Equity-Based Compensation - Summary of NQO Grants (Detail) - Non-Qualified Options - $ / shares  | 
1 Months Ended | 12 Months Ended | 
|---|---|---|
Oct. 31, 2018  | 
Dec. 31, 2018  | 
|
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||
| Granted, Units | 105,398 | |
| Ending Balance, Units | 105,398 | |
| Fair Value per unit | $ 13.97 | |
| Granted in October 2018 | ||
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||
| Granted, Units | 105,398 | |
| Fair Value per unit, Granted | $ 13.97 | 
| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available. 
  | 
| X | ||||||||||
- Definition Gross number of share options (or share units) granted during the period. No definition available. 
  | 
| X | ||||||||||
- Definition The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
  | 
| X | ||||||||||
- Definition Number of options outstanding, including both vested and non-vested options. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
  | 
| X | ||||||||||
- Definition Weighted average grant-date fair value of non-vested options outstanding. No definition available. 
  | 
| X | ||||||||||
- Details 
  | 
| X | ||||||||||
- Details 
  |