Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Jul. 31, 2012	Jul. 31, 2011
Cash Flows From Operating Activities:
Net income	$ 190,327	$ 181,986
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	19,007	18,539
Amortization of deferred sales commissions	15,973	28,457
Stock-based compensation	42,819	40,184
Deferred income taxes	(7,315)	68,022
Net gains on investments and derivatives	(7,786)	(14,481)
Equity in net income of affiliates	(2,642)	(4,273)
Dividends received from affiliates	11,117	1,592
Consolidated CLO entity operating activities:
Net (gains) losses on bank loans, other investments and note obligations	(15,366)	25,539
Amortization of investments	(790)	(984)
Net decrease in other assets and liabilities, including cash	(19,655)	(11,953)
Changes in operating assets and liabilities:
Investment advisory fees and other receivables	3,469	(7,867)
Investments in trading securities	(72,400)	(173,322)
Deferred sales commissions	(8,462)	(13,739)
Other assets	(169)	(19,935)
Accrued compensation	(27,307)	(8,581)
Accounts payable and accrued expenses	6,027	9,005
Other liabilities	17,941	5,483
Net cash provided by operating activities	144,788	123,672
Cash Flows From Investing Activities:
Additions to equipment and leasehold improvements	(2,928)	(8,919)
Net cash paid in acquisition	(12,334)	(11,595)
Cash paid for intangible assets	(200)	(1,650)
Proceeds from sales of investments	72,597	119,839
Purchase of investments	(21,624)	(1,226)
Consolidated CLO entity investing activities:
Proceeds from sales and maturities of bank loans and other investments	182,784	250,689
Purchase of bank loans and other investments	(163,037)	(241,310)
Net cash provided by investing activities	55,258	105,828
Cash Flows From Financing Activities:
Purchase of additional non-controlling interest	(19,864)	(6,611)
Proceeds from issuance of Voting Common Stock	56
Proceeds from issuance of Non-Voting Common Stock	22,848	36,494
Repurchase of Non-Voting Common Stock	(76,586)	(118,872)
Principal repayments on notes receivable from stock option exercises	764	839
Excess tax benefit of stock option exercises	2,228	4,336
Dividends paid	(65,950)	(64,116)
Line of credit issuance costs	(1,192)
Net subscriptions received from (redemptions/distributions paid to) non-controlling interest holders	27,138	112,451
Net cash used for financing activities	(110,558)	(35,479)
Effect of currency rate changes on cash and cash equivalents	(219)	355
Net increase in cash and cash equivalents	89,269	194,376
Cash and cash equivalents, beginning of period	510,913	307,886
Cash and cash equivalents, end of period	600,182	502,262
Supplemental Cash Flow Information:
Cash paid for interest	24,524	24,481
Cash paid for interest by consolidated CLO entity	13,584	10,360
Cash paid for income taxes, net of refunds	117,829	41,534
Supplemental Disclosure of Non-Cash Information:
Increase in equipment and leasehold improvements due to non-cash additions	174	3,350
Exercise of stock options through issuance of notes receivable	211	602
Consolidation of CLO Entity:
Increase in other assets, net of other liabilities		10,418
Increase in investments		466,440
Increase in borrowings		446,192
Deconsolidations of Sponsored Investment Funds:
Decrease in investments	(23,639)	(121,274)
Decrease in non-controlling interests	$ (21,586)	$ (120,260)