Significant Customers - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2014 Customer	Jun. 30, 2013 Customer	Jun. 30, 2014 Customer	Jun. 30, 2013 Customer	Dec. 31, 2013
Revenue, Major Customer [Line Items]
Number of significant customer	2	2	2	2
Number of other customers accounted for more than 10% of revenue	0		0
Trade receivables	10.00%		10.00%
Accounts receivable	57.00%		57.00%		47.00%
Customer One [Member]
Revenue, Major Customer [Line Items]
Revenue	29.00%	30.00%	24.00%	46.00%
Customer Two [Member]
Revenue, Major Customer [Line Items]
Revenue	10.00%	27.00%	10.00%	15.00%
All Other Customers [Member] | Maximum [Member]
Revenue, Major Customer [Line Items]
Revenue			10.00%	10.00%