XML 33 R140.htm IDEA: XBRL DOCUMENT
v3.20.1

Regulatory Capital Requirements - Additional Information (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018
Bank |  |
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items] |  |
Proceeds from Dividends Received |  | $ 0
Bank | Trust Preferred Securities Interest and Preferred Dividends |  |
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items] |  |
Proceeds from Dividends Received | $ 13,500,000 | $ 2,900,000
Federal Deposit Corporation And Federal Reserve Board |  |
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items] |  |
Capital conservation buffer above the minimum capital requirements | 6.43% |
Federal Deposit Corporation And Federal Reserve Board | Bank |  |
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items] |  |
Capital conservation buffer above the minimum capital requirements | 5.87% |
Federal Deposit Corporation And Federal Reserve Board | Rules Phased in beginning January 2016 |  |
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items] |  |
Additional capital conservation buffer requirement subsequent years ratio | 2.50% |

X
- Definition The additional capital conservation buffer ratio requirement in subsequent years. + References No definition available. + Details
Name: | by_AdditionalCapitalConservationBufferRequirementSubsequentYearsRatio
Namespace Prefix: | by_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Capital conservation buffer above the minimum capital requirements. + References No definition available. + Details
Name: | by_CapitalConservationBufferAboveTheMinimumCapitalRequirements
Namespace Prefix: | by_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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

X
- Definition Dividends received on equity and other investments during the current period. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 16 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3337-108585 + Details
Name: | us-gaap_ProceedsFromDividendsReceived
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=srt_SubsidiariesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DividendsAxis=by_TrustPreferredSecuritiesInterestAndPreferredDividendsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAgencyAxis=by_FederalDepositCorporationAndFederalReserveBoardMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementScenarioAxis=by_RulesEffective2016January1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |