Significant accounting policies

6 Months Ended

Jun. 30, 2017

Accounting Policies [Abstract]

Significant accounting policies

1. Significant accounting policies

The consolidated financial statements of M&T Bank Corporation (“M&T”) and subsidiaries (“the Company”) were compiled in accordance with generally accepted accounting principles (“GAAP”) using the accounting policies set forth in note 1 of Notes to Financial Statements included in Form 10-K for the year ended December 31, 2016 (“2016 Annual Report”), except that effective January 2017 the Company adopted amended accounting guidance that is discussed in note 16 herein.  The most significant of those changes related to the accounting for excess tax benefits or deficiencies associated with share-based compensation whereby beginning in 2017 those amounts are recognized in income tax expense.  Previously, tax effects resulting from changes in M&T’s share price subsequent to the grant date were recorded through shareholders’ equity.  The adoption of this new accounting guidance resulted in a reduction of income tax expense for the three months ended March 31, 2017 of $18 million, or $.12 of diluted earnings per common share. The impact on income tax expense and diluted earnings per common share in the second quarter of 2017 was not significant.  In the opinion of management, all adjustments necessary for a fair presentation have been made and were all of a normal recurring nature.