We account for acquisitions using the acquisition method of accounting, and, accordingly, the assets and liabilities acquired are recorded at their estimated fair values and the results of operations for each acquisition have been included in our consolidated results from their respective acquisition dates. We have assessed our acquisitions in accordance with the guidance in ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business.

a. Acquisition of Recall

On May 2, 2016, we completed the Recall Transaction. At the closing of the Recall Transaction, we paid approximately $331,800 in cash and issued 50,233,412 shares of our common stock which, based on the closing price of our common stock as of April 29, 2016 (the last day of trading on the NYSE prior to the closing of the Recall Transaction) of $36.53 per share, resulted in a total purchase price to Recall shareholders of approximately $2,166,900.

Regulatory Approvals

In connection with the acquisition of Recall, we sought regulatory approval of the Recall Transaction from the United States Department of Justice (the "DOJ"), the Australian Competition and Consumer Commission (the "ACCC"), the Canada Competition Bureau (the "CCB") and the United Kingdom Competition and Markets Authority (the "CMA").

As part of the regulatory approval process, we agreed to make certain divestments, which are described below, in order to address competition concerns raised by the DOJ, the ACCC, the CCB and the CMA in respect of the Recall Transaction (the "Divestments").

See Note 13 for additional information regarding the presentation of the Divestments in our Consolidated Statements of Operations and our Consolidated Statements of Cash Flows for the years ended December 31, 2016, 2017 and 2018, respectively.

Divestments

i. United States

The DOJ’s approval of the Recall Transaction was subject to the following divestments being made by us following the closing of the Recall Transaction:

•

Recall’s records and information management facilities, including all associated tangible and intangible assets, in the following 13 United States cities: Buffalo, New York; Charlotte, North Carolina; Detroit, Michigan; Durham, North Carolina; Greenville/Spartanburg, South Carolina; Kansas City, Kansas/Missouri; Nashville, Tennessee; Pittsburgh, Pennsylvania; Raleigh, North Carolina; Richmond, Virginia; San Antonio, Texas; Tulsa, Oklahoma; and San Diego, California (the “Initial United States Divestments”); and


•	Recall’s records and information management facility in Seattle, Washington and certain of Recall’s records and information management facilities in Atlanta, Georgia, including in each case associated tangible and intangible assets (the “Seattle/Atlanta Divestments”).

On May 4, 2016, we completed the sale of the Initial United States Divestments to Access CIG, LLC, a privately held provider of information management services throughout the United States (“Access CIG”), for total consideration of approximately $80,000, subject to adjustments (the “Access Sale”). Of the total consideration, we received $55,000 in cash proceeds upon closing of the Access Sale, and were entitled to receive up to $25,000 of additional cash proceeds (the "Access Contingent Consideration"). The Access Contingent Consideration was subject to adjustments subsequent to the closing of the Access Sale. We were also subject to potential indemnity obligations as part of the Access Sale. We recorded a non-trade receivable related to our estimate of the Access Contingent Consideration included in Prepaid expenses and other in our Consolidated Balance Sheet as of December 31, 2017. During the third quarter of 2018, we settled the Access Contingent Consideration with Access CIG, as well as indemnification claims Access CIG previously raised in connection with the Access Sale. Changes to the realizable value of the Access Contingent Consideration were recorded to our Consolidated Statement of Operations as a component of discontinued operations.

The assets subject to the Access Sale were acquired in the Recall Transaction and, therefore, the estimated fair value of the Initial United States Divestments (including the estimated fair value of the Access Contingent Consideration) has been reflected in the allocation of the purchase price for Recall as a component of “Fair Value of Recall Divestments”. Our policy related to the recognition of contingent consideration (from a seller’s perspective) is to recognize contingent consideration at its estimated fair value upon closing of the transaction. Our policy related to the subsequent measurement of contingent consideration (from a seller’s perspective) is (i) to recognize contingent consideration in excess of our original estimate of fair value upon cash receipt of such consideration and (ii) to recognize any impairment of the contingent consideration compared to our original estimate in the period in which we determine such an impairment exists.

