Acquisitions - Intangible Assets Acquired (Details) - Cedexis, Inc. [Member] $ in Thousands	Feb. 06, 2018 USD ($)
Acquired Finite-Lived Intangible Assets [Line Items]
Identifiable intangible assets acquired	$ 27,200
Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Identifiable intangible assets acquired	$ 2,000
Weighted average useful life	1 year
Developed Technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Identifiable intangible assets acquired	$ 23,800
Tradenames [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Identifiable intangible assets acquired	$ 1,400
Weighted average useful life	1 year
Minimum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average useful life	1 year
Minimum [Member] | Developed Technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average useful life	5 years
Maximum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average useful life	6 years
Maximum [Member] | Developed Technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average useful life	6 years