Nature of Operations (Details)	6 Months Ended
	Jun. 30, 2018 segment county country item
Nature of Operations
The minimum number of countries in which the entity operates | country	25
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	35
Number of reportable segments | segment	5