Revenue from Contracts with Customers - Summary of Sources of Noninterest Income that are Subject to Revenue Recognition Guidance (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation Of Revenue [Line Items]
Brokerage services income	$ 62,791	$ 47,428	$ 48,922
Other revenues from operations:
Total other income	2,166,994	2,088,444	2,061,679
Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	402,113	370,788	432,978
Trust Income [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	644,716	601,884	572,608
ASU 2014-09 [Member]
Disaggregation Of Revenue [Line Items]
Brokerage services income	62,791	47,428	48,922
Other revenues from operations:
Merchant discount and credit card fees	131,405	102,472	107,042
Other	83,648	84,611	91,613
Total other income	1,324,673	1,207,183	1,253,163
ASU 2014-09 [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	402,113	370,788	432,978
ASU 2014-09 [Member] | Trust Income [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	644,716	601,884	572,608
ASU 2014-09 [Member] | Business Banking [Member]
Other revenues from operations:
Merchant discount and credit card fees	52,343	40,475	36,844
Total other income	106,159	90,612	97,565
ASU 2014-09 [Member] | Business Banking [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	53,816	50,119	60,690
ASU 2014-09 [Member] | Business Banking [Member] | Trust Income [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer		18	31
ASU 2014-09 [Member] | Commercial Banking [Member]
Other revenues from operations:
Merchant discount and credit card fees	55,164	45,528	52,161
Other	5,968	9,408	7,498
Total other income	160,012	148,098	153,666
ASU 2014-09 [Member] | Commercial Banking [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	98,880	92,720	93,044
ASU 2014-09 [Member] | Commercial Banking [Member] | Trust Income [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer		442	963
ASU 2014-09 [Member] | Commercial Real Estate [Member]
Other revenues from operations:
Merchant discount and credit card fees	2,661	2,221	2,516
Other	7,304	6,218	8,615
Total other income	21,818	18,691	20,959
ASU 2014-09 [Member] | Commercial Real Estate [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	11,853	10,252	9,828
ASU 2014-09 [Member] | Discretionary Portfolio [Member]
Other revenues from operations:
Other	1,359	1,625	1,776
Total other income	1,359	1,625	1,776
ASU 2014-09 [Member] | Residential Mortgage Banking [Member]
Other revenues from operations:
Other	6,166	4,732	3,492
Total other income	6,166	4,732	3,496
ASU 2014-09 [Member] | Residential Mortgage Banking [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer			4
ASU 2014-09 [Member] | Retail Banking [Member]
Other revenues from operations:
Merchant discount and credit card fees	20,850	13,481	12,140
Other	22,878	20,813	36,144
Total other income	276,007	246,152	311,943
ASU 2014-09 [Member] | Retail Banking [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	232,279	211,858	263,659
ASU 2014-09 [Member] | All Other [Member]
Disaggregation Of Revenue [Line Items]
Brokerage services income	62,791	47,428	48,922
Other revenues from operations:
Merchant discount and credit card fees	387	767	3,381
Other	39,973	41,815	34,088
Total other income	753,152	697,273	663,758
ASU 2014-09 [Member] | All Other [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	5,285	5,839	5,753
ASU 2014-09 [Member] | All Other [Member] | Trust Income [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	$ 644,716	$ 601,424	$ 571,614