XML 56 R113.htm IDEA: XBRL DOCUMENT
v3.20.1

Income Taxes - Operating loss and credit carryforwards (Parenthetical) (Details) | 12 Months Ended
--- | ---
Dec. 31, 2019
Federal |
Operating loss carryforwards |
Operating loss carryforwards expiration year | 2030
Illinois |
Operating loss carryforwards |
Operating loss carryforwards expiration year | 2022

X
- Definition Operating loss carryforwards expiration year. + References No definition available. + Details
Name: | by_OperatingLossCarryforwardsExpirationYear
Namespace Prefix: | by_
Data Type: | xbrli:gYearItemType
Balance Type: | na
Period Type: | duration

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_OperatingLossCarryforwardsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_IncomeTaxAuthorityAxis=us-gaap_DomesticCountryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeTaxAuthorityAxis=us-gaap_StateAndLocalJurisdictionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |