Modification charge related to the ESPP reset.

No definition available.

Name:	pstg_ESPPModificationCharge
Namespace Prefix:	pstg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Employee stock purchase plan offering period.

+ References

No definition available.

+ Details

Name:	pstg_EmployeeStockPurchasePlanOfferingPeriod
Namespace Prefix:	pstg_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of Purchase Periods

+ References

No definition available.

+ Details

Name:	pstg_NumberofPurchasePeriods
Namespace Prefix:	pstg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Purchase Period, Term

+ References

No definition available.

+ Details

Name:	pstg_PurchasePeriodTerm
Namespace Prefix:	pstg_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Share cap for ESPP at each purchase date.

+ References

No definition available.

+ Details

Name:	pstg_ShareCapForESPPAtPurchaseDate
Namespace Prefix:	pstg_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

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.

+ References

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
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-Section S99
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809

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-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

+ Details

Name:	us-gaap_AllocatedShareBasedCompensationExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Aggregate number of common shares reserved for future issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_CommonStockCapitalSharesReservedForFutureIssuance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Unrecognized cost of unvested share-based compensation awards.

+ References

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

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The highest percentage of annual salary that an employee is permitted to utilize with respect to the plan.

+ References

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

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Maximum number of shares that may be issued in accordance with the plan as a proportion of outstanding capital stock.

+ References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfOutstandingStockMaximum
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of capitalized and expensed compensation cost from equity-based compensation arrangements.

+ References

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

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Purchase price of common stock expressed as a percentage of its fair value.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_PlanNameAxis=pstg_TwentyFifteenEmployeeStockPurchasePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardDateAxis=pstg_ThroughMarch152018Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardDateAxis=pstg_ThroughMarch152019Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=pstg_TwentyFifteenEquityIncentivePlanMember
Namespace Prefix:
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Period Type:

Equity Incentive Plans - 2015 Employee Stock Purchase Plan (Details)			1 Months Ended	12 Months Ended
	Mar. 16, 2017 USD ($)	Mar. 16, 2016 USD ($)	Aug. 31, 2015 USD ($) period shares	Jan. 31, 2019 USD ($) shares	Jan. 31, 2018 USD ($)	Jan. 31, 2017 USD ($)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for future equity awards (in shares) \| shares				74,494,496
Stock-based compensation expense				$ 210,645,000	$ 150,673,000	$ 116,668,000
Unrecognized compensation cost related to stock awards, weighted-average period				1 year 9 months 18 days
2015 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Employee stock purchase plan offering period		24 months
Number of purchase periods \| period			4
Purchase period, term			6 months
Stock-based compensation expense				$ 35,400,000	$ 18,300,000	$ 18,300,000
Unrecognized stock-based compensation expense				$ 18,400,000
Unrecognized compensation cost related to stock awards, weighted-average period				10 months 24 days
2015 Employee Stock Purchase Plan \| Through March 15, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Employee stock purchase plan offering period		24 months
ESPP modification charge		$ 10,600,000
2015 Employee Stock Purchase Plan \| Through March 15, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Employee stock purchase plan offering period		24 months
ESPP modification charge	$ 9,000,000
Class A common stock \| 2015 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for future equity awards (in shares) \| shares			3,500,000
Increase in shares reserved by percentage of capital stock			1.00%
Payroll deductions percentage			30.00%
Share cap for ESPP at purchase date (in shares) \| shares			3,000
Calendar year gap for ESPP contribution amount			$ 25,000
Purchase price as percentage of fair market value of common stock			85.00%
Class A common stock \| 2015 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Increase in shares reserved by percentage of capital stock				5.00%