Business Segment Information (Unaudited Financial Information) (Details) (USD $) In Thousands, unless otherwise specified | 3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2011 | Sep. 30, 2010 | Sep. 30, 2011 | Sep. 30, 2010 | |
| Revenues | $ 233,227 | $ 219,513 | $ 703,480 | $ 669,436 |
| Expenses | 171,309 | 155,672 | 512,445 | 476,097 |
| Operating profit (loss) | 61,918 | 63,841 | 191,035 | 193,339 |
| Operating margin | 27.00% | 29.00% | 27.00% | 29.00% |
Private Banks [Member] | ||||
| Revenues | 87,697 | 83,518 | 262,279 | 260,730 |
| Expenses | 85,893 | 73,463 | 254,570 | 229,674 |
| Operating profit (loss) | 1,804 | 10,055 | 7,709 | 31,056 |
| Operating margin | 2.00% | 12.00% | 3.00% | 12.00% |
Investment Advisors [Member] | ||||
| Revenues | 46,798 | 43,422 | 144,674 | 135,283 |
| Expenses | 28,051 | 26,426 | 82,825 | 82,129 |
| Operating profit (loss) | 18,747 | 16,996 | 61,849 | 53,154 |
| Operating margin | 40.00% | 39.00% | 43.00% | 39.00% |
Institutional Investors [Member] | ||||
| Revenues | 52,216 | 51,036 | 160,132 | 152,821 |
| Expenses | 25,524 | 25,940 | 79,883 | 78,896 |
| Operating profit (loss) | 26,692 | 25,096 | 80,249 | 73,925 |
| Operating margin | 51.00% | 49.00% | 50.00% | 48.00% |
Investment Managers [Member] | ||||
| Revenues | 45,585 | 40,548 | 133,478 | 117,598 |
| Expenses | 29,412 | 25,763 | 86,693 | 75,918 |
| Operating profit (loss) | 16,173 | 14,785 | 46,785 | 41,680 |
| Operating margin | 35.00% | 36.00% | 35.00% | 35.00% |
Investments In New Businesses [Member] | ||||
| Revenues | 931 | 989 | 2,917 | 3,004 |
| Expenses | 2,429 | 4,080 | 8,474 | 9,480 |
| Operating profit (loss) | $ (1,498) | $ (3,091) | $ (5,557) | $ (6,476) |
| Operating margin | 0.00% | 0.00% | 0.00% | 0.00% |