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		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Disaggregation Of Revenue [Line Items]
Brokerage services income	$ 24,138	$ 10,265	$ 44,328	$ 23,378
Other revenues from operations:
Total other income	571,100	513,633	1,111,987	1,019,231
Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	124,170	98,518	225,677	191,295
Trust Income [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	190,084	162,991	359,297	319,013
ASU 2014-09 [Member]
Disaggregation Of Revenue [Line Items]
Brokerage services income	24,138	10,265	44,328	23,378
Other revenues from operations:
Merchant discount and credit card fees	42,849	34,102	74,604	58,465
Other	26,490	20,011	51,269	42,921
Total other income	407,731	325,887	755,175	635,072
ASU 2014-09 [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	124,170	98,518	225,677	191,295
ASU 2014-09 [Member] | Trust Income [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	190,084	162,991	359,297	319,013
ASU 2014-09 [Member] | Business Banking [Member]
Other revenues from operations:
Merchant discount and credit card fees	16,835	13,713	29,640	23,194
Total other income	36,458	26,655	63,944	48,633
ASU 2014-09 [Member] | Business Banking [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	19,623	12,942	34,304	25,439
ASU 2014-09 [Member] | Commercial Banking [Member]
Other revenues from operations:
Merchant discount and credit card fees	16,854	14,435	30,313	24,842
Other	1,259	1,053	3,162	2,011
Total other income	47,942	40,443	88,875	76,103
ASU 2014-09 [Member] | Commercial Banking [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	29,829	24,955	55,400	49,250
ASU 2014-09 [Member] | Commercial Real Estate [Member]
Other revenues from operations:
Merchant discount and credit card fees	858	500	1,732	945
Other	3,803	1,926	6,267	3,017
Total other income	8,403	5,324	15,219	9,753
ASU 2014-09 [Member] | Commercial Real Estate [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	3,742	2,898	7,220	5,791
ASU 2014-09 [Member] | Discretionary Portfolio [Member]
Other revenues from operations:
Other	871	376	1,564	760
Total other income	871	376	1,564	760
ASU 2014-09 [Member] | Residential Mortgage Banking [Member]
Other revenues from operations:
Other	1,126	1,447	2,855	3,169
Total other income	1,126	1,447	2,855	3,169
ASU 2014-09 [Member] | Retail Banking [Member]
Disaggregation Of Revenue [Line Items]
Brokerage services income		20		20
Other revenues from operations:
Merchant discount and credit card fees	8,024	5,908	12,534	9,829
Other	7,673	6,012	12,772	11,819
Total other income	84,117	68,526	150,073	129,706
ASU 2014-09 [Member] | Retail Banking [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	68,420	56,586	124,767	108,038
ASU 2014-09 [Member] | All Other [Member]
Disaggregation Of Revenue [Line Items]
Brokerage services income	24,138	10,245	44,328	23,358
Other revenues from operations:
Merchant discount and credit card fees	278	(454)	385	(345)
Other	11,758	9,197	24,649	22,145
Total other income	228,814	183,116	432,645	366,948
ASU 2014-09 [Member] | All Other [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	2,556	1,137	3,986	2,777
ASU 2014-09 [Member] | All Other [Member] | Trust Income [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	$ 190,084	$ 162,991	$ 359,297	$ 319,013