Nature of Business (Details) (Continuing operations)	Sep. 30, 2014 drillingunit
Continuing operations
Number of mobile offshore drilling units	79
Number of High-Specification Floaters (in drilling units)	48
Number of Midwater Floaters (in drilling units)	21
Number of High-Specification Jackups (in drilling units)	10
Number of Ultra-Deepwater drillships under construction (in drilling units)	7
Number of High-Specification Jackup under construction (in drilling units)	5

Number of High-Specification Jackups. High-Specification Jackups are harsh environment and high-performance jackups. Jackups are self-elevating drilling platforms that have legs that can be lowered to the ocean floor to establish a foundation to support the drilling platform. These units are generally suited for water depths of 400 feet or less.

No definition available.

Name:	rig_NumberOfHighSpecificationJackups
Namespace Prefix:	rig_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant