Retirement Benefit Plans - Contributions and Funding Status of the Fund (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Retirement Benefits [Abstract]
Contributions by Webster Bank	$ 448	$ 692	$ 998
Multiemployer Plan, Pension, Significant, Funded Status [Fixed List]	At least 80 percent	At least 80 percent