Common Stock - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands |
12 Months Ended | ||
---|---|---|---|
May 31, 2018 |
May 31, 2017 |
May 31, 2016 |
|
Shareholder Rights [Line Items] | |||
Authorization of stock repurchase program | Jan. 08, 2008 | ||
Shares repurchased | 0 | 0 | 800,000 |
Shares repurchased, value | $ 35,098 | ||
Repurchase of common stock price per shares | $ 43.88 | ||
Minimum | |||
Shareholder Rights [Line Items] | |||
Shares authorized to be repurchased, per year | 1,000,000 | 1,000,000 | 1,000,000 |
Maximum | |||
Shareholder Rights [Line Items] | |||
Shares authorized to be repurchased, per year | 2,000,000 | 2,000,000 | 2,000,000 |