XML 136 R120.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Commitments and Contingent Liabilities - Summary of Contract or Notional Amount of Outstanding Loan and Lease Commitments (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016
Commitments And Contingencies Liabilities [Line Items] |  |
Fixed Rate | $ 57,150 | $ 38,791
Variable Rate | 470,766 | 337,063
Commitments to Extend Credit |  |
Commitments And Contingencies Liabilities [Line Items] |  |
Fixed Rate | 55,924 | 37,731
Variable Rate | 467,429 | 332,928
Standby Letters of Credit |  |
Commitments And Contingencies Liabilities [Line Items] |  |
Fixed Rate | 1,226 | 1,060
Variable Rate | $ 3,337 | $ 4,135

X
- Definition Commitments and contingencies liabilities. + References No definition available. + Details
Name: | by_CommitmentsAndContingenciesLiabilitiesLineItems
Namespace Prefix: | by_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Reflects the amount of cash required to fully fund agreements to provide advances to borrowers and lessees at stated interest rates. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 825 -Section 50 -Paragraph 1 -Subparagraph (b)(2) -URI http://asc.fasb.org/extlink&oid=75032840&loc=d3e61044-112788 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 825 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=75032840&loc=d3e61082-112788 + Details
Name: | us-gaap_LoansAndLeasesReceivableCommitmentsFixedRates
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Reflects the amount of cash required to fully fund agreements to provide advances to borrowers and lessees at interest rates that increase or decrease depending on certain facts or circumstances. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 825 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=75032840&loc=d3e61082-112788 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 825 -Section 50 -Paragraph 1 -Subparagraph (b)(2) -URI http://asc.fasb.org/extlink&oid=75032840&loc=d3e61044-112788 + Details
Name: | us-gaap_LoansAndLeasesReceivableCommitmentsVariableRates
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CommitmentsToExtendCreditMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=us-gaap_StandbyLettersOfCreditMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |