Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash Flows From Operating Activities
Net Income	$ 41,271	$ 22,279
Adjustments to Reconcile Net Income to Net Cash Provided by (Used in) Operating Activities:
Net (Gains) Losses on Investments, Marketable Securities and Contingent Consideration	198	2,313
Equity Method Investments	4,251	3,118
Equity-Based and Other Deferred Compensation	124,348	106,139
Depreciation, Amortization and Accretion	13,067	13,846
Bad Debt Expense	554	141
Deferred Taxes	(958)	9,557
Decrease (Increase) in Operating Assets:
Marketable Securities	339	310
Financial Instruments Owned and Pledged as Collateral at Fair Value	27,417	48,004
Securities Purchased Under Agreements to Resell	(20,468)	(26,962)
Accounts Receivable	(17,790)	9,618
Receivable from Employees and Related Parties	3,027	195
Other Assets	(7,671)	(18,618)
(Decrease) Increase in Operating Liabilities:
Accrued Compensation and Benefits	(148,263)	(113,581)
Accounts Payable and Accrued Expenses	(6,753)	(963)
Securities Sold Under Agreements to Repurchase	(7,011)	(21,135)
Payables to Employees and Related Parties	3,598	12,062
Taxes Payable	(11,291)	448
Other Liabilities	11,305	(437)
Net Cash Provided by Operating Activities	9,170	46,334
Cash Flows From Investing Activities
Investments Purchased	(1,529)	(224)
Distributions of Private Equity Investments	107	6,593
Marketable Securities:
Proceeds from Sales and Maturities	18,260	20,369
Purchases	(43,820)	(15,704)
Loans Receivable	0	(3,500)
Cash Classified in Assets Held for Sale	(906)	0
Purchase of Furniture, Equipment and Leasehold Improvements	(4,732)	(7,695)
Net Cash Provided by (Used in) Investing Activities	(32,620)	(161)
Cash Flows From Financing Activities
Issuance of Noncontrolling Interests	885	307
Purchase of Noncontrolling Interests	(6,482)	0
Distributions to Noncontrolling Interests	(17,193)	(10,291)
Cash Paid for Deferred and Contingent Consideration	(5,050)	0
Short-Term Borrowing	50,000	45,000
Repayment of Short-Term Borrowing	(50,000)	(45,000)
Repayment of Subordinated Borrowings	(6,000)	0
Payment of Notes Payable - Mizuho	(120,000)	0
Issuance of Notes Payable	170,000	0
Debt Issuance Costs	(2,084)	0
Purchase of Treasury Stock	(159,779)	(123,639)
Excess Tax Benefits Associated with Equity-Based Awards	4,385	8,877
Dividends - Class A Stockholders	(24,397)	(22,703)
Net Cash Provided by (Used in) Financing Activities	(165,715)	(147,449)
Effect of Exchange Rate Changes on Cash	(12,329)	(805)
Net Increase (Decrease) in Cash and Cash Equivalents	(201,494)	(102,081)
Cash and Cash Equivalents-Beginning of Period	448,764	352,160
Cash and Cash Equivalents-End of Period	247,270	250,079
SUPPLEMENTAL CASH FLOW DISCLOSURE
Payments for Interest	4,757	8,661
Payments for Income Taxes	50,131	16,841
Increase (Decrease) in Fair Value of Redeemable Noncontrolling Interest	0	(610)
Dividend Equivalents Issued	3,870	3,295
Receipt of Securities in Settlement of Accounts Receivable	0	1,079
Purchase of Noncontrolling Interest	$ 0	$ 1,123