Share Repurchase Program - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2018 |
Feb. 06, 2018 |
Dec. 31, 2017 |
|
| Class of Stock [Line Items] | |||
| Stock repurchase program expiration date | Feb. 06, 2021 | ||
| Class A Common Stock [Member] | |||
| Class of Stock [Line Items] | |||
| Common Stock, par value | $ 0.001 | $ 0.001 | |
| Stock repurchase program authorized amount | $ 150 | ||
| Class A Common Stock [Member] | Share Repurchase Program [Member] | |||
| Class of Stock [Line Items] | |||
| Common Stock, par value | $ 0.001 |
| 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 Face amount or stated value per share of common stock. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount of stock repurchase plan authorized. No definition available.
|
| X | ||||||||||
- Definition Expiration date for the purchase of an entity's own shares under a stock repurchase plan, in the CCYY-MM-DD format. No definition available.
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|