On December 29, 2016, we completed the sale of the Seattle/Atlanta Divestments and the Canadian Divestments (as defined below) to Arkive Information Management LLC and Arkive Information Management Ltd., both information management companies (collectively, "ARKIVE"), for total consideration of approximately $50,000, subject to adjustments (the “ARKIVE Sale”). Of the total consideration, we received approximately $45,000 in cash proceeds upon the closing of the ARKIVE Sale and the remaining consideration is held in escrow. Following a notice and resolution period, ARKIVE may be entitled to receive from us cash payments, up to the total consideration paid by ARKIVE, based on lost revenues attributable to the acquired customer base calculated based upon the 24-month period following the closing of the ARKIVE sale. The assets included in the Seattle/Atlanta Divestments and the Recall Canadian Divestments (as defined below) were acquired in the Recall Transaction and, therefore, the estimated fair value of the Seattle/Atlanta Divestments and the Recall Canadian Divestments (as determined based upon the total consideration for the ARKIVE Sale) has been reflected in the allocation of the purchase price for Recall as a component of "Fair Value of Recall Divestments".

ii. Australia

The ACCC approved the Recall Transaction after accepting an undertaking from us pursuant to section 87B of the Australian Competition and Consumer Act 2010 (Cth) (the “ACCC Undertaking”). Pursuant to the ACCC Undertaking, we agreed to divest the majority of our Australian operations as they existed prior to the closing of the Recall Transaction by way of a share sale, which effectively involved the sale of our Australian business (as it existed prior to the closing of the Recall Transaction) other than our data management business throughout Australia and our records and information management business in the Northern Territory of Australia, except in relation to customers who have holdings in other Australian states or territories (the “Australia Divestment Business”).

On October 31, 2016, after receiving approval of the proposed transaction from the ACCC, we completed the sale of the Australia Divestment Business (the “Australia Sale”) to a consortium led by Housatonic Partners (the “Australia Divestment Business Purchasers”) for total consideration of approximately 70,000 Australian dollars (or approximately $53,200, based upon the exchange rate between the United States dollar and the Australian dollar as of October 31, 2016), subject to adjustments. The total consideration consists of (i) 35,000 Australian dollars in cash received upon the closing of the Australia Sale and (ii) 35,000 Australian dollars in the form of a note due from the Australia Divestment Business Purchasers to us (the “Bridging Loan Note”). The Bridging Loan Note bore interest at 3.3% per annum and matured on December 29, 2017, at which point all outstanding obligations became due. During the fourth quarter of 2017, we received proceeds for the full outstanding amount of the Bridging Loan Note. The total consideration for the Australia Sale is subject to certain adjustments associated with customer attrition subsequent to the closing of the Australia Sale. We recorded a charge of $15,417 to other expense, net associated with the loss on disposal of the Australia Divestment Business during the year ended December 31, 2016, representing the excess of the carrying value of the Australia Divestment Business compared to its fair value (less costs to sell). Approximately $7,099 of cumulative translation adjustment associated with the Australia Divestment Business was reclassified from accumulated other comprehensive items, net and reduced the loss recorded on the sale of the Australia Divestment Business by the same amount during the year ended December 31, 2016.

iii. Canada

The CCB approved the Recall Transaction on the basis of us divesting the following assets:

•

Recall’s record and information management facilities, including associated tangible and intangible assets and employees, in Edmonton, Alberta and Montreal (Laval), Quebec and certain of Recall’s record and information management facilities, including all associated tangible and intangible assets and employees, in Calgary, Alberta and Toronto, Ontario, (the “Recall Canadian Divestments”); and


•	One of our records and information management facilities in Vancouver (Burnaby), British Columbia and one of our records and information management facilities in Ottawa, Ontario, including associated tangible and intangible assets and employees (the “Iron Mountain Canadian Divestments” and together with the Recall Canadian Divestments, the "Canadian Divestments").

