Share-based awards- Expense by function (Details) - CNY (¥) ¥ in Millions	12 Months Ended
Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Share-based awards
Share-based compensation expense	¥ 37,491	¥ 20,075	¥ 15,995
Cost of revenue
Share-based awards
Share-based compensation expense	8,915	5,505	3,893
Product development expenses
Share-based awards
Share-based compensation expense	15,378	7,374	5,712
Sales and marketing expenses
Share-based awards
Share-based compensation expense	4,411	2,037	1,772
General and administrative expenses
Share-based awards
Share-based compensation expense	¥ 8,787	¥ 5,159	¥ 4,618

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5047-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration