Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail)

v3.8.0.1
Fair Value Measurements - Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring [Member]
$ in Thousands
Sep. 30, 2017
USD ($)
Assets  
Total assets $ 8,293
Warrant [Member]  
Liabilities  
Liabilities 3
Cash [Member]  
Assets  
Total assets 3,010
Money market securities (cash equivalents) [Member]  
Assets  
Total assets 5,011
Restricted cash [Member]  
Assets  
Total assets 272
Level 1 [Member]  
Assets  
Total assets 8,293
Level 1 [Member] | Cash [Member]  
Assets  
Total assets 3,010
Level 1 [Member] | Money market securities (cash equivalents) [Member]  
Assets  
Total assets 5,011
Level 1 [Member] | Restricted cash [Member]  
Assets  
Total assets 272
Level 3 [Member] | Warrant [Member]  
Liabilities  
Liabilities $ 3