Derivative Instruments And Hedging Activities Notional Contracts by Derivative Type (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014
economic hedges by derivative type [Line Items]
Available-for-sale Securities, Change in Net Unrealized Holding Gain (Loss) before Taxes	$ 4.1
Commodity WCS Spread [Member]
economic hedges by derivative type [Line Items]
Derivative, Nonmonetary Notional Amount	4,812,500
Natural Gas - long [Member]
economic hedges by derivative type [Line Items]
Portion of future gas production hedged for price risk	36,000,000
Portion Of Future Gas Production Being Hedged	36,000,000
Natural Gas - Short [Member]
economic hedges by derivative type [Line Items]
Portion Of Future Gas Production Being Hedged	36,000,000
Commodity WTI short [Member]
economic hedges by derivative type [Line Items]
Derivative, Nonmonetary Notional Amount	2,914,000
WTI Crude Oil [Member]
economic hedges by derivative type [Line Items]
Portion of oil and gas production hedged for price risk	24,042,500
Ultra Low Sulfur Diesel Member
economic hedges by derivative type [Line Items]
Portion of oil and gas production hedged for price risk	14,142,500
Sub octane gasoline - short [Member]
economic hedges by derivative type [Line Items]
Derivative, Nonmonetary Notional Amount	9,900,000
Gasoline And Diesel Member
economic hedges by derivative type [Line Items]
Derivative, Nonmonetary Notional Amount	825,000
Maturing in next twelve months [Member] | Commodity WCS Spread [Member]
economic hedges by derivative type [Line Items]
Derivative, Nonmonetary Notional Amount	4,812,500
Maturing in next twelve months [Member] | Natural Gas - long [Member]
economic hedges by derivative type [Line Items]
Portion of future gas production hedged for price risk	7,200,000
Portion Of Future Gas Production Being Hedged	7,200,000
Maturing in next twelve months [Member] | Natural Gas - Short [Member]
economic hedges by derivative type [Line Items]
Portion Of Future Gas Production Being Hedged	7,200,000
Maturing in next twelve months [Member] | Commodity WTI short [Member]
economic hedges by derivative type [Line Items]
Derivative, Nonmonetary Notional Amount	2,914,000
Maturing in next twelve months [Member] | WTI Crude Oil [Member]
economic hedges by derivative type [Line Items]
Portion of oil and gas production hedged for price risk	19,662,500
Maturing in next twelve months [Member] | Ultra Low Sulfur Diesel Member
economic hedges by derivative type [Line Items]
Portion of oil and gas production hedged for price risk	9,762,500
Maturing in next twelve months [Member] | Sub octane gasoline - short [Member]
economic hedges by derivative type [Line Items]
Derivative, Nonmonetary Notional Amount	9,900,000
Maturing in next twelve months [Member] | Gasoline And Diesel Member
economic hedges by derivative type [Line Items]
Derivative, Nonmonetary Notional Amount	825,000
Maturing in year two [Member] | Commodity WCS Spread [Member]
economic hedges by derivative type [Line Items]
Derivative, Nonmonetary Notional Amount	0
Maturing in year two [Member] | Natural Gas - long [Member]
economic hedges by derivative type [Line Items]
Portion of future gas production hedged for price risk	9,600,000
Portion Of Future Gas Production Being Hedged	9,600,000
Maturing in year two [Member] | Natural Gas - Short [Member]
economic hedges by derivative type [Line Items]
Portion Of Future Gas Production Being Hedged	9,600,000
Maturing in year two [Member] | Commodity WTI short [Member]
economic hedges by derivative type [Line Items]
Derivative, Nonmonetary Notional Amount	0
Maturing in year two [Member] | WTI Crude Oil [Member]
economic hedges by derivative type [Line Items]
Portion of oil and gas production hedged for price risk	4,380,000
Maturing in year two [Member] | Ultra Low Sulfur Diesel Member
economic hedges by derivative type [Line Items]
Portion of oil and gas production hedged for price risk	4,380,000
Maturing in year three [Member] | Natural Gas - long [Member]
economic hedges by derivative type [Line Items]
Portion of future gas production hedged for price risk	9,600,000
Portion Of Future Gas Production Being Hedged	9,600,000
Maturing in year three [Member] | Natural Gas - Short [Member]
economic hedges by derivative type [Line Items]
Portion Of Future Gas Production Being Hedged	9,600,000
Maturing in year four [Member] | Natural Gas - long [Member]
economic hedges by derivative type [Line Items]
Portion of future gas production hedged for price risk	9,600,000
Portion Of Future Gas Production Being Hedged	9,600,000
Maturing in year four [Member] | Natural Gas - Short [Member]
economic hedges by derivative type [Line Items]
Portion Of Future Gas Production Being Hedged	9,600,000