Derivative Instruments And Hedging Activities Notional Contracts by Derivative Type (Details) - Jun. 30, 2015 $ in Millions	USD ($) MMBTU bbl
economic hedges by derivative type [Line Items]
Available-for-sale Securities, Change in Net Unrealized Holding Gain (Loss) before Taxes | $	$ 13.3
Accumulated Other Comprehensive Income (Loss), Unrealized Gain (Loss) From Hedging Activites | $	$ 2.7
Commodity Contract [Member]
economic hedges by derivative type [Line Items]
Price Risk Fair Value Hedge Derivative, at Fair Value, Net | bbl	4,412,000
Natural Gas Liquids [Member]
economic hedges by derivative type [Line Items]
Derivative, Nonmonetary Notional Amount, Energy Measure	17,820,000
Natural Gas - long [Member]
economic hedges by derivative type [Line Items]
Derivative, Nonmonetary Notional Amount, Energy Measure	24,000,000
Natural Gas - Short [Member]
economic hedges by derivative type [Line Items]
Derivative, Nonmonetary Notional Amount, Energy Measure	24,000,000
Commodity WTI short [Member]
economic hedges by derivative type [Line Items]
Price Risk Fair Value Hedge Derivative, at Fair Value, Net | bbl	1,095,000
Maturing in Next Twelve Months [Member] | Commodity Contract [Member]
economic hedges by derivative type [Line Items]
Price Risk Fair Value Hedge Derivative, at Fair Value, Net | bbl	3,680,000
Maturing in Next Twelve Months [Member] | Natural Gas Liquids [Member]
economic hedges by derivative type [Line Items]
Derivative, Nonmonetary Notional Amount, Energy Measure	4,020,000
Maturing in Next Twelve Months [Member] | Natural Gas - long [Member]
economic hedges by derivative type [Line Items]
Derivative, Nonmonetary Notional Amount, Energy Measure	4,800,000
Maturing in Next Twelve Months [Member] | Natural Gas - Short [Member]
economic hedges by derivative type [Line Items]
Derivative, Nonmonetary Notional Amount, Energy Measure	4,800,000
Maturing in Next Twelve Months [Member] | Commodity WTI short [Member]
economic hedges by derivative type [Line Items]
Price Risk Fair Value Hedge Derivative, at Fair Value, Net | bbl	1,095,000
Maturing in Year Three [Member] | Natural Gas Liquids [Member]
economic hedges by derivative type [Line Items]
Derivative, Nonmonetary Notional Amount, Energy Measure	6,900,000
Maturing in Year Three [Member] | Natural Gas - long [Member]
economic hedges by derivative type [Line Items]
Derivative, Nonmonetary Notional Amount, Energy Measure	9,600,000
Maturing in Year Three [Member] | Natural Gas - Short [Member]
economic hedges by derivative type [Line Items]
Derivative, Nonmonetary Notional Amount, Energy Measure	9,600,000
Maturing in Year Two [Member] | Commodity Contract [Member]
economic hedges by derivative type [Line Items]
Price Risk Fair Value Hedge Derivative, at Fair Value, Net | bbl	732,000
Maturing in Year Two [Member] | Natural Gas Liquids [Member]
economic hedges by derivative type [Line Items]
Derivative, Nonmonetary Notional Amount, Energy Measure	6,900,000
Maturing in Year Two [Member] | Natural Gas - long [Member]
economic hedges by derivative type [Line Items]
Derivative, Nonmonetary Notional Amount, Energy Measure	9,600,000
Maturing in Year Two [Member] | Natural Gas - Short [Member]
economic hedges by derivative type [Line Items]
Derivative, Nonmonetary Notional Amount, Energy Measure	9,600,000