Loans and Allowance for Credit Losses - Information related to nonaccrual loans by class (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Loans and Leases Receivable Disclosure [Line Items]
Nonaccrual with No Allowance for Credit Loss	$ 25,869		$ 30,354
Nonaccrual with an Allowance for Credit Loss	26,407		30,589
Total Nonaccrual Loans	52,276		60,943
Interest on nonaccrual loans	800		3,700
Nonaccrual loans, recorded interest income	0	$ 0
Performing Financial Instruments
Loans and Leases Receivable Disclosure [Line Items]
Troubled debt restructuring	10,300		10,500
Commercial
Loans and Leases Receivable Disclosure [Line Items]
Nonaccrual with No Allowance for Credit Loss	8,493		3,263
Nonaccrual with an Allowance for Credit Loss	9,998		12,089
Total Nonaccrual Loans	18,491		15,352
Income producing - commercial real estate
Loans and Leases Receivable Disclosure [Line Items]
Nonaccrual with No Allowance for Credit Loss	6,092		6,500
Nonaccrual with an Allowance for Credit Loss	11,065		12,380
Total Nonaccrual Loans	17,157		18,880
Owner occupied - commercial real estate
Loans and Leases Receivable Disclosure [Line Items]
Nonaccrual with No Allowance for Credit Loss	10,675		18,941
Nonaccrual with an Allowance for Credit Loss	3,402		4,217
Total Nonaccrual Loans	14,077		23,158
Real estate mortgage - residential
Loans and Leases Receivable Disclosure [Line Items]
Nonaccrual with No Allowance for Credit Loss	0		1,234
Nonaccrual with an Allowance for Credit Loss	1,942		1,697
Total Nonaccrual Loans	1,942		2,931
Construction - commercial and residential
Loans and Leases Receivable Disclosure [Line Items]
Nonaccrual with No Allowance for Credit Loss	196		0
Nonaccrual with an Allowance for Credit Loss	0		206
Total Nonaccrual Loans	196		206
Home equity
Loans and Leases Receivable Disclosure [Line Items]
Nonaccrual with No Allowance for Credit Loss	413		416
Nonaccrual with an Allowance for Credit Loss	0		0
Total Nonaccrual Loans	$ 413		$ 416

Financing Receivable, Impaired, Interest Lost on Nonaccrual Loans

No definition available.

Name:	egbn_FinancingReceivableImpairedInterestLostOnNonaccrualLoans
Namespace Prefix:	egbn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of Financing Receivable Non accrual an Allowance

+ References

No definition available.

+ Details

Name:	egbn_FinancingReceivableNonAccrualanAllowance
Namespace Prefix:	egbn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of interest income recorded on nonaccrual loans for the period.

+ References

No definition available.

+ Details

Name:	egbn_NonaccrualLoansRecordedInterestIncome
Namespace Prefix:	egbn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of financing receivable modified as troubled debt restructuring.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=121585226&loc=d3e18845-111554

+ Details

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

- Definition

Amount of financing receivable on nonaccrual status with no allowance for credit loss.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 16
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919258-210447

+ Details

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

- Definition

Amount of financing receivable on nonaccrual status.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5111-111524

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 16
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919258-210447

+ Details

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

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

- Details

Name:	us-gaap_FinancialInstrumentPerformanceStatusAxis=us-gaap_PerformingFinancingReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=egbn_IncomeProducingPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=egbn_OwnerOccupiedPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=egbn_ConstructionPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=egbn_HomeEquityPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: