Commitments- Capital commitments (Details) - CNY (¥) ¥ in Millions	Mar. 31, 2018	Mar. 31, 2017
Capital expenditures
Capital commitments
Contracted but not provided for	¥ 5,788	¥ 4,609
Purchase of property and equipment
Capital commitments
Contracted but not provided for	3,181	1,771
Construction of corporate campuses
Capital commitments
Contracted but not provided for	¥ 2,607	¥ 2,838

Amount of the unrecorded obligation to transfer funds in the future for fixed or minimum amounts or quantities of goods or services at fixed or minimum prices (for example, as in take-or-pay contracts or throughput contracts).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 440
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=77896938&loc=d3e25336-109308

Name:	us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant