Contingencies and Commitments Commitments - Undiscounted Future Driling Commitments Table (Details) (Drilling Obligations [Member], USD $) In Millions, unless otherwise specified	Dec. 31, 2013
Drilling Obligations [Member]
Other Commitments [Line Items]
Other Commitment, Due in Next Twelve Months	$ 36
Other Commitment, Due in Second Year	5
Other Commitment	$ 41

Minimum amount of other commitment maturing in the next fiscal year following the latest fiscal year for commitments not otherwise specified in the taxonomy. Excludes commitments explicitly modeled in this taxonomy, including but not limited to, long-term and short-term purchase commitments, recorded and unrecorded purchase obligations, supply commitments, registration payment arrangements, leases, debt, product warranties, guarantees, environmental remediation obligations, and pensions.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant