Property and Equipment - Schedule of Property and Equipment (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,480,349us-gaap_PropertyPlantAndEquipmentGross	$ 1,214,277us-gaap_PropertyPlantAndEquipmentGross
Accumulated depreciation and amortization	(878,758)	(763,990)
Property and equipment, net	601,591us-gaap_PropertyPlantAndEquipmentNet	450,287us-gaap_PropertyPlantAndEquipmentNet
Computer and networking equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	850,533	737,957
Purchased software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	46,537	40,237
Estimated useful life (in years)	3 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	27,923	20,838
Estimated useful life (in years)	5 years
Office equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	14,035	10,353
Estimated useful life (in years)	3 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	92,544	64,471
Internal-use software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 448,777	$ 340,421
Minimum \| Computer and networking equipment
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	3 years
Minimum \| Leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	2 years
Minimum \| Internal-use software
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	2 years
Maximum \| Computer and networking equipment
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	4 years
Maximum \| Leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	12 years
Maximum \| Internal-use software
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	7 years

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.14)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 14

-Article 5

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- Definition

Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

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-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.13)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.13)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

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-Subparagraph a

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

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-Name Regulation S-X (SX)

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- Definition

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References

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