Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Millions |
3 Months Ended | 9 Months Ended | |||
|---|---|---|---|---|---|
May 31, 2019 |
Jan. 31, 2019 |
Jan. 31, 2018 |
Apr. 30, 2019 |
Apr. 30, 2018 |
|
| Equity, Class of Treasury Stock [Line Items] | |||||
| Number of shares authorized to be repurchased (in shares) | 14,000,000 | ||||
| Stock repurchased during the period (in shares) | 2,100,000 | ||||
| Stock repurchased during the period | $ 104.4 | $ 107.7 | |||
| Shares with remaining authorization for repurchase under stock repurchase plan (in shares) | 2,400,000 | ||||
| Cash dividend declared per common share (in usd per share) | $ 0.38 | $ 0.36 | |||
| Subsequent Event | |||||
| Equity, Class of Treasury Stock [Line Items] | |||||
| Number of shares authorized to be repurchased (in shares) | 13,000,000 | ||||
| Cash dividend declared per common share (in usd per share) | $ 0.210 | ||||