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Summary of Significant of Accounting Policies - Estimated Useful Lives of Intangible Asset (Detail) | 12 Months Ended
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Dec. 31, 2017
Platform |
Finite Lived Intangible Asset useful life | 5 years
Minimum [Member] | Customer relationship |
Finite Lived Intangible Asset useful life | 2 years
Minimum [Member] | Trademarks |
Finite Lived Intangible Asset useful life | 3 years
Minimum [Member] | Technology |
Finite Lived Intangible Asset useful life | 1 year
Minimum [Member] | Online game licenses |
Finite Lived Intangible Asset useful life | 1 year
Minimum [Member] | User base |
Finite Lived Intangible Asset useful life | 1 year
Minimum [Member] | Domain names |
Finite Lived Intangible Asset useful life | 1 year
Maximum [Member] | Customer relationship |
Finite Lived Intangible Asset useful life | 6 years
Maximum [Member] | Trademarks |
Finite Lived Intangible Asset useful life | 10 years
Maximum [Member] | Technology |
Finite Lived Intangible Asset useful life | 10 years
Maximum [Member] | Online game licenses |
Finite Lived Intangible Asset useful life | 5 years
Maximum [Member] | User base |
Finite Lived Intangible Asset useful life | 3 years
Maximum [Member] | Domain names |
Finite Lived Intangible Asset useful life | 10 years

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- Definition Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
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