Breakage fees and premium.

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Debt agreement termination costs.

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Line Of Credit Facility Early Repayment Penalty

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Line of Credit Facility Percentage of Principal Repayment

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Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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Amount of debt issuance costs (for example, but not limited to, legal, accounting, broker, and regulatory fees).

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Amount of write-off of deferred financing costs and debt discounts related to prepetition debt obligations.

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Weighted average interest rate of debt outstanding.

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For an unclassified balance sheet, the carrying amount (net of accumulated amortization) as of the balance sheet date of capitalized costs associated with the issuance of debt instruments (for example, legal, accounting, underwriting, printing, and registration costs) that will be charged against earnings over the life of the debt instruments to which such costs pertain.

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The amount of cash paid for interest during the period.

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Amount of increase (decrease) of the credit facility.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

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The cash outflow for the settlement of obligation drawn from a contractual arrangement with the lender, including letter of credit, standby letter of credit and revolving credit arrangements, under which borrowings can be made up to a specific amount at any point in time with maturities due beyond one year or the operating cycle, if longer.

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Debt - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended	12 Months Ended
Debt - Additional Information (Detail) (USD $)	Mar. 31, 2013	Mar. 31, 2012	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 13, 2013
Debt Instrument [Line Items]
Secured credit facility							$ 225,000,000
Line of credit facility, amount outstanding				0us-gaap_LineOfCredit
Breakage Fees And Premium					4,200,000fss_BreakageFeesAndPremium
Early repayment penalty	4,200,000
Remaining borrowing capacity				23,900,000
Interest paid				3,000,000us-gaap_InterestPaid	9,400,000us-gaap_InterestPaid	20,600,000us-gaap_InterestPaid
Weighted average interest rate on short-term borrowings				2.20%us-gaap_DebtWeightedAverageInterestRate
Line Of Credit Facility Covenant Terms Leverage Ratio Maximum				3.25
Debt agreement termination costs	8,700,000fss_DebtAgreementTerminationCosts	8,700,000fss_DebtAgreementTerminationCosts
Debtor Reorganization Items, Write-off of Deferred Financing Costs and Debt Discounts	4,500,000
Debt Issuance Cost			1,900,000us-gaap_DebtIssuanceCosts
Deferred Finance Costs, Net				100,000us-gaap_DeferredFinanceCostsNet
Derivative Liability, Fair Value, Gross Liability				200,000
Letter of Credit
Debt Instrument [Line Items]
Secured credit facility							50,000,000
Non-US lines of credit
Debt Instrument [Line Items]
Secured credit facility				12,300,000
Line of Credit Facility, Increase (Decrease), Net				0
Term Loan
Debt Instrument [Line Items]
Secured credit facility							75,000,000
Expiration Period				5 years
Repayments of Debt				15,000,000
ABL Facility \| Minimum
Debt Instrument [Line Items]
Commitment fee				0.25%
ABL Facility \| Maximum
Debt Instrument [Line Items]
Commitment fee				0.45%
ABL Facility \| Base Rate [Member] \| Minimum
Debt Instrument [Line Items]
Base rate borrowings margin ranges				1.00%
ABL Facility \| Base Rate [Member] \| Maximum
Debt Instrument [Line Items]
Base rate borrowings margin ranges				2.00%
ABL Facility \| Libor Borrowings \| Minimum
Debt Instrument [Line Items]
Base rate borrowings margin ranges				2.00%
ABL Facility \| Libor Borrowings \| Maximum
Debt Instrument [Line Items]
Base rate borrowings margin ranges				3.00%
ABL Facility \| Term Loan
Debt Instrument [Line Items]
Maturities payment, 2014				6,200,000
Maturities payment, 2015				7,300,000
Maturities payment, 2016				7,400,000
Maturities payment, 2017				29,300,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Secured credit facility							150,000,000
Expiration Period				5 years
Remaining borrowing capacity				126,100,000
Senior Secured Credit Facility [Member]
Debt Instrument [Line Items]
Expiration Period				5 years
Due In Year One [Member] \| Senior Secured Credit Facility [Member]
Debt Instrument [Line Items]
Percentage of principal repayment				7.50%
Due In Year Two [Member] \| Senior Secured Credit Facility [Member]
Debt Instrument [Line Items]
Percentage of principal repayment				10.00%
Due In Year Four [Member] \| Senior Secured Credit Facility [Member]
Debt Instrument [Line Items]
Percentage of principal repayment				12.50%
Interest Rate Swap [Member]
Debt Instrument [Line Items]
Notional Amount							75,000,000
Interest Rate Derivatives Expiration Date				March 13, 2018
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax				200,000
Domestic Revolving Credit Facility [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, amount outstanding				6,500,000	123,700,000	116,700,000
Repayments of lines of credit				$ 26,500,000	$ 106,200,000	$ 290,000,000