Monthly EURIBOR + 1.00% GBP Revolver — 157.0 Monthly LIBOR + 1.00% 2023 Term Loan Facility (a) 100.0 100.0 Monthly LIBOR + 1.20% March 2023 (c) 2025 Term Loan Facility (a) 700.0 700.0 Monthly LIBOR + 1.20% March 2025 2024 Notes, including bond discount of $0.6 million and $0.7 million, respectively 599.4 599.3 2.900 % November 2024 2027 Notes, including bond discount of $0.6 million and $0.6 million, respectively (d) 578.9 612.6 1.450 % January 2027 2028 Notes, including bond discount of $7.4 million (e) 572.1 — 1.125 % May 2028 2029 Notes, including bond discount of $1.4 million and $1.6 million, respectively 598.6 598.4 3.450 % November 2029 2030 Notes, including bond discount of $4.3 million and $4.7 million, respectively 395.7 395.3 2.150 % November 2030 Deferred financing costs (29.6) (29.5) — — Total $ 3,515.1 $ 3,409.0 (a) - Monthly USD LIBOR as of September 30, 2021 was 0.09%. (b) - The Company has an option to exercise a one-year extension option, subject to certain conditions. (c) - The Company has an option to exercise two 1-year extension options, subject to certain conditions. (d) - The 2027 Notes represent €495.3 million, including bond discount of €0.7 million, of Euro bonds. (e) - The 2028 Notes represent €489.2 million, including bond discount of €6.7 million, of Euro bonds.

Fair Value of Financial Instr_2

Fair Value of Financial Instruments and Hedging Activities (Tables)	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Carrying Value and Fair Value of Other Financial Instruments	The carrying value and fair value of other financial instruments are as follows (in millions): September 30, 2021 December 31, 2020 Carrying Value Fair Value Carrying Value Fair Value Debt: Variable Rate Debt: Revolving Credit Facility $ — $ — $ 432.9 $ 432.9 2023 Term Loan Facility 100.0 100.0 100.0 100.0 2025 Term Loan Facility 700.0 700.0 700.0 700.0 Fixed Rate Debt: 2024 Notes - 2.900% (1) 599.4 629.8 599.3 640.7 2027 Notes - 1.450% (1) 578.9 581.8 612.6 619.9 2028 Notes - 1.125% (1) 572.1 568.3 — — 2029 Notes - 3.450% (1) 598.6 623.0 598.4 644.1 2030 Notes - 2.150% (1) 395.7 370.1 395.3 388.6 Derivative Contracts: Cross Currency Swaps Liability (2) 22.3 22.3 52.2 52.2 Interest Rate Swap Liability (2) 4.4 4.4 7.0 7.0 Equity Investments carried at Fair Value: GDS equity investment (3) — — 44.2 44.2 (1) - The fair value of notes are based on quoted market prices for these notes, which is considered Level 1 of the fair value hierarchy. (2) - The fair values of our cross currency and interest rate swaps are determined using the market standard methodology of netting the discounted future fixed cash flows and the discounted expected variable cash flows based on an expectation of future interest rates derived from Level 2 observable market interest rate curves. (3) - The fair value is based on quoted market prices for the GDS ADSs, which is considered Level 1 of the fair value hierarchy.
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	The following table summarizes the Company's derivative positions as of September 30, 2021 and December 31, 2020, (in millions): September 30, 2021 December 31, 2020 Maturity Date Notional Amount Hedged Risk Asset Liability Asset Liability Designated derivatives Cross Currency Swaps EUR - USD 3/29/2023 $ 250.0 Net investment hedge $ — $ 11.1 $ — $ 26.0 EUR - USD 3/29/2023 250.0 Net investment hedge — 11.2 — 26.2 Interest Rate Swaps USD Libor 3/29/2023 300.0 Interest rate hedge - Float to fixed — 4.4 — 7.0 Total $ — $ 26.7 $ — $ 59.2
Schedule of Derivative Instruments	The following table presents the effect of our derivative financial instruments on our accompanying condensed consolidated financial statements (in millions): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2021 2020 2021 2020 Derivatives in Cash Flow Hedging Relationships Cross-Currency and Interest Rate Swaps: Amount of gain (loss) recognized in OCI for derivatives $ 13.6 $ (20.9) $ 32.5 $ (31.5) Amount of gain (loss) reclassified from Accumulated OCI for derivatives (1) $ (0.8) $ (0.8) $ (2.5) $ (0.9) (1) - Gains and (losses) are recognized in Interest expense, net.

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Schedule of Summary of Forward Sales of Equity	The following table represents a summary of forward sale of equity of our common stock for the nine months ended September 30, 2021 (in millions): Offering Program Forward Shares Sold/(Settled) Net Proceeds Received Remaining Proceeds Available (1) Total at December 31, 2020 6.8 $ — $ 484.7 Forward adjustments — — (7.6) May 2020 Forward Offering settlement (1.4) 95.3 (95.3) May 2020 Forward Offering settlement (1.3) 95.5 (95.5) May 2021 Forward Offering - Sales 0.3 22.5 June 2021 Forward Offering - Sales 1.6 116.7 June 2021 Forward Offering - Sales 1.1 91.0 September 2020 Forward Offering settlement (1.4) 100.5 (100.5) September 2020 Forward Offering settlement (1.6) 112.5 (112.5) Total at September 30, 2021 4.1 $ 403.8 $ 303.5 (1) As of September 30, 2021, the total estimated proceeds, net of adjustments for (i) a floating interest rate factor equal to a specified daily rate less a spread and (ii) scheduled dividends adjustments is $303.5 million subject to further adjustment when the forward offerings are settled as described above.

