Derivative Instruments (Narrative) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2013
Foreign Currency Derivatives [Member]
Derivative [Line Items]
Notional amounts of foreign currency derivatives	$ 237.1
Refined Oil Products [Member] | Commodity Derivative Contracts [Member]
Derivative [Line Items]
Outstanding derivative swap contracts	$ 29.8
Minimum [Member] | Foreign Currency Derivatives [Member]
Derivative [Line Items]
Derivative maturities	October 2013
Minimum [Member] | Commodity Derivative Contracts [Member]
Derivative [Line Items]
Derivative maturities	October 2013
Maximum [Member] | Foreign Currency Derivatives [Member]
Derivative [Line Items]
Derivative maturities	June 2014
Maximum [Member] | Commodity Derivative Contracts [Member]
Derivative [Line Items]
Derivative maturities	March 2014