XML 80 R58.htm IDEA: XBRL DOCUMENT v2.4.0.6
Derivative Instruments and Risk Management (Details) (USD $)
In Millions, unless otherwise specified
Mar. 31, 2013
T
Dec. 31, 2012
T
Summary of commodity swaps    
Commodity swaps, notional quantity 100 275
Derivatives (Level 1 measurement) [Member] | Recurring [Member] | Carrying Amount [Member]
   
Summary of commodity swaps    
Commodity swaps 0 0.1
Derivatives (Level 1 measurement) [Member] | Recurring [Member] | Fair Value [Member]
   
Summary of commodity swaps    
Commodity swaps 0 0.1