Annual report pursuant to Section 13 and 15(d)

Derivative Liability and Fair Value Measurements (Additional Information) (Detail)

v3.19.1
Derivative Liability and Fair Value Measurements (Additional Information) (Detail) - shares
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right 0 38,100
Percentage of Outstanding Warrants Issued By Parent 86.00%