GOODWILL AND INTANGIBLE ASSETS - Schedule of Allocation of Goodwill to our Reportable Operating Segments for Purposes of Goodwill Impairment Testing (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2025 USD ($)
Goodwill [Roll Forward]
Goodwill beginning balance	$ 885,898
Goodwill adjustments	(674)
Goodwill ending balance	885,224
WSFS Bank
Goodwill [Roll Forward]
Goodwill beginning balance	753,586
Goodwill adjustments	0
Goodwill ending balance	753,586
Wealth and Trust
Goodwill [Roll Forward]
Goodwill beginning balance	132,312
Goodwill adjustments	(674)
Goodwill ending balance	$ 131,638