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Schedule of Restricted Stock and Restricted Stock Units Activity	The following tables summarize the unvested restricted stock, restricted stock units, stock options and LTIP Units activity and the weighted average fair value of these shares at the date of grant for the nine months ended September 30, 2021 and 2020 (market-based awards are reflected at the target amount of the grant): Restricted Stock ("RS") 2021 2020 Restricted Stock Weighted Average Grant Date Fair Value Restricted Stock Weighted Average Grant Date Fair Value Outstanding January 1, 118,233 $ 74.12 16,681 $ 52.46 Granted 119,323 74.10 100,649 74.64 Exercised (96,410) 74.61 (16,681) 52.46 Forfeited (8,586) 72.44 — — Outstanding September 30, 132,560 $ 73.85 100,649 $ 74.64 Time-based RS outstanding 120,275 $ 71.53 100,649 $ 74.64 Market-based RS outstanding 12,285 $ 96.60 — $ — Restricted Stock Units ("RSUs") 2021 2020 Restricted Stock Units Weighted Average Grant Date Fair Value Restricted Stock Units Weighted Average Grant Date Fair Value Outstanding January 1, 484,890 $ 66.66 646,619 $ 55.80 Granted 20,222 69.92 220,176 97.49 TSR and other adjustments (a) 106,628 92.67 164,071 91.32 Exercised (387,815) 61.74 (371,186) 81.23 Forfeited (34,823) 131.32 (155,466) 58.68 Outstanding September 30, 189,102 $ 79.86 504,214 $ 67.87 Time-based RSUs outstanding 115,316 $ 61.96 230,951 $ 60.32 Market-based RSUs outstanding 73,786 $ 107.83 273,263 $ 74.24 (a) TSR adjustments represent the incremental shares earned for the TSR performance metric exceeding target and resulting in 200% payout for the 2018 LTIP Performance Awards. LTIP Units 2021 2020 LTIP Units Weighted Average Grant Date Fair Value LTIP Units Weighted Average Grant Date Fair Value Outstanding January 1, — $ — — $ — Granted 149,061 83.15 — — Exercised — — — — Forfeited (52,331) 87.70 — — Outstanding September 30, 96,730 $ 80.69 — $ — Time-based LTIP Units outstanding 47,291 $ 65.62 — $ — Market-based LTIP Units outstanding 49,439 $ 95.10 — $ —
Schedule of Stock Option Activity	Stock Options 2021 2020 Options Weighted Average Exercise Price Options Weighted Average Exercise Price Outstanding January 1, 97,801 $ 30.87 375,086 $ 31.64 Granted — — — — Exercised (95,196) 31.07 (277,285) 31.92 Forfeited — — — — Outstanding September 30, 2,605 $ 23.58 97,801 $ 30.87 Time-based stock options outstanding — $ — 80,871 $ 32.40 Market-based stock options outstanding 1,881 $ 23.58 12,754 $ 23.58 Performance-based stock options outstanding 724 $ 23.58 4,176 $ 23.58

Income (Loss) per Share (Tables

Income (Loss) per Share (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Computation of Basic and Diluted Net Income (Loss) per Share	The following table reflects the computation of basic and diluted Net income (loss) per share for the three and nine months ended September 30, 2021 and 2020: IN MILLIONS, except per share amounts Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Basic Diluted Basic Diluted Basic Diluted Basic Diluted Numerator: Net income (loss) $ 6.7 $ 6.7 $ (37.3) $ (37.3) $ 32.3 $ 32.3 $ 22.4 $ 22.4 Less: Restricted stock dividends (0.2) (0.2) (0.1) (0.1) (0.4) (0.4) (0.4) (0.4) Net income (loss) available to stockholders $ 6.5 $ 6.5 $ (37.4) $ (37.4) $ 31.9 $ 31.9 $ 22.0 $ 22.0 Denominator: Weighted average common outstanding - basic 124.2 124.2 118.7 118.7 122.4 122.4 116.3 116.3 Performance-based restricted stock and units — — 0.1 0.4 Dilutive forward shares 0.1 — — — Weighted average shares outstanding - diluted 124.3 118.7 122.5 116.7 EPS: Net income (loss) per share - basic $ 0.05 $ (0.32) $ 0.26 $ 0.19 Effect of dilutive shares: Net income (loss) per share - diluted $ 0.05 $ (0.32) $ 0.26 $ 0.19

Description of Business (Detail

Description of Business (Details)	9 Months Ended
	Sep. 30, 2021dataCenterrecoveryCenter
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of data operating centers | dataCenter	57
Number of data recovery centers | recoveryCenter	1

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Summary Of Significant Accounting Policies [Line Items]
Impairment loss	$ 0	$ 8,800,000	$ 0	$ 11,200,000
Contract assets	700,000		700,000		$ 400,000
U.S. Data Centers
Summary Of Significant Accounting Policies [Line Items]
Impairment loss		$ 8,800,000		8,800,000
Atlanta
Summary Of Significant Accounting Policies [Line Items]
Impairment loss				$ 2,400,000
Straight-Line Rent Receivable, Net
Summary Of Significant Accounting Policies [Line Items]
Rent and other receivables	$ 175,800,000		$ 175,800,000		$ 172,600,000
Minimum
Summary Of Significant Accounting Policies [Line Items]
Management service contracts, term			1 year
Maximum
Summary Of Significant Accounting Policies [Line Items]
Management service contracts, term			5 years

Revenue Recognition - Minimum L

Revenue Recognition - Minimum Lease Payments to be Received (Details) - USD ($) $ in Millions	Sep. 30, 2021	Sep. 30, 2020
Revenue from Contract with Customer [Abstract]
2021	$ 219.8	$ 198.9
2022	802.7	721.9
2023	659.5	614.5
2024	526.6	493.7
2025	442.4	377.7
2026	344.3	307.8
Thereafter	971.5	837.3
Total	$ 3,966.8	$ 3,551.8

Revenue Recognition - Disaggreg

Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 304.1	$ 262.8	$ 887.3	$ 765.1
Total lease revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	298.9	257.1	870.1	740.5
Colocation (Minimum lease payments)
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	236.4	212.5	681.5	624
Metered power reimbursements (Variable lease payments)
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	62.5	44.6	188.6	116.5
Total revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	5.2	5.7	17.2	24.6
Equipment sales and services
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0.8	0.6	3.4	10
Other revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 4.4	$ 5.1	$ 13.8	$ 14.6

