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The collection periods covered under the value added tax receivables extended by the Company, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Period of time between acquisition and maturity of held-to-maturity securities, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Represents the period of time within which the results of equity method earnings are recognized in arrears.

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Any certificate of deposit or savings account held by a bank or other financial institution for a short-term specified period of time between three months and one year.

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Any certificate of deposit or savings account held by a bank or other financial institution for a short-term specified period of time between three months and one year and other investments not otherwise specified in the taxonomy that will be realized in a short period of time, usually less than one year or the normal operating cycle, whichever is longer.

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n/a.

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A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible.

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Amount of cost for defined contribution plan.

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The total expense recognized in the period for promotion, public relations, and brand or product advertising.

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Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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The portion of net income or loss attributable to temporary equity interest.

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Summary of significant accounting policies- Various (Details) ¥ in Millions, $ in Millions	12 Months Ended
	Mar. 31, 2018 CNY (¥) segment	Mar. 31, 2017 CNY (¥) segment	Mar. 31, 2016 CNY (¥) segment	Mar. 31, 2018 USD ($)	Mar. 31, 2018 CNY (¥)	Mar. 31, 2017 USD ($)	Mar. 31, 2017 CNY (¥)	Mar. 31, 2015 CNY (¥)
Business combinations and noncontrolling interests
Net loss attributable to mezzanine equity holders	¥ 930
Segment reporting
Number of operating segment \| segment	4	4	1
Number of reportable segment \| segment	4	4	1
Sales and marketing expenses
Advertising and promotional expenses	¥ 16,814	¥ 8,799	¥ 5,524
Cash and cash equivalents
Amount of cash and cash equivalents			106,818	$ 31,775	¥ 199,309	$ 22,915	¥ 143,736	¥ 108,193
Short term investments
Short-term investments- fixed deposits					2,919		1,075
Short-term investments				$ 970	6,086		3,011
Investment in equity investees
Period of time within which results of equity method earnings are recognized in arrears	3 months
Minimum
VAT receivables
Collection periods extended for VAT receivables	3 months
Investment securities
Maturities of held-to-maturity securities held	1 year
Maximum
VAT receivables
Collection periods extended for VAT receivables	6 months
Investment securities
Maturities of held-to-maturity securities held	10 years
VAT receivables \| Cost of revenue \| Core commerce
VAT receivables
Allowance for doubtful accounts relating to VAT receivables			474		153		1,321
Cash held in accounts managed by Alipay
Cash and cash equivalents
Amount of cash and cash equivalents					1,687		991
Short term investments held in accounts managed by Alipay
Short term investments
Short-term investments					¥ 890		¥ 982
Government-mandated multi-employer defined contribution plan in PRC
Other employee benefits
Contribution amount charged to the consolidated income statements	¥ 3,587	¥ 2,710	¥ 2,094