On December 29, 2016, we completed the sale of the Canadian Divestments (along with the Seattle/Atlanta Divestments) in the ARKIVE Sale, as discussed above. We recorded a charge of $1,421 to other expense, net associated with the loss on disposal of the Iron Mountain Canadian Divestments during the year ended December 31, 2016, representing the excess of the carrying value of the Iron Mountain Canadian Divestments compared to its fair value (as determined based upon the total consideration received in the ARKIVE Sale), less costs to sell.

iv. United Kingdom

On June 16, 2016, the CMA published its findings, pursuant to which we agreed to divest Recall’s record and information management facilities, including associated tangible and intangible assets and employees, in the Aberdeen and Dundee areas of Scotland (the “UK Divestments”).

On December 9, 2016, we completed the sale of the UK Divestments (the "UK Sale") to the Oasis Group for total consideration of approximately 1,800 British pounds sterling (or approximately $2,200, based upon the exchange rate between the United States dollar and the British pound sterling as of December 9, 2016), subject to adjustments. The assets included in the UK Sale were acquired in the Recall Transaction and, therefore, the estimated fair value of the UK Divestments (as determined based upon the total consideration received in the UK Sale) has been reflected in the allocation of the purchase price for Recall as a component of “Fair Value of Recall Divestments”.

b. Acquisition of IO Data Centers

On January 10, 2018, we completed the acquisition of the United States operations of IODC, a leading data center colocation space and solutions provider based in Phoenix, Arizona, including the land and buildings associated with four data centers in Phoenix and Scottsdale, Arizona; Edison, New Jersey; and Columbus, Ohio (the “IODC Transaction”). At the closing of the IODC Transaction, we paid approximately $1,347,000. In addition to the amount paid at the closing of the IODC Transaction, there was the potential of $35,000 in additional payments associated with the execution of future customer contracts through the one-year anniversary of the IODC Transaction, of which approximately $31,000 is accrued at December 31, 2018. This amount is reported as a third-party commissions asset as a component of Other within Other assets, net, on our Consolidated Balance Sheet at December 31, 2018. We have accounted for the IODC Transaction as an acquisition of a business in accordance with the guidance in ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business.

_______________________________________________________________________________

The unaudited consolidated pro forma financial information (the "Pro Forma Financial Information") below summarizes the combined results of us, Recall and IODC on a pro forma basis as if the Recall Transaction had occurred on January 1, 2015, and the IODC Transaction had occurred on January 1, 2017. The Pro Forma Financial Information is presented for informational purposes and is not necessarily indicative of the results of operations that would have been achieved if the acquisitions had taken place on the dates indicated above. The Pro Forma Financial Information for the year ended December 31, 2016, includes adjustments to convert Recall's historical results from International Financial Reporting Standards to GAAP, purchase accounting adjustments (including amortization of acquired intangible assets, depreciation of acquired property, plant and equipment and amortization of favorable and unfavorable leases), stock-based compensation and related tax effects. Through December 31, 2018, we and Recall have collectively incurred $140,661 of operating expenditures to complete the Recall Transaction (including advisory and professional fees and costs to complete the Divestments and to provide transitional services required to support the divested businesses during a transition period) and we and IODC have collectively incurred $28,064 of operating expenditures to complete the IODC Transaction (including advisory and professional fees). The operating expenditures to complete the Recall Transaction and the IODC Transaction have been reflected within the results of operations in the Pro Forma Financial Information as if they were incurred on January 1, 2015 and January 1, 2017, respectively. The costs we have incurred to integrate Recall with our existing operations (including moving, severance, facility upgrade, REIT integration and system upgrade costs) are reflected in the Pro Forma Financial Information in the period in which they were incurred.

