Concentrations and Risks (Details)	12 Months Ended
Dec. 31, 2020 item customer	Dec. 31, 2019 customer item	Dec. 31, 2018 item customer
Service providers \| Server and bandwidth service provider
Concentrations and Risks
Total number of telecommunications service providers	87	79	49
Number of service providers provided by 10% or more of the Group's server and bandwidth service expenditure	3	2	3
Concentration risk (as a percent)	62.30%	56.30%	57.80%
Service providers \| Server and bandwidth service provider \| Equal to or more than
Concentrations and Risks
Threshold for disclosure of risk (as a percent)	10.00%	10.00%	10.00%
Accounts receivable \| Credit risk
Concentrations and Risks
Number of distribution channel	1	1
Accounts receivable \| Credit risk \| Distribution channel A
Concentrations and Risks
Concentration risk (as a percent)	24.50%	24.70%
Accounts receivable \| Credit risk \| Equal to or more than
Concentrations and Risks
Threshold for disclosure of risk (as a percent)	10.00%	10.00%
Total net revenues \| Major customers
Concentrations and Risks
Number of customers \| customer	0	0	0
Total net revenues \| Major customers \| Equal to or more than
Concentrations and Risks
Threshold for disclosure of risk (as a percent)	10.00%	10.00%	10.00%
Total net revenues \| Top 5 online games
Concentrations and Risks
Concentration risk (as a percent)	33.10%	36.80%	39.60%
Top online games	5	5	5
Total net game revenues \| Mobile games
Concentrations and Risks
Concentration risk (as a percent)	71.90%	71.40%	71.00%
Short-term investments \| Credit risk \| Equal to or more than
Concentrations and Risks
Effective yields of short-term investments	2.00%
Short-term investments \| Credit risk \| Less than
Concentrations and Risks
Effective yields of short-term investments	4.25%

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For an entity that discloses a concentration risk in relation to number of distribution channels.

+ References

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Represents the number of major telecommunications service providers providing bandwidth and server custody service.

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Represents the total number of telecommunications service providers providing bandwidth and server custody service.

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Represents the number of top online games.

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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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition

Rate of interest on investment.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
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