Commitments And Contingencies (Details) In Millions, unless otherwise specified	1 Months Ended			12 Months Ended			12 Months Ended
	Jul. 31, 2013 USD ($)	Aug. 31, 2011 USD ($)	Dec. 31, 2010 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 acre	Dec. 31, 2014 Exploration and Production [Member] Pressure Pumping Equipment [Member] USD ($) item	Dec. 31, 2014 Exploration and Production [Member] Drilling Rigs [Member] USD ($) item	Dec. 31, 2014 Exploration and Production [Member] Maximum [Member] Pressure Pumping Equipment [Member]	Dec. 31, 2014 Exploration and Production [Member] Minimum [Member] Pressure Pumping Equipment [Member]	Dec. 31, 2014 Midstream Services and E&P [Member] USD ($)	Dec. 31, 2014 Exploration Program in Canada [Member] USD ($)	Dec. 31, 2014 Exploration Program in Canada [Member] CAD	Mar. 31, 2010 Exploration Program in Canada [Member] CAD acre
Commitments And Contingencies [Line Items]
Future demand transportation charges, 2015				$ 478
Future demand transportation charges, 2016				515
Future demand transportation charges, 2017				543
Future demand transportation charges, 2018				549
Future Demand Transportation Charges Due 2019				502
Future demand transportation charges, thereafter				2,802
Number of leases						11	7
Lease expiration date				Dec. 31, 2027			Dec. 31, 2020	Jan. 01, 2018	Dec. 01, 2017
Aggregate annual lease payment						8	13
Operating leases, future minimum payments, 2015				73						41
Operating leases, future minimum payments, 2016				62						28
Operating leases, future minimum payments, 2017				45						19
Operating leases, future minimum payments, 2018				25						10
Operating leases, future minimum payments, 2019				21						4
Operating leases, future minimum payments, thereafter				45
Obligations for demand and similar charges under transportation agreements				5,400							44	45
Guarantee obligations relative to the firms transportation agreements and gathering project and services				173
Unrecorded capital investments obligation, Exploration program acres coverage (acres)													2,500,000
Unrecorded capital investments obligation													47
Unrecorded promissory note payable													45
Area of land being constructed					26
Current obligation for construction costs incurred				137
Litigation settlement, gross			11
Litigation, portion of profits considered for disgorgement			382
Actual damages recoverable by plaintiff per August 2011 judgement		11
Disgorgement recoverable by plaintiff per August 2011 judgement		24
Prejudgement interest and attorney's fees recoverable by plaintiff per August 2011 judgement		9
Disgorgement recoverable by plaintiff to be reversed	24
Actual damages recoverable by plaintiff to be reversed	11
Litigation settlement upheld	$ 11.0