Revenue Recognition - Narrative

Revenue Recognition - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customer	$ 304.1	$ 262.8	$ 887.3	$ 765.1
Accounts receivable	0.3		$ 0.3		$ 2.3
Revenue | Customer Concentration Risk | One Customer
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk, percentage			19.00%	19.00%
Contracts With Customers
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customer	$ 3.6	4	$ 11.4	$ 11.9
Non-US | Contracts With Customers
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customer		$ 0.2		$ 4.4

Leases - As a Lessee - Addition

Leases - As a Lessee - Additional Information (Details) - facility	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Number of facilities, finance lease	7
Minimum
Lessee, Lease, Description [Line Items]
Finance lease, remaining term of contract	1 year
Operating lease, term of contract	1 year
Maximum
Lessee, Lease, Description [Line Items]
Finance lease, remaining term of contract	29 years
Operating lease, term of contract	23 years
Data Center
Lessee, Lease, Description [Line Items]
Number of facilities, operating lease	10
Office
Lessee, Lease, Description [Line Items]
Number of facilities, operating lease	3
Dublin, Ireland | Ground Lease For Future Development
Lessee, Lease, Description [Line Items]
Finance lease, term of contract		999 years

Leases - As a Lessee - Lease Co

Leases - As a Lessee - Lease Cost (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Leases [Abstract]
Operating lease cost	$ 5	$ 5.1		$ 15
Amortization of assets	0.4	0.7	$ 1.5	1.5
Interest on lease liabilities	1.1	0.4	2.3	1.1
Total net lease cost	$ 6.5	$ 6.2	$ 19.1	$ 17.6

Leases - As a Lessee - Suppleme

Leases - As a Lessee - Supplemental Balance Sheet (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Operating leases:
Operating lease right-of-use assets, net	$ 148.5	$ 211.4
Operating lease liabilities	183.9	249.1
Finance leases:
Property and equipment, at cost	163.1	34.7
Accumulated amortization	$ (8.6)	(7.1)
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Other assets
Property and equipment, net	$ 154.5	27.6
Finance lease liabilities	$ 157.2	$ 29.1
Weighted average remaining lease term (in years):
Operating leases	16 years 6 months	14 years 3 months 18 days
Finance leases	27 years 6 months	18 years 2 months 12 days
Weighted average discount rate:
Operating leases	4.00%	3.70%
Finance leases	2.60%	4.70%

Leases - As a Lessee - Supple_2

Leases - As a Lessee - Supplemental Cash Flow (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 18.2	$ 16.7
Operating cash flows from finance leases		1.1
Financing cash flows from finance leases	3.5	2
Non-cash right-of-use assets obtained in exchange for lease liabilities:
Operating leases	0	56.9
Finance leases	$ 128.4	$ 0

Leases - As a Lessee - Maturiti

Leases - As a Lessee - Maturities of Operating and Financing Lease Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Operating Leases
2021	$ 6.6
2022	24.7	$ 27.8
2023	20.8	27.9
2024	16.2	23.9
2025	14.4	19.4
2026	9.4	17.8
Thereafter	159.7	221.6
Total lease payments	251.8	338.4
Less: Imputed interest	(67.9)	(89.3)
Operating lease liabilities	183.9	249.1
Finance Leases
2021	2
2022	7.7	4.2
2023	6.6	3
2024	6.4	2
2025	6.5	1.4
2026	6.9	1.5
Thereafter	187.1	30.5
Total lease payments	223.2	42.6
Less: Imputed interest	(66)	(13.5)
Finance lease liabilities	$ 157.2	$ 29.1

Investment in Real Estate - Lan

Investment in Real Estate - Land for Future Development (Details) - Land For Future Development $ in Millions	9 Months Ended
	Sep. 30, 2021USD ($)a	Sep. 30, 2020USD ($)a
Madrid, Spain and Amsterdam, The Netherlands
Business Acquisition [Line Items]
Area of land | a	22
Purchase price | $	$ 39.8
Frankfurt, Germany And London
Business Acquisition [Line Items]
Area of land | a		35
Purchase price | $		$ 58.7

Investment in Real Estate - Lea

Investment in Real Estate - Leases of Real Estate (Details) ft² in Thousands	1 Months Ended
	Jun. 30, 2021dataCenter	Feb. 28, 2021ft²extensionMW	Mar. 31, 2020ft²extensionMW
Paris, France
Business Acquisition [Line Items]
Operating lease, term of contract			25 years
Area Leased And Purchased For Future Development | London, United Kingdom
Business Acquisition [Line Items]
Operating lease, term of contract		20 years
Area of building | ft²		130
Data center output (MW) | MW		18
Number of renewal options | extension		3
Renewal term		15 years
Number of data centers | dataCenter	2
Area Leased And Purchased For Future Development | Paris, France
Business Acquisition [Line Items]
Area of building | ft²			45
Data center output (MW) | MW			27
Number of renewal options | extension			1
Renewal term			25 years

Investment in Real Estate - Rea

Investment in Real Estate - Real Estate Related Capital Expenditures (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Business Acquisition [Line Items]
Cost of construction in progress	$ 729.8		$ 982.2
Construction in progress, land under active development	12.9		$ 5.1
Investments in real estate	$ (580.2)	$ (692.2)
Capital expenditures		692.2
Land Acquired For Development | Frankfurt, Germany And London
Business Acquisition [Line Items]
Land acquired for development		$ 58.7

Investment in Real Estate - R_2

Investment in Real Estate - Real Estate Investments and Intangibles and Related Depreciation and Amortization (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Investment in real estate
Buildings and improvements, cost	$ 2,336.3		$ 2,336.3		$ 2,035.2
Equipment, cost	4,064.7		4,064.7		3,538.9
Buildings and improvements, accumulated depreciation	(714.1)		(714.1)		(639.4)
Equipment, accumulated depreciation	(1,366.3)		(1,366.3)		(1,128.5)
Buildings and improvements, net	1,622.2		1,622.2		1,395.8
Equipment, net	2,698.4		2,698.4		2,410.4
Intangible assets
Cost	405.2		405.2		407.1
Accumulated Depreciation and Amortization	(272.5)		(272.5)		(249.3)
Net book value	132.7		132.7		157.8
Depreciation expense	115.4	$ 99.7	335.8	$ 291.2
Amortization expense	12.1	$ 13.4	36.8	$ 39.7
Customer relationships
Intangible assets
Cost	247.1		247.1		247.1
Accumulated Depreciation and Amortization	(171.4)		(171.4)		(163.1)
Net book value	75.7		75.7		84
In-place leases
Intangible assets
Cost	138.6		138.6		140.4
Accumulated Depreciation and Amortization	(88.3)		(88.3)		(74.6)
Net book value	50.3		50.3		65.8
Other contractual
Intangible assets
Cost	19.5		19.5		19.6
Accumulated Depreciation and Amortization	(12.8)		(12.8)		(11.6)
Net book value	$ 6.7		$ 6.7		$ 8
Buildings
Intangible assets
Useful life of asset			30 years
Building improvements
Intangible assets
Useful life of asset			30 years
Equipment
Intangible assets
Useful life of asset			20 years

