Segment Information - Summary of Revenues on Percentage Basis by Geographic Regions (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Information [Line Items]
Revenues on a percentage basis by geographic regions, based on the country	100.00%	100.00%	100.00%	100.00%
United States [Member]
Segment Information [Line Items]
Revenues on a percentage basis by geographic regions, based on the country	64.00%	74.00%	64.00%	77.00%
South America [Member]
Segment Information [Line Items]
Revenues on a percentage basis by geographic regions, based on the country	14.00%		14.00%
Japan [Member]
Segment Information [Line Items]
Revenues on a percentage basis by geographic regions, based on the country	2.00%	6.00%	2.00%	6.00%
Europe [Member]
Segment Information [Line Items]
Revenues on a percentage basis by geographic regions, based on the country	19.00%	17.00%	19.00%	13.00%
Other [Member]
Segment Information [Line Items]
Revenues on a percentage basis by geographic regions, based on the country	1.00%	3.00%	1.00%	4.00%