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, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Segment Reporting Information
Net interest income (loss) before provision for credit losses	$ 553,229	$ 566,746	$ 1,118,368	$ 1,166,607
(Reversal of) provision for credit losses	37,000	26,000	62,000	46,000
Noninterest income (loss)	84,673	78,631	163,661	138,609
Noninterest expense	236,434	261,789	483,309	480,236
INCOME BEFORE INCOME TAXES	364,468	357,588	736,720	778,980
Segment net income	288,230	312,031	573,305	634,470
Segment assets	72,468,272	68,532,681	72,468,272	68,532,681	$ 69,612,884
Consumer and Business Banking
Segment Reporting Information
Net interest income (loss) before provision for credit losses	293,292	307,522	585,056	611,764
(Reversal of) provision for credit losses	(3,245)	5,524	(680)	20,536
Noninterest income (loss)	26,769	27,120	52,311	53,122
Noninterest expense	108,124	107,027	227,424	220,850
INCOME BEFORE INCOME TAXES	215,182	222,091	410,623	423,500
Segment net income	151,578	156,853	289,250	299,100
Segment assets	19,909,978	18,411,209	19,909,978	18,411,209
Commercial Banking
Segment Reporting Information
Net interest income (loss) before provision for credit losses	260,780	263,040	521,129	499,763
(Reversal of) provision for credit losses	40,245	20,476	62,680	25,464
Noninterest income (loss)	50,720	42,538	97,186	86,137
Noninterest expense	92,064	88,333	198,371	175,581
INCOME BEFORE INCOME TAXES	179,191	196,769	357,264	384,855
Segment net income	126,441	139,030	252,022	273,487
Segment assets	35,510,954	33,754,957	35,510,954	33,754,957
Other
Segment Reporting Information
Net interest income (loss) before provision for credit losses	(843)	(3,816)	12,183	55,080
(Reversal of) provision for credit losses	0	0	0	0
Noninterest income (loss)	7,184	8,973	14,164	(650)
Noninterest expense	36,246	66,429	57,514	83,805
INCOME BEFORE INCOME TAXES	(29,905)	(61,272)	(31,167)	(29,375)
Segment net income	10,211	16,148	32,033	61,883
Segment assets	$ 17,047,340	$ 16,366,515	$ 17,047,340	$ 16,366,515