SECURITIES - Summary of Held to Maturity Investment Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Held to maturity:
Amortized Cost	$ 149,512	$ 160,163
Gross Unrealized Gains	815	457
Gross Unrealized Losses	(2,694)	(3,828)
Estimated Fair Value	147,633	156,792
State and municipal obligations
Held to maturity:
Amortized Cost	45,284	53,540
Gross Unrealized Gains	504	290
Gross Unrealized Losses	(35)	(276)
Estimated Fair Value	45,753	53,554
U.S. GSE residential mortgage-backed securities
Held to maturity:
Amortized Cost	9,309	9,688
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(234)	(336)
Estimated Fair Value	9,075	9,352
U.S. GSE residential collateralized mortgage obligations
Held to maturity:
Amortized Cost	47,204	48,244
Gross Unrealized Gains	291	163
Gross Unrealized Losses	(746)	(1,130)
Estimated Fair Value	46,749	47,277
U.S. GSE commercial mortgage-backed securities
Held to maturity:
Amortized Cost	18,909	19,098
Gross Unrealized Gains	20	4
Gross Unrealized Losses	(393)	(620)
Estimated Fair Value	18,536	18,482
U.S. GSE commercial collateralized mortgage obligations
Held to maturity:
Amortized Cost	28,806	29,593
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1,286)	(1,466)
Estimated Fair Value	$ 27,520	$ 28,127

Amount of investment in debt security measured at amortized cost (held-to-maturity).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109979856&loc=d3e26610-111562

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27232-111563

+ Details

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

- Definition

Amount of accumulated unrecognized gain on investment in debt security measured at amortized cost (held-to-maturity).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27232-111563

+ Details

Name:	us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27232-111563

+ Details

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

- References

No definition available.

+ Details

Name:	us-gaap_HeldToMaturitySecuritiesClassifiedAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value of investment in debt security measured at amortized cost (held-to-maturity).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27232-111563

+ Details

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

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USStatesAndPoliticalSubdivisionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=bdge_ResidentialCollateralizedMortgageObligationsIssuedByUSGovernmentSponsoredEnterprisesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=bdge_CommercialMortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=bdge_CommercialCollateralizedMortgageObligationsIssuedByUSGovernmentSponsoredEnterprisesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: