Loans and Leases - Certain Information Relating to Commercial Real Estate Loans (Detail) - Loan portfolio diversification risk - Commercial real estate loans	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Percent owner-occupied
Financing Receivable, Allowance for Credit Loss [Line Items]
Percent of total loans and leases	28.80%	28.10%
Percent non-owner-occupied
Financing Receivable, Allowance for Credit Loss [Line Items]
Percent of total loans and leases	71.20%	71.90%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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