SEGMENT INFORMATION - Segment Results (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting Information [Line Items]
Interest income	$ 99,577	$ 67,613
Noninterest income	41,122	47,467
Total revenue	140,699	115,080
Interest expense	16,263	9,899
Noninterest expenses	97,592	53,412
Provision for loan losses	7,654	3,650
Total expenses	121,509	66,961
Income before taxes	19,190	48,119
Income tax provision	6,260	10,769
Net income	12,930	37,350
Less: Net loss attributable to noncontrolling interest	(93)	0
Net income attributable to WSFS	13,023	37,350
Inter-Segment Eliminations
Segment Reporting Information [Line Items]
Interest income	7,797	5,331
Noninterest income	2,246	2,323
Total revenue	10,043	7,654
Interest expense	7,797	5,331
Noninterest expenses	2,246	2,323
Total expenses	10,043	7,654
Operating Segments
Segment Reporting Information [Line Items]
Total revenue	150,742	122,734
Total expenses	131,552	74,615
Income before taxes	19,190	48,119
WSFS Bank
Segment Reporting Information [Line Items]
Interest income	96,946	65,290
Noninterest income	17,264	26,606
Total revenue	114,210	91,896
Interest expense	15,136	9,503
Noninterest expenses	82,577	39,435
Provision for loan losses	7,286	3,661
Total expenses	104,999	52,599
WSFS Bank | Inter-Segment Eliminations
Segment Reporting Information [Line Items]
Interest income	3,792	2,968
Noninterest income	1,883	2,108
Total revenue	5,675	5,076
Interest expense	4,005	2,363
Noninterest expenses	363	215
Total expenses	4,368	2,578
WSFS Bank | Operating Segments
Segment Reporting Information [Line Items]
Total revenue	119,885	96,972
Total expenses	109,367	55,177
Income before taxes	10,518	41,795
Cash Connect
Segment Reporting Information [Line Items]
Interest income	0	0
Noninterest income	12,402	11,353
Total revenue	12,402	11,353
Interest expense	0	0
Noninterest expenses	8,030	7,319
Provision for loan losses	0	0
Total expenses	8,030	7,319
Cash Connect | Inter-Segment Eliminations
Segment Reporting Information [Line Items]
Interest income	0	0
Noninterest income	177	181
Total revenue	177	181
Interest expense	2,558	2,059
Noninterest expenses	545	672
Total expenses	3,103	2,731
Cash Connect | Operating Segments
Segment Reporting Information [Line Items]
Total revenue	12,579	11,534
Total expenses	11,133	10,050
Income before taxes	1,446	1,484
Wealth Management
Segment Reporting Information [Line Items]
Interest income	2,631	2,323
Noninterest income	11,456	9,508
Total revenue	14,087	11,831
Interest expense	1,127	396
Noninterest expenses	6,985	6,658
Provision for loan losses	368	(11)
Total expenses	8,480	7,043
Wealth Management | Inter-Segment Eliminations
Segment Reporting Information [Line Items]
Interest income	4,005	2,363
Noninterest income	186	34
Total revenue	4,191	2,397
Interest expense	1,234	909
Noninterest expenses	1,338	1,436
Total expenses	2,572	2,345
Wealth Management | Operating Segments
Segment Reporting Information [Line Items]
Total revenue	18,278	14,228
Total expenses	11,052	9,388
Income before taxes	$ 7,226	$ 4,840