Commitments and Contingencies (Details) $ in Millions	9 Months Ended
	Sep. 30, 2015 USD ($)
Self-Insurance disclosures
Employer's liability claims subject to per-occurrence deductible	$ 3.0
Workers automobile claims	2.5
General liability claims subject to per-occurrence deductible	5.0
Deductions in land rigs and for offshore rigs	5.0
Mexico | Minimum
Income tax
Aggregate remaining amounts assessed or expected to assessed range	30.0
Mexico | Maximum
Income tax
Aggregate remaining amounts assessed or expected to assessed range	$ 35.0