The Pro Forma Financial Information for the year ended December 31, 2016, excludes from income (loss) from continuing operations the results of operations of the Initial United States Divestments, the Seattle/Atlanta Divestments, the Recall Canadian Divestments and the UK Divestments, as these businesses are presented as discontinued operations. See Note 13 for information regarding our conclusion with respect to the presentation of these divestments as discontinued operations. The results of the Australia Divestment Business and the Iron Mountain Canadian Divestments are included within the results from continuing operations in the Pro Forma Financial Information through the closing date of the Australia Sale, in the case of the Australia Divestment Business, and through the closing date of the ARKIVE Sale, in the case of the Iron Mountain Canadian Divestments, as these businesses do not qualify for discontinued operations. See Note 13 for information regarding our conclusion that these divestments do not meet the criteria to be reported as discontinued operations. The Australia Divestment Business and the Iron Mountain Canadian Divestments, collectively, represent $46,655 of total revenues and $2,603 of total income from continuing operations for the year ended December 31, 2016, respectively.



	(Unaudited) Year Ended December 31,
	2016(1)		2017(2)		2018(2)
Total Revenues	$	3,763,929	$	3,983,016	$	4,229,251
Income (Loss) from Continuing Operations	$	138,954	$	124,385	$	386,928
Per Share Income (Loss) from Continuing Operations - Basic	$	0.53	$	0.43	$	1.35
Per Share Income (Loss) from Continuing Operations - Diluted	$	0.53	$	0.43	$	1.35

______________________________________________________________________________


(1)	The Pro Forma Financial Information for the year ended December 31, 2016 only reflect the pro forma results of us and Recall.


(2)	The Pro Forma Financial Information for the years ended December 31, 2017 and 2018 only reflect pro forma results of us and IODC as Recall was included in our actual financial results for the years ended December 31, 2017 and 2018.

The amount of revenue and earnings in our Consolidated Statements of Operations for the years ended December 31, 2016, 2017 and 2018 related to Recall and IODC is impracticable for us to determine. Subsequent to the closings of the Recall Transaction and IODC Transaction, we began integrating Recall and IODC and our existing operations in order to achieve operational synergies. As a result, the revenue generated by Recall and IODC, as well as the underlying costs of sales and selling, general and administrative expenses to support Recall's and IODC's businesses, are now integrated with the revenue we generate, as well as the costs of sales and selling, general and administrative expenses that supported our business, prior to the acquisitions of Recall and IODC.

In addition to our acquisitions of Recall and IODC, we completed certain other acquisitions during 2016, 2017 and 2018. The Pro Forma Financial Information does not reflect these acquisitions due to the insignificant impact of these acquisitions on our consolidated results of operations.

c. Other Noteworthy Acquisitions

Acquisitions Completed During the Year Ended December 31, 2016

In March 2016, we acquired a controlling interest in Docufile Holdings Proprietary Limited ("Docufile"), a storage and records management company with operations in South Africa, for approximately $15,000. The acquisition of Docufile represents our entrance into Africa.

In November 2016, we entered into a binding agreement to acquire the storage and information management assets and operations of Santa Fe Group A/S ("Santa Fe") in ten regions within Europe and Asia in order to expand our presence in southeast Asia and western Europe. In December 2016, we acquired the storage and information management assets and operations of Santa Fe in Hong Kong, Malaysia, Singapore, Spain and Taiwan for approximately 15,200 Euros (or approximately $16,000, based upon the exchange rate between the United States dollar and the Euro as of December 30, 2016, the closing date of the 2016 Santa Fe Transaction). Of the total purchase price, 13,500 Euros (or approximately $14,200, based upon the exchange rate between the United States dollar and the Euro on the closing date of the 2016 Santa Fe Transaction) was paid during the year ended December 31, 2016, and the remaining balance is due on the 18-month anniversary of the closing of the 2016 Santa Fe Transaction.

