FINANCIAL AND CAPITAL RISK MANAGEMENT - Fair value (Details) - CNY (¥) ¥ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Fair value measurement of assets
Financial assets	¥ 25,635,302	¥ 28,038,730
Fair value measurement of liabilities
Financial liabilities	117,717,290	126,084,772
Financial liabilities at amortized cost
Fair value measurement of liabilities
Financial liabilities	52,297,135	53,386,442
Financial liabilities, at fair value	50,632,689	52,099,569
Financial liabilities included in other non-current liabilities
Fair value measurement of liabilities
Financial liabilities	1,036,917	1,153,487
Financial liabilities, at fair value	903,141	1,146,893
Long-term interest-bearing loans and borrowings, excluding lease liability
Fair value measurement of liabilities
Financial liabilities	51,260,218	52,232,955
Financial liabilities, at fair value	49,729,548	50,952,676
Other non-current assets
Fair value measurement of assets
Financial assets	127,754	128,673
Financial assets, at fair value	¥ 117,537	¥ 111,935

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The amount of assets that are: (a) cash; (b) an equity instrument of another entity; (c) a contractual right: (i) to receive cash or another financial asset from another entity; or (ii) to exchange financial assets or financial liabilities with another entity under conditions that are potentially favourable to the entity; or (d) a contract that will, or may be, settled in the entity’s own equity instruments and is: (i) a non-derivative for which the entity is, or may be, obliged to receive a variable number of the entity’s own equity instruments; or (ii) a derivative that will, or may be, settled other than by the exchange of a fixed amount of cash or another financial asset for a fixed number of the entity’s own equity instruments. For this purpose the entity’s own equity instruments do not include puttable financial instruments classified as equity instruments in accordance with paragraphs 16A-16B of IAS 32, instruments that impose on the entity an obligation to deliver to another party a pro rata share of the net assets of the entity only on liquidation and are classified as equity instruments in accordance with paragraphs 16C-16D of IAS 32, or instruments that are contracts for the future receipt or delivery of the entity’s own equity instruments. [Refer: Financial instruments, class [member]; Financial liabilities]

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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The fair value of financial assets. [Refer: At fair value [member]; Financial assets]

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The amount of liabilities that are: (a) a contractual obligation: (i) to deliver cash or another financial asset to another entity; or (ii) to exchange financial assets or financial liabilities with another entity under conditions that are potentially unfavourable to the entity; or (b) a contract that will, or may be, settled in the entity’s own equity instruments and is: (i) a non-derivative for which the entity is, or may be, obliged to deliver a variable number of the entity’s own equity instruments; or (ii) a derivative that will, or may be, settled other than by the exchange of a fixed amount of cash or another financial asset for a fixed number of the entity’s own equity instruments. For this purpose, rights, options or warrants to acquire a fixed number of the entity’s own equity instruments for a fixed amount of any currency are equity instruments if the entity offers the rights, options or warrants pro rata to all of its existing owners of the same class of its own non-derivative equity instruments. Also, for those purposes the entity’s own equity instruments do not include puttable financial instruments that are classified as equity instruments in accordance with paragraphs 16A-16B of IAS 32, instruments that impose on the entity an obligation to deliver to another party a pro rata share of the net assets of the entity only on liquidation and are classified as equity instruments in accordance with paragraphs 16C-16D of IAS 32, or instruments that are contracts for the future receipt or delivery of the entity’s own equity instruments. As an exception, an instrument that meets the definition of a financial liability is classified as an equity instrument if it has all the features and meets the conditions in paragraphs 16A-16B or paragraphs 16C-16D of IAS 32. [Refer: Financial instruments, class [member]; Financial assets; Derivatives [member]]

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