Parent Company Condensed Financial Statements - Schedule of Condensed Statement of Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Statement of income
Compensation and employee benefits	$ 618,753	$ 550,734	$ 508,538
Other expense (income)	165,039	148,301	136,305
Income tax benefit	(400,272)	(316,275)	(298,609)
NET INCOME	1,325,188	1,165,586	1,161,161
Parent Company
Statement of income
Other investment income (losses)	2,115	(954)	(2,738)
Other income	714	31	0
Total income	752,895	539,204	701,584
Interest expense on long-term debt	2,527	4,507	10,889
Compensation and employee benefits	11,132	7,283	7,204
Other expense (income)	1,850	1,839	(1,086)
Total expense	15,509	13,629	17,007
Income before income tax benefit and equity in undistributed income of subsidiaries	737,386	525,575	684,577
Income tax benefit	3,510	4,143	5,844
Undistributed earnings of subsidiaries, primarily bank	584,292	635,868	470,740
NET INCOME	1,325,188	1,165,586	1,161,161
Parent Company | Other investment income (losses)
Statement of income
Other noninterest recovery	1,000
Parent Company | Other Noninterest Expense
Statement of income
Other noninterest recovery	307		3,000
Parent Company | Bank
Statement of income
Dividends from subsidiaries	750,000	540,000	704,000
Parent Company | Nonbank
Statement of income
Dividends from subsidiaries	$ 66	$ 127	$ 322