Nature of Operations (Details)	9 Months Ended
Sep. 30, 2017 segment county item
Nature of Operations
Actively marketed rigs for land based drilling operations	405
Number of countries company has actively marketed rigs for land based drilling operations \| county	20
Actively marketed rigs for offshore based drilling operations	40
Number of Operating Segments \| segment	4

Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

No definition available.

Name:	us-gaap_NumberOfOperatingSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration