Goodwill and Intangible Assets - Additional Information (Details) - Boston-based Dataxu, Inc, Demand-Side Platform (DSP) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Finite Lived Intangible Assets [Line Items]
Adjustment to reduce the total purchase consideration paid for acquisition and allocation to goodwill	$ 1.1
Amortization of intangible assets	$ 3.8	$ 0.1

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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