Note 5 - Loans and Allowance for Credit Losses (Details) - Loans (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	$ 4,312,399	$ 2,945,158
Loans, percent	100.00%egbn_LoanPercent	100.00%egbn_LoanPercent
Less: Allowance for Credit Losses	(46,075)	(40,921)
Net loans	4,266,324	2,904,237
Secured Loan [Member] \| Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	916,226	694,350
Loans, percent	21.00%	24.00%
Secured Loan [Member] \| Commercial Real Estate Investment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	1,703,172	1,119,800
Loans, percent	40.00%	38.00%
Secured Loan [Member] \| Commercial Real Estate Owner Occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	461,581	317,491
Loans, percent	11.00%	11.00%
Secured Loan [Member] \| Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	148,018	90,418
Loans, percent	3.00%	3.00%
Secured Loan [Member] \| Home Equity Line of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	122,536	110,242
Loans, percent	3.00%	4.00%
Secured Loan [Member] \| Consumer, Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	109,402	4,031
Loans, percent	3.00%
Secured Loan [Member] \| Construction Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	793,432	574,167
Loans, percent	18.00%	19.00%
Secured Loan [Member] \| Construction - C&I (owner occupied) [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	58,032	34,659
Loans, percent	1.00%	1.00%
Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	916,226	694,350
Less: Allowance for Credit Losses	(13,222)	(9,780)
Commercial Real Estate Investment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	1,703,172	1,119,800
Less: Allowance for Credit Losses	(11,442)	(10,359)
Commercial Real Estate Owner Occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	461,581	317,491
Less: Allowance for Credit Losses	(2,954)	(3,899)
Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	148,018	90,418
Less: Allowance for Credit Losses	(1,259)	(944)
Home Equity Line of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	122,536	110,242
Less: Allowance for Credit Losses	(1,469)	(1,871)
Consumer, Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	109,402	4,031
Less: Allowance for Credit Losses	(104)	(134)
Construction Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	851,464	608,826
Less: Allowance for Credit Losses	$ (15,625)	$ (13,934)

Percent of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

No definition available.

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- Definition

A valuation allowance for financing receivables that are expected to be uncollectible.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953423-111524

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- Definition

Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5074-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=28367877&loc=d3e4428-111522

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- Definition

Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=28367877&loc=d3e4428-111522

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.7)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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