Goodwill and Intangibles - Schedule of Allocation of Goodwill to Our Reportable Operating Segments for Purposes of Goodwill Impairment Testing (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 166,007	$ 167,539
Goodwill adjustments	0	(1,532)	$ 2,112
Goodwill, ending balance	166,007	166,007	167,539
WSFS Bank
Goodwill [Roll Forward]
Goodwill, beginning balance	145,808	147,396
Goodwill adjustments	0	(1,588)
Goodwill, ending balance	145,808	145,808	147,396
Wealth Management
Goodwill [Roll Forward]
Goodwill, beginning balance	20,199	20,143
Goodwill adjustments	0	56
Goodwill, ending balance	$ 20,199	$ 20,199	$ 20,143