Acquisition and Divestitures - Summary of Merger Related Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outside data processing and software	$ 376,493	$ 291,839	$ 258,480
Advertising and marketing	90,748	64,428	$ 61,904
Peoples United Financial Inc [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Salaries and employee benefits	102,150	176
Equipment and net occupancy	6,709	341
Outside data processing and software	5,438	1,119
Advertising and marketing	9,262	866
Printing, postage and supplies	6,786	2,965
Other cost of operations	207,976	38,393
Other Expenses	$ 338,321	$ 43,860