Income Taxes - Principal Reasons for the Difference Between the Effective Tax Rate and UBT Statutory Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Amount
U.S. Federal Statutory Tax Rate	$ 0
State and local income tax	9,411	$ 50,345	$ 32,707
Corporate subsidiaries' federal tax effects	2,013
Statutory tax rate differential		42,384	36,788
Corporate subsidiaries' federal, state, and local		2,236	4,538
FIN 48 reserve (release)		0	(2,838)
UBT business allocation percentage rate change		(634)	(1,049)
Deferred tax and payable write-offs		911	1,750
Foreign outside basis difference		126	3,414
Valuation allowance reserve (release)		(16)	(22,447)
Effect of ASC 740 adjustments, miscellaneous taxes, and other		3,474	3,553
Tax Credits		(29)	(1,604)
Income not taxable resulting from use of UBT business apportionment factors and effect of compensation charge		(33,654)	(25,761)
Income tax expense	$ 61,600	$ 65,143	$ 29,051
Percent
U.S. Federal Statutory Tax Rate	0.00%
State and local income tax	0.90%	4.00%	4.00%
Corporate subsidiaries' federal tax effects	0.20%
Statutory tax rate differential		3.40%	4.50%
Corporate subsidiaries' federal, state, and local		0.20%	0.60%
FIN 48 reserve (release)		0.00%	(0.30%)
UBT business allocation percentage rate change		(0.10%)	(0.10%)
Deferred tax and payable write-offs		0.10%	0.20%
Foreign outside basis difference		0.00%	0.40%
Valuation allowance reserve (release)		0.00%	(2.70%)
Effect of ASC 740 adjustments, miscellaneous taxes, and other		0.30%	0.40%
Tax Credits		0.00%	(0.20%)
Income not taxable resulting from use of UBT business apportionment factors and effect of compensation charge		(2.70%)	(3.20%)
Income tax expense and effective tax rate	5.90%	5.20%	3.60%
United Kingdom
Amount
Statutory tax rate differential	$ 19,203
Other	$ (109)
Percent
Statutory tax rate differential	1.80%
Other	0.00%
Luxembourg
Amount
Statutory tax rate differential	$ 7,397
Other	$ 8
Percent
Statutory tax rate differential	0.70%
Other	0.00%
Other foreign jurisdictions
Amount
Statutory tax rate differential	$ 23,677
Percent
Statutory tax rate differential	2.30%