Off-Balance Sheet Arrangements Commitments Guarantees and Contingencies (Narrative) (Detail) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2022 |
Dec. 31, 2021 |
Dec. 31, 2020 |
|
| Commitments And Guarantees [Line Items] | |||
| Credit card guarantees | $ 8,000 | $ 8,600 | |
| Fully collateralized credit card guarantees | 897 | 962 | |
| Frost Wealth Advisors [Member] | |||
| Commitments And Guarantees [Line Items] | |||
| Fair value of off-balance sheet managed and custody assets | $ 43,600,000 | $ 43,300,000 | $ 38,600,000 |