Foreign currency translation:
The majority of our subsidiaries have a U.S. dollar functional currency, which represents the currency of the primary economic environment in which they operate. For these subsidiaries, we translate monetary assets and liabilities denominated in foreign currencies into U.S. dollars at the period-end exchange rates. We translate non-monetary assets and liabilities denominated in foreign currencies into U.S. dollars at historic rates, and we translate revenue and expenses into U.S. dollars at the average exchange rates prevailing during the month of the transaction. Exchange gains and losses also arise on the settlement of foreign-currency denominated transactions. We recognize foreign currency differences arising on translation in our consolidated statement of operations.
For our subsidiaries with a non-U.S. dollar functional currency, we translate assets and liabilities into U.S. dollars using the period-end exchange rates, and we translate revenue and expenses into U.S. dollars at the average exchange rates prevailing during the month of the transaction. We defer gains and losses arising from the translation of these operations in the foreign currency translation account included in accumulated other comprehensive income.
