CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 50,823	$ 53,595	$ 53,579	$ 102,494
Less: Net loss attributable to noncontrolling interest	(322)	(287)	(1,382)	(611)
Net income attributable to WSFS	51,145	53,882	54,961	103,105
Net change in unrealized (losses) gains on investment securities available-for-sale
Net unrealized (losses) gains arising during the period, net of tax (benefit) expense of $(1,097), $2,911, $14,610 and $14,565, respectively	(3,474)	9,268	46,264	46,124
Less: reclassification adjustment for net gains on sales realized in net income, net of tax expense of $797, $—, $1,421, and $19, respectively	(2,525)	0	(4,501)	(59)
Net change in unrealized gains (losses) on investment securities available-for-sale	(5,999)	9,268	41,763	46,065
Net change in securities held-to-maturity
Amortization of unrealized gain on securities reclassified to held-to-maturity, net of tax expense of $12, $22, $50, and $78, respectively	(39)	(70)	(161)	(247)
Net change in unfunded pension liability
Change in unfunded pension liability related to unrealized loss, prior service cost and transition obligation, net of tax benefit of $8, $11, $15, and $66, respectively	(25)	(35)	(47)	(210)
Pension settlement, net of tax expense of $—, $—, $67, and $—, respectively	0	0	212	0
Net change in unfunded pension liability	(25)	(35)	165	(210)
Net change in cash flow hedge
Net unrealized gain arising during the period, net of tax expense of $—, $116, $493, and $633, respectively	0	368	1,560	2,005
Amortization of unrealized gain on terminated cash flow hedges, net of tax benefit of $36, $—, $71, and $—, respectively	(113)	0	(224)	0
Net change in cash flow hedge	(113)	368	1,336	2,005
Net change in other comprehensive loss of equity method investments, net of tax benefit of $3, $—, $3, and $—, respectively	(9)	0	(9)	0
Total other comprehensive (loss) income	(6,185)	9,531	43,094	47,613
Total comprehensive income	$ 44,960	$ 63,413	$ 98,055	$ 150,718