Borrowings	9 Months Ended
Sep. 30, 2020
Debt Disclosure [Abstract]
Borrowings	4. Borrowings M&T had $527 million of fixed and variable rate junior subordinated deferrable interest debentures ("Junior Subordinated Debentures") outstanding at September 30, 2020 that are held by various trusts that were issued in connection with the issuance by those trusts of preferred capital securities ("Capital Securities") and common securities ("Common Securities"). The proceeds from the issuances of the Capital Securities and the Common Securities were used by the trusts to purchase the Junior Subordinated Debentures. The Common Securities of each of those trusts are wholly owned by M&T and are the only class of each trust's securities possessing general voting powers. The Capital Securities represent preferred undivided interests in the assets of the corresponding trust. Under the Federal Reserve Board’s risk-based capital guidelines, the securities are includable in M&T’s Tier 2 regulatory capital. Holders of the Capital Securities receive preferential cumulative cash distributions unless M&T exercises its right to extend the payment of interest on the Junior Subordinated Debentures as allowed by the terms of each such debenture, in which case payment of distributions on the respective Capital Securities will be deferred for comparable periods. During an extended interest period, M&T may not pay dividends or distributions on, or repurchase, redeem or acquire any shares of its capital stock. In general, the agreements governing the Capital Securities, in the aggregate, provide a full, irrevocable and unconditional guarantee by M&T of the payment of distributions on, the redemption of, and any liquidation distribution with respect to the Capital Securities. The obligations under such guarantee and the Capital Securities are subordinate and junior in right of payment to all senior indebtedness of M&T. The Capital Securities will remain outstanding until the Junior Subordinated Debentures are repaid at maturity, are redeemed prior to maturity or are distributed in liquidation to the trusts. The Capital Securities are mandatorily redeemable in whole, but not in part, upon repayment at the stated maturity dates (ranging from 2027 to 2033) of the Junior Subordinated Debentures or the earlier redemption of the Junior Subordinated Debentures in whole upon the occurrence of one or more events set forth in the indentures relating to the Capital Securities, and in whole or in part at any time after an optional redemption prior to contractual maturity contemporaneously with the optional redemption of the related Junior Subordinated Debentures in whole or in part, subject to possible regulatory approval. On January 7, 2020, M&T Bank, the principal bank subsidiary of M&T, redeemed $750 million of fixed rate senior notes that were due to mature on February 6, 2020. In addition, M&T Bank redeemed $750 million of fixed rate senior notes on July 17, 2020 that were due to mature on August 17, 2020. Also included in long-term borrowings was an agreement to repurchase securities that totaled $102 million at December 31, 2019. The outstanding agreement matured in July 2020. The agreement was subject to legally enforceable master netting arrangements, however, the Company did not offset any amounts related to the agreement in its consolidated financial statements. The Company posted collateral consisting primarily of government guaranteed mortgage-backed securities of $108 million at December 31, 2019.

Borrowings

9 Months Ended

Sep. 30, 2020

4. Borrowings

M&T had $527 million of fixed and variable rate junior subordinated deferrable interest debentures ("Junior Subordinated Debentures") outstanding at September 30, 2020 that are held by various trusts that were issued in connection with the issuance by those trusts of preferred capital securities ("Capital Securities") and common securities ("Common Securities"). The proceeds from the issuances of the Capital Securities and the Common Securities were used by the trusts to purchase the Junior Subordinated Debentures. The Common Securities of each of those trusts are wholly owned by M&T and are the only class of each trust's securities possessing general voting powers. The Capital Securities represent preferred undivided interests in the assets of the corresponding trust. Under the Federal Reserve Board’s risk-based capital guidelines, the securities are includable in M&T’s Tier 2 regulatory capital.

Holders of the Capital Securities receive preferential cumulative cash distributions unless M&T exercises its right to extend the payment of interest on the Junior Subordinated Debentures as allowed by the terms of each such debenture, in which case payment of distributions on the respective Capital Securities will be deferred for comparable periods. During an extended interest period, M&T may not pay dividends or distributions on, or repurchase, redeem or acquire any shares of its capital stock. In general, the agreements governing the Capital Securities, in the aggregate, provide a full, irrevocable and unconditional guarantee by M&T of the payment of distributions on, the redemption of, and any liquidation distribution with respect to the Capital Securities. The obligations under such guarantee and the Capital Securities are subordinate and junior in right of payment to all senior indebtedness of M&T.

The Capital Securities will remain outstanding until the Junior Subordinated Debentures are repaid at maturity, are redeemed prior to maturity or are distributed in liquidation to the trusts. The Capital Securities are mandatorily redeemable in whole, but not in part, upon repayment at the stated maturity dates (ranging from 2027 to 2033) of the Junior Subordinated Debentures or the earlier redemption of the Junior Subordinated Debentures in whole upon the occurrence of one or more events set forth in the indentures relating to the Capital Securities, and in whole or in part at any time after an optional redemption prior to contractual maturity contemporaneously with the optional redemption of the related Junior Subordinated Debentures in whole or in part, subject to possible regulatory approval.

On January 7, 2020, M&T Bank, the principal bank subsidiary of M&T, redeemed $750 million of fixed rate senior notes that were due to mature on February 6, 2020. In addition, M&T Bank redeemed $750 million of fixed rate senior notes on July 17, 2020 that were due to mature on August 17, 2020.

Also included in long-term borrowings was an agreement to repurchase securities that totaled $102 million at December 31, 2019. The outstanding agreement matured in July 2020. The agreement was subject to legally enforceable master netting arrangements, however, the Company did not offset any amounts related to the agreement in its consolidated financial statements. The Company posted collateral consisting primarily of government guaranteed mortgage-backed securities of $108 million at December 31, 2019.