Balance Sheet Components - Property and Equipment, Net (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
	Jan. 01, 2020	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Gross property and equipment		$ 198,307		$ 198,307		$ 168,655
Less accumulated depreciation and amortization		(83,758)		(83,758)		(67,189)
Total property and equipment, net		114,549		114,549		101,466
Depreciation and amortization expense		10,800	$ 7,000	20,700	$ 13,100
Servers—network infrastructure
Property, Plant and Equipment [Line Items]
Gross property and equipment		102,183		102,183		84,979
Buildings
Property, Plant and Equipment [Line Items]
Gross property and equipment		0		0		13,035
Buildings | ASC 842
Property, Plant and Equipment [Line Items]
Change in property and equipment for adoption of new ASU	$ (13,000)
Construction in progress
Property, Plant and Equipment [Line Items]
Gross property and equipment		15,706		15,706		8,692
Capitalized internal-use software
Property, Plant and Equipment [Line Items]
Gross property and equipment		42,666		42,666		31,171
Depreciation and amortization expense				5,300	$ 2,800
Office and computer equipment
Property, Plant and Equipment [Line Items]
Gross property and equipment		17,886		17,886		13,528
Office furniture
Property, Plant and Equipment [Line Items]
Gross property and equipment		6,478		6,478		6,124
Software
Property, Plant and Equipment [Line Items]
Gross property and equipment		1,331		1,331		1,025
Depreciation and amortization expense		2,800	$ 1,500
Leasehold improvements
Property, Plant and Equipment [Line Items]
Gross property and equipment		11,628		11,628		9,870
Leasehold improvements | ASC 842
Property, Plant and Equipment [Line Items]
Change in property and equipment for adoption of new ASU	$ 1,600
Asset retirement obligation
Property, Plant and Equipment [Line Items]
Gross property and equipment		$ 429		$ 429		$ 231