XML 142 R84.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2

Pension and Other Post-Employment Plans - Summary of Weighted-Average Assumptions Used in Determining Benefit Obligations (Details)	Dec. 31, 2019	Dec. 31, 2018
U.S. Benefit Plan
Schedule of Net Periodic Benefit Costs Weighted Average Assumptions [Line Items]
Discount rate	3.50%	4.40%
Non-U.S. Benefit Plan
Schedule of Net Periodic Benefit Costs Weighted Average Assumptions [Line Items]
Discount rate	2.00%	2.80%

X

- Definition

Schedule of Net Periodic Benefit Costs Weighted Average Assumptions [Line Items]

+ References

No definition available.

+ Details

Name:	fss_ScheduleOfNetPeriodicBenefitCostsWeightedAverageAssumptionsLineItems
Namespace Prefix:	fss_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Weighted average rate for present value of future retirement benefits cash flows, used to determine benefit obligation of defined benefit plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(1)
-URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920

+ Details

Name:	us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Details

Name:	us-gaap_RetirementPlanSponsorLocationAxis=country_US
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RetirementPlanSponsorLocationAxis=us-gaap_ForeignPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: