Share Repurchase Program - Summary of Stock Repurchase Activities (Detail) - USD ($) |
3 Months Ended | 6 Months Ended |
|---|---|---|
Jun. 30, 2018 |
Jun. 30, 2018 |
|
| Share Repurchase Program [Abstract] | ||
| Shares repurchased | 510,581 | 586,572 |
| Average cost per share | $ 29.38 | $ 30.69 |
| Total cost of shares repurchased | $ 15,000,000 | $ 18,000,000 |
| X | ||||||||||
- Definition Share repurchase program. No definition available.
|
| X | ||||||||||
- Definition Stock repurchased average cost per share. No definition available.
|
| X | ||||||||||
- Definition Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Equity impact of the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|