CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS UNAUDITED (USD $)	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Operating activities
Net income	$ 50,592,000	$ 38,829,000
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Equity in net gains from partnerships	1,418,000	(2,651,000)
Depreciation and amortization	406,000	359,000
Stock based compensation expense	29,000	1,740,000
Deferred income taxes	1,421,000	1,434,000
Tax benefit from exercise of stock options	16,000	24,000
Foreign currency translation gain/(loss)	(48,000)	5,000
Other-than-temporary loss on available for sale securities	14,000	20,000
Fair value of donated securities	277,000	181,000
Gains on sales of available for sale securities	(10,446,000)	(408,000)
Accretion of zero coupon debentures	645,000	2,497,000
Loss on extinguishment of debt	137,000	1,000
(Increase) decrease in assets:
Investments in trading securities	2,538,000	(10,137,000)
Investments in partnerships:
Contributions to partnerships	(8,221,000)	(25,743,000)
Distributions from partnerships	9,818,000	27,168,000
Receivable from brokers	10,986,000	(20,601,000)
Investment advisory fees receivable	14,189,000	6,131,000
Income tax receivable and deferred tax assets	605,000	(362,000)
Other assets	2,246,000	5,466,000
Increase (decrease) in liabilities:
Payable to brokers	640,000	9,343,000
Income taxes payable and deferred tax liabilities	1,551,000	(4,401,000)
Compensation payable	49,108,000	11,289,000
Mandatorily redeemable noncontrolling interests	(20,000)	(34,000)
Accrued expenses and other liabilities	5,530,000	4,988,000
Total adjustments	82,839,000	6,309,000
Net cash provided by operating activities	133,431,000	45,138,000
Investing activities
Purchases of available for sale securities	(3,953,000)	(8,000)
Proceeds from sales of available for sale securities	21,978,000	780,000
Return of capital on available for sale securities	625,000	842,000
Net cash provided by investing activities	18,650,000	1,614,000
Financing activities
Contributions from redeemable noncontrolling interests	2,875,000	20,508,000
Redemptions of redeemable noncontrolling interests	(13,394,000)	(393,000)
Repayments of Senior Debt, Total	(99,000,000)	0
Payments to Noncontrolling Interests	(524,000)	0
Proceeds from exercise of stock options	76,000	58,000
Repurchase of zero coupon subordinated debentures	(1,119,000)	(18,000)
Dividends paid	(2,570,000)	(8,685,000)
Purchase of treasury stock	(6,275,000)	(10,119,000)
Net cash provided used in financing activities	(119,931,000)	1,351,000
Effect of exchange rates on cash and cash equivalents	18,000	(3,000)
Net increase in cash and cash equivalents	32,168,000	48,100,000
Cash and cash equivalents at beginning of period	190,608,000	276,340,000
Cash and cash equivalents at end of period	222,776,000	324,440,000
Supplemental disclosures of cash flow information:
Cash paid for interest	6,262,000	4,979,000
Cash paid for taxes	$ 25,165,000	$ 25,479,000