Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Consolidated Statements of Operations
Net sales	$ 607,192us-gaap_SalesRevenueGoodsNet	$ 597,963us-gaap_SalesRevenueGoodsNet	$ 588,541us-gaap_SalesRevenueGoodsNet
Cost of goods sold	485,601us-gaap_CostOfGoodsSold	482,024us-gaap_CostOfGoodsSold	496,272us-gaap_CostOfGoodsSold
Gross profit	121,591us-gaap_GrossProfit	115,939us-gaap_GrossProfit	92,269us-gaap_GrossProfit
Selling and administrative expenses	79,814	71,256	66,651
Amortization expense	4,695us-gaap_AmortizationOfIntangibleAssets	3,112us-gaap_AmortizationOfIntangibleAssets	2,961us-gaap_AmortizationOfIntangibleAssets
Interest expense	512us-gaap_InterestExpense	485us-gaap_InterestExpense	542us-gaap_InterestExpense
Interest income	(530)us-gaap_InvestmentIncomeInterest	(659)us-gaap_InvestmentIncomeInterest	(452)us-gaap_InvestmentIncomeInterest
Equity in income of nonconsolidated investment	(1,282)	(1,316)	(837)
Other income	(674)us-gaap_OtherNonoperatingIncomeExpense	(1,054)us-gaap_OtherNonoperatingIncomeExpense	(426)us-gaap_OtherNonoperatingIncomeExpense
Total Operating Expenses	82,535fstr_TotalOperatingExpenses	71,824fstr_TotalOperatingExpenses	68,439fstr_TotalOperatingExpenses
Income from continuing operations before income taxes	39,056	44,115	23,830
Income tax expense	13,402us-gaap_IncomeTaxExpenseBenefit	14,839us-gaap_IncomeTaxExpenseBenefit	9,066us-gaap_IncomeTaxExpenseBenefit
Income from continuing operations	25,654	29,276	14,764
Discontinued operations:
(Loss) Income from discontinued operations before income taxes	4	23	3,842
Income tax (benefit) expense	2	9	2,418
(Loss) Income from discontinued operations	2	14	1,424
Net income	$ 25,656us-gaap_NetIncomeLoss	$ 29,290us-gaap_NetIncomeLoss	$ 16,188us-gaap_NetIncomeLoss
Basic earnings per common share:
From continuing operations	$ 2.51	$ 2.88	$ 1.46
From discontinued operations	$ 0.00	$ 0.00	$ 0.14
Basic earnings per common share	$ 2.51us-gaap_EarningsPerShareBasic	$ 2.88us-gaap_EarningsPerShareBasic	$ 1.60us-gaap_EarningsPerShareBasic
Diluted earnings per common share:
From continuing operations	$ 2.48	$ 2.85	$ 1.44
From discontinued operations	$ 0.00	$ 0.00	$ 0.14
Diluted earnings per common share	$ 2.48us-gaap_EarningsPerShareDiluted	$ 2.85us-gaap_EarningsPerShareDiluted	$ 1.58us-gaap_EarningsPerShareDiluted
Dividends paid per common share	$ 0.13	$ 0.12	$ 0.10

Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Includes selling, general and administrative expense. This item also represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. Such amount typically reflects adjustments similar to those made in preparing consolidated statements, including adjustments to eliminate intercompany gains and losses, and to amortize, if appropriate, any difference between cost and underlying equity in net assets of the investee at the date of investment.

No definition available.