Borrowings	3 Months Ended
Mar. 31, 2014
Debt Disclosure [Abstract]
Borrowings	5. Borrowings M&T had $834 million of fixed and floating rate junior subordinated deferrable interest debentures (“Junior Subordinated Debentures”) outstanding at March 31, 2014 that are held by various trusts and 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 current risk-based capital guidelines, the Capital Securities are includable in M&T’s Tier 1 capital. However, in July 2013, the Federal Reserve Board, the Office of the Comptroller of the Currency and the Federal Deposit Insurance Corporation issued a final rule to comprehensively revise the capital framework for the U.S. banking sector. Under that rule, trust preferred capital securities will be phased out from inclusion in Tier 1 capital such that in 2015 only 25% of then-outstanding securities will be included in Tier 1 capital and beginning in 2016 none of the securities will be included in Tier 1 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 February 27, 2014, M&T redeemed all of the issued and outstanding 8.5% $350 million trust preferred securities issued by M&T Capital Trust IV and the related junior subordinated debentures held by M&T Capital Trust IV. Also included in long-term borrowings are agreements to repurchase securities of $1.4 billion at each of March 31, 2014 and December 31, 2013. The agreements are subject to master netting arrangements, however the Company has not offset any amounts related to these agreements in its consolidated financial statements. The Company posted collateral of $1.6 billion at each of March 31, 2014 and December 31, 2013.

5. Borrowings

M&T had $834 million of fixed and floating rate junior subordinated deferrable interest debentures (“Junior Subordinated Debentures”) outstanding at March 31, 2014 that are held by various trusts and 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 current risk-based capital guidelines, the Capital Securities are includable in M&T’s Tier 1 capital. However, in July 2013, the Federal Reserve Board, the Office of the Comptroller of the Currency and the Federal Deposit Insurance Corporation issued a final rule to comprehensively revise the capital framework for the U.S. banking sector. Under that rule, trust preferred capital securities will be phased out from inclusion in Tier 1 capital such that in 2015 only 25% of then-outstanding securities will be included in Tier 1 capital and beginning in 2016 none of the securities will be included in Tier 1 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 February 27, 2014, M&T redeemed all of the issued and outstanding 8.5% $350 million trust preferred securities issued by M&T Capital Trust IV and the related junior subordinated debentures held by M&T Capital Trust IV.

Also included in long-term borrowings are agreements to repurchase securities of $1.4 billion at each of March 31, 2014 and December 31, 2013. The agreements are subject to master netting arrangements, however the Company has not offset any amounts related to these agreements in its consolidated financial statements. The Company posted collateral of $1.6 billion at each of March 31, 2014 and December 31, 2013.