Operating Segments - Schedule of Financial Data for Business Segments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Segment Reporting Information [Line Items]
Average interest earning assets	$ 56,891,691	$ 56,618,797
Interest income	784,752	828,656
Interest expense	364,647	435,108
Net interest income	420,105	393,548
Provision (credit) for credit losses	62,661	45,200
Net interest income after provision for credit losses	357,444	348,348
Non-interest income	58,294	61,415
Salary and employee benefits expense	142,618	141,831
Net occupancy expense	25,888	24,323
Technology, furniture and equipment expense	29,896	35,462
FDIC insurance assessment	12,867	18,236
Professional and legal fees	15,670	16,465
Other segment items	49,679	43,993
Non-interest expense	276,618	280,310
Income Before Income Taxes	$ 139,120	$ 129,453
Return on average interest earning assets (pre-tax)	0.98%	0.91%
Net interest margin	2.95%	2.78%
Treasury and Corporate Other
Segment Reporting Information [Line Items]
Average interest earning assets	$ 8,236,770	$ 6,372,206
Interest income	82,393	57,103
Interest expense	52,794	48,970
Net interest income	29,599	8,133
Provision (credit) for credit losses	(14)	(74)
Net interest income after provision for credit losses	29,613	8,207
Non-interest income	4,938	5,120
Salary and employee benefits expense	7,654	11,315
Net occupancy expense	3,726	2,692
Technology, furniture and equipment expense	3,806	3,661
FDIC insurance assessment	0	7,394
Professional and legal fees	1,828	1,556
Other segment items	19,950	18,199
Non-interest expense	36,964	44,817
Income Before Income Taxes	$ (2,413)	$ (31,490)
Return on average interest earning assets (pre-tax)	(0.12%)	(1.98%)
Net interest margin	1.44%	0.51%
Consumer Banking | Operating Segments
Segment Reporting Information [Line Items]
Average interest earning assets	$ 10,210,226	$ 9,796,681
Interest income	122,463	113,762
Interest expense	65,442	75,286
Net interest income	57,021	38,476
Provision (credit) for credit losses	(8,733)	3,072
Net interest income after provision for credit losses	65,754	35,404
Non-interest income	34,354	33,165
Salary and employee benefits expense	31,974	28,658
Net occupancy expense	4,705	4,268
Technology, furniture and equipment expense	6,237	6,537
FDIC insurance assessment	2,700	2,114
Professional and legal fees	2,899	2,827
Other segment items	14,286	12,591
Non-interest expense	62,801	56,995
Income Before Income Taxes	$ 37,307	$ 11,574
Return on average interest earning assets (pre-tax)	1.46%	0.47%
Net interest margin	2.24%	1.57%
Commercial Banking | Operating Segments
Segment Reporting Information [Line Items]
Average interest earning assets	$ 38,444,695	$ 40,449,910
Interest income	579,896	657,791
Interest expense	246,411	310,852
Net interest income	333,485	346,939
Provision (credit) for credit losses	71,408	42,202
Net interest income after provision for credit losses	262,077	304,737
Non-interest income	19,002	23,130
Salary and employee benefits expense	102,990	101,858
Net occupancy expense	17,457	17,363
Technology, furniture and equipment expense	19,853	25,264
FDIC insurance assessment	10,167	8,728
Professional and legal fees	10,943	12,082
Other segment items	15,443	13,203
Non-interest expense	176,853	178,498
Income Before Income Taxes	$ 104,226	$ 149,369
Return on average interest earning assets (pre-tax)	1.08%	1.48%
Net interest margin	3.47%	3.43%