XML 60 R38.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Description of Business and Summary of Significant Accounting Policies - Revenue Recognition (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Accounting Policies [Abstract] |  |  |
USF contributions and other regulatory costs, before reversal |  | $ 7,700 |
Reversal of accrued federal fees | $ 0 | (3,114) | $ 0
USF contributions and other regulatory costs | $ 8,600 | $ 4,600 | $ 6,200

X
- Definition Cost of Revenue, Universal Service Fund Contributions and Other Regulatory Costs + References No definition available. + Details
Name: | fivn_CostofRevenueUniversalServiceFundContributionsandOtherRegulatoryCosts
Namespace Prefix: | fivn_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Cost of Revenue, Universal Service Fund Contributions and Other Regulatory Costs, Gross + References No definition available. + Details
Name: | fivn_CostofRevenueUniversalServiceFundContributionsandOtherRegulatoryCostsGross
Namespace Prefix: | fivn_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Increase (Decrease) of Accrued Federal Fees + References No definition available. + Details
Name: | fivn_IncreaseDecreaseofAccruedFederalFees
Namespace Prefix: | fivn_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_AccountingPoliciesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration