Note 5 - Loans and Allowance for Credit Losses (Details) - Loans (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	$ 4,444,893	$ 4,312,399	$ 3,063,975
Loans, percent	100.00%egbn_LoanPercent	100.00%egbn_LoanPercent	100.00%egbn_LoanPercent
Less: Allowance for Credit Losses	(47,779)	(46,075)	(42,018)
Net loans	4,397,114	4,266,324	3,021,957
Secured Loan [Member] \| Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	933,715	916,226	704,386
Loans, percent	21.00%	21.00%	23.00%
Secured Loan [Member] \| Commercial Real Estate Investment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	1,739,483	1,703,172	1,196,405
Loans, percent	40.00%	40.00%	40.00%
Secured Loan [Member] \| Commercial Real Estate Owner Occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	493,003	461,581	320,994
Loans, percent	11.00%	11.00%	10.00%
Secured Loan [Member] \| Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	147,871	148,018	97,846
Loans, percent	3.00%	3.00%	3.00%
Secured Loan [Member] \| Home Equity Line of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	120,543	122,536	108,839
Loans, percent	3.00%	3.00%	4.00%
Secured Loan [Member] \| Consumer, Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	98,707	109,402	6,058
Loans, percent	2.00%	3.00%
Secured Loan [Member] \| Construction Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	862,013	793,432	593,967
Loans, percent	19.00%	18.00%	19.00%
Secured Loan [Member] \| Construction - C&I (Owner Occupied) [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	49,558	58,032	35,480
Loans, percent	1.00%	1.00%	1.00%
Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	933,715	916,226	704,386
Less: Allowance for Credit Losses	(13,777)		(11,420)
Commercial Real Estate Investment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	1,739,483	1,703,172	1,196,405
Less: Allowance for Credit Losses	(11,652)		(10,590)
Commercial Real Estate Owner Occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	493,003	461,581	320,994
Less: Allowance for Credit Losses	(3,127)		(3,195)
Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	147,871	148,018	97,846
Less: Allowance for Credit Losses	(1,055)		(754)
Home Equity Line of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	120,543	122,536	108,839
Less: Allowance for Credit Losses	(1,509)		(1,507)
Consumer, Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	98,707	109,402	6,058
Less: Allowance for Credit Losses	(276)		(373)
Construction Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amount	911,571	851,464	629,447
Less: Allowance for Credit Losses	$ (16,383)		$ (14,179)

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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