Parent Company Condensed Financial Statements - Condensed Statement of Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of income
Other investment losses	$ (2,738)	$ 0	$ 0
Interest expense on long-term debt	1,381,551	275,350	87,163
Compensation and employee benefits	508,538	477,635	433,728
(Impairment recoveries) amortization of tax credit and other investments	120,299	113,358	122,457
Other expense	140,222	118,166	96,330
Income tax benefit	(298,609)	(283,571)	(183,396)
NET INCOME	1,161,161	1,128,083	872,981
Parent Company
Statement of income
Other income	0	0	11
Total income	701,584	240,157	200,093
Interest expense on long-term debt	10,889	5,450	2,974
Compensation and employee benefits	7,204	6,708	6,370
(Impairment recoveries) amortization of tax credit and other investments	(2,901)	(786)	425
Other expense	1,815	2,040	1,306
Total expense	17,007	13,412	11,075
Income before income tax benefit and equity in undistributed income of subsidiaries	684,577	226,745	189,018
Income tax benefit	5,844	4,269	3,005
Undistributed earnings of subsidiaries, primarily bank	470,740	897,069	680,958
NET INCOME	1,161,161	1,128,083	872,981
Parent Company | Bank
Statement of income
Dividends from subsidiaries	704,000	240,000	200,000
Parent Company | Nonbank
Statement of income
Dividends from subsidiaries	$ 322	$ 157	$ 82