Consolidated Statements of Cash Flows (USD $)
In Thousands, unless otherwise specified
 12 Months Ended
Oct. 31, 2011
Oct. 31, 2010
Oct. 31, 2009
Cash Flows From Operating Activities:      
Net income $ 227,574 $ 201,225 $ 135,525
Adjustments to reconcile net income to net cash provided by operating activities:      
Depreciation and amortization 25,269 24,911 22,010
Amortization of deferred sales commissions 35,723 35,518 35,144
Stock-based compensation 52,030 47,858 41,474
Deferred income taxes 54,868 (16,504) (38,141)
Net gains on investments and derivatives (11,931) (7,150) (6,361)
Impairment losses on investments     (1,863)
Equity in net (income) loss of affiliates (4,898) (848) 1,744
Dividends received from affiliates 1,608 1,313 3,069
Consolidated collateralized loan obligation entity operating activities:      
Net losses on bank loans, other investments and note obligations 38,153 0 0
Amortization of investments (1,221) 0 0
Net decrease in other assets and liabilities, including cash (3,122) 0 0
Changes in operating assets and liabilities:      
Investment advisory fees and other receivables 456 (21,651) 2,895
Investments in trading securities (214,826) (208,793) (12,757)
Deferred sales commissions (15,505) (31,696) (14,004)
Other assets (38,948) (15,397) (1,623)
Accrued compensation 17,471 34,692 (7,892)
Accounts payable and accrued expenses (7,406) 9,937 1,453
Other liabilities 17,017 42,484 (44)
Net cash provided by operating activities 172,312 95,899 164,355
Cash Flows From Investing Activities:      
Additions to equipment and leasehold improvements (10,639) (12,205) (46,302)
Net cash paid in acquisition (11,595) (8,797) (30,941)
Cash paid for intangible assets (1,650) 0 0
Payments received on note receivable from affiliate 0 8,000 7,000
Issuance of note receivable to affiliate 0 0 (5,000)
Proceeds from sales of investments 158,439 40,497 127,847
Purchase of investments (1,569) (41,520) (11,259)
Consolidated collateralized loan obligation entity investing activities:      
Proceeds from sales and maturities of investments 291,381 0 0
Purchase of investments (290,847) 0 0
Net cash provided by (used for) investing activities 133,520 (14,025) 41,345
Cash Flows From Financing Activities:      
Purchase of additional non-controlling interest (6,611) (11,244) (17,072)
Proceeds from issuance of Voting Common Stock 0 0 86
Proceeds from issuance of Non-Voting Common Stock 60,941 56,237 29,208
Repurchase of Voting Common Stock 0 (96) 0
Repurchase of Non-Voting Common Stock (198,627) (111,173) (41,083)
Principal repayments on notes receivable from stock option exercises 941 1,864 3,084
Excess tax benefit of stock option exercises 7,022 10,825 13,649
Dividends paid (85,240) (75,651) (72,427)
Net subscriptions received from (redemptions/distributions paid to) non-controlling interest holders 118,527 44,986 (7,308)
Net cash used for financing activities (103,047) (84,252) (91,863)
Effect of currency rate changes on cash and cash equivalents 242 (322) (174)
Net increase (decrease) in cash and cash equivalents 203,027 (2,700) 113,663
Cash and cash equivalents, beginning of period 307,886 310,586 196,923
Cash and cash equivalents, end of period 510,913 307,886 310,586
Supplemental Cash Flow Information:      
Cash paid for interest 32,642 32,642 32,642
Cash paid for interest by consolidated collateralized loan obligation entity 11,100 0 0
Cash paid for income taxes, net of refunds 83,610 135,853 103,033
Supplemental Disclosure of Non-Cash Information:      
Increase in equipment and leasehold improvements due to non-cash additions 3,350 860 3,160
Exercise of stock options through issuance of notes receivable 2,224 1,944 1,458
Consolidation of CLO Entity:      
Increase in other assets, net of other liabilities 10,418 0 0
Increase in investments 446,440 0 0
Increase in borrowings 446,192 0 0
Deconsolidations of Sponsored Investment Funds:      
Decrease in investments (124,253) (52,594) (4,438)
Decrease in non-controlling interests $ (125,844) $ (36,372) $ (4,461)