Share-based compensation (Summary of Restricted Share Units Activity) (Details) - Restricted share units [Member] - $ / shares	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
2011 Incentive Scheme [Member]
Number of restricted shares
Outstanding at the beginning of the period (in shares)	25,229,634	30,874,144	20,955,720
Granted (in shares)	16,114,095	11,977,794	22,090,030
Forfeited (in shares)	(6,381,786)	(5,115,304)	(4,007,728)
Vested (in shares)	(7,848,811)	(12,507,000)	(8,163,878)
Outstanding at the end of the period (in shares)	27,113,132	25,229,634	30,874,144
Expected to vest at the end of the period (in shares)	25,703,976
Weighted average grant-date fair value
Outstanding at the beginning of the period (in dollars per share)	$ 4.9639	$ 4.4969	$ 2.4320
Granted (in dollars per share)	3.0005	4.7052	5.3001
Forfeited (in dollars per share)	4.7840	4.6843	2.5561
Vested (in dollars per share)	4.7427	3.6776	2.3227
Outstanding at the end of the period (in dollars per share)	3.9034	$ 4.9639	$ 4.4969
Expected to vest at the end of the period (in dollars per share)	$ 3.8916
Huya 2017 Share Incentive Plan [Member]
Number of restricted shares
Outstanding at the beginning of the period (in shares)	4,107,185	0
Granted (in shares)	2,908,370	4,193,685
Forfeited (in shares)	(270,707)	(76,500)
Vested (in shares)	(465,000)	(10,000)
Outstanding at the end of the period (in shares)	6,279,848	4,107,185	0
Expected to vest at the end of the period (in shares)	6,040,024
Weighted average grant-date fair value
Outstanding at the beginning of the period (in dollars per share)	$ 9.0331	$ 0
Granted (in dollars per share)	22.7642	9.0242
Forfeited (in dollars per share)	14.8129	7.1600
Vested (in dollars per share)	7.1600	19.5900
Outstanding at the end of the period (in dollars per share)	15.4350	$ 9.0331	$ 0
Expected to vest at the end of the period (in dollars per share)	$ 15.0623

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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 (c)(1)(iv)(3)
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- Definition

Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

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-Publisher FASB
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- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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- Definition

As of the balance sheet date, the weighted-average exercise price for awards that are expected to vest.

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As of the balance sheet date, the number of shares into which expected to vest stock options outstanding can be converted under the option plan.

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