Quarterly report pursuant to Section 13 or 15(d)

Equity-Based Compensation - Summary of RSU Grants (Detail)

v3.10.0.1
Equity-Based Compensation - Summary of RSU Grants (Detail) - Restricted Stock Units - $ / shares
9 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Beginning Balance, Units 491,786 739,256
Vested, Units (244,470) (247,471)
Ending Balance, Units 247,316 491,785
Minimum    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Fair Value per unit $ 13.19 $ 13.19
Fair Value per unit, Vested 13.19 13.19
Fair Value per unit 13.19 13.19
Maximum    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Fair Value per unit 13.23 13.23
Fair Value per unit, Vested 13.23 13.23
Fair Value per unit $ 13.23 $ 13.23