Principal Accounting Policies (Details 7)	12 Months Ended
Dec. 31, 2020
Share based Compensation
Number of preceding years considered for estimating forfeiture	5 years
2009 Plan and 2019 Plan \| Restricted share units \| Equal to or more than
Share based Compensation
Service vesting period	1 year
2009 Plan and 2019 Plan \| Restricted share units \| Less than
Share based Compensation
Service vesting period	5 years
Certain subsidiaries \| Stock Options \| Equal to or more than
Share based Compensation
Expiration period	5 years
Certain subsidiaries \| Stock Options \| Less than
Share based Compensation
Expiration period	10 years

Represents the number of preceding years considered for estimating the forfeiture under the share-based compensation plan.

No definition available.

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- Definition

Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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- 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

Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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