Basis of Presentation and Summary of Significant Accounting Policies - Additional Information - Concentration Risk (Detail)	3 Months Ended		9 Months Ended	3 Months Ended		9 Months Ended			12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended
	Sep. 30, 2014 Revenue [Member] Customer Concentration Risk [Member] Customer	Sep. 30, 2013 Revenue [Member] Customer Concentration Risk [Member] Customer	Sep. 30, 2014 Revenue [Member] Customer Concentration Risk [Member] Customer	Sep. 30, 2014 Revenue [Member] Customer Concentration Risk [Member] Minimum [Member]	Sep. 30, 2013 Revenue [Member] Customer Concentration Risk [Member] Minimum [Member]	Sep. 30, 2014 Revenue [Member] Customer Concentration Risk [Member] Minimum [Member]	Sep. 30, 2013 Revenue [Member] Customer Concentration Risk [Member] Minimum [Member]	Sep. 30, 2013 Revenue [Member] Customer Concentration Risk [Member] Customer One [Member] Customer	Dec. 31, 2013 Accounts Receivable [Member] Credit Concentration Risk [Member] Customer	Sep. 30, 2014 Accounts Receivable [Member] Credit Concentration Risk [Member] Minimum [Member]	Dec. 31, 2013 Accounts Receivable [Member] Credit Concentration Risk [Member] Minimum [Member]	Sep. 30, 2014 Accounts Receivable [Member] Credit Concentration Risk [Member] Customer Two [Member] Customer
Concentration Risk [Line Items]
Number of customers representing more than 10% threshold	0	0	0					1	0			1
Percentage of revenue or gross accounts receivable				10.00%	10.00%	10.00%	10.00%	10.00%		10.00%	10.00%	12.00%