Subsequent Events (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014 item
U.S. Land | Scenario Forecast | Maximum | Subsequent Event.
Subsequent Event
Number of active rigs	200
U.S. Land | Scenario Forecast | Minimum | Subsequent Event.
Subsequent Event
Early termination revenue	$ 60
International Land
Subsequent Event
Number of termination received		1
International Land | Scenario Forecast | Subsequent Event.
Subsequent Event
Early termination revenue	$ 8