Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Cash Flows From Operating Activities
Net Income	$ 48,643	$ 14,494
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Net (Gains) Losses on Investments, Marketable Securities and Contingent Consideration	(2,790)	251
Equity Method Investments	4,041	(1,862)
Equity-Based and Other Deferred Compensation	92,313	86,950
Depreciation, Amortization and Accretion	12,237	14,202
Bad Debt Expense	417	566
Deferred Taxes	1,608	(1,109)
Decrease (Increase) in Operating Assets:
Marketable Securities	166	553
Financial Instruments Owned and Pledged as Collateral at Fair Value	35,540	(856)
Securities Purchased Under Agreements to Resell	(7,333)	1,321
Accounts Receivable	28,172	(19,995)
Receivable from Employees and Related Parties	(5,018)	2,254
Other Assets	(17,955)	5,221
(Decrease) Increase in Operating Liabilities:
Accrued Compensation and Benefits	(31,204)	(49,418)
Accounts Payable and Accrued Expenses	272	(1,185)
Securities Sold Under Agreements to Repurchase	(28,228)	(478)
Payables to Employees and Related Parties	1,989	(2,388)
Taxes Payable	(12,440)	(886)
Other Liabilities	(1,628)	(594)
Net Cash Provided by Operating Activities	118,802	47,041
Cash Flows From Investing Activities
Investments Purchased	(2,327)	(1,214)
Distributions of Private Equity Investments	1,175	906
Marketable Securities:
Proceeds from Sales and Maturities	26,739	60,642
Purchases	(29,141)	(22,618)
Cash Acquired from Acquisitions	66	0
Change in Restricted Cash	0	2,393
Purchase of Furniture, Equipment and Leasehold Improvements	(1,988)	(11,874)
Net Cash Provided by (Used In) Investing Activities	(5,476)	28,235
Cash Flows From Financing Activities
Issuance of Noncontrolling Interests	3,189	296
Distributions to Noncontrolling Interests	(17,341)	(11,984)
Cash Paid for Deferred and Contingent Consideration	0	(3,000)
Purchase of Treasury Stock and Noncontrolling Interests	(99,730)	(65,159)
Excess Tax Benefits Associated with Equity-Based Awards	7,720	865
Dividends - Class A Stockholders	(21,214)	(17,703)
Other	0	(78)
Net Cash Provided by (Used in) Financing Activities	(127,376)	(96,763)
Effect of Exchange Rate Changes on Cash	(1,583)	923
Net Increase (Decrease) in Cash and Cash Equivalents	(15,633)	(20,564)
Cash and Cash Equivalents-Beginning of Period	259,431	182,905
Cash and Cash Equivalents-End of Period	243,798	162,341
SUPPLEMENTAL CASH FLOW DISCLOSURE
Payments for Interest	10,767	11,694
Payments for Income Taxes	50,187	8,565
Furniture, Equipment and Leasehold Improvements Accrued	621	397
Increase (Decrease) in Fair Value of Redeemable Noncontrolling Interest	123	(1,303)
Dividend Equivalents Issued	4,409	3,598
Notes Exchanged for Equity in Subsidiary	1,042	0
Settlement of Contingent Consideration	2,494	0
Receipt of Marketable Securities in Settlement of Accounts Receivable	$ 1,730	$ 0