Investments (Summarized Financial Data of Nonconsolidated Affiliates) (Details 3) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Schedule of Equity Method Investments [Line Items]
Other current assets	$ 1,298				$ 1,547				$ 1,298	$ 1,547
Current assets	1,849,296				1,679,256				1,849,296	1,679,256
Total Assets	7,187,730				6,553,377				7,187,730	6,553,377
Current liabilities	1,229,679				1,145,169				1,229,679	1,145,169
Total Liabilities	3,161,677				2,778,889				3,161,677	2,778,889
Total Liabilities and Equity	7,187,730				6,553,377				7,187,730	6,553,377
Noncontrolling Interests	26,131				21,278				26,131	21,278
Net Income (Loss)	55,690	$ (21,134)	$ 124,171	$ 52,977	6,643	$ 33,840	$ (66,615)	$ 96,566	211,704	70,434	$ 353,327
Net (loss) income attributable to the entity	53,259	$ (23,031)	$ 122,788	$ 52,272	6,160	$ 32,780	$ (67,485)	$ 95,624	205,288	67,079	352,075
Private Equity Fund Investment [Member]
Schedule of Equity Method Investments [Line Items]
Investments in securities, at estimated fair value	1,528,908				1,974,189				1,528,908	1,974,189
Other current assets	28,505				19,072				28,505	19,072
Total Assets	1,557,413				1,993,261				1,557,413	1,993,261
Total Liabilities	6,963				3,945				6,963	3,945
Total partners’ capital	1,550,450				1,989,316				1,550,450	1,989,316
Total Liabilities and Equity	1,557,413				1,993,261				1,557,413	1,993,261
Net investment loss									(13,820)	(14,129)	(13,324)
Net realized gain on investments									194,324	162,644	190,368
Net change in unrealized (depreciation) appreciation on investments									(449,553)	(66,333)	1,043,627
(Decrease) increase in net assets from operations									(269,049)	82,182	1,220,671
Operating Entity Investment [Member]
Schedule of Equity Method Investments [Line Items]
Current assets	166,783				174,027				166,783	174,027
Noncurrent assets	520,439				542,625				520,439	542,625
Total Assets	687,222				716,652				687,222	716,652
Current liabilities	126,396				126,365				126,396	126,365
Noncurrent liabilities	374,127				386,425				374,127	386,425
Total Liabilities	500,523				512,790				500,523	512,790
Noncontrolling Interests	$ (33,162)				$ (26,593)				(33,162)	(26,593)
Net sales									458,541	459,949	358,928
Gross profit									183,207	196,481	146,312
Net Income (Loss)									(37,169)	3,206	135,241
Net (loss) income attributable to the entity									$ (30,694)	$ 5,124	$ 102,829