Equity Investments - Shcedule o

Equity Investments - Shcedule of Investees (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Schedule of Equity Method Investments [Line Items]
Equity investments	$ 30.3	$ 67.1
GDS, Class A share equivalent
Schedule of Equity Method Investments [Line Items]
Fair value	0	44.2
ODATA investments
Schedule of Equity Method Investments [Line Items]
Cost method	$ 30.3	$ 22.9

Equity Investments - Narrative

Equity Investments - Narrative (Details) shares in Millions, $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Jan. 31, 2021USD ($)shares	Sep. 30, 2021USD ($)venture	Sep. 30, 2020USD ($)	Sep. 30, 2021USD ($)venture	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)venture
Schedule of Equity Method Investments [Line Items]
Net gain on marketable equity investments		$ 0	$ 4.7	$ 2.4	$ 69.8
Less: Net gain recognized on marketable equity investments sold		0	0.6	2.4	12.4
Unrealized gain on marketable equity investments held		$ 0	4.1	$ 0	57.4
GDS
Schedule of Equity Method Investments [Line Items]
Number of GDS ADSs sold (in shares) | shares	0.5
Proceeds from sale of equity investments	$ 46.6
Affiliated Entity | ODATA
Schedule of Equity Method Investments [Line Items]
Cost method investments						$ 22.9
Number of unconsolidated ventures | venture		4		4		4
Additional investment		$ 0.3	$ 1.8	$ 7.4	$ 6.5

Other Assets (Details)

Other Assets (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deferred leasing and other contract costs	$ 63.7	$ 62.4
Prepaid expenses	22.8	19.1
Non-real estate assets, net	9.9	13.8
Other assets	31.6	38.1
Total	$ 128	$ 133.4

Debt - Components of Debt (Deta

Debt - Components of Debt (Details) € in Millions	May 26, 2021EUR (€)	Sep. 21, 2020USD ($)	Jan. 22, 2020EUR (€)	Sep. 30, 2021USD ($)extension	Sep. 30, 2021EUR (€)	Dec. 31, 2020USD ($)	Dec. 05, 2019
Debt Instrument [Line Items]
Deferred financing costs				$ (29,600,000)		$ (29,500,000)
Total				$ 3,515,100,000		3,409,000,000
LIBOR
Debt Instrument [Line Items]
Stated interest rate				0.09%	0.09%
Term Loan | LIBOR | 2023 Term Loan Facility
Debt Instrument [Line Items]
Basis spread on variable rate				1.20%
Term Loan | LIBOR | 2025 Term Loan Facility
Debt Instrument [Line Items]
Basis spread on variable rate				1.20%
Senior Notes | 2024 Notes, including bond discount of $0.6 million and $0.7 million, respectively
Debt Instrument [Line Items]
Bond discount				$ 600,000		700,000
Long-term debt				$ 599,400,000		599,300,000
Stated interest rate				2.90%	2.90%		2.90%
Senior Notes | 2024 Notes, including bond discount of $0.6 million and $0.7 million, respectively | Carrying Value
Debt Instrument [Line Items]
Long-term debt				$ 599,400,000		599,300,000
Senior Notes | 2027 Notes, including bond discount of $0.7 million
Debt Instrument [Line Items]
Bond discount				600,000	€ 0.7	600,000
Long-term debt				$ 578,900,000		612,600,000
Stated interest rate			1.45%	1.45%	1.45%
Proceeds from debt issuance, net of underwriting and other deferred financing cost | €			€ 495.3
Senior Notes | 2027 Notes, including bond discount of $0.7 million | Carrying Value
Debt Instrument [Line Items]
Long-term debt				$ 578,900,000		612,600,000
Senior Notes | 2028 Notes, including bond discount of $7.8 million
Debt Instrument [Line Items]
Bond discount				$ 7,400,000	€ 6.7
Stated interest rate	1.125%			1.125%	1.125%
Proceeds from debt issuance, net of underwriting and other deferred financing cost | €	€ 490.8		€ 489.2
Senior Notes | 2028 Notes, including bond discount of $7.8 million | Carrying Value
Debt Instrument [Line Items]
Long-term debt				$ 572,100,000		0
Senior Notes | 2029 Notes, including bond discount of $1.4 million and $1.6 million, respectively
Debt Instrument [Line Items]
Bond discount				1,400,000		1,600,000
Long-term debt				$ 598,600,000		598,400,000
Stated interest rate				3.45%	3.45%		3.45%
Senior Notes | 2029 Notes, including bond discount of $1.4 million and $1.6 million, respectively | Carrying Value
Debt Instrument [Line Items]
Long-term debt				$ 598,600,000		598,400,000
Senior Notes | 2030 Notes, including bond discount of $4.3 million and $4.7 million, respectively
Debt Instrument [Line Items]
Bond discount				$ 4,300,000		4,700,000
Stated interest rate		2.15%		2.15%	2.15%
Proceeds from debt issuance, net of underwriting and other deferred financing cost		$ 392,600,000
Senior Notes | 2030 Notes, including bond discount of $4.3 million and $4.7 million, respectively | Carrying Value
Debt Instrument [Line Items]
Long-term debt				$ 395,700,000		395,300,000
Revolving Credit Facility
Debt Instrument [Line Items]
Term of extension option				1 year
Revolving Credit Facility | Carrying Value
Debt Instrument [Line Items]
Long-term debt				$ 0		432,900,000
Revolving Credit Facility | 1.4 Billion Senior Multi Currency Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility				$ 0
Term of extension option				12 months
Number of extension options | extension				1
Revolving Credit Facility | 1.4 Billion EUR Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility				$ 0		275,900,000
Revolving Credit Facility | 1.4 Billion GBP Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility				$ 0		157,000,000
Revolving Credit Facility | 2023 Term Loan Facility
Debt Instrument [Line Items]
Term of extension option				1 year
Number of extension options | extension				2
Revolving Credit Facility | 2023 Term Loan Facility | Carrying Value
Debt Instrument [Line Items]
Credit facility				$ 100,000,000		100,000,000
Revolving Credit Facility | 2025 Term Loan Facility | Carrying Value
Debt Instrument [Line Items]
Credit facility				$ 700,000,000		$ 700,000,000
Revolving Credit Facility | EURIBOR | 1.4 Billion EUR Revolving Credit Facility
Debt Instrument [Line Items]
Basis spread on variable rate				1.00%
Revolving Credit Facility | GPB LIBOR | 1.4 Billion GBP Revolving Credit Facility
Debt Instrument [Line Items]
Basis spread on variable rate				1.00%

