Interest expense (Details) ¥ in Millions, $ in Millions	12 Months Ended
Dec. 31, 2021 CNY (¥)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 CNY (¥)	Dec. 31, 2019 CNY (¥)
Interest expense	¥ (1,213)	$ (190)	¥ (1,125)	¥ (725)
Nonrecourse securitization debt
Interest expense				(38)
Unsecured Senior Notes Bank Borrowings and Others
Interest expense	¥ (1,213)		¥ (1,125)	¥ (687)

Amount of the cost of borrowed funds accounted for as interest expense.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration