Derivative Financial Instruments (Schedule Of Open NGL Derivative Positions) (Details)	3 Months Ended
	Mar. 31, 2021 $ / bbl bbl
OPIS Mont Belvieu Texas Natural Gasoline Price Swaps NGL Q2-Q4 2021 [Member]
Derivative [Line Items]
Volume Per Day (Bbls/d) | bbl	1,000
Weighted Average Price Swap | $ / bbl	47.57
OPIS Mont Belvieu Texas Normal Butane Price Swaps NGL Q2-Q4 2021 [Member]
Derivative [Line Items]
Volume Per Day (Bbls/d) | bbl	1,000
Weighted Average Price Swap | $ / bbl	31.40
OPIS Mont Belvieu Texas Propane Price Swaps NGL Q2-Q4 2021 [Member]
Derivative [Line Items]
Volume Per Day (Bbls/d) | bbl	1,000
Weighted Average Price Swap | $ / bbl	27.88