Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation - Summary of Activity of Restricted Stock Units (Detail)

v3.19.1
Stock-Based Compensation - Summary of Activity of Restricted Stock Units (Detail) - Restricted Stock Units [Member]
3 Months Ended
Mar. 31, 2019
$ / shares
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Number of restricted stock units outstanding, Unvested beginning balance | shares 1,051,414
Number of restricted stock units outstanding, Vested | shares (8,894)
Number of restricted stock units outstanding, Unvested ending balance | shares 1,042,520
Weighted-average grant date fair value, Unvested beginning balance | $ / shares $ 10.15
Weighted-average grant date fair value, Vested | $ / shares 14.91
Weighted-average grant date fair value, Unvested ending balance | $ / shares $ 9.64