Quarterly report pursuant to Section 13 or 15(d)

Subsequent Events - Additional Information (Detail)

Subsequent Events - Additional Information (Detail) - One-Time Option Exchange [Member] - shares
6 Months Ended
Aug. 07, 2019
Jun. 30, 2019
Subsequent Event [Line Items]    
Stock options exchange description   The participants received one new RSU for every two stock options tendered for exchange.
Subsequent Event [Member]    
Subsequent Event [Line Items]    
Number of stock options exchanged 3,200,375  
Additional stock compensation expense expected service term 1 year  
Subsequent Event [Member] | Restricted Stock Units (RSUs) [Member]    
Subsequent Event [Line Items]    
Number of shares granted 1,600,186  
Shares granted, vesting period 1 year