Face amount or stated value per share of common stock.

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The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

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Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

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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.

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No definition available.

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Amount of cumulative effect of the change in accounting principle or new accounting pronouncement on retained earnings or other components of equity or net assets in the statement of financial position as of the beginning of the earliest period presented.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Additional information: condensed financial statements of the Company (Condensed balance sheets) (Parenthetical) (Details) ¥ in Millions	Dec. 31, 2016 CNY (¥) shares	Dec. 31, 2016 $ / shares	Dec. 31, 2015 $ / shares shares	Dec. 31, 2014 shares
Accounting Standards Update 2015-03 [Member]
Condensed balance sheets [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets \| ¥	¥ 25.3
Class A common shares [Member]
Condensed balance sheets [Line Items]
Common shares, par value (in dollars per share) \| $ / shares		$ 0.00001	$ 0.00001
Common shares, shares authorized	10,000,000,000		10,000,000,000	10,000,000,000
Common shares, shares issued	750,115,028		728,227,848	706,173,568
Common shares, shares outstanding	750,115,028		728,227,848	706,173,568
Class B common shares [Member]
Condensed balance sheets [Line Items]
Common shares, par value (in dollars per share) \| $ / shares		0.00001	$ 0.00001
Common shares, shares authorized	1,000,000,000		1,000,000,000	1,000,000,000
Common shares, shares issued	359,557,976		369,557,976	427,352,696
Common shares, shares outstanding	359,557,976		369,557,976	427,352,696
Parent [Member] \| Class A common shares [Member]
Condensed balance sheets [Line Items]
Common shares, par value (in dollars per share) \| $ / shares		0.00001	$ 0.00001
Common shares, shares authorized	10,000,000,000		10,000,000,000
Common shares, shares issued	750,115,028		728,227,848
Common shares, shares outstanding	750,115,028		728,227,848
Parent [Member] \| Class B common shares [Member]
Condensed balance sheets [Line Items]
Common shares, par value (in dollars per share) \| $ / shares		$ 0.00001	$ 0.00001
Common shares, shares authorized	1,000,000,000		1,000,000,000
Common shares, shares issued	359,557,976		369,557,976
Common shares, shares outstanding	359,557,976		369,557,976