Description of business and significant accounting policies and practices (Policies)	6 Months Ended
	Jun. 30, 2011
Description of business and significant accounting policies and practices Policies [Abstract]
Use of Derivatives and Hedging	Use of Derivatives and Hedging - In connection with the issuance of long-term debt in May 2011, as more fully described in Note 3, we entered into an interest rate swap designated as a hedge of the variability of cash flows related to interest payments on the variable-rate portion of the debt. Gains and losses from changes in the fair value of the interest rate swap are credited or charged to accumulated other comprehensive income (AOCI). We also use derivative financial instruments to manage exposure to foreign exchange risk. These instruments are primarily forward foreign currency exchange contracts that are used as economic hedges to reduce the earnings impact exchange rate fluctuations may have on our non-U.S. dollar net balance sheet exposures or for specified non-U.S. dollar forecasted transactions. Gains and losses from changes in the fair value of these forward foreign currency exchange contracts are credited or charged to other income (expense) net (OI&E). We do not apply hedge accounting to our foreign currency derivative instruments. We do not use derivatives for speculative or trading purposes.
Fair values of Financial Instruments	Fair Values of Financial Instruments - The fair values of our derivative financial instruments were not significant at June 30, 2011. Our investments in cash equivalents, short-term investments and certain long-term investments are carried at fair value and are discussed in Note 6. The carrying values for other current financial assets and liabilities, such as accounts receivable and accounts payable, approximate fair value due to the short maturity of such instruments. The fair value of our long-term debt approximates the carrying value.

Describes an entity's accounting policies for its derivative instruments and hedging activities. Disclosure may include: (1) Each method used to account for derivative financial instruments and derivative commodity instruments ("derivatives"); (2) the types of derivatives accounted for under each method; (3) the criteria required to be met for each accounting method used, including a discussion of the criteria required to be met for hedge or deferral accounting and accrual or settlement accounting (for example: whether and how risk reduction, correlation, designation, and effectiveness tests are applied); (4) the accounting method used if the criteria specified for hedge accounting are not met; (5) the method used to account for termination of derivatives designated as hedges or derivatives used to affect directly or indirectly the terms, fair values, or cash flows of a designated item; (6) the method used to account for derivatives when the designated item matures, is sold, is extinguished, or is terminated. In addition, the method used to account for derivatives designated to an anticipated transaction, when the anticipated transaction is no longer likely to occur; and (7) where and when derivatives, and their related gains (losses) are reported in the statement of financial position, cash flows, and results of operations and (8) an accounting policy decision to offset fair value amounts with counterparties. An entity should also consider describing its embedded derivatives, and the method(s) used to determine the fair values of derivatives and any significant assumptions used in such valuations.

+ References+ Details