Commitments - Undiscounted Gathering Processing and Transportation Agreements Commitments Table (Details) (Gas Gathering and Processing Equipment [Member], USD $) In Millions, unless otherwise specified	Dec. 31, 2013
Gas Gathering and Processing Equipment [Member]
Other Commitments [Line Items]
Other Commitment, Due in Next Twelve Months	$ 2,002
Other Commitment, Due in Second Year	1,829
Other Commitment, Due in Third Year	1,921
Other Commitment, Due in Fourth Year	1,948
Other Commitment, Due in Fifth Year	1,762
Other Commitment, Due after Fifth Year	7,728
Other Commitment	$ 17,190