Segment Information - Capital Expenditures (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Cash	$ 620,757	$ 723,866	$ 821,923	$ 561,179
Goodwill	166,007	166,007	167,539
Other segment assets	6,462,106	6,109,667
Other assets	7,248,870	6,999,540
Capital expenditures	5,498	8,994
WSFS Bank
Segment Reporting Information [Line Items]
Cash	115,147	104,530
Goodwill	145,808	145,808	$ 147,396
Other segment assets	6,225,820	5,882,910
Other assets	6,486,775	6,133,248
Capital expenditures	4,779	8,197
Cash Connect
Segment Reporting Information [Line Items]
Cash	491,863	611,385
Goodwill	0	0
Other segment assets	7,743	6,078
Other assets	499,606	617,463
Capital expenditures	375	184
Wealth Management
Segment Reporting Information [Line Items]
Cash	13,747	7,951
Goodwill	20,199	20,199
Other segment assets	228,543	220,679
Other assets	262,489	248,829
Capital expenditures	$ 344	$ 613