Consolidated Statements of Cash Flow - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash Flows from Operating Activities:
Net income (loss)	$ 152,453	$ 141,476	$ 106,628
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation expense, intangible asset and other amortization	69,002	70,046	68,557
Stock-based compensation	32,841	26,825	24,042
Equity in earnings of equity method investments	(2,713)	198	(187)
Distributions from equity method investments	5,387	2,327	2,244
Change in fair value of contingent consideration	(5,608)	(5,510)	8,020
Deferred taxes, net	7,120	1,394	(1,960)
Lease termination	(1,318)	0	3,222
Changes in operating assets and liabilities:
Sales (purchases) of investments, net	26,114	(16)	(9,309)
Accounts receivable, net and other assets	8,834	5,388	35,483
Accrued compensation and benefits, accounts payable, accrued liabilities and other liabilities	(23,166)	3,863	(47,379)
Operating activities of consolidated investment products ("CIP"):
Net cash provided by (used in) operating activities	1,755	237,157	132,670
Cash Flows from Investing Activities:
Capital expenditures and other asset purchases	(5,579)	(8,821)	(6,582)
Purchase of equity method investment	0	(11,645)	0
Acquisition of business, net of cash acquired of $4,395 and $8,443 for the years ended December 31, 2023 and 2022, respectively	0	(108,999)	(20,577)
Net cash provided by (used in) investing activities	(16,951)	(129,732)	(27,467)
Cash Flows from Financing Activities:
Borrowings on credit agreement	0	50,000	0
Repayments on credit agreement	(22,750)	(52,750)	(12,750)
Payment of contingent consideration	(24,234)	(27,179)	(33,036)
Repurchase of common shares	(44,868)	(45,000)	(90,000)
Common stock dividends paid	(58,123)	(52,047)	(47,254)
Taxes paid related to net share settlement of restricted stock units	(11,681)	(13,774)	(16,830)
Affiliate equity sales (purchases)	(29,015)	(20,784)	(11,089)
Net contributions from (distributions to) noncontrolling interests	32,822	6,080	(5,527)
Net cash provided by (used in) financing activities	74,947	(356,113)	(102,057)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(456)	523	(112)
Net increase (decrease) in cash and cash equivalents	59,295	(248,165)	3,034
Cash, cash equivalents and restricted cash, beginning of year	341,014	589,179	586,145
Cash, cash equivalents and restricted cash, end of year	400,309	341,014	589,179
Supplemental Disclosure of Cash Flow Information
Interest paid	20,260	22,307	11,134
Income taxes paid, net	56,379	31,160	74,313
Supplemental Disclosure of Non-Cash Investing and Financing Activities
Common stock dividends payable	15,676	13,467	11,850
Contingent consideration	0	0	1,200
Reconciliation of cash, cash equivalents and restricted cash
Cash, cash equivalents and restricted cash at end of year	400,309	341,014	589,179
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	(2,795)	(6,132)	13,105
Operating activities of consolidated investment products ("CIP"):
Realized and unrealized (gains) losses on investments, net	(2,795)	(6,132)	13,105
Reconciliation of cash, cash equivalents and restricted cash
Cash and cash equivalents	265,888	239,602
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	5,279	(4,664)	36,054
Operating activities of consolidated investment products ("CIP"):
Realized and unrealized (gains) losses on investments, net	5,279	(4,664)	36,054
Purchases of investments by CIP	(1,468,615)	(1,264,708)	(939,017)
Sales of investments by CIP	1,196,438	1,263,580	820,497
Net proceeds (purchases) of short-term investments and securities sold short by CIP	49	(261)	(13)
Change in other assets and liabilities of CIP	(2,073)	1,666	6,813
Amortization of discount on notes payable of CIP	4,526	1,685	5,870
Cash Flows from Investing Activities:
Change in cash and cash equivalents of CIP due to consolidation (deconsolidation), net	(11,372)	(267)	(308)
Cash Flows from Financing Activities:
Borrowings by CIP	1,016,232	269,260	306,296
Payments on borrowings by CIP	(783,436)	(469,919)	(191,867)
Supplemental Disclosure of Non-Cash Investing and Financing Activities
Increase (decrease) to noncontrolling interests due to consolidation (deconsolidation) of CIP, net	(31,255)	(7,170)	$ (338)
Reconciliation of cash, cash equivalents and restricted cash
Cash and cash equivalents	133,694	100,732
Cash pledged or on deposit of consolidated investment products	$ 727	$ 680