Debt - Credit Facilities (Detai

Debt - Credit Facilities (Details)	Mar. 31, 2020USD ($)	Mar. 29, 2018USD ($)	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Sep. 30, 2021USD ($)extension	Sep. 30, 2020USD ($)
Line of Credit Facility [Line Items]
Loss on early extinguishment of debt			$ 0	$ 3,100,000		$ 0	$ 6,500,000
Letters of credit outstanding			8,400,000			$ 8,400,000
Revolving Credit Facility
Line of Credit Facility [Line Items]
Option to extend maturity						1 year
$3 Billion Credit Facility | Revolving Credit Facility
Line of Credit Facility [Line Items]
Credit agreement amount		$ 3,000,000,000
Repayments of long-term debt	$ 1,300,000,000
Line of credit	$ 1,300,000,000				$ 1,300,000,000
Loss on early extinguishment of debt					$ 3,400,000
Available capacity			1,400,000,000			$ 1,400,000,000
$1.7 Billion Credit Facility | Revolving Credit Facility
Line of Credit Facility [Line Items]
Credit agreement amount		1,700,000,000
Multicurrency borrowing sublimit		$ 750,000,000
Commitment fee rate per annum upon 50% or greater utilization						0.25%
Commitment fee amount			700,000	$ 600,000		$ 2,100,000	$ 2,400,000
2023 Term Loan
Line of Credit Facility [Line Items]
Debt instrument, term		5 years
2023 Term Loan | Term Loan
Line of Credit Facility [Line Items]
Credit agreement amount		$ 1,000,000,000
2025 Term Loan
Line of Credit Facility [Line Items]
Debt instrument, term		7 years
2025 Term Loan | Term Loan
Line of Credit Facility [Line Items]
Credit agreement amount		$ 300,000,000
1.4 Billion Senior Multi Currency Revolving Credit Facility | Revolving Credit Facility
Line of Credit Facility [Line Items]
Credit agreement amount			1,400,000,000			1,400,000,000
Additional maximum borrowing capacity			4,000,000,000			4,000,000,000
Multicurrency borrowing sublimit			750,000,000			$ 750,000,000
Number of extension options | extension						1
Option to extend maturity						12 months
Line of credit			0			$ 0
2023 Term Loan Facility | Revolving Credit Facility
Line of Credit Facility [Line Items]
Credit agreement amount			400,000,000			$ 400,000,000
Number of extension options | extension						2
Option to extend maturity						1 year
2025 Term Loan Facility | Revolving Credit Facility
Line of Credit Facility [Line Items]
Credit agreement amount			$ 700,000,000			$ 700,000,000

Debt - Senior Notes (Details)

Debt - Senior Notes (Details)	May 26, 2021EUR (€)	Sep. 21, 2020USD ($)	Jan. 22, 2020EUR (€)	Dec. 05, 2019USD ($)	Sep. 30, 2020USD ($)	Dec. 31, 2019USD ($)	Sep. 30, 2021
1.4 Billion US Revolving Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Repayments of debt		$ 20,000,000
Senior Notes | 1.450% Senior Notes due 2027
Debt Instrument [Line Items]
Debt principal amount | €			€ 500,000,000
Stated interest rate			1.45%				1.45%
Proceeds from debt issuance, net of underwriting and other deferred financing cost | €			€ 495,300,000
Senior Notes | 2.900% Senior Notes Due 2024
Debt Instrument [Line Items]
Debt principal amount				$ 600,000,000
Stated interest rate				2.90%			2.90%
Senior Notes | 3.450% Senior Notes Due 2029
Debt Instrument [Line Items]
Debt principal amount				$ 600,000,000
Stated interest rate				3.45%			3.45%
Senior Notes | 5.000% Senior Notes Due 2024
Debt Instrument [Line Items]
Stated interest rate				5.00%
Senior Notes | 5.375% Senior Notes Due 2027
Debt Instrument [Line Items]
Stated interest rate				5.375%
Senior Notes | 2.900% Senior Notes Due 2024 And 3.450% Senior Notes Due 2029
Debt Instrument [Line Items]
Proceeds from debt issuance, net of underwriting and other deferred financing cost				$ 1,197,400,000
Senior Notes | 5.000% senior notes due 2024 and 5.375% senior notes due 2027
Debt Instrument [Line Items]
Loss on early extinguishment of debt						$ 71,800,000
Senior Notes | 2.150% Senior Notes due 2030
Debt Instrument [Line Items]
Debt principal amount		$ 400,000,000
Stated interest rate		2.15%					2.15%
Proceeds from debt issuance, net of underwriting and other deferred financing cost		$ 392,600,000
Senior Notes | 2028 Notes, including bond discount of $7.8 million
Debt Instrument [Line Items]
Debt principal amount | €	€ 500,000,000
Stated interest rate	1.125%						1.125%
Proceeds from debt issuance, net of underwriting and other deferred financing cost | €	€ 490,800,000		€ 489,200,000
Term Loan | 2023 Term Loan
Debt Instrument [Line Items]
Loss on early extinguishment of debt					$ 3,100,000
Repayments of debt		$ 300,000,000

