CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating Activities
Net Income Including the Noncontrolling Interests in Subsidiaries	$ 304,781,000	$ 234,564,000	$ 272,308,000
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities
Depreciation and Other Amortization	26,835,000	28,085,000	30,010,000
Share-Based Compensation Expense	33,947,000	34,798,000	30,294,000
Subsidiary Share-Based Compensation Expense	0	707,000	9,411,000
(Gain) Loss on Disposal of Assets	260,000	4,844,000	(6,964,000)
Provision (Benefit) for Deferred Income Taxes	4,252,000	(18,822,000)	18,163,000
Impairment of Intangible Asset	0	31,520,000	0
Net Unrealized (Gain) Loss on Investments	(13,423,000)	24,383,000	(1,965,000)
Net Sales (Purchases) of Investments—Consolidated Investment Companies	(34,328,000)	(20,170,000)	(179,419,000)
Consolidation/(Deconsolidation) of Investment Companies	1,647,000	(20,000)	10,379,000
Other Changes in Assets and Liabilities:
(Increase) Decrease in Receivables, net	(27,568,000)	(4,367,000)	6,662,000
(Increase) Decrease in Prepaid Expenses and Other Assets	20,748,000	18,582,000	10,275,000
Increase (Decrease) in Accounts Payable and Accrued Expenses	14,627,000	4,669,000	(6,365,000)
Increase (Decrease) in Other Liabilities	(19,947,000)	(14,825,000)	(22,406,000)
Net Cash Provided (Used) by Operating Activities	311,831,000	323,948,000	170,383,000
Investing Activities
Purchases of Investments—Affiliates and Other	(57,999,000)	(22,644,000)	(9,429,000)
Cash Paid for Business Acquisitions, net of Cash Acquired	0	(28,111,000)	0
Cash Paid for Asset Acquisitions	0	0	(5,324,000)
Proceeds from Redemptions of Investments—Affiliates and Other	35,304,000	22,770,000	35,990,000
Cash Paid for Property and Equipment	(7,915,000)	(4,372,000)	(10,421,000)
Net Cash Provided (Used) by Investing Activities	(30,610,000)	(32,357,000)	10,816,000
Financing Activities
Dividends Paid	(98,093,000)	(97,915,000)	(105,764,000)
Purchases of Treasury Stock	(177,066,000)	(218,141,000)	(228,349,000)
Distributions to Noncontrolling Interests in Subsidiaries	(39,960,000)	(25,979,000)	(4,926,000)
Contributions from Noncontrolling Interests in Subsidiaries	72,823,000	55,171,000	107,635,000
Payments to Acquire Additional Equity in FHL	0	0	(165,886,000)
Cash paid for Business Acquisitions	(2,065,000)	(7,105,000)	(2,007,000)
Proceeds from New Borrowings	0	488,300,000	295,650,000
Payments on Debt	0	(361,650,000)	(147,300,000)
Other Financing Activities	1,274,000	(1,194,000)	1,475,000
Net Cash Provided (Used) by Financing Activities	(243,087,000)	(168,513,000)	(249,472,000)
Effect of Exchange Rates on Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents	7,865,000	(20,174,000)	(2,311,000)
Net Increase (Decrease) in Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	45,999,000	102,904,000	(70,584,000)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Beginning of Period	340,955,000	238,051,000	308,635,000
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, End of Period	386,954,000	340,955,000	238,051,000
Less: Restricted Cash Recorded in Other Current Assets	3,498,000	3,773,000	4,419,000
Less: Restricted Cash and Restricted Cash Equivalents Recorded in Other Long-Term Assets	276,000	400,000	305,000
Cash and Cash Equivalents	383,180,000	336,782,000	233,327,000
Cash paid during the year for:
Income taxes	108,639,000	85,579,000	91,925,000
Interest	$ 11,648,000	$ 7,184,000	$ 1,133,000