Geographic Areas - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Sales Information [Line Items]
Sales to an individual customer	No other customer accounted for more than 10% of the Company's total revenues in 2014, 2013 or 2012.
Chevron [Member] | Sales Revenue, Net [Member] | Customer Concentration Risk [Member]
Sales Information [Line Items]
Percentage of revenue accounted by one customer	10.00%
Petrobras [Member] | Sales Revenue, Net [Member] | Customer Concentration Risk [Member]
Sales Information [Line Items]
Percentage of revenue accounted by one customer		11.00%	12.00%