Adjustments to additional paid in capital deferred tax liability.

No definition available.

Name:	hubs_AdjustmentsToAdditionalPaidInCapitalDeferredTaxLiability
Namespace Prefix:	hubs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Common stock shares reserved for underlying warrants.

+ References

No definition available.

+ Details

Name:	hubs_CommonStockSharesReservedForUnderlyingWarrants
Namespace Prefix:	hubs_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Convertible notes hedge and warrant transactions cost net.

+ References

No definition available.

+ Details

Name:	hubs_ConvertibleNotesHedgeAndWarrantTransactionsCostNet
Namespace Prefix:	hubs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Debt instrument convertible conversion ratio denominator.

+ References

No definition available.

+ Details

Name:	hubs_DebtInstrumentConvertibleConversionRatioDenominator
Namespace Prefix:	hubs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Debt instrument convertible gross carrying amount of the equity component.

+ References

No definition available.

+ Details

Name:	hubs_DebtInstrumentConvertibleGrossCarryingAmountOfTheEquityComponent
Namespace Prefix:	hubs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Hedging option strike price per common stock.

+ References

No definition available.

+ Details

Name:	hubs_HedgingOptionStrikePricePerCommonStock
Namespace Prefix:	hubs_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of common shares to be repurchased under convertible note hedge transactions.

+ References

No definition available.

+ Details

Name:	hubs_NumberOfCommonSharesToBeRepurchasedUnderConvertibleNoteHedgeTransactions
Namespace Prefix:	hubs_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Settlement period of warrants excess price over strike price.

+ References

No definition available.

+ Details

Name:	hubs_SettlementPeriodOfWarrantsExcessPriceOverStrikePrice
Namespace Prefix:	hubs_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Warrants expected to settle, commencement date.

+ References

No definition available.

+ Details

Name:	hubs_WarrantsExpectedToSettleCommencementDate
Namespace Prefix:	hubs_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Warrants expected to settle description.

+ References

No definition available.

+ Details

Name:	hubs_WarrantsExpectedToSettleDescription
Namespace Prefix:	hubs_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Exercise price per share or per unit of warrants or rights outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i)(4))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

Name:	us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i)(2))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

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

- Definition

Aggregate number of common shares reserved for future issuance.

+ References

+ Details

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

- Definition

The price per share of the conversion feature embedded in the debt instrument.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031898-161870

+ Details

Name:	us-gaap_DebtInstrumentConvertibleConversionPrice1
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Ratio applied to the conversion of debt instrument into equity with equity shares divided by debt principal amount.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21521-112644

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21506-112644

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(5))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644

+ Details

Name:	us-gaap_DebtInstrumentConvertibleConversionRatio1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Threshold period of specified consecutive trading days within which common stock price to conversion price of convertible debt instrument must exceed threshold percentage for specified number of trading days to trigger conversion feature.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentConvertibleThresholdConsecutiveTradingDays1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Minimum percentage of common stock price to conversion price of convertible debt instruments to determine eligibility of conversion.

+ References

No definition available.

+ Details

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

- Definition

Threshold number of specified trading days that common stock price to conversion price of convertible debt instruments must exceed threshold percentage within a specified consecutive trading period to trigger conversion feature.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentConvertibleThresholdTradingDays
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

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

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 6
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6036836-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
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_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(2))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258

+ Details

Name:	us-gaap_DebtInstrumentMaturityDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of the payment terms of the debt instrument (for example, whether periodic payments include principal and frequency of payments) and discussion about any contingencies associated with the payment.

+ 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 210.5-02.22(a)(3))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

+ Details

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

- Definition

Description of debt redemption features under terms of the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph e
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

+ Details

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

- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

+ References

+ Details

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

- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ 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 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28555-108399

+ Details

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

- Definition

The premium (cost) of a hedge, expensed during the period.

+ References

No definition available.