Fair Value of Financial Instr_3

Fair Value of Financial Instruments and Hedging Activities - Carrying Value and Fair Value of Other Financial Instruments (Details) - USD ($) $ in Millions	Sep. 30, 2021	May 26, 2021	Dec. 31, 2020	Sep. 21, 2020	Jan. 22, 2020	Dec. 05, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liability	$ 26.7		$ 59.2
Carrying Value | Currency Swap
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liability	22.3		52.2
Carrying Value | Interest Rate Swaps
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liability	4.4		7
Carrying Value | Revolving Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	0		432.9
Fair Value | Currency Swap
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liability	22.3		52.2
Fair Value | Interest Rate Swaps
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liability	4.4		7
Fair Value | Revolving Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	0		432.9
2023 Term Loan Facility | Carrying Value | Revolving Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit facility	100		100
2023 Term Loan Facility | Fair Value | Revolving Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit facility	100		100
2025 Term Loan Facility | Carrying Value | Revolving Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit facility	700		700
2025 Term Loan Facility | Fair Value | Revolving Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit facility	$ 700		700
Senior Notes | 2.900% Senior Notes Due 2024
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate	2.90%					2.90%
Long-term debt	$ 599.4		599.3
Senior Notes | 2.900% Senior Notes Due 2024 | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	$ 599.4		599.3
Senior Notes | 1.450% Senior Notes due 2027
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate	1.45%				1.45%
Long-term debt	$ 578.9		612.6
Senior Notes | 1.450% Senior Notes due 2027 | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	$ 578.9		612.6
Senior Notes | 1.125% Senior Notes due May 2028
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate	1.125%	1.125%
Senior Notes | 1.125% Senior Notes due May 2028 | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	$ 572.1		0
Senior Notes | 3.450% Senior Notes Due 2029
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate	3.45%					3.45%
Long-term debt	$ 598.6		598.4
Senior Notes | 3.450% Senior Notes Due 2029 | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	$ 598.6		598.4
Senior Notes | 2.150% Senior Notes due 2030
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate	2.15%			2.15%
Senior Notes | 2.150% Senior Notes due 2030 | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	$ 395.7		395.3
Level 1 | Senior Notes | 2.900% Senior Notes Due 2024 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	629.8		640.7
Level 1 | Senior Notes | 1.450% Senior Notes due 2027 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	581.8		619.9
Level 1 | Senior Notes | 1.125% Senior Notes due May 2028 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	568.3		0
Level 1 | Senior Notes | 3.450% Senior Notes Due 2029 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	623		644.1
Level 1 | Senior Notes | 2.150% Senior Notes due 2030 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	370.1		388.6
GDS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity investments	0		44.2
GDS | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity investments	0		44.2
GDS | Level 2 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity investments	$ 0		$ 44.2

Fair Value of Financial Instr_4

Fair Value of Financial Instruments and Hedging Activities - Derivative Positions (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Amount
Asset	0	$ 0
Liability	26.7	59.2
3/29/2023 | Net investment hedge | Cross Currency Swaps | Designated derivatives
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Amount	250
Asset	0	0
Liability	11.1	26
3/29/2023 | Net investment hedge | Cross Currency Swaps | Designated derivatives
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Amount	250
Asset	0	0
Liability	11.2	26.2
3/29/2023 | Interest rate hedge - Float to fixed | Interest Rate Swaps | Designated derivatives
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Amount	300
Asset	0	0
Liability	$ 4.4	$ 7

Fair Value of Financial Instr_5

Fair Value of Financial Instruments and Hedging Activities - Derivative instruments (Details) € in Millions, $ in Millions	Sep. 21, 2020USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2021USD ($)instrument	Sep. 30, 2021EUR (€)instrument	Dec. 31, 2020USD ($)	Sep. 03, 2019USD ($)
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative liability			$ 26.7		$ 59.2
Derivative asset			$ 0		0
Term Loan | 2023 Term Loan Facility
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Repayments of debt	$ 300
Term Loan | Interest Rate Swaps
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative liability, notional amount						$ 300
Derivative, fixed interest rate						1.19%
Maturing March 2023 | Cross Currency Swaps
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of derivative instruments | instrument			2	2
Derivative asset, notional amount			$ 500
Derivative liability, notional amount | €				€ 450.7
Amount of gain recognized in earnings		$ 4.5
Other Liabilities | Cross Currency Swaps
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative liability			22.3		52.2
Other Liabilities | Interest Rate Swaps
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative liability			$ 4.4
Other Assets | Interest Rate Swaps
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative asset					$ 7

Fair Value of Financial Instr_6

Fair Value of Financial Instruments and Hedging Activities - Derivative Instruments Gain (Loss) (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in OCI for derivatives	$ 13.6	$ (5)	$ 23.9	$ (20.9)	$ (9.5)	$ (1.1)	$ 32.5	$ (31.5)
Cross-Currency and Interest Rate Swaps:
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in OCI for derivatives	13.6			(20.9)			32.5	(31.5)
Amount of gain (loss) reclassified from accumulated OCI for derivatives	$ (0.8)			$ (0.8)			(2.5)	$ (0.9)
Expected reclassification from Accumulated OCI to Net Income							$ 3.3

