Australia Research and Development Tax Incentive - Additional Information (Detail) - Spero Potentiator Australia Pty Limited [Member] - USD ($) |
3 Months Ended | ||
---|---|---|---|
Mar. 31, 2018 |
Mar. 31, 2017 |
Dec. 31, 2017 |
|
Australia [Member] | |||
Schedule Of Income Tax [Line Items] | |||
Tax incentive receivable | $ 1,900,000 | $ 1,900,000 | |
Research and Development Expenses [Member] | |||
Schedule Of Income Tax [Line Items] | |||
Percentage of refundable tax incentive | 43.50% | ||
Reduction to research and development expenses | $ 100,000 | $ 0 |