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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

+ References

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

-Publisher FASB

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-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.7(d))

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Subparagraph d

-Article 9

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 10

-Section 50

-Paragraph 11B

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-Name Accounting Standards Codification

-Topic 310

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

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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.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

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-Paragraph 2

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

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The balance of deferred loan origination fees less deferred loan origination costs.

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No definition available.

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Loans - Summary of Loan Portfolio by Category (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 3,234,959	$ 3,202,498	$ 3,004,672
Deferred fees, net	6,314wsfs_DeferredFees	6,420wsfs_DeferredFees
Allowance for loan losses	39,507	39,426	41,328	41,244
Net loans	3,189,138	3,156,652
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	923,070	920,072	838,181
Allowance for loan losses	13,048	12,837	12,404	12,751
Owner Occupied Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	797,400	788,598	799,213
Allowance for loan losses	7,039	6,643	8,789	7,638
Construction Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	153,224	142,497
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	324,232	327,543
Commercial Mortgage [Member] \| Real Estate Mortgage Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	820,836	805,459
Residential (1-4 Family) [Member] \| Real Estate Mortgage Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 216,197	$ 218,329