Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Disaggregation of Revenue [Line Items]
Noninterest income (in-scope of Topic 606)	$ 52,344	$ 51,762
Noninterest income (out-of-scope of Topic 606)(b)	22,123	43,581
Total noninterest income	74,467	95,343
Whitnell
Disaggregation of Revenue [Line Items]
Gain (Loss) on Sale and Maturity of Other Investments, Before Tax	2,000	2,000
Wealth management fees
Disaggregation of Revenue [Line Items]
Noninterest income (in-scope of Topic 606)	22,404	22,414
Service charges and deposit account fees
Disaggregation of Revenue [Line Items]
Noninterest income (in-scope of Topic 606)	16,856	14,855
Card-based fees(a)
Disaggregation of Revenue [Line Items]
Noninterest income (in-scope of Topic 606)	9,949	9,764
Other revenue
Disaggregation of Revenue [Line Items]
Noninterest income (in-scope of Topic 606)	3,135	4,729
Corporate and Commercial Specialty
Disaggregation of Revenue [Line Items]
Noninterest income (in-scope of Topic 606)	27,840	27,365
Noninterest income (out-of-scope of Topic 606)(b)	9,950	14,464
Corporate and Commercial Specialty | Wealth management fees
Disaggregation of Revenue [Line Items]
Noninterest income (in-scope of Topic 606)	22,404	22,414
Corporate and Commercial Specialty | Service charges and deposit account fees
Disaggregation of Revenue [Line Items]
Noninterest income (in-scope of Topic 606)	3,784	3,941
Corporate and Commercial Specialty | Card-based fees(a)
Disaggregation of Revenue [Line Items]
Noninterest income (in-scope of Topic 606)	417	346
Corporate and Commercial Specialty | Other revenue
Disaggregation of Revenue [Line Items]
Noninterest income (in-scope of Topic 606)	1,235	664
Community, Consumer, and Business
Disaggregation of Revenue [Line Items]
Noninterest income (in-scope of Topic 606)	24,455	23,988
Noninterest income (out-of-scope of Topic 606)(b)	8,751	23,342
Community, Consumer, and Business | Service charges and deposit account fees
Disaggregation of Revenue [Line Items]
Noninterest income (in-scope of Topic 606)	13,069	10,900
Community, Consumer, and Business | Card-based fees(a)
Disaggregation of Revenue [Line Items]
Noninterest income (in-scope of Topic 606)	9,524	9,414
Community, Consumer, and Business | Other revenue
Disaggregation of Revenue [Line Items]
Noninterest income (in-scope of Topic 606)	1,862	3,674
Risk Management and Shared Services
Disaggregation of Revenue [Line Items]
Noninterest income (in-scope of Topic 606)	49	409
Noninterest income (out-of-scope of Topic 606)(b)	3,421	5,775
Risk Management and Shared Services | Service charges and deposit account fees
Disaggregation of Revenue [Line Items]
Noninterest income (in-scope of Topic 606)	3	15
Risk Management and Shared Services | Card-based fees(a)
Disaggregation of Revenue [Line Items]
Noninterest income (in-scope of Topic 606)	7	4
Risk Management and Shared Services | Other revenue
Disaggregation of Revenue [Line Items]
Noninterest income (in-scope of Topic 606)	38	391
Operating Segments [Member] | Corporate and Commercial Specialty
Disaggregation of Revenue [Line Items]
Total noninterest income	37,790	41,828
Operating Segments [Member] | Community, Consumer, and Business
Disaggregation of Revenue [Line Items]
Total noninterest income	33,207	47,331
Operating Segments [Member] | Risk Management and Shared Services
Disaggregation of Revenue [Line Items]
Total noninterest income	$ 3,470	$ 6,184