Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 113,320	$ 147,918	$ 134,743
Less: Net loss attributable to noncontrolling interest	(1,454)	(891)	0
Net income attributable to WSFS	114,774	148,809	134,743
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 $12,585, $13,179, and $(2,223), respectively	39,853	41,733	(6,695)
Less: reclassification adjustment for net gains on sales realized in net income, net of tax expense of $2,178, $80, and $5, respectively	(6,898)	(253)	(16)
Net change in unrealized gains (losses) on investment securities available-for-sale	32,955	41,480	(6,711)
Net change in securities held-to-maturity
Amortization of unrealized gain on securities reclassified to held-to-maturity, net of tax expense of $60, $98, and $136, respectively	(192)	(311)	(444)
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 $585, $1,439, and $10, respectively	(1,683)	(4,151)	(31)
Pension settlement, net of tax expense of $67, $— and $—, respectively	212	0	0
Net change in unfunded pension liability	(1,471)	(4,151)	(31)
Net change in cash flow hedge
Net unrealized gain (loss) arising during the period, net of tax expense (benefit) of $493, $593, and $(29), respectively	1,560	1,877	(56)
Amortization of unrealized gain on terminated cash flow hedges, net of tax benefit of $106, $— and $—, respectively	(337)	0	0
Net change in cash flow hedge	1,223	1,877	(56)
Net change in other comprehensive loss of equity method investments, net of tax benefit of $3, $—, and $—, respectively	(9)	0	0
Total other comprehensive income (loss)	32,506	38,895	(7,242)
Total comprehensive income	$ 147,280	$ 187,704	$ 127,501