Amount of amortization expense attributable to debt discount (premium) and debt issuance costs.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-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_AmortizationOfFinancingCostsAndDiscounts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ 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 (b)
-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 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.8)
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227

+ Details

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

- Definition

Represents the portion of interest incurred in the period on debt arrangements that was charged against earnings, excluding amortization of debt discount (premium) and financing costs.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph 8
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227

+ Details

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

- Details

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

- Details

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

- Details

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

- Details

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

Convertible Senior Notes - Summary of Total Interest Expense Recognized Related To Convertible Senior Notes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
0.125% Convertible Senior Notes Due 2024
Debt Instrument [Line Items]
Amortization of debt discount and transaction costs	$ 4,466		$ 8,872
Total interest expense	4,606		9,153
0.125% Convertible Senior Notes Due 2024 \| 0.125% coupon
Debt Instrument [Line Items]
Interest expense	140		281
1.50% Convertible Senior Notes Due 2022
Debt Instrument [Line Items]
Amortization of debt discount and transaction costs	1,047	$ 1,223	2,077	$ 2,424
Total interest expense	1,392	1,656	2,767	3,289
1.50% Convertible Senior Notes Due 2022 \| 1.50% Coupon
Debt Instrument [Line Items]
Interest expense	$ 345	$ 433	$ 690	$ 865