Commitments and Contingencies - Self Insurance Disclosures (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	May 22, 2018
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
Insurance on platform rig		$ 200.0
Deductions in windstorm damage		$ 5.0
Latin American tax authority | Minimum
Income tax
Aggregate remaining amounts assessed or expected to assessed range	3.0
Latin American tax authority | Maximum
Income tax
Aggregate remaining amounts assessed or expected to assessed range	$ 8.0