Financial Instruments and Risk Management	12 Months Ended
Dec. 31, 2012
Financial Instruments and Risk Management
Financial Instruments and Risk Management	26. Financial Instruments and Risk Management The Company is exposed to market risks brought on by changes in interest and currency exchange rates. The Company has not entered into foreign currency transactions or derivative financial instruments to reduce risks associated with changes in currency exchange rates. The Company may use derivative financial instruments to reduce risks associated with changes in interest rates. Notional amounts and credit exposures of derivatives The notional amount of derivatives does not represent amounts that are exchanged by the parties, and thus are not a measure of the Company's exposure. The amounts exchanged are calculated on the basis of the notional or contract amounts, as well as on other terms of the interest rate derivatives and the volatility of these rates and prices. The Company would be exposed to credit-related losses in the event of nonperformance by the counter parties that issued the financial instruments, although the Company does not expect that the counter parties to interest rate derivatives will fail to meet their obligations, given their typically high credit ratings. The credit exposure of derivative contracts is represented by the positive fair value of contracts at the reporting date, reduced by the effects of master netting agreements and collateral posted by the counterparty. Interest Rate Risk Management From time to time, the Company enters into derivative financial instruments to reduce exposure to interest rate risk. The Company does not hold or issue derivative financial instruments for trading purposes. Derivative financial instruments are intended to enable the Company to achieve a level of variable-rate or fixed-rate debt that is acceptable to management and to limit interest rate exposure. The Company agrees with another party to exchange the difference between fixed-rate and floating rate interest amounts calculated by reference to an agreed notional principal amount.

26. Financial Instruments and Risk Management

The Company is exposed to market risks brought on by changes in interest and currency exchange rates. The Company has not entered into foreign currency transactions or derivative financial instruments to reduce risks associated with changes in currency exchange rates. The Company may use derivative financial instruments to reduce risks associated with changes in interest rates.

Notional amounts and credit exposures of derivatives

The notional amount of derivatives does not represent amounts that are exchanged by the parties, and thus are not a measure of the Company's exposure. The amounts exchanged are calculated on the basis of the notional or contract amounts, as well as on other terms of the interest rate derivatives and the volatility of these rates and prices.

The Company would be exposed to credit-related losses in the event of nonperformance by the counter parties that issued the financial instruments, although the Company does not expect that the counter parties to interest rate derivatives will fail to meet their obligations, given their typically high credit ratings. The credit exposure of derivative contracts is represented by the positive fair value of contracts at the reporting date, reduced by the effects of master netting agreements and collateral posted by the counterparty.

Interest Rate Risk Management

From time to time, the Company enters into derivative financial instruments to reduce exposure to interest rate risk. The Company does not hold or issue derivative financial instruments for trading purposes. Derivative financial instruments are intended to enable the Company to achieve a level of variable-rate or fixed-rate debt that is acceptable to management and to limit interest rate exposure. The Company agrees with another party to exchange the difference between fixed-rate and floating rate interest amounts calculated by reference to an agreed notional principal amount.