Credit Agreement	12 Months Ended
Dec. 31, 2012
Line of Credit Facility [Abstract]
Credit Agreements	Credit Agreement On February 8, 2011, the Company entered into a Credit Agreement (“Credit Agreement”) with Bank of America, N.A., U.S. Bank National Association, JPMorgan Chase Bank N.A. and other Lenders. The Credit Agreement provides for a $200 million, five-year revolving line of credit. The Company has the right, subject to certain conditions including approval of additional commitments by qualified lenders, to increase the line of credit by an additional $150 million until February 8, 2016. The Credit Agreement allows the Company and certain designated subsidiaries to borrow in euro, kroner, pound sterling and other agreed upon currencies. Borrowing rates under the Credit Agreement are determined at the Company’s option at the time of each borrowing and are generally based on either the prime lending rate of Bank of America, N.A. or the rate of interest paid for deposits in the relevant currency, plus a specified margin based on an established consolidated total leverage ratio grid. The Eurodollar interest rate was 1.805 percent and the prime lending rate was 3.25 percent at December 31, 2012. The Credit Agreement requires the Company to pay a commitment fee on the amount of unused credit at a rate, based on the Company’s leverage ratio, which ranges from 0.25 percent to 0.40 percent. At December 31, 2012, the commitment fee rate was 0.25 percent. The Credit Agreement contains two financial covenants that require the maintenance of certain leverage ratios. The five-year revolving line of credit available under the Credit Agreement is unsecured. At December 31, 2012, the Company had no amounts outstanding under the Credit Agreement and had $10.6 million of letters of credit outstanding, which reduces the total available credit.

Credit Agreement

On February 8, 2011, the Company entered into a Credit Agreement (“Credit Agreement”) with Bank of America, N.A., U.S. Bank National Association, JPMorgan Chase Bank N.A. and other Lenders. The Credit Agreement provides for a $200 million, five-year revolving line of credit. The Company has the right, subject to certain conditions including approval of additional commitments by qualified lenders, to increase the line of credit by an additional $150 million until February 8, 2016. The Credit Agreement allows the Company and certain designated subsidiaries to borrow in euro, kroner, pound sterling and other agreed upon currencies. Borrowing rates under the Credit Agreement are determined at the Company’s option at the time of each borrowing and are generally based on either the prime lending rate of Bank of America, N.A. or the rate of interest paid for deposits in the relevant currency, plus a specified margin based on an established consolidated total leverage ratio grid. The Eurodollar interest rate was 1.805 percent and the prime lending rate was 3.25 percent at December 31, 2012. The Credit Agreement requires the Company to pay a commitment fee on the amount of unused credit at a rate, based on the Company’s leverage ratio, which ranges from 0.25 percent to 0.40 percent. At December 31, 2012, the commitment fee rate was 0.25 percent. The Credit Agreement contains two financial covenants that require the maintenance of certain leverage ratios. The five-year revolving line of credit available under the Credit Agreement is unsecured. At December 31, 2012, the Company had no amounts outstanding under the Credit Agreement and had $10.6 million of letters of credit outstanding, which reduces the total available credit.