Capitalized Software Development Costs - Schedule of Expected Amortization of Capitalized Software Development Costs (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Capitalized Computer Software Net [Abstract]
2017 (for the remaining three months)	$ 1,475
2018	4,384
2019	3,127
2020	686
Net carrying amount	$ 9,672	$ 8,792

Capitalized software development costs amortization expense remainder of fiscal year.

No definition available.

Name:	evbg_CapitalizedSoftwareDevelopmentCostsAmortizationExpenseRemainderOfFiscalYear
Namespace Prefix:	evbg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Capitalized software development costs amortization expense year four.

+ References

No definition available.

+ Details

Name:	evbg_CapitalizedSoftwareDevelopmentCostsAmortizationExpenseYearFour
Namespace Prefix:	evbg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Capitalized software development costs amortization expense year three.

+ References

No definition available.

+ Details

Name:	evbg_CapitalizedSoftwareDevelopmentCostsAmortizationExpenseYearThree
Namespace Prefix:	evbg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Capitalized software development costs amortization expense year two.

+ References

No definition available.

+ Details

Name:	evbg_CapitalizedSoftwareDevelopmentCostsAmortizationExpenseYearTwo
Namespace Prefix:	evbg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The carrying amount of capitalized computer software costs net of accumulated amortization as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 985
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 985
-SubTopic 20
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128487-111756

+ Details

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

- References

No definition available.

+ Details

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