Business Combinations - Narrative (Details) $ / shares in Units, $ in Thousands		3 Months Ended
	Mar. 01, 2019 USD ($) Branch $ / shares	Jun. 30, 2019 Branch	Dec. 31, 2018 Branch	Dec. 31, 2020 Branch
Business Acquisition [Line Items]
Share price (USD per share) | $ / shares	$ 43.28
Number of offices sold			11
Beneficial
Business Acquisition [Line Items]
Shares issued	0.3013
Cash paid per share (USD per share) | $ / shares	$ 2.93
Stock consideration | $	$ 949,968
Cash paid to Beneficial stock and option holders | $	228,239
Value of consideration | $	$ 1,178,207
Number of branches acquired	74
Number of offices sold			14
Number of remaining retail locations				6
Number of offices sold during acquisition		5
Deposit premium percentage		7.37%