Debt Instrument, Number of Monthly Payments

No definition available.

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Namespace Prefix:	fivn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of long-term debt before deduction of unamortized discount or premium. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, with initial maturities beyond one year or the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-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=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 20
-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 16
-Article 9

+ Details

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

The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

+ Details

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

- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. 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/presentationRef
-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=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-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=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.16)
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 20, 22
-Article 5

+ Details

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

- Definition

Amount of loss contingency liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14326-108349

+ Details

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

- Details

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

- Details

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

- Details

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

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=fivn_USFobligationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=fivn_FCCEnforcementBureauCivilPenaltyMember
Namespace Prefix:
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Debt - Promissory Note/FCC Civil Penalty (Details) $ in Thousands	1 Months Ended
	Jul. 31, 2013 USD ($) installment	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Jun. 30, 2015 USD ($)	Jun. 12, 2015 USD ($)	Sep. 30, 2014 USD ($)
Debt Instrument [Line Items]
Debt, gross		$ 36,473
Discount on debt		954	$ 1,087
Total debt, net carrying value		35,519	37,039
FCC Civil Penalty
Debt Instrument [Line Items]
Debt, gross					$ 2,000
Notes Payable
Debt Instrument [Line Items]
Debt, gross		23,973	25,626
Total debt, net carrying value		23,019	24,539
Notes Payable \| Promissory Note
Debt Instrument [Line Items]
Debt instrument, stated interest rate	12.75%
Debt instrument, number of monthly payments \| installment	42
Debt, gross	$ 4,100	$ 1,100	1,500
Notes Payable \| FCC Civil Penalty
Debt Instrument [Line Items]
Debt instrument, stated interest rate		12.75%
Debt, gross		$ 1,500	1,667	$ 2,000
Discount on debt				300
Total debt, net carrying value		1,300	1,400	$ 1,700
USF obligations \| Promissory Note
Debt Instrument [Line Items]
Debt, gross	$ 4,100
USF obligations \| Notes Payable \| Promissory Note
Debt Instrument [Line Items]
Debt, gross		$ 1,100	$ 1,500
FCC Civil Penalty
Debt Instrument [Line Items]
Accrued liability						$ 2,000