Common stock shares covered under capped call transactions.

No definition available.

Name:	box_CommonStockSharesCoveredUnderCappedCallTransactions
Namespace Prefix:	box_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Cost of purchased capped calls.

+ References

No definition available.

+ Details

Name:	box_CostOfPurchasedCappedCalls
Namespace Prefix:	box_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Debt instrument convertible equity issuance costs.

+ References

No definition available.

+ Details

Name:	box_DebtInstrumentConvertibleEquityIssuanceCosts
Namespace Prefix:	box_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Debt instrument convertible gross carrying amount of the equity component.

+ References

No definition available.

+ Details

Name:	box_DebtInstrumentConvertibleGrossCarryingAmountOfTheEquityComponent
Namespace Prefix:	box_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Debt instrument, convertible, threshold maximum percentage of product of last reported sale price of common stock.

+ References

No definition available.

+ Details

Name:	box_DebtInstrumentConvertibleThresholdMaximumPercentageOfProductOfLastReportedSalePriceOfCommonStock
Namespace Prefix:	box_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Leverage ratio maximum.

+ References

No definition available.

+ Details

Name:	box_LeverageRatioMaximum
Namespace Prefix:	box_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line of credit facility additional borrowing capacity.

+ References

No definition available.

+ Details

Name:	box_LineOfCreditFacilityAdditionalBorrowingCapacity
Namespace Prefix:	box_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line of credit facility finance leases and debt covenant limit.

+ References

No definition available.

+ Details

Name:	box_LineOfCreditFacilityFinanceLeasesAndDebtCovenantLimit
Namespace Prefix:	box_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line of credit facility maximum borrowing capacity sublimit.

+ References

No definition available.

+ Details

Name:	box_LineOfCreditFacilityMaximumBorrowingCapacitySublimit
Namespace Prefix:	box_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Principal amount of notes used in conversion rate.

+ References

No definition available.

+ Details

Name:	box_PrincipalAmountOfNotesUsedInConversionRate
Namespace Prefix:	box_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The number of shares issued in exchange for the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or payments in the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=121583591&loc=d3e4332-108586

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=121583591&loc=d3e4304-108586

+ Details

Name:	us-gaap_DebtConversionConvertedInstrumentSharesIssued1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- 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=120520924&loc=SL6031898-161870

+ Details

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

- Definition

Latest date when the debt instrument can be converted into equity, in CCYY-MM-DD format.

+ 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)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: 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 3: 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_DebtInstrumentConvertibleLatestDate1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
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=119993939&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=120520924&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=119993939&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=120391452&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=120391452&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=117815213&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=120391452&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

Start date of debt instrument redemption period, in CCYY-MM-DD format.

+ 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_DebtInstrumentRedemptionPeriodStartDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of principal amount of debt redeemed.

+ References

No definition available.

+ Details

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

- Definition

Amount paid into a fund, which is used to retire the debt instrument.

+ References

Reference 1: 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_DebtInstrumentSinkingFundPayment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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

+ Details

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

- Definition

The cap rate on a price risk derivative such as a cap or collar. A payment or receipt is triggered if the market rate exceeds the cap rate on the contract.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeCapPrice
Namespace Prefix:	us-gaap_
Data Type:	srt-types:perUnitItemType
Balance Type:	na
Period Type:	instant

- Definition

The strike price on the price risk option contract such as a put option or a call option.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativePriceRiskOptionStrikePrice
Namespace Prefix:	us-gaap_
Data Type:	srt-types:perUnitItemType
Balance Type:	na
Period Type:	instant

- Definition

Aggregate amount of interest expense on all borrowings.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.7,8)
-URI http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

+ Details

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

- Definition

Amount of the cost of borrowed funds accounted for as interest expense for debt.

+ References

+ Details

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

- Definition

Date the credit facility terminates, in CCYY-MM-DD format.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityExpirationDate1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=120520924&loc=SL6031897-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 4: 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))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Definition

The cash outflow for the settlement of obligation drawn from a contractual arrangement with the lender, including letter of credit, standby letter of credit and revolving credit arrangements, under which borrowings can be made up to a specific amount at any point in time with maturities due beyond one year or 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 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3291-108585

