Goodwill and Intangible Assets - Additional Information (Details) - USD ($) |
12 Months Ended | |||
|---|---|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
Nov. 08, 2019 |
|
| Finite Lived Intangible Assets [Line Items] | ||||
| Goodwill | $ 74,116,000 | $ 1,382,000 | ||
| Boston-based Dataxu, Inc, Demand-Side Platform (DSP) | ||||
| Finite Lived Intangible Assets [Line Items] | ||||
| Goodwill | 72,700 | $ 72,733,000 | ||
| Goodwill impairment loss | 0 | 0 | $ 0 | |
| Amortization of intangible assets | 2,800,000 | $ 600,000 | $ 200,000 | |
| Boston-based Dataxu, Inc, Demand-Side Platform (DSP) | Developed Technology, Customer Relationships, and Tradename | ||||
| Finite Lived Intangible Assets [Line Items] | ||||
| Acquired intangible assets | 70,200,000 | |||
| Boston-based Dataxu, Inc, Demand-Side Platform (DSP) | Patents | ||||
| Finite Lived Intangible Assets [Line Items] | ||||
| Acquired intangible assets | 4,100,000 | |||
| Boston-based Dataxu, Inc, Demand-Side Platform (DSP) | Developed Technology | ||||
| Finite Lived Intangible Assets [Line Items] | ||||
| Acquired intangible assets | $ 3,800,000 | |||