Business Segments - Schedule of Operating Results and Other Key Financial Measures for The Individual Operating Segments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Segment Reporting Information
Net interest income before provision for credit losses	$ 600,201	$ 565,139
Noninterest income	92,102	78,487
Total revenue (loss) before provision for credit losses	692,303	643,626
Provision for credit losses	49,000	25,000
Compensation and employee benefits	146,435	141,812
Other noninterest expense	105,713	104,562
Total noninterest expense	252,148	246,374
INCOME BEFORE INCOME TAXES	391,155	372,252
Segment net income	290,270	285,075
Loans	53,337,711	51,924,840
Deposits	62,637,582	57,442,403
Segment assets	76,165,013	70,875,670	$ 75,976,475
Consumer and Business Banking
Segment Reporting Information
Net interest income before provision for credit losses	269,733	296,839
Noninterest income	32,285	25,422
Total revenue (loss) before provision for credit losses	302,018	322,261
Provision for credit losses	7,685	2,564
Compensation and employee benefits	61,964	53,949
Other noninterest expense	57,192	63,171
Total noninterest expense	119,156	117,120
INCOME BEFORE INCOME TAXES	175,177	202,577
Segment net income	123,088	142,700
Loans	19,762,287	18,615,350
Deposits	32,326,906	29,306,788
Segment assets	20,404,813	19,109,687
Commercial Banking
Segment Reporting Information
Net interest income before provision for credit losses	253,001	288,616
Noninterest income	53,579	45,239
Total revenue (loss) before provision for credit losses	306,580	333,855
Provision for credit losses	40,779	22,907
Compensation and employee benefits	61,187	61,459
Other noninterest expense	42,318	44,354
Total noninterest expense	103,505	105,813
INCOME BEFORE INCOME TAXES	162,296	205,135
Segment net income	114,025	144,643
Loans	33,211,037	32,881,346
Deposits	26,131,654	25,163,151
Segment assets	35,790,014	35,154,317
Treasury and Other
Segment Reporting Information
Net interest income before provision for credit losses	77,467	(20,316)
Noninterest income	6,238	7,826
Total revenue (loss) before provision for credit losses	83,705	(12,490)
Provision for credit losses	536	(471)
Compensation and employee benefits	23,284	26,404
Other noninterest expense	6,203	(2,963)
Total noninterest expense	29,487	23,441
INCOME BEFORE INCOME TAXES	53,682	(35,460)
Segment net income	53,157	(2,268)
Loans	364,387	428,144
Deposits	4,179,022	2,972,464
Segment assets	$ 19,970,186	$ 16,611,666