Fair Value of Financial Instruments - Schedule of Assets Measured at Fair Value (Detail) - USD ($) $ in Thousands	Aug. 01, 2015	Jan. 31, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash equivalents	$ 49,965	$ 19,293
Total	199,657	99,799
Money market funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash equivalents	2	44
Commercial paper [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash equivalents	48,882	18,248
Government agency obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash equivalents	1,081	1,001
Short-term investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	149,692	62,168
Short-term investments [Member] \| Commercial paper [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	20,532	13,996
Short-term investments [Member] \| Government agency obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	129,160	48,172
Long-term investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments		18,338
Long-term investments [Member] \| Government agency obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments		18,338
Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash equivalents	2	44
Total	2	44
Level 1 [Member] \| Money market funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash equivalents	2	44
Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash equivalents	49,963	19,249
Total	199,655	99,755
Level 2 [Member] \| Commercial paper [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash equivalents	48,882	18,248
Level 2 [Member] \| Government agency obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash equivalents	1,081	1,001
Level 2 [Member] \| Short-term investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	149,692	62,168
Level 2 [Member] \| Short-term investments [Member] \| Commercial paper [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	20,532	13,996
Level 2 [Member] \| Short-term investments [Member] \| Government agency obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	$ 129,160	48,172
Level 2 [Member] \| Long-term investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments		18,338
Level 2 [Member] \| Long-term investments [Member] \| Government agency obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments		$ 18,338

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

+ Details

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

- Definition

Fair value portion 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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash

-URI http://asc.fasb.org/extlink&oid=6506951

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash Equivalents

-URI http://asc.fasb.org/extlink&oid=6507016

+ Details

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

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

- Definition

Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Trading Securities

-URI http://asc.fasb.org/extlink&oid=6526789

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 35

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=27723805&loc=d3e24584-111560

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=51813488&loc=d3e22054-111558

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Available-for-Sale Securities

-URI http://asc.fasb.org/extlink&oid=6505594

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Subparagraph a, f, g

-Article 7

+ Details

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

- Details

Name:	us-gaap_CashAndCashEquivalentsAxis=us-gaap_MoneyMarketFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CashAndCashEquivalentsAxis=us-gaap_CommercialPaperMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CashAndCashEquivalentsAxis=us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ScheduleOfFairValueOfSeparateAccountsByMajorCategoryOfInvestmentAxis=us-gaap_ShortTermInvestmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ScheduleOfFairValueOfSeparateAccountsByMajorCategoryOfInvestmentAxis=rh_LongTermInvestmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: