Business Segments - Schedule of Financial Data for Business Segments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Segment Reporting Information [Line Items]
Average interest earning assets	$ 40,283,048	$ 37,386,219
Interest income	340,458	331,798
Interest expense	22,789	39,131
Net Interest Income	317,669	292,667
Provision for credit losses	3,557	8,656
Net Interest Income After Provision for Credit Losses	314,112	284,011
Non-interest income	39,270	31,233
Non-interest expense	197,340	160,213
Internal transfer expense (income)	0	0
Income Before Income Taxes	$ 156,042	$ 155,031
Return on average interest earning assets (pre-tax)	1.55%	1.66%
Consumer Lending | Operating Segments
Segment Reporting Information [Line Items]
Average interest earning assets	$ 7,638,942	$ 7,049,252
Interest income	59,459	60,845
Interest expense	3,207	6,415
Net Interest Income	56,252	54,430
Provision for credit losses	1,873	(2,635)
Net Interest Income After Provision for Credit Losses	54,379	57,065
Non-interest income	13,817	13,685
Non-interest expense	16,568	19,849
Internal transfer expense (income)	28,647	19,502
Income Before Income Taxes	$ 22,981	$ 31,399
Return on average interest earning assets (pre-tax)	1.20%	1.78%
Commercial Lending | Operating Segments
Segment Reporting Information [Line Items]
Average interest earning assets	$ 26,984,460	$ 25,533,227
Interest income	257,906	252,336
Interest expense	11,327	23,235
Net Interest Income	246,579	229,101
Provision for credit losses	1,627	11,676
Net Interest Income After Provision for Credit Losses	244,952	217,425
Non-interest income	16,880	7,713
Non-interest expense	25,085	25,531
Internal transfer expense (income)	99,916	70,555
Income Before Income Taxes	$ 136,831	$ 129,052
Return on average interest earning assets (pre-tax)	2.03%	2.02%
Investment Management | Operating Segments
Segment Reporting Information [Line Items]
Average interest earning assets	$ 5,659,646	$ 4,803,740
Interest income	23,787	19,509
Interest expense	2,376	4,371
Net Interest Income	21,411	15,138
Provision for credit losses	57	(385)
Net Interest Income After Provision for Credit Losses	21,354	15,523
Non-interest income	2,073	2,331
Non-interest expense	836	1,777
Internal transfer expense (income)	17,061	13,277
Income Before Income Taxes	$ 5,530	$ 2,800
Return on average interest earning assets (pre-tax)	0.39%	0.23%
Corporate and Other Adjustments | Corporate and Other Adjustments
Segment Reporting Information [Line Items]
Average interest earning assets	$ 0	$ 0
Interest income	(694)	(892)
Interest expense	5,879	5,110
Net Interest Income	(6,573)	(6,002)
Provision for credit losses	0	0
Net Interest Income After Provision for Credit Losses	(6,573)	(6,002)
Non-interest income	6,500	7,504
Non-interest expense	154,851	113,056
Internal transfer expense (income)	(145,624)	(103,334)
Income Before Income Taxes	$ (9,300)	$ (8,220)