Operating Segments - Schedule of Financial Data for Business Segments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Segment Reporting Information [Line Items]
Average interest earning assets	$ 57,553,624	$ 56,772,950	$ 57,224,486	$ 56,695,874
Interest income	805,012	833,466	1,589,764	1,662,122
Interest expense	372,604	431,781	737,251	866,889
Net interest income	432,408	401,685	852,513	795,233
Provision for credit losses	37,799	82,070	100,460	127,270
Net interest income after provision for credit losses	394,609	319,615	752,053	667,963
Non-interest income	62,604	51,213	120,898	112,628
Salary and employee benefits expense	145,422	140,815	288,040	282,646
Net occupancy expense	25,483	24,252	51,371	48,575
Technology, furniture and equipment expense	30,667	35,203	60,563	70,665
FDIC insurance assessment	12,192	14,446	25,059	32,682
Professional and legal fees	19,970	17,938	35,640	34,403
Gain (loss) on extinguishment of debt	(922)	0	(922)	0
Other segment items	49,466	44,843	99,145	88,836
Non-interest expense	284,122	277,497	560,740	557,807
Income Before Income Taxes	$ 173,091	$ 93,331	$ 312,211	$ 222,784
Return on average interest earning assets (pre-tax)	1.20%	0.66%	1.09%	0.79%
Net interest margin	3.01%	2.83%	2.98%	2.80%
Treasury and Corporate Other
Segment Reporting Information [Line Items]
Average interest earning assets	$ 8,520,987	$ 6,752,049	$ 8,379,663	$ 6,562,128
Interest income	85,974	62,502	168,367	119,605
Interest expense	55,165	51,366	107,960	100,336
Net interest income	30,809	11,136	60,407
Provision for credit losses	4	(41)	(10)	(115)
Net interest income after provision for credit losses	30,805	11,177	60,417
Non-interest income	5,413	3,151	10,351	8,271
Salary and employee benefits expense	13,955	11,617	21,609	22,932
Net occupancy expense	3,751	2,843	7,477	5,535
Technology, furniture and equipment expense	3,932	3,874	7,738	7,535
FDIC insurance assessment	0	1,363	0	8,756
Professional and legal fees	2,435	1,305	4,263	2,862
Gain (loss) on extinguishment of debt	(922)		(922)
Other segment items	20,108	20,258	40,058	38,457
Non-interest expense	45,103	41,260	82,067	$ 86,077
Income Before Income Taxes	$ (8,885)	$ (26,932)	$ (11,299)
Return on average interest earning assets (pre-tax)	(0.42%)	(1.60%)	(0.27%)	(1.78%)
Net interest margin	1.45%	0.66%	1.44%	0.59%
Consumer Banking | Operating Segments
Segment Reporting Information [Line Items]
Average interest earning assets	$ 10,428,625	$ 9,836,298	$ 10,428,621	$ 9,814,532
Interest income	130,616	118,537	253,079	232,299
Interest expense	68,915	74,780	134,357	150,066
Net interest income	61,701	43,757	118,722	82,233
Provision for credit losses	717	4,820	(8,016)	7,892
Net interest income after provision for credit losses	60,984	38,937	126,738	74,341
Non-interest income	32,192	31,568	66,546	64,733
Salary and employee benefits expense	32,294	29,776	64,268	58,434
Net occupancy expense	4,772	4,262	9,477	8,530
Technology, furniture and equipment expense	6,266	6,589	12,503	13,126
FDIC insurance assessment	2,650	2,570	5,350	4,684
Professional and legal fees	3,344	2,377	6,243	5,204
Gain (loss) on extinguishment of debt	0		0
Other segment items	12,021	12,940	26,307	25,531
Non-interest expense	61,347	58,514	124,148	115,509
Income Before Income Taxes	$ 31,829	$ 11,991	$ 69,136	$ 23,565
Return on average interest earning assets (pre-tax)	1.22%	0.49%	1.33%	0.48%
Net interest margin	2.37%	1.78%	2.27%	1.67%
Commercial Banking | Operating Segments
Segment Reporting Information [Line Items]
Average interest earning assets	$ 38,604,012	$ 40,184,603	$ 38,416,202	$ 40,319,214
Interest income	588,422	652,427	1,168,318	1,310,218
Interest expense	248,524	305,635	494,934	616,487
Net interest income	339,898	346,792	673,384	693,731
Provision for credit losses	37,078	77,291	108,486	119,493
Net interest income after provision for credit losses	302,820	269,501	564,898	574,238
Non-interest income	24,999	16,494	44,001	39,624
Salary and employee benefits expense	99,173	99,422	202,163	201,280
Net occupancy expense	16,960	17,147	34,417	34,510
Technology, furniture and equipment expense	20,469	24,740	40,322	50,004
FDIC insurance assessment	9,542	10,513	19,709	19,242
Professional and legal fees	14,191	14,256	25,134	26,337
Gain (loss) on extinguishment of debt	0		0
Other segment items	17,337	11,645	32,780	24,848
Non-interest expense	177,672	177,723	354,525	356,221
Income Before Income Taxes	$ 150,147	$ 108,272	$ 254,374	$ 257,641
Return on average interest earning assets (pre-tax)	1.56%	1.08%	1.32%	1.28%
Net interest margin	3.52%	3.45%	3.50%	3.44%
Treasury and Corporate Other | Operating Segments
Segment Reporting Information [Line Items]
Net interest income				$ 19,269
Net interest income after provision for credit losses				19,384
Income Before Income Taxes				$ (58,422)