Consolidated Statements of Cash Flow - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash Flows from Operating Activities:
Net income (loss)	$ 262,835	$ 119,963	$ 105,508
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation expense, intangible asset and other amortization	50,769	38,853	39,643
Stock-based compensation	26,225	21,481	22,230
Amortization of deferred commissions	3,956	2,052	2,940
Payments of deferred commissions	(5,963)	(2,089)	(2,097)
Equity in earnings of equity method investments	(4,403)	(1,964)	(2,600)
Distributions from equity method investments	3,710	1,192	828
Sales (purchases) of investments, net	(7,952)	12,296	9,057
(Gain) loss on extinguishment of debt	0	(705)	0
Change in fair value of contingent consideration	12,400	0	0
Deferred taxes, net	(9,664)	6,332	5,982
Changes in operating assets and liabilities:
Accounts receivable, net and other assets	(30,057)	(9,698)	(1,382)
Accrued compensation and benefits, accounts payable, accrued liabilities and other liabilities	72,628	13,743	(2,991)
Operating activities of consolidated investment products ("CIP"):
Net cash provided by (used in) operating activities	665,729	(226,103)	(36,723)
Cash Flows from Investing Activities:
Capital expenditures and other asset purchases	(5,838)	(1,043)	(7,555)
Payments to Acquire Businesses, Net of Cash Acquired	(155,636)	0	0
Sale of available-for-sale securities	0	0	2,023
Net cash provided by (used in) investing activities	(175,033)	8,681	4,448
Cash Flows from Financing Activities:
Refinancing of credit agreement	81,155	0	0
Payment of long-term debt	(12,513)	(79,086)	(54,851)
Payment of deferred financing costs	(7,039)	0	0
Repurchase of common shares	(57,499)	(32,500)	(40,000)
Preferred stock dividends paid	0	(2,084)	(8,338)
Common stock dividends paid	(31,411)	(22,800)	(16,977)
Proceeds from exercise of stock options	66	163	726
Taxes paid related to net share settlement of restricted stock units	(19,509)	(6,608)	(7,696)
Net contributions from (distributions to) noncontrolling interests	(3,270)	(7,263)	7,786
Net cash provided by (used in) financing activities	(244,400)	235,332	99,558
Net increase (decrease) in cash and cash equivalents	246,296	17,910	67,283
Cash, cash equivalents and restricted cash, beginning of year	339,849	321,939	254,656
Cash, cash equivalents and restricted cash, end of year	586,145	339,849	321,939	$ 254,656
Supplemental Disclosure of Cash Flow Information
Interest paid	6,478	8,857	18,072
Income taxes paid, net	95,411	35,388	29,062
Supplemental Disclosure of Non-Cash Investing and Financing Activities
Capital expenditures	(47)	55	(1,791)
Conversion of preferred stock to common stock	0	115,000	0
Preferred stock dividends payable	0	0	2,084
Common stock dividends payable	11,261	6,218	4,562
Contingent consideration		150,164	0	0
Reconciliation of cash, cash equivalents and restricted cash
Cash, cash equivalents and restricted cash at end of year	586,145	339,849	321,939	$ 254,656
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	(2,721)	(7,128)	(6,855)
Operating activities of consolidated investment products ("CIP"):
Realized and unrealized (gains) losses on investments of CIP, net	2,721	7,128	6,855
Reconciliation of cash, cash equivalents and restricted cash
Cash and cash equivalents	378,921	246,511
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	(4,264)	(5,889)	(106)
Operating activities of consolidated investment products ("CIP"):
Realized and unrealized (gains) losses on investments of CIP, net	4,264	5,889	106
Purchases of investments by CIP	(1,176,936)	(1,304,723)	(1,029,746)
Sales of investments by CIP	1,454,591	883,888	810,749
Net proceeds (purchases) of short-term investments and securities sold short by CIP	16,272	(934)	5,643
Change in other assets and liabilities of CIP	(856)	(3,942)	1,969
Amortization of discount on notes payable of CIP	5,159	11,169	4,505
Cash Flows from Investing Activities:
Change in cash and cash equivalents of CIP due to consolidation (deconsolidation), net	(13,559)	9,724	9,980
Cash Flows from Financing Activities:
Borrowings by CIP	363,539	779,982	414,605
Payments on borrowings by CIP	(557,919)	(394,472)	(195,697)
Supplemental Disclosure of Non-Cash Investing and Financing Activities
Consolidation (Deconsolidation) of CIP, net	(30,550)	17,137	$ (13,926)
Reconciliation of cash, cash equivalents and restricted cash
Cash and cash equivalents	206,620	86,980
Cash pledged or on deposit of consolidated investment products	$ 604	$ 6,358