Debt and Credit Arrangements Senior Credit Facility (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Apr. 25, 2012
Debt Instrument [Line Items]
Financing costs amortization	$ 327,000	$ 556,000	$ 653,000	$ 877,000
Term of Restated Credit Facility					five-year
Debt Issuance Cost			1,445,000
Fronting Fee Percentage Charged For Issuance Of Letters Of Credit	0.125%		0.125%
Line Of Credit Facility Initial Percentage Of Term Loan Payable Quarterly Due To Restated Credit Facility	5.00%		5.00%
Line Of Credit Facility Final Percentage Of Term Loan Payable Quarterly Due To Restated Credit Facility	10.00%		10.00%
Final Duration Of Quarterly Payments On Term Loan Under The Terms Of The Restated Credit Facility			2 years
Senior Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity					375,000,000
Line Of Credit Facility, Amount Of Expansion Option To Increase The Aggregate Principal Amount Of The Term Loan Or Revolving Credity Facility					150,000,000
Line of Credit Facility, Interest Rate Description	Loans under the Senior Credit Facility 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 Restated Credit Facility) for a one month interest period on such day (or if such day is not a business day, the immediately preceding business day) plus 1%, plus a margin that varies with the Company's net debt to EBITDA ratio.
Initial Duration Of Quarterly Payments On Term Loan Under The Terms Of The Restated Credit Facility			3 years
Line of Credit Facility, Covenant Terms	Significant financial covenants for the Senior Credit Facility include a maximum net debt to EBITDA ratio of 3.25 and a minimum interest coverage to EBITDA ratio of 3.0, which are the same limits that applied under the Prior Credit Facility.
Line of Credit Facility, Amount Outstanding	0		0
Senior Term Loan Due 2017 [Member] | Senior Credit Facility [Member]
Debt Instrument [Line Items]
Financing costs amortization	149,000	379,000	298,000	522,000
Line of Credit Facility, Maximum Borrowing Capacity					75,000,000
Term Loan [Member] | Senior Term Loan Due 2017 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	70,313,000		70,313,000
Line of Credit [Member] | Senior Credit Facility [Member]
Debt Instrument [Line Items]
Maximum Percentage Of Capital Stock Guaranteed By Company's Material Non-U.S. Subsidiaries For Obligations Under The Senior Credit Facility	65.00%		65.00%
Revolving Line of Credit [Member] | Amended Revolver [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount	24,286,000		24,286,000
Line of Credit Facility, Remaining Borrowing Capacity	275,714,000		275,714,000
Revolving Credit Facility [Member] | Senior Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity					300,000,000
Sub-limit For Issuance Of Swingline Loans					25,000,000
Sub-limit For Letters Of Credit					100,000,000
Maximum Amount For Foreign Currency Denominated Letters Of Credit And Borrowings					50,000,000
Maximum Amount Of Permitable Subsidiary Borrowings					$ 50,000,000
Minimum [Member] | Revolving Line of Credit [Member] | Revolver [Member]
Debt Instrument [Line Items]
Applicable Margin For Eurocurrency Revolving Facility Borrowings	1.50%		1.50%
Minimum [Member] | Line of Credit [Member] | Revolver [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Commitment Fee Percentage			0.25%
Maximum [Member] | Revolving Line of Credit [Member] | Revolver [Member]
Debt Instrument [Line Items]
Applicable Margin For Eurocurrency Revolving Facility Borrowings	3.00%		3.00%
Maximum [Member] | Line of Credit [Member] | Revolver [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Commitment Fee Percentage			0.40%