Nature of Business and Summary of Significant Accounting Policies - Additional Information (Detail)		12 Months Ended
	Sep. 30, 2016 USD ($)	Dec. 31, 2018 USD ($) service_providers data_center_site reporting_unit market continent	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Jan. 01, 2019 USD ($)	Mar. 31, 2018 USD ($)	Jan. 01, 2018 USD ($)	May 01, 2017 data_center_building	Jan. 01, 2017 USD ($)	Jun. 30, 2016
Item Effected [Line Items]
Number of network providers that provide internet access | service_providers		1,800
Data centers sites | data_center_site		200
Number of markets data center operates in | market		52
Data centers operates In number of continents | continent		5
Cash equivalents maturity period (in days)		90 days
Cumulative adjustment							$ 269,776,000		$ 1,123,000
Impairment charges	$ 7,700,000	$ 0	$ 0	$ 7,698,000
Number of reporting units | reporting_unit		3
Impairment charges, intangible assets		$ 0	0	$ 0
Percentage of recurring revenue		90.00%
Equity awards vesting period (in years)		4 years
Revenue, requirement of payment, terms		P24M
4.75% convertible subordinated notes
Item Effected [Line Items]
Interest rate (percent)		4.75%								4.75%
Property, plant and equipment
Item Effected [Line Items]
Impairment charges		$ 0	$ 0
Minimum
Item Effected [Line Items]
Short term investment maturity (in days and years)		90 days
Revenue, Performance Obligation, Description of Payment Terms		P30D
Maximum
Item Effected [Line Items]
Short term investment maturity (in days and years)		1 year
Revenue, Performance Obligation, Description of Payment Terms		P45D
Executives | Minimum
Item Effected [Line Items]
Equity awards vesting period (in years)		2 years
Executives | Maximum
Item Effected [Line Items]
Equity awards vesting period (in years)		4 years
Verizon
Item Effected [Line Items]
Data center buildings | data_center_building								29
Accounting Standards Update 2016-01
Item Effected [Line Items]
Cumulative adjustment						$ 2,100,000
Retained Earnings (Accumulated Deficit)
Item Effected [Line Items]
Cumulative adjustment							271,900,000		$ 1,123,000
Retained Earnings (Accumulated Deficit) | Accounting Standards Update 2016-01
Item Effected [Line Items]
Cumulative adjustment							$ 2,100,000
Paris IBX Data Center | Minimum
Item Effected [Line Items]
Revenue, requirement of payment, terms		P1Y
Paris IBX Data Center | Maximum
Item Effected [Line Items]
Revenue, requirement of payment, terms		P3Y
Scenario, forecast | Accounting Standards Update 2016-02 | Minimum
Item Effected [Line Items]
Operating lease, right-of-use asset					$ 1,300,000,000
Operating lease, liability					1,400,000,000
Scenario, forecast | Accounting Standards Update 2016-02 | Maximum
Item Effected [Line Items]
Operating lease, right-of-use asset					1,600,000,000
Operating lease, liability					$ 1,600,000,000