Other Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Other comprehesive income
Net unrealized holding gains (losses) on securities available-for-sale arising during the period, net of taxes (2011 - $5,807; 2010 - $5,727; 2009 - $(6,491);	$ 7,702	$ 9,344	$ 11,845
Other Comprehensive Income Reclassification Adjustment For Held To Maturity Transferred To Available For Sale Securities Net Of Tax		(54)
Other Comprehensive Income Reclassification Of Defined Benefit Plan Net Transition Asset Obligation Recognized In Net Periodic Benefit Cost Net Of Tax		38
Other Comprehensive Income Reclassification Adjustment For Sale Of Securities Included In Net Income Net Of Tax	(3,024)	(782)	(1,254)
Total other comprehensive income	$ 4,678	$ 8,546	$ 10,591

Unrealized holding gain or loss, net of tax, at the date of the transfer for a debt security from the held-to-maturity category transferred into the available-for-sale category. Also includes the unrealized gain or loss at the date of transfer for a debt security from the available-for-sale category transferred into the held-to-maturity category.

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

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 38

-Subparagraph c(3)

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 15

-Subparagraph c, d

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 130

-Paragraph 39

-Subparagraph g

+ Details

Name:	us-gaap_OtherComprehensiveIncomeReclassificationAdjustmentForHeldToMaturityTransferredToAvailableForSaleSecuritiesNetOfTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Reclassification adjustment for unrealized gains or losses realized upon the sale of securities, after tax.

+ References

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

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 38

-Subparagraph c(3)

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 130

-Paragraph 24

-Subparagraph b

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 130

-Paragraph 18, 19

+ Details

Name:	us-gaap_OtherComprehensiveIncomeReclassificationAdjustmentForSaleOfSecuritiesIncludedInNetIncomeNetOfTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The adjustment out of other comprehensive income for the net transition asset or obligation recognized as a component of net periodic benefit cost during the period, after tax.

+ References

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

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 38

-Subparagraph c(3)

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 158

-Paragraph 7

-Subparagraph a

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 158

-Paragraph 4

-Subparagraph c, d

+ Details

Name:	us-gaap_OtherComprehensiveIncomeReclassificationOfDefinedBenefitPlanNetTransitionAssetObligationRecognizedInNetPeriodicBenefitCostNetOfTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Net unrealized holding gains (losses)

+ References

No definition available.

+ Details

Name:	wsfs_NetUnrealizedHoldingGainsLosses
Namespace Prefix:	wsfs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	wsfs_OtherComprehesiveIncome
Namespace Prefix:	wsfs_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

No authoritative reference available.

+ References

No definition available.

+ Details

Name:	wsfs_TotalOtherComprehensiveIncome
Namespace Prefix:	wsfs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration