Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash Flows From Operating Activities
Net Income	$ 27,714	$ 68,262
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Net (Gains) Losses on Investments, Marketable Securities and Contingent Consideration	3,411	(904)
Equity Method Investments	3,304	5,620
Equity-Based and Other Deferred Compensation	155,174	82,857
Impairment of Goodwill	28,000	0
Depreciation, Amortization and Accretion	22,821	12,716
Bad Debt Expense	1,214	1,582
Deferred Taxes	(2,920)	15,984
Decrease (Increase) in Operating Assets:
Marketable Securities	342	400
Financial Instruments Owned and Pledged as Collateral at Fair Value	36,728	(40,853)
Securities Purchased Under Agreements to Resell	6,870	13,803
Accounts Receivable	(30,743)	(24,583)
Receivable from Employees and Related Parties	(1,532)	(2,973)
Other Assets	(7,570)	(29,279)
(Decrease) Increase in Operating Liabilities:
Accrued Compensation and Benefits	(69,590)	(47,708)
Accounts Payable and Accrued Expenses	1,216	11,638
Securities Sold Under Agreements to Repurchase	(43,713)	27,050
Payables to Employees and Related Parties	10,097	(6,998)
Taxes Payable	1,669	(4,145)
Other Liabilities	350	6,782
Net Cash Provided by Operating Activities	142,842	89,251
Cash Flows From Investing Activities
Investments Purchased	(235)	(10,783)
Distributions of Private Equity Investments	6,752	216
Marketable Securities:
Proceeds from Sales and Maturities	25,295	31,999
Purchases	(30,859)	(16,549)
Cash Paid for Acquisitions, net of Cash Acquired	(3,253)	0
Loans Receivable	(3,500)	0
Purchase of Furniture, Equipment and Leasehold Improvements	(12,855)	(10,223)
Net Cash Provided by (Used in) Investing Activities	(18,655)	(5,340)
Cash Flows From Financing Activities
Issuance of Noncontrolling Interests	373	2,135
Distributions to Noncontrolling Interests	(15,059)	(8,553)
Cash Paid for Deferred and Contingent Consideration	0	(2,255)
Short-Term Borrowing	45,000	75,000
Repayment of Short-Term Borrowing	(45,000)	(75,000)
Purchase of Treasury Stock and Noncontrolling Interests	(152,788)	(137,443)
Excess Tax Benefits Associated with Equity-Based Awards	9,905	33,045
Dividends - Class A Stockholders	(33,794)	(27,911)
Net Cash Provided by (Used in) Financing Activities	(191,363)	(140,982)
Effect of Exchange Rate Changes on Cash	(6,839)	(2,313)
Net Increase (Decrease) in Cash and Cash Equivalents	(74,015)	(59,384)
Cash and Cash Equivalents-Beginning of Period	352,160	298,453
Cash and Cash Equivalents-End of Period	278,145	239,069
SUPPLEMENTAL CASH FLOW DISCLOSURE
Payments for Interest	14,062	11,518
Payments for Income Taxes	29,327	14,640
Increase (Decrease) in Fair Value of Redeemable Noncontrolling Interest	(1,379)	14,616
Dividend Equivalents Issued	4,814	4,481
Settlement of Contingent Consideration	0	7,232
Receipt of Securities in Settlement of Accounts Receivable	1,079	2,083
Purchase of Noncontrolling Interest	0	7,100
Contingent Consideration Accrued	10,787	2,162
Reclassification from Redeemable Noncontrolling Interest to Noncontrolling Interest	$ 0	$ 31,268