+ Details

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

- Definition

The cash outflow for cost incurred directly with the issuance of an equity security.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3291-108585

+ Details

Name:	us-gaap_PaymentsOfStockIssuanceCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3255-108585

+ Details

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

- Definition

The cash inflow from issuance of rights to purchase common shares at predetermined price (usually issued together with corporate debt).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3255-108585

+ Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=hubs_ZeroPointTwoFivePercentConvertibleSeniorNotesDueTwoThousandTwentyTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_CommonStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=hubs_LiabilityComponentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=hubs_EquityComponentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=hubs_ScenarioOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=hubs_ScenarioTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=us-gaap_PrivatePlacementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=us-gaap_OverAllotmentOptionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

0.25% Convertible Senior Notes, Convertible Note Hedge and Warrant - Additional Information (Detail) $ / shares in Units, shares in Thousands	1 Months Ended	3 Months Ended	12 Months Ended
	May 31, 2017 USD ($) d $ / shares shares	Dec. 31, 2018 d shares	Dec. 31, 2018 shares	Dec. 31, 2017 USD ($) $ / shares shares
Debt Instrument [Line Items]
Net proceeds from the debt offering				$ 389,233,000
Common stock for issuance upon conversion \| shares		3,823	3,823	4,400
Sales of warrants				$ 58,880,000
0.25% Convertible Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	0.25%
Debt instrument, maturity date			Jun. 01, 2022
Debt instrument, payment terms			The interest rates are fixed at 0.25% per annum and are payable semi-annually in arrears on June 1 and December 1 of each year, commencing on December 1, 2017.
Net proceeds from the debt offering	$ 389,200,000
Principal amount of each convertible note	$ 1,000
Debt instrument, conversion ratio	10.5519
Debt instrument, conversion price per share \| $ / shares	$ 94.77
Debt instrument, convertible, threshold trading days \| d		20
Debt instrument, convertible, threshold consecutive trading days \| d		30
Common stock for issuance upon conversion \| shares	4,200
Debt Instrument, Redemption Price, Percentage	100.00%
Debt Instrument, Redemption, Description			Repurchase price equal to 100% of the principal amount of the notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date.
Carrying amount of equity component	$ 106,000,000
Debt instrument, effective interest rate	6.95%
Debt issuance costs	$ 10,800,000
Number of common shares to be repurchased under convertible note hedge transactions with certain counterparties \| shares		4,200	4,200	4,200
Hedging option strike price per common stock \| $ / shares				$ 94.77
Cost of convertible note hedge transactions				$ 78,900,000
Warrants expected to settle, description			The warrants are expected to settle three business days from each trading day commencing on September 1, 2022 and ending on the 79th trading day thereafter.
Settlement period of warrants excess price over strike price				3 days
Warrants expected to settle, commencement date			Sep. 01, 2022
Sales of warrants				$ 58,900,000
Warrants, issuance costs				200,000
Convertible notes hedge and warrant transactions cost net				20,000,000
Reserved common stock for underlying warrants \| shares		4,200	4,200
Deferred tax liability adjustment to additional paid-in capital				$ 9,400,000
0.25% Convertible Senior Notes Due 2022 [Member] \| Common Stock [Member]
Debt Instrument [Line Items]
Warrants holders option to purchase number of shares of company’s common stock \| shares		4,200	4,200	4,200
Warrants exercise price per share \| $ / shares				$ 115.8
0.25% Convertible Senior Notes Due 2022 [Member] \| Liability Component [Member]
Debt Instrument [Line Items]
Debt issuance costs	7,900,000
0.25% Convertible Senior Notes Due 2022 [Member] \| Equity Component [Member]
Debt Instrument [Line Items]
Debt issuance costs	$ 2,900,000
0.25% Convertible Senior Notes Due 2022 [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, conversion price per share \| $ / shares				94.77
Percentage of closing price to trigger debt conversion	130.00%	130.00%
0.25% Convertible Senior Notes Due 2022 [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, conversion price per share \| $ / shares				$ 115.83
Percentage of closing price to trigger debt conversion	98.00%
0.25% Convertible Senior Notes Due 2022 [Member] \| Scenario 1 [Member]
Debt Instrument [Line Items]
Debt instrument, convertible, threshold trading days \| d	20
Debt instrument, convertible, threshold consecutive trading days \| d	30
0.25% Convertible Senior Notes Due 2022 [Member] \| Scenario Two [Member]
Debt Instrument [Line Items]
Debt instrument, convertible, threshold trading days \| d	5
Debt instrument, convertible, threshold consecutive trading days \| d	5
0.25% Convertible Senior Notes Due 2022 [Member] \| Private Offering [Member]
Debt Instrument [Line Items]
Principal amount of long term debt	$ 350,000,000
0.25% Convertible Senior Notes Due 2022 [Member] \| Over-Allotment Options [Member]
Debt Instrument [Line Items]
Principal amount of long term debt	$ 50,000,000