Business Combinations - Narrative (Details) $ / shares in Units, $ in Thousands				3 Months Ended	6 Months Ended
	Apr. 01, 2022 USD ($) $ / shares shares	Feb. 01, 2022 USD ($)	Dec. 01, 2021 USD ($) Branch shares	Jun. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)
Business Acquisition [Line Items]
Non-credit discount at acquisition	$ 18,814
Goodwill				$ 1,871,505	$ 1,871,505	$ 1,459,008
Assets				54,438,807	54,438,807	43,446,443
Loans				43,091,958	43,091,958	33,794,455
Deposits				43,881,051	43,881,051	$ 35,632,412
Goodwill increase					5,000
Merger expenses				$ 54,500	$ 58,900
Other
Business Acquisition [Line Items]
Finite-lived intangible asset, useful life	10 years
Finite-lived intangible assets, remaining amortization period	14 years
Westchester Bank Holding Corporation
Business Acquisition [Line Items]
Assets			$ 1,400,000
Loans			915,000
Deposits			$ 1,200,000
Number of branches | Branch			7
Landmark Insurance of the Palm Beaches
Business Acquisition [Line Items]
Cash paid in acquisition		$ 8,600
Contingent consideration		1,000
Goodwill		4,400
Other intangible assets		$ 6,200
Westchester Bank Holding Corporation
Business Acquisition [Line Items]
Number of shares issued for every share owned (in shares) | shares			229.645
Shares issued in connection with acquisition (in shares) | shares			15,700,000
Consideration transferred			$ 211,100
Bank Leumi Le-Israel Corporation
Business Acquisition [Line Items]
Number of shares issued for every share owned (in shares) | shares	3.8025
Cash paid for every share owned (in dollars per share) | $ / shares	$ 5.08
Shares issued in connection with acquisition (in shares) | shares	85,000,000
Cash paid in acquisition	$ 113,400
Consideration transferred	$ 1,200,000
Percentage of common stock transferred	14.00%