Stockholders' Equity - Narrativ

Stockholders' Equity - Narrative (Details) - USD ($)	Oct. 27, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of common stock, net								$ 407,900,000	$ 325,900,000
Common stock outstanding (in shares)		126,913,710						126,913,710		120,442,521
Dividends paid per share (in dollars per share)								$ 1.54	$ 1.51
Payments of dividends								$ 187,900,000	$ 174,700,000
Dividends declared per share (in dollars per share)		$ 0.52	$ 0.51	$ 0.51	$ 0.51	$ 0.50	$ 0.50
Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividends declared per share (in dollars per share)	$ 0.52
New 2018 ATM Stock Offering Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Value of shares authorized											$ 750,000,000
2020 ATM Stock Offering Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Value of shares authorized						$ 750,000,000
ATM Stock Offering Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Value of shares authorized			$ 750,000,000
Common stock outstanding (in shares)		126,900,000						126,900,000
2021 ATM Stock Offering Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Value of shares available to grant		$ 513,400,000						$ 513,400,000
Forward Sale Agreement | ATM Stock Offering Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of common stock, net (in shares)					3,000,000
Issuance of common stock, net					$ 218,700,000
Forward Offering Settlement
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Forward offering settlement (in shares)								5,700,000	5,000,000
Initial forward price (in dollars per share)		$ 69.91			$ 63.61			$ 69.91	$ 63.61
Proceeds from settlement of forward equity sale agreement								$ 403,800,000	$ 315,600,000

Stockholders' Equity - Forward

Stockholders' Equity - Forward Sale of Equity (Details) - Forward Sale Agreement shares in Millions, $ in Millions	9 Months Ended
	Sep. 30, 2021USD ($)shares
Forward Sale Of Equity Of Common Stock [Roll Forward]
Beginning balance (in shares) | shares	6.8
Ending balance (in shares) | shares	4.1
Forward Sales Of Equity Of Common Stock, Net Proceeds Received [Roll Forward]
Net proceeds received, beginning balance	$ 0
Net proceeds received, ending balance	403.8
Forward Sales Of Equity Of Common Stock, Remaining Expected Proceeds Available [Roll Forward]
Remaining proceeds available, beginning balance	484.7
Remaining proceeds available, ending balance	$ 303.5
Forward adjustments
Forward Sale Of Equity Of Common Stock [Roll Forward]
Forward offering settlement (in shares) | shares	0
Forward Sales Of Equity Of Common Stock, Net Proceeds Received [Roll Forward]
Proceeds from settlement of forward equity sale agreement	$ 0
Forward Sales Of Equity Of Common Stock, Remaining Expected Proceeds Available [Roll Forward]
Remaining proceeds available, settlements	$ (7.6)
May 2020 Forward Offering settlement
Forward Sale Of Equity Of Common Stock [Roll Forward]
Forward offering settlement (in shares) | shares	(1.4)
Forward Sales Of Equity Of Common Stock, Net Proceeds Received [Roll Forward]
Proceeds from settlement of forward equity sale agreement	$ 95.3
Forward Sales Of Equity Of Common Stock, Remaining Expected Proceeds Available [Roll Forward]
Remaining proceeds available, settlements	$ (95.3)
May 2020 Forward Offering Settlement, 2
Forward Sale Of Equity Of Common Stock [Roll Forward]
Forward offering settlement (in shares) | shares	(1.3)
Forward Sales Of Equity Of Common Stock, Net Proceeds Received [Roll Forward]
Proceeds from settlement of forward equity sale agreement	$ 95.5
Forward Sales Of Equity Of Common Stock, Remaining Expected Proceeds Available [Roll Forward]
Remaining proceeds available, settlements	$ (95.5)
May 2021 Forward Offering - Sales
Forward Sale Of Equity Of Common Stock [Roll Forward]
Forward offering sales (in shares) | shares	0.3
Forward Sales Of Equity Of Common Stock, Net Proceeds Received [Roll Forward]
Proceeds from settlement of forward equity sale agreement
Forward Sales Of Equity Of Common Stock, Remaining Expected Proceeds Available [Roll Forward]
Remaining proceeds available, additions	$ 22.5
June 2021 Forward Offering, Sales
Forward Sale Of Equity Of Common Stock [Roll Forward]
Forward offering sales (in shares) | shares	1.6
Forward Sales Of Equity Of Common Stock, Net Proceeds Received [Roll Forward]
Proceeds from settlement of forward equity sale agreement
Forward Sales Of Equity Of Common Stock, Remaining Expected Proceeds Available [Roll Forward]
Remaining proceeds available, additions	$ 116.7
June 2021 Forward Offering, Sales 2
Forward Sale Of Equity Of Common Stock [Roll Forward]
Forward offering sales (in shares) | shares	1.1
Forward Sales Of Equity Of Common Stock, Net Proceeds Received [Roll Forward]
Proceeds from settlement of forward equity sale agreement
Forward Sales Of Equity Of Common Stock, Remaining Expected Proceeds Available [Roll Forward]
Remaining proceeds available, additions	$ 91
September 2020 Forward Offering settlement
Forward Sale Of Equity Of Common Stock [Roll Forward]
Forward offering settlement (in shares) | shares	(1.4)
Forward Sales Of Equity Of Common Stock, Net Proceeds Received [Roll Forward]
Proceeds from settlement of forward equity sale agreement	$ 100.5
Forward Sales Of Equity Of Common Stock, Remaining Expected Proceeds Available [Roll Forward]
Remaining proceeds available, settlements	$ (100.5)
September 2020 Forward Offering settlement, 2
Forward Sale Of Equity Of Common Stock [Roll Forward]
Forward offering settlement (in shares) | shares	(1.6)
Forward Sales Of Equity Of Common Stock, Net Proceeds Received [Roll Forward]
Proceeds from settlement of forward equity sale agreement	$ 112.5
Forward Sales Of Equity Of Common Stock, Remaining Expected Proceeds Available [Roll Forward]
Remaining proceeds available, settlements	$ (112.5)

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021USD ($)shares	Sep. 30, 2020USD ($)	Sep. 30, 2021USD ($)shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense | $	$ 8.5	$ 6.7	$ 17.2
LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Conversion of stock, conversion ratio	1		1
LTIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized (in shares)	8,900,000		8,900,000
Shares available for grant (in shares)	4,200,000		4,200,000

