Drilling and Other Property and Equipment - Additional Information (Detail) (Assets Placed in Service [Member], USD $) In Billions, unless otherwise specified	12 Months Ended
Dec. 31, 2013
Assets Placed in Service [Member]
Property, Plant and Equipment [Line Items]
Construction work-in-progress	$ 1.3

Amount of reclassification, impairment, donation, or other change to long-lived, physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6391110&loc=d3e2921-110230

Name:	us-gaap_PropertyPlantAndEquipmentTransfersAndChanges
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration