Fixed Assets - Additional Information (Detail) - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property Plant And Equipment [Line Items]
Depreciation expense relating to fixed assets	$ 2.3	$ 2.7	$ 3.2
Building and Building Improvements | Minimum
Property Plant And Equipment [Line Items]
Useful Life	25 years
Building and Building Improvements | Maximum
Property Plant And Equipment [Line Items]
Useful Life	30 years
Machinery and Equipment | Minimum
Property Plant And Equipment [Line Items]
Useful Life	5 years
Machinery and Equipment | Maximum
Property Plant And Equipment [Line Items]
Useful Life	10 years
Seismic Vessels | Minimum
Property Plant And Equipment [Line Items]
Useful Life	20 years
Seismic Vessels | Maximum
Property Plant And Equipment [Line Items]
Useful Life	30 years