Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 147,918	$ 134,743	$ 50,244
Less: Net loss attributable to noncontrolling interest	(891)	0	0
Net income attributable to WSFS	148,809	134,743	50,244
Net change in unrealized gains (losses) on investment securities available for sale
Net unrealized gains (losses) arising during the period, net of tax expense (benefit) of $13,179, $(2,223), and $1,813, respectively	41,733	(6,695)	3,073
Less: reclassification adjustment for net gains on sales realized in net income, net of tax expense of $80, $5, and $704, respectively	(253)	(16)	(1,280)
Net change in unrealized gains (losses) on investment securities available-for-sale	41,480	(6,711)	1,793
Net change in securities held to maturity
Amortization of unrealized gain on securities reclassified to held-to-maturity, net of tax expense of $98, $136, and $241, respectively	(311)	(444)	(394)
Net change in unfunded pension liability
Change in unfunded pension liability related to unrealized loss and prior service cost, net of tax benefit of $(1,439), $(10), and $(56), respectively	4,151	31	90
Net change in cash flow hedge
Net unrealized gain (loss) arising during the period, net of tax expense (benefit) of $593, $(29), and $(113), respectively	1,877
Net unrealized (loss) arising during the period, net of tax (benefit)		(56)	(184)
Total other comprehensive income (loss)	38,895	(7,242)	1,125
Total comprehensive income	$ 187,704	$ 127,501	$ 51,369