Segment Information - Details of Segment Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Cash and cash equivalents	$ 530,612	$ 500,887	$ 459,695	$ 468,017
Other segment assets	3,824,031	3,874,261
Total assets	4,354,643	4,375,148
Capital expenditures	956	1,933
Interest income	35,591		39,223
Noninterest income	18,074		16,758
Total external customer revenues	53,665		55,981
Total inter-segment revenues	4,210		4,421
Total revenue	57,875		60,402
Interest expense	4,011		6,693
Noninterest expenses	32,370		30,989
Provision for loan loss	2,231		8,245
Total external customer expenses	38,612		45,927
Total inter-segment expenses	4,210		4,421
Total expenses	42,822		50,348
Income before taxes	15,053		10,054
Provision for income taxes	5,313		3,610
Consolidated net income	9,740		6,444
External customer [Member]
Segment Reporting Information [Line Items]
Interest income	35,591		39,223
Noninterest income	18,074		16,758
Interest expense	4,011		6,693
Noninterest expenses	32,370		30,989
Provision for loan loss	2,231		8,245
Inter-segment [Member]
Segment Reporting Information [Line Items]
Interest income	2,334		2,187
Noninterest income	1,876		2,234
Interest expense	2,334		2,187
Noninterest expenses	1,876		2,234
WSFS Bank [Member]
Segment Reporting Information [Line Items]
Cash and cash equivalents	53,517	68,419
Other segment assets	3,640,122	3,683,073
Total assets	3,693,639	3,751,492
Capital expenditures	773	1,713
Total external customer revenues	42,827		46,564
Total inter-segment revenues	2,553		3,021
Total revenue	45,380		49,585
Total external customer expenses	32,516		41,109
Total inter-segment expenses	1,657		1,400
Total expenses	34,173		42,509
Income before taxes	11,207		7,076
WSFS Bank [Member] | External customer [Member]
Segment Reporting Information [Line Items]
Interest income	33,600		37,036
Noninterest income	9,227		9,528
Interest expense	3,840		6,475
Noninterest expenses	26,430		26,338
Provision for loan loss	2,246		8,296
WSFS Bank [Member] | Inter-segment [Member]
Segment Reporting Information [Line Items]
Interest income	903		960
Noninterest income	1,650		2,061
Interest expense	1,431		1,227
Noninterest expenses	226		173
Cash Connect [Member]
Segment Reporting Information [Line Items]
Cash and cash equivalents	474,842	430,382
Other segment assets	2,943	1,605
Total assets	477,785	431,987
Capital expenditures	183	156
Total external customer revenues	5,027		4,074
Total inter-segment revenues	200		173
Total revenue	5,227		4,247
Total external customer expenses	2,992		1,972
Total inter-segment expenses	921		859
Total expenses	3,913		2,831
Income before taxes	1,314		1,416
Cash Connect [Member] | External customer [Member]
Segment Reporting Information [Line Items]
Interest income
Noninterest income	5,027		4,074
Interest expense
Noninterest expenses	2,992		1,972
Provision for loan loss
Cash Connect [Member] | Inter-segment [Member]
Segment Reporting Information [Line Items]
Interest income
Noninterest income	200		173
Interest expense	371		334
Noninterest expenses	550		525
Trust & Wealth Management [Member]
Segment Reporting Information [Line Items]
Cash and cash equivalents	2,253	2,086
Other segment assets	180,966	189,583
Total assets	183,219	191,669
Capital expenditures		64
Total external customer revenues	5,811		5,343
Total inter-segment revenues	1,457		1,227
Total revenue	7,268		6,570
Total external customer expenses	3,104		2,846
Total inter-segment expenses	1,632		2,162
Total expenses	4,736		5,008
Income before taxes	2,532		1,562
Trust & Wealth Management [Member] | External customer [Member]
Segment Reporting Information [Line Items]
Interest income	1,991		2,187
Noninterest income	3,820		3,156
Interest expense	171		218
Noninterest expenses	2,948		2,679
Provision for loan loss	(15)		(51)
Trust & Wealth Management [Member] | Inter-segment [Member]
Segment Reporting Information [Line Items]
Interest income	1,431		1,227
Noninterest income	26
Interest expense	532		626
Noninterest expenses	$ 1,100		$ 1,536