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Schedules of Concentration of Risk Based on Consolidated Revenue (Detail)	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Customer Concentration Risk | Advertiser A | Consolidated Revenue
Concentration Risk [Line Items]
Revenues by geographic region	17.00%	18.00%

X

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

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