Segment Information (Segment Information) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting Information [Line Items]
Interest income	$ 36,514	$ 40,091	$ 113,500	$ 119,057
Cash and cash equivalents	447,100	463,553	447,100	463,553	468,017	376,759
Noninterest income	19,748	16,924	65,498	46,592
Other segment assets	3,814,232		3,814,232		3,820,991
Total external customer revenues	56,262	57,015	178,998	165,649
Total assets	4,261,332		4,261,332		4,289,008
Total inter-segment revenues	4,596	4,558	14,458	14,076
Total revenue	60,858	61,573	193,456	179,725
Interest expense	5,621	7,911	17,999	25,436
Noninterest expenses	32,153	32,412	96,159	94,451
Provision for loan loss	3,751	6,558	28,379	21,048
Total external customer expenses	41,525	46,881	142,537	140,935
Total inter-segment expenses	4,596	4,558	14,458	14,076
Total expenses	46,121	51,439	156,995	155,011
Income before taxes and extraordinary items	14,737	10,134	36,461	24,714
Provision for income taxes	4,758	3,348	12,708	8,199
Consolidated net income	9,979	6,786	23,753	16,515
Capital expenditures	1,603	3,213	5,747	8,090
Cash and cash equivalents	447,100	463,553	447,100	463,553	468,017	376,759
Other segment assets	3,814,232		3,814,232		3,820,991
Total segment assets	4,261,332		4,261,332		4,289,008
External Customer [Member]
Segment Reporting Information [Line Items]
Interest income	36,514	40,091	113,500	119,057
Noninterest income	19,748	16,924	65,498	46,592
Interest expense	5,621	7,911	17,999	25,436
Noninterest expenses	32,153	32,412	96,159	94,451
Provision for loan loss	3,751	6,558	28,379	21,048
Inter-Segment [Member]
Segment Reporting Information [Line Items]
Interest income	2,302	2,542	7,443	7,849
Noninterest income	2,294	2,016	7,015	6,227
Interest expense	2,302	2,542	7,443	7,849
Noninterest expenses	2,294	2,016	7,015	6,227
WSFS Bank [Member]
Segment Reporting Information [Line Items]
Cash and cash equivalents	52,821		52,821		48,107
Other segment assets	3,622,291		3,622,291		3,618,744
Total external customer revenues	46,161	47,118	149,437	137,259
Total assets	3,675,112		3,675,112		3,666,851
Total inter-segment revenues	3,066	2,929	9,467	8,954
Total revenue	49,227	50,047	158,904	146,213
Total external customer expenses	35,674	41,192	125,383	124,102
Total inter-segment expenses	1,530	1,629	4,991	5,122
Total expenses	37,204	42,821	130,374	129,224
Income before taxes and extraordinary items	12,023	7,226	28,530	16,989
Capital expenditures	1,289	2,374	5,406	6,768
Cash and cash equivalents	52,821		52,821		48,107
Other segment assets	3,622,291		3,622,291		3,618,744
Total segment assets	3,675,112		3,675,112		3,666,851
WSFS Bank [Member] | External Customer [Member]
Segment Reporting Information [Line Items]
Interest income	34,475	37,729	107,199	111,984
Noninterest income	11,686	9,389	42,238	25,275
Interest expense	5,377	7,600	17,330	24,434
Noninterest expenses	27,300	27,524	81,267	79,866
Provision for loan loss	2,997	6,068	26,786	19,802
WSFS Bank [Member] | Inter-Segment [Member]
Segment Reporting Information [Line Items]
Interest income	944	1,136	3,099	3,344
Noninterest income	2,122	1,793	6,368	5,610
Interest expense	1,358	1,406	4,344	4,505
Noninterest expenses	172	223	647	617
Cash Connect [Member]
Segment Reporting Information [Line Items]
Cash and cash equivalents	390,356		390,356		416,949
Other segment assets	1,976		1,976		2,155
Total external customer revenues	4,707	4,235	13,254	11,484
Total assets	392,332		392,332		419,104
Total inter-segment revenues	148	202	568	524
Total revenue	4,855	4,437	13,822	12,008
Total external customer expenses	2,113	2,187	6,628	5,824
Total inter-segment expenses	924	707	2,719	2,075
Total expenses	3,037	2,894	9,347	7,899
Income before taxes and extraordinary items	1,818	1,543	4,475	4,109
Capital expenditures	311	837	321	1,014
Cash and cash equivalents	390,356		390,356		416,949
Other segment assets	1,976		1,976		2,155
Total segment assets	392,332		392,332		419,104
Cash Connect [Member] | External Customer [Member]
Segment Reporting Information [Line Items]
Noninterest income	4,707	4,235	13,254	11,484
Noninterest expenses	2,113	2,187	6,628	5,824
Cash Connect [Member] | Inter-Segment [Member]
Segment Reporting Information [Line Items]
Noninterest income	148	202	568	524
Interest expense	338	349	1,008	913
Noninterest expenses	586	358	1,711	1,162
Trust & Wealth Management [Member]
Segment Reporting Information [Line Items]
Cash and cash equivalents	3,923		3,923		2,961
Other segment assets	189,965		189,965		200,092
Total external customer revenues	5,394	5,662	16,307	16,906
Total assets	193,888		193,888		203,053
Total inter-segment revenues	1,382	1,427	4,423	4,598
Total revenue	6,776	7,089	20,730	21,504
Total external customer expenses	3,738	3,502	10,526	11,009
Total inter-segment expenses	2,142	2,222	6,748	6,879
Total expenses	5,880	5,724	17,274	17,888
Income before taxes and extraordinary items	896	1,365	3,456	3,616
Capital expenditures	3	2	20	308
Cash and cash equivalents	3,923		3,923		2,961
Other segment assets	189,965		189,965		200,092
Total segment assets	193,888		193,888		203,053
Trust & Wealth Management [Member] | External Customer [Member]
Segment Reporting Information [Line Items]
Interest income	2,039	2,362	6,301	7,073
Noninterest income	3,355	3,300	10,006	9,833
Interest expense	244	311	669	1,002
Noninterest expenses	2,740	2,701	8,264	8,761
Provision for loan loss	754	490	1,593	1,246
Trust & Wealth Management [Member] | Inter-Segment [Member]
Segment Reporting Information [Line Items]
Interest income	1,358	1,406	4,344	4,505
Noninterest income	24	21	79	93
Interest expense	606	787	2,091	2,431
Noninterest expenses	$ 1,536	$ 1,435	$ 4,657	$ 4,448