Stock-Based Compensation - Rest

Stock-Based Compensation - Restricted Stock Awards Activity (Details) - $ / shares	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Restricted Stock
Shares
Non-vested beginning balance (in shares)	118,233	16,681
Granted (in shares)	119,323	100,649
Exercised (in shares)	(96,410)	(16,681)
Forfeited (in shares)	(8,586)	0
Non-vested ending balance (in shares)	132,560	100,649
Weighted Average Grant Date Fair Value
Non-vested beginning balance (in dollars per share)	$ 74.12	$ 52.46
Granted (in dollars per share)	74.10	74.64
Exercised (in dollars per share)	74.61	52.46
Forfeited (in dollars per share)	72.44	0
Non-vested ending balance (in dollars per share)	$ 73.85	$ 74.64
Restricted Stock, Time-Based
Shares
Non-vested ending balance (in shares)	120,275	100,649
Weighted Average Grant Date Fair Value
Non-vested ending balance (in dollars per share)	$ 71.53	$ 74.64
Restricted Stock, Market Based
Shares
Non-vested ending balance (in shares)	12,285	0
Weighted Average Grant Date Fair Value
Non-vested ending balance (in dollars per share)	$ 96.60	$ 0
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
TSR performance metric, payout percent	200.00%
Shares
Non-vested beginning balance (in shares)	484,890	646,619
Granted (in shares)	20,222	220,176
TSR and other adjustments (in shares)	106,628	164,071
Exercised (in shares)	(387,815)	(371,186)
Forfeited (in shares)	(34,823)	(155,466)
Non-vested ending balance (in shares)	189,102	504,214
Weighted Average Grant Date Fair Value
Non-vested beginning balance (in dollars per share)	$ 66.66	$ 55.80
Granted (in dollars per share)	69.92	97.49
TSR and other adjustments (in dollars per share)	92.67	91.32
Exercised (in dollars per share)	61.74	81.23
Forfeited (in dollars per share)	131.32	58.68
Non-vested ending balance (in dollars per share)	$ 79.86	$ 67.87
Restricted Stock Units, Time-Based
Shares
Non-vested ending balance (in shares)	115,316	230,951
Weighted Average Grant Date Fair Value
Non-vested ending balance (in dollars per share)	$ 61.96	$ 60.32
Restricted Stock Units, Market Based
Shares
Non-vested ending balance (in shares)	73,786	273,263
Weighted Average Grant Date Fair Value
Non-vested ending balance (in dollars per share)	$ 107.83	$ 74.24
LTIP Units
Shares
Non-vested beginning balance (in shares)	0	0
Granted (in shares)	149,061	0
Exercised (in shares)	0	0
Forfeited (in shares)	(52,331)	0
Non-vested ending balance (in shares)	96,730	0
Weighted Average Grant Date Fair Value
Non-vested beginning balance (in dollars per share)	$ 0	$ 0
Granted (in dollars per share)	83.15	0
Exercised (in dollars per share)	0	0
Forfeited (in dollars per share)	87.70	0
Non-vested ending balance (in dollars per share)	$ 80.69	$ 0
LTIP Units, Time Based
Shares
Non-vested ending balance (in shares)	47,291	0
Weighted Average Grant Date Fair Value
Non-vested ending balance (in dollars per share)	$ 65.62	$ 0
LTIP Units, Market Based
Shares
Non-vested ending balance (in shares)	49,439	0
Weighted Average Grant Date Fair Value
Non-vested ending balance (in dollars per share)	$ 95.10	$ 0

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Options (Details) - $ / shares	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Options
Beginning balance (in shares)	97,801	375,086
Granted (in shares)	0	0
Exercised (in shares)	(95,196)	(277,285)
Forfeited or expired (in shares)	0	0
Ending balance (in shares)	2,605	97,801
Weighted Average Exercise Price
Beginning balance (in dollars per share)	$ 30.87	$ 31.64
Granted (in dollars per share)	0	0
Exercised (in dollars per share)	31.07	31.92
Forfeited or expired (in dollars per share)	0	0
Ending balance (in dollars per share)	$ 23.58	$ 30.87
Time-based stock options outstanding
Options
Ending balance (in shares)	0	80,871
Weighted Average Exercise Price
Ending balance (in dollars per share)	$ 0	$ 32.40
Market-based stock options outstanding
Options
Ending balance (in shares)	1,881	12,754
Weighted Average Exercise Price
Ending balance (in dollars per share)	$ 23.58	$ 23.58
Performance-based stock options outstanding
Options
Ending balance (in shares)	724	4,176
Weighted Average Exercise Price
Ending balance (in dollars per share)	$ 23.58	$ 23.58

Income (Loss) per Share - Compu

Income (Loss) per Share - Computation of Basic and Diluted Net Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share [Abstract]
Shares excluded from calculation of diluted net income per share (in shares)	4.2			5.5			4.1	5.7
Numerator:
Net income (loss)	$ 6.7	$ 7.4	$ 18.2	$ (37.3)	$ 45	$ 14.7	$ 32.3	$ 22.4
Less: Restricted stock dividends, Basic	(0.2)			(0.1)			(0.4)	(0.4)
Less: Restricted stock dividends, Diluted	(0.2)			(0.1)			(0.4)	(0.4)
Net income available to stockholders, Basic	6.5			(37.4)			31.9	22
Net income available to stockholders, Diluted	$ 6.5			$ (37.4)			$ 31.9	$ 22
Denominator:
Weighted average shares outstanding - basic (in shares)	124.2			118.7			122.4	116.3
Performance-based restricted stock and units (in shares)	0			0			0.1	0.4
Dilutive forward shares (in shares)	0.1			0			0	0
Weighted average shares outstanding- diluted (in shares)	124.3			118.7			122.5	116.7
EPS:
Net income (loss) per share - basic (in dollars per share)	$ 0.05			$ (0.32)			$ 0.26	$ 0.19
Effect of dilutive shares:
Net income (loss) per share - diluted (in dollars per share)	$ 0.05			$ (0.32)			$ 0.26	$ 0.19

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Letters of credit outstanding	$ 8.4
Performance Guarantee
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Contingent losses	0.8	$ 0.3
Data center facilities and equipment
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Amount of minimum purchase commitment	$ 176.3
Data center facilities and equipment | Minimum
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Term of purchase commitment	1 year
Data center facilities and equipment | Maximum
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Term of purchase commitment	2 years
Services
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Amount of minimum purchase commitment	$ 214.8
Services | Minimum
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Term of purchase commitment	1 year
Services | Maximum
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Term of purchase commitment	7 years