Borrowings - Schedule of Borrowings (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Short-term borrowings
Federal funds purchased and repurchased agreements	$ 530,663	$ 354,670
FHLB Advances	6,200,000	3,200,281
Total short-term borrowings	6,730,663	3,554,951
Long-term borrowings
Asset-backed notes	516,668
FHLB Advances	4,956	5,183
Senior notes	3,741,161	1,249,141
Subordinated notes	857,876	866,296
Other	9,509	9,535
Total long-term borrowings	7,123,426	3,964,537
M&T [Member]
Long-term borrowings
Senior notes	1,377,985	1,220,965
Subordinated notes	76,339	77,337
Junior subordinated debentures	$ 538,932	$ 536,080