Debt And Credit Arrangements Senior Secured Revolving Credit Facility (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Amortization of Financing Costs	$ 1,290,000	$ 1,392,000	$ 1,306,000
Senior Secured Revolving Credit Facility [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Amortization of Financing Costs	$ 579,000	$ 586,000	$ 595,000
Senior Secured Revolving Credit Facility [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Term	5 years
Fronting Fee Percentage Charged For Issuance Of Letters Of Credit	0.125%
Line of Credit Facility, Interest Rate Description	Revolving loans under the SSRCF bear interest, at the applicable Borrower’s election, at either LIBOR or the greatest of (a) the JPMorgan prime rate in effect on such day, (b) the Federal Funds Effective Rate in effect on such day plus 1/2 of 1% or (c) the Adjusted LIBOR Rate (as defined in the SSRCF) for the relative interest period on such day (or if such day is not a business day, the immediately preceding business day) plus 1% (the “Adjusted Base Rate”), plus a margin that varies with the Company’s leverage ratio.
Debt Instrument, Covenant Description	Significant financial covenants for the SSRCF include a minimum liquidity requirement equal to the principal amount of the Convertible Notes outstanding six months prior to the maturity date of the Convertible Notes and when holders of the Convertible Notes have the option to require the Company to repurchase the Convertible Notes, a maximum leverage ratio of 3.25 and a minimum interest coverage to EBITDA ratio of 3.0. The required leverage ratio can be relaxed on up to two occasions, upon notification to the lenders, to 3.75 for up to four consecutive fiscal quarters, for acquisitions and plant expansions of $100,000 or greater. The SSRCF contains a number of other customary covenants,including, but not limited to, restrictions on the Company’s ability to incur additional indebtedness, create liens or other encumbrances, sell assets, enter into sale and lease-back transactions, make certain payments, investments, loans, advances or guarantees, make acquisitions and engage in mergers or consolidations and pay dividends or distributions.
Debt Instrument, Covenant Compliance	At December 31, 2015, the Company was in compliance with all covenants.
Senior Secured Revolving Credit Facility [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Unamortized Debt Issuance Expense	$ 2,869
Senior Secured Revolving Credit Facility [Member] | Revolving Credit Facility [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	450,000,000
Senior Secured Revolving Credit Facility [Member] | Revolving Credit Facility Sub-limit - Swingline [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	25,000,000
Senior Secured Revolving Credit Facility [Member] | Revolving Credit Facility Sub-limit - Letters of Credit [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	100,000,000
Senior Secured Revolving Credit Facility [Member] | Revolving Credit Facility Sub-limit - Foreign Currency [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	100,000,000
Senior Secured Revolving Credit Facility [Member] | Revolving Credit Facility Sub-limit - Foreign Borrower [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount	28,683,000
Line of Credit Facility, Remaining Borrowing Capacity	$ 421,317,000
Maximum Percentage Of Capital Stock Guaranteed By Company's Material Non-U.S. Subsidiaries For Obligations Under The Senior Credit Facility	65.00%
Senior Secured Revolving Credit Facility [Member] | Revolving Credit Facility Sub-limit - Foreign Borrower [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 100,000,000
Senior Secured Revolving Credit Facility [Member] | Revolving Credit Facility Sub-limit - Expansion Option [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 200,000,000
Minimum [Member] | Senior Secured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage	0.25%
Line of Credit, Participation Fee Percentage	1.50%
Maximum [Member] | Senior Secured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage	0.40%
Line of Credit, Participation Fee Percentage	2.75%