Significant Customers - Additional Information (Detail) - Customer	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Revenue, Major Customer [Line Items]
Number of significant customer	1	2	2	2
Number of other customers accounted for more than 10% of revenue	0	0	0	0
Trade receivables	10.00%		10.00%
Accounts receivable	64.00%		64.00%		57.00%
Customer One [Member] | Customer Concentration Risk [Member]
Revenue, Major Customer [Line Items]
Revenue	76.00%	30.00%	55.00%	18.00%
Customer Two [Member] | Customer Concentration Risk [Member]
Revenue, Major Customer [Line Items]
Revenue		13.00%	10.00%	15.00%
All Other Customers [Member] | Customer Concentration Risk [Member] | Maximum [Member]
Revenue, Major Customer [Line Items]
Revenue			10.00%	10.00%