Operating Segments - Schedule of Financial Data for Business Segments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Average interest earning assets (unaudited)	$ 48,067,381	$ 38,227,815	$ 37,010,933
Interest income	1,976,683	1,334,226	1,383,719
Interest expense	321,043	124,325	264,815
Net interest income	1,655,640	1,209,901	1,118,904
Provision for credit losses	56,817	32,633	125,722
Net interest income after provision for credit losses	1,598,823	1,177,268	993,182
Non-interest income	206,793	155,013	183,032
Non-interest expense	1,024,949	691,542	646,148
Internal transfer expense (income)	0	0	0
Income Before Income Taxes	$ 780,667	$ 640,739	$ 530,066
Return on average interest earning assets (pre-tax) (unaudited)	1.62%	1.68%	1.43%
Consumer Banking
Segment Reporting Information [Line Items]
Average interest earning assets (unaudited)	$ 8,133,665	$ 7,262,808	$ 7,160,793
Interest income	272,295	238,715	257,196
Interest expense	48,843	19,117	47,712
Net interest income	223,452	219,598	209,484
Provision for credit losses	20,880	(6,807)	11,502
Net interest income after provision for credit losses	202,572	226,405	197,982
Non-interest income	56,506	72,063	81,499
Non-interest expense	73,105	78,853	77,582
Internal transfer expense (income)	121,220	81,423	77,835
Income Before Income Taxes	$ 64,753	$ 138,192	$ 124,064
Return on average interest earning assets (pre-tax) (unaudited)	0.80%	1.90%	1.73%
Commercial Banking
Segment Reporting Information [Line Items]
Average interest earning assets (unaudited)	$ 33,796,688	$ 25,554,177	$ 24,625,066
Interest income	1,556,182	1,018,674	1,027,796
Interest expense	202,948	67,265	164,075
Net interest income	1,353,234	951,409	863,721
Provision for credit losses	35,456	39,703	113,585
Net interest income after provision for credit losses	1,317,778	911,706	750,136
Non-interest income	79,695	35,600	64,783
Non-interest expense	118,919	108,577	98,710
Internal transfer expense (income)	491,507	286,335	267,588
Income Before Income Taxes	$ 787,047	$ 552,394	$ 448,621
Return on average interest earning assets (pre-tax) (unaudited)	2.33%	2.16%	1.82%
Treasury and Corporate Other
Segment Reporting Information [Line Items]
Average interest earning assets (unaudited)	$ 6,137,028	$ 5,410,830	$ 5,225,074
Interest income	148,206	76,837	98,727
Interest expense	69,252	37,943	53,028
Net interest income	78,954	38,894	45,699
Provision for credit losses	481	(263)	635
Net interest income after provision for credit losses	78,473	39,157	45,064
Non-interest income	70,592	47,350	36,750
Non-interest expense	832,925	504,112	469,856
Internal transfer expense (income)	(612,727)	(367,758)	(345,423)
Income Before Income Taxes	$ (71,133)	$ (49,847)	$ (42,619)
Return on average interest earning assets (pre-tax) (unaudited)	(1.16%)	(0.92%)	(0.82%)