Acquisitions Completed During the Year Ended December 31, 2017

During the first half of 2017, we acquired, in two separate transactions, (i) the storage and information management assets and operations of Santa Fe in Macau and South Korea, and (ii) the storage and information management assets and operations of Santa Fe in India, Indonesia and the Philippines for an aggregate cash purchase price of approximately 11,700 Euros (or approximately $13,000, based upon the exchange rate between the United States dollar and the Euro on the closing dates of the respective transactions).

In November 2017, we entered into an agreement to acquire the storage and information management assets and operations of Santa Fe in China (the “Santa Fe China Transaction”) for approximately $16,800, subject to customary purchase price adjustments. On December 29, 2017, we closed on the Santa Fe China Transaction. The purchase price for the Santa Fe China Transaction was not paid until January 2018 and, therefore, we accrued for the purchase price of the Santa Fe China Transaction in our Consolidated Balance Sheet as of December 31, 2017 (the “Accrued Purchase Price”). The Accrued Purchase Price is presented as a component of the current portion of long-term debt in our Consolidated Balance Sheet as of December 31, 2017.

In June 2017, in order to expand our presence in Peru, we acquired the storage and information management assets and operations of Ransa Comercial, S.A. and Depositos, S.A., two records and storage and information management companies with operations in Peru, for approximately $14,700.

In July 2017, in order to expand our European operations, we acquired Fileminders Ltd., a storage and records management company with operations in Cyprus, for approximately 24,900 Euros (or approximately $28,500, based upon the exchange rate between the United States dollar and the Euro on the closing date of the acquisition).

In September 2017, in order to expand our data center operations in the United States, we acquired Mag Datacenters LLC, which operated Fortrust, a private data center business with operations in Denver, Colorado (the “Fortrust Transaction”). At the closing of the Fortrust Transaction, we paid approximately $54,500 in cash (the "Fortrust Cash Consideration") and issued 2,193,637 shares of our common stock (the "Fortrust Stock Consideration"). The shares of our common stock issued to the former owners of Fortrust in connection with the Fortrust Transaction contain certain restrictions that impact the marketability of such shares for a period of six months following the closing date of the Fortrust Transaction (the “Lack of Marketability Restriction”). The 2,193,637 shares issued as part of the Fortrust Stock Consideration were valued at approximately $37.84 per share, which reflects a discount related to the Lack of Marketability Restriction, resulting in a total purchase price (including the Fortrust Cash Consideration and the Fortrust Stock Consideration) of approximately $137,500.

In September 2017, in order to expand our existing entertainment storage and services operations in the United States and to expand our entertainment storage and services operations into Canada, the United Kingdom, France, the Netherlands and Hong Kong, we completed the acquisition of Bonded Services of America, Inc. and Bonded Services Acquisition, Ltd. (together, "Bonded") (the "Bonded Transaction"), providers of media asset storage and management services for global entertainment and media companies, for approximately 62,000 British pounds sterling (or approximately $83,000, based upon the exchange rate between the British pound sterling and the United States dollar on the closing date of the Bonded Transaction).

In October 2017, in order to expand our presence in India, we acquired OEC Records Management, a storage and information management company with operations in India for approximately $19,300.

In addition to the transactions noted above, during 2017, in order to enhance our existing operations in the United States, Greece and South Africa and to expand our operations into the United Arab Emirates, we completed the acquisition of five storage and records management companies, one storage and data management company and one art storage company for total consideration of approximately $22,700. The individual purchase prices of these acquisitions were each less than $5,000.

Acquisitions Completed During the Year Ended December 31, 2018

On March 8, 2018, in order to expand our data center operations into Europe and Asia, we acquired the operations of two data centers in London and Singapore from Credit Suisse International and Credit Suisse AG (together, "Credit Suisse") for a total of (i) 34,600 British pounds sterling and (ii) 81,000 Singapore dollars (or collectively, approximately $111,400, based upon the exchange rates between the United States dollar and the British pound sterling and Singapore dollar on the closing date of the Credit Suisse transaction) (the “Credit Suisse Transaction”). As part of the Credit Suisse Transaction, Credit Suisse entered into a long-term lease with us to maintain existing data center operations.

