Contingencies and Commitments Commitments - Undiscounted Future Lease Payments Table (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013
Operating Leased Assets [Line Items]
Other Commitment, Due in Second Year	$ 72
Other Commitment, Due in Third Year	119
Other Commitment, Due in Fourth Year	33
Operating Leases, Future Minimum Payments, Due in Five Years	32
Operating Leases, Future Minimum Payments Due, Next Twelve Months	117
Other Commitment, Due after Fifth Year	2
Other Commitment	375
Drilling Rigs [Member]
Operating Leased Assets [Line Items]
Other Commitment, Due in Second Year	11
Other Commitment, Due in Third Year	6
Other Commitment, Due in Fourth Year	7
Operating Leases, Future Minimum Payments, Due in Five Years	1
Operating Leases, Future Minimum Payments Due, Next Twelve Months	51
Other Commitment, Due after Fifth Year	0
Other Commitment	76
Compressor [Member]
Operating Leased Assets [Line Items]
Other Commitment, Due in Second Year	50
Other Commitment, Due in Third Year	104
Other Commitment, Due in Fourth Year	23
Operating Leases, Future Minimum Payments, Due in Five Years	29
Operating Leases, Future Minimum Payments Due, Next Twelve Months	53
Other Commitment, Due after Fifth Year	1
Other Commitment	260
Property, Plant and Equipment, Other Types
Operating Leased Assets [Line Items]
Other Commitment, Due in Second Year	11
Other Commitment, Due in Third Year	9
Other Commitment, Due in Fourth Year	3
Operating Leases, Future Minimum Payments, Due in Five Years	2
Operating Leases, Future Minimum Payments Due, Next Twelve Months	13
Other Commitment, Due after Fifth Year	1
Other Commitment	$ 39