Basis of presentation (Policies)	9 Months Ended
Sep. 30, 2022
Accounting Policies [Abstract]
Basis of presentation	Basis of presentation The accounting and financial reporting policies of BNY Mellon, a global financial services company, conform to U.S. generally accepted accounting principles (“GAAP”) and prevailing industry practices. For information on our significant accounting and reporting policies, see Note 1 of the Notes to Consolidated Financial Statements in our Annual Report on Form 10-K for the year ended Dec. 31, 2021 (the “2021 Annual Report”). The accompanying consolidated financial statements are unaudited. In the opinion of management, all adjustments necessary, consisting of normal recurring adjustments, for a fair presentation of financial position, results of operations and cash flows for the periods presented have been made. These financial statements should be read in conjunction with our Consolidated Financial Statements included in our 2021 Annual Report.
Reclassifications	Certain additional immaterial reclassifications have been made to prior periods to place them on a basis comparable with the current period presentation.
Use of estimates	Use of estimatesThe preparation of financial statements in conformity with U.S. GAAP requires management to make estimates based upon assumptions about future economic and market conditions which affect reported amounts and related disclosures in our financial statements. Although our current estimates contemplate current conditions and how we expect them to change in the future, it is reasonably possible that actual conditions could be worse than anticipated in those estimates, which could materially affect our results of operations and financial condition.
New accounting guidance	Staff Accounting Bulletin No. 121 In March 2022, the SEC staff released Staff Accounting Bulletin No. 121 (“SAB 121”). SAB 121 expresses the staff’s views regarding the accounting for entities that have obligations to safeguard “crypto-assets” held for their platform users. SAB 121 provides that these entities should present a liability and corresponding asset in respect of the crypto-assets safeguarded for their platform users, with the liability and asset measured at the fair value of the crypto-assets. This differs from the accounting treatment of non-crypto-assets held in custody, which do not result in assets recorded on a custodian’s balance sheet. We adopted the guidance in the third quarter of 2022 and recorded a de minimis asset and liability related to digital assets we safeguard.
Fair value measurement	Fair value measurementFair value is defined as the price that would be received to sell an asset, or paid to transfer a liability, in an orderly transaction between market participants at the measurement date. A three-level hierarchy for fair value measurements is utilized based upon the transparency of inputs to the valuation of an asset or liability as of the measurement date. BNY Mellon’s own creditworthiness is considered when valuing liabilities. See Note 20 of the Notes to Consolidated Financial Statements in our 2021 Annual Report for information on how we determine fair value and the fair value hierarchy.

Basis of presentation (Policies)

9 Months Ended

Sep. 30, 2022

The accounting and financial reporting policies of BNY Mellon, a global financial services company, conform to U.S. generally accepted accounting principles (“GAAP”) and prevailing industry practices. For information on our significant accounting and reporting policies, see Note 1 of the Notes to Consolidated Financial Statements in our Annual Report on Form 10-K for the year ended Dec. 31, 2021 (the “2021 Annual Report”).

The accompanying consolidated financial statements are unaudited. In the opinion of management, all adjustments necessary, consisting of normal recurring adjustments, for a fair presentation of financial position, results of operations and cash flows for the periods presented have been made. These financial statements should be read in conjunction with our Consolidated Financial Statements included in our 2021 Annual Report.

Reclassifications

Certain additional immaterial reclassifications have been made to prior periods to place them on a basis comparable with the current period presentation.

Use of estimates

Use of estimatesThe preparation of financial statements in conformity with U.S. GAAP requires management to make estimates based upon assumptions about future economic and market conditions which affect reported amounts and related disclosures in our financial statements. Although our current estimates contemplate current conditions and how we expect them to change in the future, it is reasonably possible that actual conditions could be worse than anticipated in those estimates, which could materially affect our results of operations and financial condition.

New accounting guidance

Staff Accounting Bulletin No. 121

In March 2022, the SEC staff released Staff Accounting Bulletin No. 121 (“SAB 121”). SAB 121

expresses the staff’s views regarding the accounting for entities that have obligations to safeguard “crypto-assets” held for their platform users. SAB 121 provides that these entities should present a liability and corresponding asset in respect of the crypto-assets safeguarded for their platform users, with the liability and asset measured at the fair value of the crypto-assets. This differs from the accounting treatment of non-crypto-assets held in custody, which do not result in assets recorded on a custodian’s balance sheet. We adopted the guidance in the third quarter of 2022 and recorded a de minimis asset and liability related to digital assets we safeguard.

Fair value measurement

Fair value measurementFair value is defined as the price that would be received to sell an asset, or paid to transfer a liability, in an orderly transaction between market participants at the measurement date. A three-level hierarchy for fair value measurements is utilized based upon the transparency of inputs to the valuation of an asset or liability as of the measurement date. BNY Mellon’s own creditworthiness is considered when valuing liabilities. See Note 20 of the Notes to Consolidated Financial Statements in our 2021 Annual Report for information on how we determine fair value and the fair value hierarchy.