Relationship with BLG and Bayview Financial	3 Months Ended
Mar. 31, 2026
Equity Method Investments and Joint Ventures [Abstract]
Relationship with BLG and Bayview Financial	M&T holds a 20% minority interest in BLG, a privately-held commercial mortgage company. That investment had no remaining carrying value at March 31, 2026 as a result of cumulative losses recognized and cash distributions received in prior years. Cash distributions now received from BLG are recognized as income by M&T and included in Other revenues from operations in the Consolidated Statement of Income. That income totaled $33 million for the three months ended March 31, 2026. No distributions were received for the three months ended March 31, 2025. Bayview Financial, a privately-held specialty finance company, is BLG's majority investor. In addition to their common investment in BLG, the Company and Bayview Financial conduct other business activities with each other. The Company has loan servicing rights for mortgage loans securitized by Bayview Financial having outstanding principal balances of $847 million at March 31, 2026 and $875 million at December 31, 2025. The Company also sub-services residential mortgage loans for Bayview Financial having outstanding principal balances of $124.0 billion and $156.9 billion at March 31, 2026 and December 31, 2025, respectively. Revenues earned for servicing and sub-servicing such loans were $63 million and $41 million for the three months ended March 31, 2026 and 2025, respectively. The Company also held $30 million and $32 million of mortgage-backed securities in its held-to-maturity portfolio at March 31, 2026 and December 31, 2025, respectively, that were securitized by Bayview Financial. The Company had various lending commitments to Bayview Financial totaling $956 million at March 31, 2026, with $802 million and $635 million of outstanding balances at March 31, 2026 and December 31, 2025, respectively. Bayview Financial also maintained $3.6 billion and $3.5 billion of deposit balances with the Company at March 31, 2026 and December 31, 2025, respectively, inclusive of deposits related to loan servicing relationships.

M&T holds a 20% minority interest in BLG, a privately-held commercial mortgage company. That investment had no remaining carrying value at March 31, 2026 as a result of cumulative losses recognized and cash distributions received in prior years. Cash distributions now received from BLG are recognized as income by M&T and included in Other revenues from operations in the Consolidated Statement of Income. That income totaled $33 million for the three months ended March 31, 2026. No distributions were received for the three months ended March 31, 2025.

Bayview Financial, a privately-held specialty finance company, is BLG's majority investor. In addition to their common investment in BLG, the Company and Bayview Financial conduct other business activities with each other. The Company has loan servicing rights for mortgage loans securitized by Bayview Financial having outstanding principal balances of $847 million at March 31, 2026 and $875 million at December 31, 2025. The Company also sub-services residential mortgage loans for Bayview Financial having outstanding principal balances of $124.0 billion and $156.9 billion at March 31, 2026 and December 31, 2025, respectively. Revenues earned for servicing and sub-servicing such loans were $63 million and $41 million for the three months ended March 31, 2026 and 2025, respectively.

The Company also held $30 million and $32 million of mortgage-backed securities in its held-to-maturity portfolio at March 31, 2026 and December 31, 2025, respectively, that were securitized by Bayview Financial. The Company had various lending commitments to Bayview Financial totaling $956 million at March 31, 2026, with $802 million and $635 million of outstanding balances at March 31, 2026 and December 31, 2025, respectively. Bayview Financial also maintained $3.6 billion and $3.5 billion of deposit balances with the Company at March 31, 2026 and December 31, 2025, respectively, inclusive of deposits related to loan servicing relationships.