v2.4.0.8

Employee Benefit Plan (Details) (USD $) In Millions, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011
Employee Benefit Plan [Abstract] |  |  |
Matching contribution on employee contributions, Percent | 50.00% |  |
Maximum contibution percentage of each employee's eligible earnings, Percent | 4.00% |  |
Matching contributions to the RRSP and 401(k) Plans | $ 2.1 | $ 1.8 | $ 1.5

X
- Definition Defined Contribution Plan, Employer Matching Contribution, Amount + References No definition available. + Details
Name: | ftnt_DefinedContributionPlanEmployerMatchingContributionAmount
Namespace Prefix: | ftnt_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | ftnt_EmployeeBenefitPlanAbstract
Namespace Prefix: | ftnt_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan. + References No definition available. + Details
Name: | us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan. + References No definition available. + Details
Name: | us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration