Acquisitions (Narrative) (Details) - USD ($) $ in Millions	Nov. 13, 2018	Feb. 06, 2018
Sapho, Inc.
Business Acquisition [Line Items]
Total consideration in business acquisitions	$ 182.7
Cash acquired from the acquisition	$ 3.7
Cedexis, Inc.
Business Acquisition [Line Items]
Total consideration in business acquisitions		$ 66.0
Cash acquired from the acquisition		$ 6.0

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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