Commitments and Contingencies (Details 2) (USD $) In Millions, unless otherwise specified			3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013 Mexico	Mar. 31, 2014 Mexico Minimum	Mar. 31, 2014 Mexico Maximum
Income tax
Aggregate remaining amounts assessed or expected to assessed range			$ 30	$ 35
Reduction in reserves		20
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