Debt - Schedule of Principal Repayment under the Financing Agreement (Detail) - Term Loan [Member] $ in Thousands	9 Months Ended
	Sep. 30, 2015 USD ($)	[1]
2015 [Member] | First Quarter [Member]
Debt Instrument [Line Items]
Debt instrument installment amount	$ 2,500
2015 [Member] | Second Quarter [Member]
Debt Instrument [Line Items]
Debt instrument installment amount	2,500
2015 [Member] | Third Quarter [Member]
Debt Instrument [Line Items]
Debt instrument installment amount	2,500
2015 [Member] | Fourth Quarter [Member]
Debt Instrument [Line Items]
Debt instrument installment amount	2,500
2016 [Member] | First Quarter [Member]
Debt Instrument [Line Items]
Debt instrument installment amount	5,000
2016 [Member] | Second Quarter [Member]
Debt Instrument [Line Items]
Debt instrument installment amount	5,000
2016 [Member] | Third Quarter [Member]
Debt Instrument [Line Items]
Debt instrument installment amount	5,000
2016 [Member] | Fourth Quarter [Member]
Debt Instrument [Line Items]
Debt instrument installment amount	5,000
2017 [Member] | First Quarter [Member]
Debt Instrument [Line Items]
Debt instrument installment amount	7,500
2017 [Member] | Second Quarter [Member]
Debt Instrument [Line Items]
Debt instrument installment amount	7,500
2017 [Member] | Third Quarter [Member]
Debt Instrument [Line Items]
Debt instrument installment amount	7,500
2017 [Member] | Fourth Quarter [Member]
Debt Instrument [Line Items]
Debt instrument installment amount	$ 47,500	[2]

[1] First business day of the month.

[2] Or the amount necessary to repay the then outstanding principal balance in full, which as of September 30, 2015 was $46,500.