Business Segments - Schedule of Operating Results and Other Key Financial Measures for The Individual Operating Segments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024
Segment Reporting Information
Net interest income (loss) before provision for credit losses	$ 617,074	$ 553,229	$ 1,217,275	$ 1,118,368
Noninterest income	86,178	84,171	178,280	162,658
Total revenue (loss) before provision for credit losses	703,252	637,400	1,395,555	1,281,026
Provision for (reversal of) credit losses	45,000	37,000	94,000	62,000
Compensation and employee benefits	144,841	133,588	291,276	275,400
Other noninterest expense	111,179	102,344	216,892	206,906
Total noninterest expense	256,020	235,932	508,168	482,306
INCOME BEFORE INCOME TAXES	402,232	364,468	793,387	736,720
Segment net income (loss)	310,253	288,230	600,523	573,305
Loans	54,281,432	51,918,788	53,812,179	51,921,814
Deposits	63,677,832	58,680,799	63,160,581	58,061,601
Segment assets	78,158,067	72,468,272	78,158,067	72,468,272	$ 75,976,475
Consumer and Business Banking
Segment Reporting Information
Net interest income (loss) before provision for credit losses	273,073	292,593	542,806	589,432
Noninterest income	27,729	26,896	60,014	52,318
Total revenue (loss) before provision for credit losses	300,802	319,489	602,820	641,750
Provision for (reversal of) credit losses	6,775	(3,245)	14,460	(681)
Compensation and employee benefits	58,151	53,743	120,115	107,692
Other noninterest expense	57,252	54,968	114,444	118,139
Total noninterest expense	115,403	108,711	234,559	225,831
INCOME BEFORE INCOME TAXES	178,624	214,023	353,801	416,600
Segment net income (loss)	128,295	150,761	251,383	293,461
Loans	20,183,539	18,785,998	19,974,077	18,700,674
Deposits	32,750,578	30,438,157	32,539,912	29,872,472
Segment assets	20,735,714	19,358,010	20,735,714	19,358,010
Commercial Banking
Segment Reporting Information
Net interest income (loss) before provision for credit losses	254,144	278,286	507,145	566,902
Noninterest income	49,751	50,818	103,330	96,057
Total revenue (loss) before provision for credit losses	303,895	329,104	610,475	662,959
Provision for (reversal of) credit losses	38,724	40,155	79,503	63,062
Compensation and employee benefits	57,592	56,840	118,779	118,299
Other noninterest expense	36,053	39,997	78,371	84,351
Total noninterest expense	93,645	96,837	197,150	202,650
INCOME BEFORE INCOME TAXES	171,526	192,112	333,822	397,247
Segment net income (loss)	123,207	135,544	237,232	280,187
Loans	33,767,859	32,706,625	33,490,986	32,793,986
Deposits	26,318,154	25,519,976	26,225,420	25,341,564
Segment assets	36,134,621	35,642,552	36,134,621	35,642,552
Treasury and Other
Segment Reporting Information
Net interest income (loss) before provision for credit losses	89,857	(17,650)	167,324	(37,966)
Noninterest income	8,698	6,457	14,936	14,283
Total revenue (loss) before provision for credit losses	98,555	(11,193)	182,260	(23,683)
Provision for (reversal of) credit losses	(499)	90	37	(381)
Compensation and employee benefits	29,098	23,005	52,382	49,409
Other noninterest expense	17,874	7,379	24,077	4,416
Total noninterest expense	46,972	30,384	76,459	53,825
INCOME BEFORE INCOME TAXES	52,082	(41,667)	105,764	(77,127)
Segment net income (loss)	58,751	1,925	111,908	(343)
Loans	330,034	426,165	347,116	427,154
Deposits	4,609,100	2,722,666	4,395,249	2,847,565
Segment assets	$ 21,287,732	$ 17,467,710	$ 21,287,732	$ 17,467,710