Revenue from Contracts with Customers - Summary of Sources of Noninterest Income that are Subject to Revenue Recognition Accounting Guidance (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Disaggregation Of Revenue [Line Items]
Brokerage services income	$ 24,041	$ 20,190
Other revenues from operations:
Total other income	587,133	540,887
Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	113,546	101,507
Trust Income [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	193,802	169,213
ASU 2014-09 [Member]
Disaggregation Of Revenue [Line Items]
Brokerage services income	24,041	20,190
Other revenues from operations:
Merchant discount and credit card fees	36,802	31,755
Other	14,654	24,779
Total other income	382,845	347,444
ASU 2014-09 [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	113,546	101,507
ASU 2014-09 [Member] | Trust Income [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	193,802	169,213
ASU 2014-09 [Member] | Business Banking [Member]
Other revenues from operations:
Merchant discount and credit card fees	14,258	12,805
Total other income	33,738	27,486
ASU 2014-09 [Member] | Business Banking [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	19,470	14,681
ASU 2014-09 [Member] | Business Banking [Member] | Trust Income [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	10
ASU 2014-09 [Member] | Commercial Banking [Member]
Other revenues from operations:
Merchant discount and credit card fees	15,791	13,459
Other	4,671	1,903
Total other income	48,935	40,933
ASU 2014-09 [Member] | Commercial Banking [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	28,473	25,571
ASU 2014-09 [Member] | Commercial Real Estate [Member]
Other revenues from operations:
Merchant discount and credit card fees	1,087	874
Other	1,186	2,464
Total other income	6,459	6,816
ASU 2014-09 [Member] | Commercial Real Estate [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	4,186	3,478
ASU 2014-09 [Member] | Discretionary Portfolio [Member]
Other revenues from operations:
Other	21	693
Total other income	21	693
ASU 2014-09 [Member] | Residential Mortgage Banking [Member]
Other revenues from operations:
Other	340	1,729
Total other income	340	1,729
ASU 2014-09 [Member] | Retail Banking [Member]
Other revenues from operations:
Merchant discount and credit card fees	5,361	4,510
Other	7,406	5,099
Total other income	72,219	65,956
ASU 2014-09 [Member] | Retail Banking [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	59,452	56,347
ASU 2014-09 [Member] | All Other [Member]
Disaggregation Of Revenue [Line Items]
Brokerage services income	24,041	20,190
Other revenues from operations:
Merchant discount and credit card fees	305	107
Other	1,030	12,891
Total other income	221,133	203,831
ASU 2014-09 [Member] | All Other [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	1,965	1,430
ASU 2014-09 [Member] | All Other [Member] | Trust Income [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	$ 193,792	$ 169,213