Nature of Business and Summary of Significant Accounting Policies - Additional Information (Detail)	3 Months Ended	12 Months Ended
	Sep. 30, 2016 USD ($)	Dec. 31, 2017 USD ($) service_providers market reporting_unit data_center continent	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 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		1,700
Data centers sites | data_center		190
Number of markets data center operates in | market		48
Data centers operates In number of continents | continent		5
Cash equivalents maturity period (in days)		90 days
A single customer is accounted for a percentage of accounts receivable or revenues for a period		10.00%	10.00%	10.00%
Impairment charges	$ 7,700,000	$ 0	$ 7,698,000	$ 0
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
Excess tax benefit, amount			$ 2,800,000	$ 30,000
4.75% convertible subordinated notes
Item Effected [Line Items]
Interest rate (percent)		4.75%	4.75%	4.75%				4.75%
Property, plant and equipment
Item Effected [Line Items]
Impairment charge		$ 0	$ 0	$ 0
Minimum
Item Effected [Line Items]
Short term investment maturity (in days and years)		90 days
Maximum
Item Effected [Line Items]
Short term investment maturity (in days and years)		1 year
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 2016-18 | Restatement Adjustment
Item Effected [Line Items]
Increase (decrease) in restricted cash			$ 453,500,000	$ (497,100,000)
Retained Earnings (Accumulated Deficit) | Accounting Standards Update 2014-09 | Forecast | Minimum
Item Effected [Line Items]
Cumulative effect of new accounting principle, in period of adoption					$ 267,000,000
Retained Earnings (Accumulated Deficit) | Accounting Standards Update 2014-09 | Forecast | Maximum
Item Effected [Line Items]
Cumulative effect of new accounting principle, in period of adoption					$ 307,000,000
New Accounting Pronouncement, Early Adoption, Effect | Retained Earnings (Accumulated Deficit) | Accounting Standards Update 2016-09
Item Effected [Line Items]
Cumulative effect of new accounting principle, in period of adoption							$ 1,100,000