XML 38 R44.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Equity-Based Compensation - Schedule of fair value assumptions (Detail) - PICU
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Minimum    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Risk-free interest rate 2.20% 1.93%
Volatility 91.00% 101.03%
Maximum    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Risk-free interest rate 2.51% 2.20%
Volatility 80.00% 91.00%