On May 25, 2018, in order to further expand our data center operations in Europe, we acquired EvoSwitch Netherlands B.V. and EvoSwitch Global Services B.V. (collectively, "EvoSwitch"), a data center colocation space and solutions provider with a data center in Amsterdam (the "EvoSwitch Transaction"), for (i) cash consideration of 189,000 Euros (or approximately $222,000, based upon the exchange rate between the Euro and the United States dollar on the closing date of the EvoSwitch Transaction) and (ii) $25,000 of additional consideration in the form of future services we will provide to the seller, which is included in purchase price holdbacks and other in the allocation of the purchase price paid table below.

In August 2018, in order to expand our presence in China, we acquired the Chinese-Mainland operations of GRM Document Management, a storage and records management company, for approximately $34,100.

In addition to the transactions noted above, during 2018, in order to enhance our existing operations in the United States, Brazil, India, Ireland, Philippines, South Korea and the United Kingdom and to expand our operations into Croatia, we completed the acquisition of ten storage and records management companies and three art storage companies for total consideration of approximately $64,000. The individual purchase prices of these acquisitions ranged from approximately $1,000 to $18,000.

d. Purchase Price Allocation

A summary of the cumulative consideration paid and the allocation of the purchase price paid for all of our acquisitions in each respective year is as follows:



	2016									2017			2018
	Recall			Other Fiscal Year 2016 Acquisitions			Total			Total			IODC Transaction			Other Fiscal Year 2018 Acquisitions			Total
Cash Paid (gross of cash acquired)(1)	$	331,834		$	37,350		$	369,184		$	234,314		$	1,347,046		$	432,078		$	1,779,124
Purchase Price Holdbacks and Other(2)	—			—			—			20,093			—			35,218			35,218
Fair Value of Common Stock Issued	1,835,026			—			1,835,026			83,014			—			—			—
Fair Value of Noncontrolling Interests	—			3,506			3,506			1,507			—			—			—
Total Consideration	2,166,860			40,856			2,207,716			338,928			1,347,046			467,296			1,814,342
Fair Value of Identifiable Assets Acquired:
Cash	76,461			576			77,037			14,746			34,307			10,227			44,534
Accounts Receivable and Prepaid Expenses	176,775			2,703			179,478			19,309			7,070			13,076			20,146
Fair Value of Recall Divestments(3)	121,689			—			121,689			—			—			—			—
Other Assets	57,563			541			58,104			5,070			—			4,586			4,586
Property, Plant and Equipment(4)	622,063			10,963			633,026			150,878			863,027			225,848			1,088,875
Customer Relationship Intangible Assets(5)	709,139			20,842			729,981			116,028			—			44,622			44,622
Data Center In-Place Leases(6)	—			—			—			6,300			104,340			36,130			140,470
Data Center Tenant Relationships(7)	—			—			—			—			77,362			18,410			95,772
Data Center Above-Market Leases(8)	—			—			—			—			16,439			2,381			18,820
Other Intangible Assets	—			—			—			14,487			—			—			—
Debt Assumed	(792,385		)	—			(792,385		)	(5,287		)	—			(12,312		)	(12,312		)
Accounts Payable, Accrued Expenses and Other Liabilities	(276,814		)	(11,504		)	(288,318		)	(24,869		)	(36,230		)	(17,206		)	(53,436		)
Deferred Income Taxes	(164,074		)	(2,985		)	(167,059		)	(18,122		)	—			(43,218		)	(43,218		)
Data Center Below-Market Leases(8)	—			—			—			—			(11,421		)	(694		)	(12,115		)
Total Fair Value of Identifiable Net Assets Acquired	530,417			21,136			551,553			278,540			1,054,894			281,850			1,336,744
Goodwill Initially Recorded(9)	$	1,636,443		$	19,720		$	1,656,163		$	60,388		$	292,152		$	185,446		$	477,598

