Goodwill and Intangible Assets - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2018 USD ($) segment	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 166,007,000	$ 166,007,000	$ 167,539,000
Impairment losses related to goodwill	$ 0	0
Number of operating segments | segment	3
Amortization expense on other intangible assets	$ 2,942,000	3,078,000	2,438,000
Impairment of other intangible assets	0	0
Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Amortization expense on other intangible assets	2,900,000	3,000,000	2,400,000
WSFS Bank
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 145,808,000	$ 145,808,000	$ 147,396,000