Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

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- Definition

Fair value as of the balance sheet date of derivative instrument not designated as hedging instrument and classified as a liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624163-113959

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- Definition

The number of derivative instruments of a particular derivative liability or group of derivative liabilities held by the entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5579245-113959

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- Definition

Period remaining until the derivative contract matures, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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- 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.

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- Definition

Amount of expense related to estimated loss from loan and lease transactions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.11)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953423-111524

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Balance Type:	debit
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- Definition

Number Of Financial Institutions

+ References

No definition available.

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Balance Type:	na
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- Definition

Number Of Loans Repurchased

+ References

No definition available.

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Balance Type:	na
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- Definition

Reserves For Swap Guarantees

+ References

No definition available.

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Namespace Prefix:	wsfs_
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Balance Type:	credit
Period Type:	instant

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Data Type:	na
Balance Type:
Period Type:

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Namespace Prefix:
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Indemnifications and Guarantees - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2017 USD ($) loan Financial_Institution Transaction	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($) loan
Guarantor Obligations [Line Items]
Provision for losses at the time of sale	$ 2,162,000	$ 780,000
Number of unrelated financial institutions \| Financial_Institution	3
Derivative transaction held for guarantee \| loan	134		134
Notional	$ 538,700,000		$ 518,800,000
Aggregate fair value of swaps to customers	10,000,000		$ 10,900,000
Reserves for swap guarantees	$ 0
Minimum
Guarantor Obligations [Line Items]
Notional amount maturity period	1 year
Maximum
Guarantor Obligations [Line Items]
Notional amount maturity period	20 years
Secondary Market Loan Sales
Guarantor Obligations [Line Items]
Provision for losses at the time of sale	$ 0
Number of loans repurchased \| Transaction	0