XML 50 R130.htm IDEA: XBRL DOCUMENT v3.20.1

Fair Value Measurement - Summary of Financial Assets Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Investment Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Balance, beginning of period	$ 886	$ 1,052
Acquired assets at fair value		314
Maturities	(195)	(494)
Amortization		5
Change in unrealized gain		9
Change in fair value	9
Balance, end of period	700	886
Servicing Assets
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Balance, beginning of period	19,693	21,400
Additions, net	6,417	7,562
Change in fair value	(6,639)	(9,269)
Balance, end of period	$ 19,471	$ 19,693

X

- Definition

Fair value measurement with unobservable inputs reconciliation recurring basis asset acquired at fair value.

+ References

No definition available.

+ Details

Name:	by_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetAcquiredAtFairValue
Namespace Prefix:	by_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Fair value, measurement with unobservable inputs reconciliation, recurring basis, asset, amortization.

+ References

No definition available.

+ Details

Name:	by_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetAmortization
Namespace Prefix:	by_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Fair value measurement with unobservable inputs reconciliation recurring basis asset change in unrealized gain loss.

+ References

No definition available.

+ Details

Name:	by_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetChangeInUnrealizedGainLoss
Namespace Prefix:	by_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Fair value measurement with unobservable inputs reconciliation recurring basis asset maturities.

+ References

No definition available.

+ Details

Name:	by_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetMaturities
Namespace Prefix:	by_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount of gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

+ Details

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

+ Details

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

+ Details

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_InvestmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FairValueByAssetClassAxis=by_ServicingAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: