Segment Information - Details of Segment Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Segment Reporting Information [Line Items]
Interest income	$ 60,826	$ 50,046
Noninterest income	28,092	23,668
Total revenue	88,918	73,714
Interest expense	7,723	4,690
Noninterest expenses	51,506	43,797
Provision for loan losses	2,162	780
Total expenses	61,391	49,267
Income before taxes	27,527	24,447
Income tax provision	8,590	8,677
Net income	18,937	15,770
Capital expenditures	2,364	1,233
Inter-Segment Eliminations
Segment Reporting Information [Line Items]
Interest income	4,061	2,956
Noninterest income	2,391	2,277
Total revenue	6,452	5,233
Interest expense	4,061	2,956
Noninterest expenses	2,391	2,277
Total expenses	6,452	5,233
External Customer
Segment Reporting Information [Line Items]
Total revenue	95,370	78,947
Total expenses	67,843	54,500
WSFS Bank
Segment Reporting Information [Line Items]
Interest income	58,688	48,038
Noninterest income	10,167	9,852
Total revenue	68,855	57,890
Interest expense	7,463	4,497
Noninterest expenses	38,960	33,812
Provision for loan losses	1,716	815
Total expenses	48,139	39,124
Income before taxes	22,584	19,775
Capital expenditures	2,088	1,211
WSFS Bank | Inter-Segment Eliminations
Segment Reporting Information [Line Items]
Interest income	1,996	1,061
Noninterest income	2,164	2,060
Total revenue	4,160	3,121
Interest expense	2,065	1,895
Noninterest expenses	227	217
Total expenses	2,292	2,112
WSFS Bank | External Customer
Segment Reporting Information [Line Items]
Total revenue	73,015	61,011
Total expenses	50,431	41,236
Cash Connect
Segment Reporting Information [Line Items]
Interest income	0	0
Noninterest income	9,677	8,271
Total revenue	9,677	8,271
Interest expense	0	0
Noninterest expenses	6,135	5,448
Provision for loan losses	0	0
Total expenses	6,135	5,448
Income before taxes	1,613	1,746
Capital expenditures	22	20
Cash Connect | Inter-Segment Eliminations
Segment Reporting Information [Line Items]
Interest income	0	0
Noninterest income	191	193
Total revenue	191	193
Interest expense	1,405	555
Noninterest expenses	715	715
Total expenses	2,120	1,270
Cash Connect | External Customer
Segment Reporting Information [Line Items]
Total revenue	9,868	8,464
Total expenses	8,255	6,718
Wealth Management
Segment Reporting Information [Line Items]
Interest income	2,138	2,008
Noninterest income	8,248	5,545
Total revenue	10,386	7,553
Interest expense	260	193
Noninterest expenses	6,411	4,537
Provision for loan losses	446	(35)
Total expenses	7,117	4,695
Income before taxes	3,330	2,926
Capital expenditures	254	2
Wealth Management | Inter-Segment Eliminations
Segment Reporting Information [Line Items]
Interest income	2,065	1,895
Noninterest income	36	24
Total revenue	2,101	1,919
Interest expense	591	506
Noninterest expenses	1,449	1,345
Total expenses	2,040	1,851
Wealth Management | External Customer
Segment Reporting Information [Line Items]
Total revenue	12,487	9,472
Total expenses	$ 9,157	$ 6,546