Consolidated Statements of Cash Flow - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash Flows from Operating Activities:
Net income (loss)	$ 141,476	$ 106,628	$ 262,835
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation expense, intangible asset and other amortization	68,437	64,215	50,769
Stock-based compensation	26,825	24,042	26,225
Amortization of deferred commissions	1,609	4,342	3,956
Payments of deferred commissions	(1,434)	(2,065)	(5,963)
Equity in earnings of equity method investments	198	(187)	(4,403)
Distributions from equity method investments	2,327	2,244	3,710
Change in fair value of contingent consideration	(5,510)	8,020	12,400
Deferred taxes, net	1,394	(1,960)	(9,664)
Right of use asset	0	3,222	0
Changes in operating assets and liabilities:
Sales (purchases) of investments, net	(16)	(9,309)	(7,952)
Accounts receivable, net and other assets	6,822	37,548	(30,057)
Accrued compensation and benefits, accounts payable, accrued liabilities and other liabilities	3,863	(47,379)	72,628
Operating activities of consolidated investment products ("CIP"):
Net cash provided by (used in) operating activities	237,157	132,670	665,729
Cash Flows from Investing Activities:
Capital expenditures and other asset purchases	(8,821)	(6,582)	(5,838)
Purchase of equity method investment	(11,645)	0	0
Acquisition of business, net of cash acquired of $4,395 and $8,443 and $1,197 for the years ended December 31, 2023, 2022 and 2021, respectively	(108,999)	(20,577)	(155,636)
Net cash provided by (used in) investing activities	(129,732)	(27,467)	(175,033)
Cash Flows from Financing Activities:
Borrowings and refinancing of credit agreement	50,000	0	81,155
Repayments on credit agreement	(52,750)	(12,750)	(12,513)
Payment of deferred financing costs	0	0	(7,039)
Payment of contingent consideration	(27,179)	(33,036)	0
Repurchase of common shares	(45,000)	(90,000)	(57,499)
Common stock dividends paid	(52,047)	(47,254)	(31,411)
Taxes paid related to net share settlement of restricted stock units	(13,774)	(16,830)	(19,443)
Affiliate equity sales (purchases)	(20,784)	(11,089)	0
Net contributions from (distributions to) noncontrolling interests	6,080	(5,527)	(3,270)
Net cash provided by (used in) financing activities	(356,113)	(102,057)	(244,400)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	523	(112)	0
Net increase (decrease) in cash and cash equivalents	(248,165)	3,034	246,296
Cash, cash equivalents and restricted cash, beginning of year	589,179	586,145	339,849
Cash, cash equivalents and restricted cash, end of year	341,014	589,179	586,145
Supplemental Disclosure of Cash Flow Information
Interest paid	22,307	11,134	6,478
Income taxes paid, net	31,160	74,313	95,411
Supplemental Disclosure of Non-Cash Investing and Financing Activities
Common stock dividends payable	13,467	11,850	11,261
Contingent consideration	0	1,200	150,164
Reconciliation of cash, cash equivalents and restricted cash
Cash, cash equivalents and restricted cash at end of year	341,014	589,179	586,145
Consolidated Entity excluding Consolidated Investment Products
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Realized and unrealized (gains) losses on investments, net	(6,132)	13,105	(2,721)
Operating activities of consolidated investment products ("CIP"):
Realized and unrealized (gains) losses on investments of CIP, net	6,132	(13,105)	2,721
Reconciliation of cash, cash equivalents and restricted cash
Cash and cash equivalents	239,602	338,234
Consolidated Investment Products
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Realized and unrealized (gains) losses on investments, net	(4,664)	36,054	(4,264)
Operating activities of consolidated investment products ("CIP"):
Realized and unrealized (gains) losses on investments of CIP, net	4,664	(36,054)	4,264
Purchases of investments by CIP	(1,264,708)	(939,017)	(1,176,936)
Sales of investments by CIP	1,263,580	820,497	1,454,591
Net proceeds (purchases) of short-term investments and securities sold short by CIP	(261)	(13)	16,272
Change in other assets and liabilities of CIP	1,666	6,813	(856)
Amortization of discount on notes payable of CIP	1,685	5,870	5,159
Cash Flows from Investing Activities:
Change in cash and cash equivalents of CIP due to consolidation (deconsolidation), net	(267)	(308)	(13,559)
Cash Flows from Financing Activities:
Borrowings by CIP	269,260	306,296	363,539
Payments on borrowings by CIP	(469,919)	(191,867)	(557,919)
Supplemental Disclosure of Non-Cash Investing and Financing Activities
Increase (decrease) to noncontrolling interests due to consolidation (deconsolidation) of CIP, net	(7,170)	(338)	$ (30,550)
Reconciliation of cash, cash equivalents and restricted cash
Cash and cash equivalents	100,732	250,301
Cash pledged or on deposit of consolidated investment products	$ 680	$ 644