Segment Information and Concentrations of Risk - Additional Information (Detail) (Customer Concentration)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net Revenues | Customer One
Segment Reporting Information [Line Items]
Concentration percentage	51.60%	58.00%
Net Revenues | Customer Two
Segment Reporting Information [Line Items]
Concentration percentage			57.50%
Accounts Receivable | Customer One
Segment Reporting Information [Line Items]
Concentration percentage	46.10%	24.50%
Accounts Receivable | Customer Two
Segment Reporting Information [Line Items]
Concentration percentage		12.60%
Accounts Receivable | Customer Three
Segment Reporting Information [Line Items]
Concentration percentage		12.00%