XML 121 R110.htm IDEA: XBRL DOCUMENT
v3.21.2

Stockholders' Equity - Summary of Preferred and Common Stock (Parenthetical) (Details) | 9 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2021 | Dec. 31, 2020
Series B 7.5% Fixed to Floating Non-Cumulative Perpetual Preferred Stock |  |
Class Of Stock [Line Items] |  |
Preferred stock, dividend rate, percentage | 7.50% | 7.50%

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_ClassOfStockLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The percentage rate used to calculate dividend payments on preferred stock. + References No definition available. + Details
Name: | us-gaap_PreferredStockDividendRatePercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=by_SeriesBSevenPointFivePercentFixedToFloatingNonCumulativePerpetualPreferredStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |