With the exception of its long-term debt and investment in GF, the Company carries financial instruments at fair value. Investments in money market mutual funds, commercial paper, time deposits, marketable equity securities and foreign currency derivative contracts are primarily classified within Level 1 or Level 2. This is because such financial instruments are valued primarily using quoted market prices or alternative pricing sources and models utilizing market observable inputs, as provided to the Company by its brokers. The Company's Level 1 assets are valued using quoted prices for identical instruments in active markets. The Company's Level 2 assets, all of which mature within one year, are valued using broker reports that utilize quoted market prices for similar instruments. The ARS investments are classified within Level 3 because they are valued using a discounted cash flow model. Some of the inputs to this model are unobservable in the market and are significant. The Company's foreign currency derivative contracts are classified within Level 2 because the valuation inputs are based on quoted prices and market observable data of similar instruments in active markets, such as currency spot and forward rates.

The fair value of the Company's long-term debt is estimated based on the quoted market prices for the same or similar issues or on the current rates offered to the Company for debt of the same remaining maturities. For the Company's investment in GF, the Company believes the fair value of the Company's investment in GF approximates its carrying value. The fair value of the Company's accounts receivable, accounts payable and other short-term obligations approximate their carrying value based on existing payment terms.