+ Details

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

- Details

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

- Details

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

- Details

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

- Details

Name:	us-gaap_DebtInstrumentRedemptionPeriodAxis=box_DebtInstrumentRedemptionPeriodOnOrAfterJanuaryTwentyTwoThousandTwentyFourMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtConversionByUniqueDescriptionAxis=box_DebtInstrumentConvertibleTermsOfConversionFeatureCircumstancesOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtConversionByUniqueDescriptionAxis=box_DebtInstrumentConvertibleTermsOfConversionFeatureCircumstancesTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_LineOfCreditFacilityAxis=box_WellsFargoBankMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_PrimeRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_LetterOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentRedemptionPeriodAxis=us-gaap_DebtInstrumentRedemptionPeriodOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentRedemptionPeriodAxis=us-gaap_DebtInstrumentRedemptionPeriodTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Debt - Additional Information (Details)			1 Months Ended	12 Months Ended
Debt - Additional Information (Details)	Jul. 12, 2019 USD ($)	Nov. 27, 2017 USD ($)	Jan. 31, 2021 USD ($) $ / shares shares	Jan. 31, 2021 USD ($) TradingDay $ / shares shares	Jan. 31, 2020 USD ($)	Jan. 31, 2019 USD ($)	Apr. 30, 2020 USD ($)
Debt Instrument [Line Items]
Repayment of outstanding principal balance				$ 40,000,000
November 2017 Facility
Debt Instrument [Line Items]
Line of credit facility, interest expense				1,100,000	$ 1,300,000	$ 1,300,000
Convertible Senior Notes \| 0.00% Convertible Senior Notes Due January 15, 2026
Debt Instrument [Line Items]
Aggregate principal amount			$ 345,000,000.0	$ 345,000,000.0
Debt instrument interest rate stated percentage			0.00%	0.00%
Debt instrument due date			Jan. 15, 2026
Principal amount of notes used in conversion rate			$ 1,000	$ 1,000
Initial conversion rate per $1,000 principal amount of notes \| shares			38.7665
Initial conversion price per share of common stock \| $ / shares			$ 25.80	$ 25.80
Debt instrument, convertible, latest date				Oct. 15, 2025
Gross carrying amount of equity component			$ 70,509,000	$ 70,509,000
Debt instrument, effective interest rate			5.19%	5.19%
Liability issuance costs			$ 7,470,000	$ 7,470,000
Equity issuance costs			$ 1,933,000	1,933,000
Interest expense, debt				$ 600,000
Initial strike price \| $ / shares			25.80	25.80
Initial cap prices \| $ / shares			35.58	35.58
Common stock shares covered under capped call transactions \| shares				13,400,000
Cost of purchased capped calls				$ 27,800,000
Total debt outstanding with carrying amount			$ 267,614,000	$ 267,614,000
Convertible Senior Notes \| 0.00% Convertible Senior Notes Due January 15, 2026 \| Debt Instrument, Redemption, Period On or After January 20, 2024
Debt Instrument [Line Items]
Debt instrument, convertible, threshold trading days \| TradingDay				20
Debt instrument, convertible, threshold consecutive trading days \| TradingDay				30
Debt instrument, convertible, threshold percentage of stock price trigger				130.00%
Debt instrument, redemption period, start date				Jan. 20, 2024
Debt instrument, redemption price, percentage of principal amount redeemed				100.00%
Debt instrument, sinking fund payment				$ 0
Convertible Senior Notes \| 0.00% Convertible Senior Notes Due January 15, 2026 \| Debt Instrument, Convertible, Terms of Conversion Feature, Circumstances One
Debt Instrument [Line Items]
Debt instrument, convertible, threshold trading days \| TradingDay				20
Debt instrument, convertible, threshold consecutive trading days \| TradingDay				30
Debt instrument, convertible, threshold percentage of stock price trigger				130.00%
Convertible Senior Notes \| 0.00% Convertible Senior Notes Due January 15, 2026 \| Debt Instrument, Convertible, Terms of Conversion Feature, Circumstances Two
Debt Instrument [Line Items]
Debt instrument, convertible, threshold consecutive trading days \| TradingDay				5
Debt instrument, convertible, threshold maximum percentage of product of last reported sale price of common stock				98.00%
Secured Debt \| November 2017 Facility
Debt Instrument [Line Items]
Aggregate principal amount		$ 350,000,000.0
Leverage ratio Maximum		6.00%
Secured Debt \| November 2017 Facility \| Wells Fargo Bank
Debt Instrument [Line Items]
Debt instrument due date	Jul. 12, 2022	Nov. 27, 2020
Line of credit facility, finance leases and debt covenant limit	$ 200,000,000.0	$ 100,000,000.0
Secured Debt \| November 2017 Facility \| Revolving Credit Facility \| Wells Fargo Bank
Debt Instrument [Line Items]
Line of credit facility, termination date		Nov. 27, 2017
Line of credit facility, maximum borrowing capacity	100,000,000.0	$ 85,000,000.0
Line of credit facility, interest payment terms				Interest on the revolving loans is payable quarterly in arrears with respect to loans based on the prime rate and at the end of an interest period in the case of loans based on the LIBOR rate (or at each three-month interval if the interest period is longer than three months).
Line of credit facility additional amount drawn							$ 30,000,000.0
Total debt outstanding with carrying amount			$ 30,000,000.0	$ 30,000,000.0
Repayment of outstanding principal balance				$ 40,000,000.0
Secured Debt \| November 2017 Facility \| Revolving Credit Facility \| Wells Fargo Bank \| Prime Rate
Debt Instrument [Line Items]
Line of credit facility, floating interest rate				0.25%
Secured Debt \| November 2017 Facility \| Revolving Credit Facility \| Wells Fargo Bank \| London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Line of credit facility, floating interest rate				1.00%
Secured Debt \| November 2017 Facility \| Letters of Credit \| Wells Fargo Bank
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity sublimit	$ 45,000,000.0	$ 30,000,000.0
Secured Debt \| November 2017 Facility \| Paid in October 2020 \| Revolving Credit Facility \| Wells Fargo Bank
Debt Instrument [Line Items]
Repayment of outstanding principal balance				$ 20,000,000.0
Secured Debt \| November 2017 Facility \| Paid in January 2021 \| Revolving Credit Facility \| Wells Fargo Bank
Debt Instrument [Line Items]
Repayment of outstanding principal balance				$ 20,000,000.0