_______________________________________________________________________________

(1)

Included in cash paid for acquisitions in the Consolidated Statement of Cash Flows for the year ended December 31, 2016 is net cash acquired of $77,037 and cash received of $182 related to acquisitions made in years prior to 2016. Included in cash paid for acquisitions in the Consolidated Statement of Cash Flows for the year ended December 31, 2017 is net cash acquired of $14,746 and contingent and other payments, net of $137 related to acquisitions made in years prior to 2017. Included in cash paid for acquisitions in the Consolidated Statement of Cash Flows for the year ended December 31, 2018 is net cash acquired of $44,534 and contingent and other payments, net of $23,967 related to acquisitions made in years prior to 2018.


(2)	Purchase price holdbacks and other includes $16,771 purchase price accrued for the Santa Fe China Transaction in 2017 and includes $18,824 purchase price accrued for the EvoSwitch Transaction in 2018.


(3)	Represents the fair value, less costs to sell, of the Initial United States Divestments, the Seattle/Atlanta Divestments, the Recall Canadian Divestments and the UK Divestments.


(4)	Consists primarily of buildings, building improvements, leasehold improvements, data center infrastructure, racking structures, warehouse equipment and computer hardware and software.


(5)	The weighted average lives of customer relationship intangible assets associated with acquisitions in 2016, 2017 and 2018 was 13 years, 12 years and 10 years, respectively.


(6)	The weighted average lives of data center in-place leases associated with acquisitions in 2018 was 6 years.


(7)	The weighted average lives of data center tenant relationships associated with acquisitions in 2018 was 9 years.


(8)	The weighted average lives of data center above-market leases associated with acquisitions in 2018 was 3 years and the weighted average lives of data center below-market leases associated with acquisitions in 2018 was 7 years.


(9)	The goodwill associated with acquisitions, including Recall and IODC, is primarily attributable to the assembled workforce, expanded market opportunities and costs and other operating synergies anticipated upon the integration of the operations of us and the acquired businesses.

Allocations of the purchase price for acquisitions made in 2016, 2017 and 2018 were based on estimates of the fair value of the net assets acquired and are subject to adjustment upon the finalization of the purchase price allocations. The accounting for business combinations requires estimates and judgments regarding expectations for future cash flows of the acquired business, and the allocations of those cash flows to identifiable tangible and intangible assets, in determining the assets acquired and liabilities assumed. The fair values assigned to tangible and intangible assets acquired and liabilities assumed, including contingent consideration, are based on management's best estimates and assumptions, as well as other information compiled by management, including valuations that utilize customary valuation procedures and techniques. The estimates and assumptions underlying the initial valuations are subject to the collection of information necessary to complete the valuations within the measurement periods, which are up to one year from the respective acquisition dates. Assets and liabilities that were acquired and classified as held for sale immediately following the Recall Transaction were valued based on the estimated fair value of the divestment, less costs to sell. The preliminary purchase price allocations that are not finalized as of December 31, 2018 primarily relate to the final assessment of the fair values of intangible assets (primarily customer relationship intangible assets and data center lease-based intangible assets), property, plant and equipment (primarily building, building improvements, data center infrastructure and racking structures), operating leases, contingencies and income taxes (primarily deferred income taxes), primarily associated with the EvoSwitch Transaction, as well as other acquisitions we closed in 2018.

As the valuation of certain assets and liabilities for purposes of purchase price allocations are preliminary in nature, they are subject to adjustment as additional information is obtained about the facts and circumstances regarding these assets and liabilities that existed at the acquisition date. Any adjustments to our estimates of purchase price allocation will be made in the periods in which the adjustments are determined and the cumulative effect of such adjustments will be calculated as if the adjustments had been completed as of the acquisition dates. Adjustments recorded during the fourth quarter of 2018 were not material to our results from operations.