Operating Segments - Schedule of Financial Data for Business Segments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Segment Reporting Information [Line Items]
Average interest earning assets	$ 55,362,790	$ 40,283,048
Interest income	720,230	340,458
Interest expense	284,210	22,789
Net interest income	436,020	317,669
Provision for credit losses	14,437	3,557
Net Interest Income After Provision for Credit Losses	421,583	314,112
Non-interest income	54,299	39,270
Non-interest expense	272,166	197,340
Internal transfer expense (income)	0	0
Income Before Income Taxes	$ 203,716	$ 156,042
Return on average interest earning assets (pre-tax)	1.47%	1.55%
Consumer Banking | Operating Segments
Segment Reporting Information [Line Items]
Average interest earning assets	$ 8,768,482	$ 7,638,942
Interest income	85,316	59,459
Interest expense	43,006	3,207
Net interest income	42,310	56,252
Provision for credit losses	6,444	1,873
Net Interest Income After Provision for Credit Losses	35,866	54,379
Non-interest income	14,290	13,817
Non-interest expense	18,249	16,568
Internal transfer expense (income)	30,883	28,647
Income Before Income Taxes	$ 1,024	$ 22,981
Return on average interest earning assets (pre-tax)	0.05%	1.20%
Commercial Banking | Operating Segments
Segment Reporting Information [Line Items]
Average interest earning assets	$ 39,090,889	$ 26,984,460
Interest income	569,910	257,906
Interest expense	191,723	11,327
Net interest income	378,187	246,579
Provision for credit losses	3,006	1,627
Net Interest Income After Provision for Credit Losses	375,181	244,952
Non-interest income	15,747	16,880
Non-interest expense	35,723	25,085
Internal transfer expense (income)	131,595	99,916
Income Before Income Taxes	$ 223,610	$ 136,831
Return on average interest earning assets (pre-tax)	2.29%	2.03%
Treasury and Corporate Other | Treasury and Corporate Other
Segment Reporting Information [Line Items]
Average interest earning assets	$ 7,503,419	$ 5,659,646
Interest income	65,004	23,093
Interest expense	49,481	8,255
Net interest income	15,523	14,838
Provision for credit losses	4,987	57
Net Interest Income After Provision for Credit Losses	10,536	14,781
Non-interest income	24,262	8,573
Non-interest expense	218,194	155,687
Internal transfer expense (income)	(162,478)	(128,563)
Income Before Income Taxes	$ (20,918)	$ (3,770)
Return on average interest earning assets (pre-tax)	(1.12%)	(0.27%)