CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Unaudited) (Parenthetical) - $ / shares |
Mar. 31, 2018 |
Dec. 31, 2017 |
|---|---|---|
| Shareholders' equity: | ||
| Preferred stock - par value (in dollars per share) | $ 0.01 | $ 0.01 |
| Preferred stock - shares authorized (in shares) | 50,000,000 | 50,000,000 |
| Preferred stock - shares issued (in shares) | 0 | 0 |
| Common stock - par value (in dollars per share) | $ 0.01 | $ 0.01 |
| Common stock - shares authorized (in shares) | 100,000,000 | 100,000,000 |
| Common stock - shares issued (in shares) | 29,323,807 | 29,501,346 |
| Common stock - shares outstanding (in shares) | 29,323,807 | 29,501,346 |
| Treasury shares (in shares) | 6,247,819 | 6,030,900 |