Loans and Leases - Summary of Outstanding Loan Balances Related to COVID-19 Payment Deferrals Granted - (Parenthetical) (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable Allowance For Credit Losses [Line Items]
Loans and leases, net of unearned discount		$ 529,323	$ 806,046	$ 127,024
Payment Deferral [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Loans and leases, net of unearned discount		246,598	545,415	$ 29,481
COVID-19 [Member] | Payment Deferral [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Loans and leases, net of unearned discount	[1]	1,204,021	3,767,523
COVID-19 [Member] | Payment Deferral [Member] | Government-Guaranteed Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Loans and leases, net of unearned discount		$ 974,000	$ 1,700,000

[1] Represents accruing loans for which a COVID-19 related payment deferral (including maturity extensions) was in effect.