- Definition

The amount of defined contribution expense recognized during the period for contributions made by the entity in the entity's own stock in lieu of cash.

+ References

No definition available.

+ Details

Name:	fnsr_DefinedContributionInEntityStockExpense
Namespace Prefix:	fnsr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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

- 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

- Definition

Percentage employer matches of the employee's percentage contribution matched.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum amount the employee may contribute to a defined contribution plan.

+ References

No definition available.

+ Details

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

- 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

- Definition

Number of shares issued during the period to an employee benefit plan, such as a defined contribution or defined benefit plan.

+ References

No definition available.

+ Details

Name:	us-gaap_StockIssuedDuringPeriodSharesEmployeeBenefitPlan
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Value of shares issued during the period to an employee benefit plan, such as a defined contribution or defined benefit plan.

+ References

No definition available.

+ Details

Name:	us-gaap_StockIssuedDuringPeriodValueEmployeeBenefitPlan
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_StatementScenarioAxis=us-gaap_ScenarioForecastMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Employee Benefit Plan (Details) (USD $)	12 Months Ended
Employee Benefit Plan (Details) (USD $)	May 03, 2015	Dec. 31, 2014	Apr. 27, 2014	Dec. 31, 2013	Apr. 28, 2013	Dec. 31, 2015
Defined Benefit Plan Disclosure
Maximum statutory contribution by employee (percentage of gross)	20.00%
Maximum statutory contribution by employee (in usd)		$ 17,500		$ 17,500
Employer matching contribution (percentage of employee's match)	50.00%
Employer matching contribution (percentage of employee's match subject to employer match)	6.00%
Employer contribution in defined contribution retirement plan (in shares)	122,979
Employer contribution in defined contribution retirement plan (in usd)	2,400,000
Defined contribution plan expenses	2,600,000		2,200,000		1,900,000
Forecast
Defined Benefit Plan Disclosure
Maximum statutory contribution by employee (in usd)						$ 18,000