Contingencies	12 Months Ended
Contingencies	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies Legal and Regulatory Matters In the ordinary course of business, we and our subsidiaries are involved in disputes, litigation, and governmental or regulatory inquiries and investigations, both pending and threatened. These matters, if resolved adversely against us or settled, may result in monetary awards or payments, fines and penalties or require changes in our business practices. The resolution or settlement of these matters is inherently difficult to predict. Based on our assessment of these pending matters, we do not believe that the amount of any judgment, settlement or other action arising from any pending matter is likely to have a material adverse effect on our consolidated financial condition. However, an adverse outcome or development in certain of the matters described below could have a material adverse effect on our consolidated results of operations for the period in which such matter is resolved, or an accrual is determined to be required, on our consolidated financial condition, or on our reputation. We evaluate our needs for accruals of loss contingencies related to legal and regulatory proceedings on a case-by-case basis. When we have a liability that we deem probable, and we deem the amount of such liability can be reasonably estimated as of the date of our consolidated financial statements, we accrue our estimate of the amount of loss. We also consider a loss probable and establish an accrual when we make, or intend to make, an offer of settlement. Once established, an accrual is subject to subsequent adjustment as a result of additional information. The resolution of legal and regulatory proceedings and the amount of reasonably estimable loss (or range thereof) are inherently difficult to predict, especially in the early stages of proceedings. Even if a loss is probable, an amount (or range) of loss might not be reasonably estimated until the later stages of the proceeding due to many factors such as the presence of complex or novel legal theories, the discretion of governmental authorities in seeking sanctions or negotiating resolutions in civil and criminal matters, the pace and timing of discovery and other assessments of facts and the procedural posture of the matter (collectively, “factors influencing reasonable estimates”). As of December 31, 2023, our aggregate accruals for loss contingencies for legal, regulatory and related matters totaled approximately $20 million, including potential fines by government agencies and civil litigation with respect to the matters specifically discussed below. To the extent that we have established accruals in our consolidated statement of condition for probable loss contingencies, such accruals may not be sufficient to cover our ultimate financial exposure associated with any settlements or judgments. Any such ultimate financial exposure, or proceedings to which we may become subject in the future, could have a material adverse effect on our businesses, on our future consolidated financial statements or on our reputation. As of December 31, 2023, for those matters for which we have accrued probable loss contingencies (including the Invoicing Matter described below) and for other matters for which loss is reasonably possible (but not probable) in future periods, and for which we are able to estimate a range of reasonably possible loss, our estimate of the aggregate reasonably possible loss (in excess of any accrued amounts) ranges up to approximately $40 million. Our estimate with respect to the aggregate reasonably possible loss is based upon currently available information and is subject to significant judgment and a variety of assumptions and known and unknown uncertainties, which may change quickly and significantly from time to time, particularly if and as we engage with applicable governmental agencies or plaintiffs in connection with a proceeding. Also, the matters underlying the reasonably possible loss will change from time to time. As a result, actual results may vary significantly from the current estimate. In certain pending matters, it is not currently feasible to reasonably estimate the amount or a range of reasonably possible loss, and such losses, which may be significant, are not included in the estimate of reasonably possible loss discussed above. This is due to, among other factors, the factors influencing reasonable estimates described above. An adverse outcome in one or more of the matters for which we have not estimated the amount or a range of reasonably possible loss, individually or in the aggregate, could have a material adverse effect on our businesses, on our future consolidated financial statements or on our reputation. Given that our actual losses from any legal or regulatory proceeding for which we have provided an estimate of the reasonably possible loss could significantly exceed such estimate, and given that we cannot estimate reasonably possible loss for all legal and regulatory proceedings as to which we may be subject now or in the future, no conclusion as to our ultimate exposure from current pending or potential legal or regulatory proceedings should be drawn from the current estimate of reasonably possible loss. The following discussion provides information with respect to significant legal, governmental and regulatory matters. Invoicing Matter In 2015, we determined that we had incorrectly invoiced clients for certain expenses. We have reimbursed most of our affected customers for those expenses, and we have implemented enhancements to our billing processes. In connection with our enhancements to our billing processes, we continue to review historical billing practices and may from time to time identify additional remediation. In 2017, we identified an additional area of incorrect expense billing associated with mailing services in our retirement services business. We currently expect the cumulative total of our payments to customers for these invoicing errors, including the error in the retirement services business, to be at least $350 million, all of which has been paid or is accrued. However, we may identify additional remediation costs. We resolved potential criminal claims that arose from these matters by entering into a deferred prosecution agreement with the office of the United States Attorney for the District of Massachusetts and paying a $115 million penalty in May 2021. In June 2019, we reached an agreement with the SEC to settle its claims that we violated the recordkeeping provisions of Section 34(b) of the Investment Company Act of 1940 and caused violations of Section 31(a) of the Investment Company Act and Rules 31a-1(a) and 31a-1(b) thereunder in connection with our overcharges of customers which are registered investment companies. In reaching this settlement, we neither admitted nor denied the claims contained in the SEC’s order, and agreed to pay a civil monetary penalty of $40 million. Also in June 2019, we reached an agreement with the Massachusetts Attorney General’s office to resolve its claims related to this matter. In reaching this settlement, we neither admitted nor denied the claims in the order, and agreed to pay a civil monetary penalty of $5.5 million. The SEC and Massachusetts Attorney General’s office settlements both recognize that the payment of $48.8 million in disgorgement and interest is satisfied by our direct reimbursements of our customers. We paid fines to resolve claims of the Securities Divisions of the Secretaries of the State of Massachusetts and New Hampshire. The costs associated with the settlements discussed above were within our related and previously established accruals for loss contingencies. We have not resolved certain claims that may be made by the U.S. Department of Labor. We do not know whether any such claims will be brought, and there can be no assurance that any settlement of any such claims will be reached on financial terms acceptable to us or at all. The aggregate amount of penalties that may potentially be imposed upon us in connection with the resolution of any such matters is not currently known. Gomes, et al. v. State Street Corp. Eight participants in our Salary Savings Program filed a purported class action complaint in May 2021 on behalf of participants and beneficiaries who participated in the Program and invested in our proprietary investment fund options between May 2015 and the present. The complaint names the Plan Sponsor as well as the committees overseeing the Plan and their respective members as defendants, and alleges breach of fiduciary duty and violations of other duties owed to retirement plan participants under the Employee Retirement Income and Security Act. We have agreed, subject to court approval, to resolve this matter and pay a cost that is within our established accruals for loss contingencies. Edmar Financial Company, LLC et al v. Currenex, Inc. et al In August 2021, two former Currenex clients filed a putative civil class action lawsuit in the Southern District of New York alleging antitrust violations, fraud and a civil Racketeer Influenced and Corrupt Organization Act violation against Currenex, State Street and others. German Tax Matter In connection with a routine audit including the period 2013-2015, German tax authorities have questioned whether State Street should have withheld and be secondarily liable for certain taxes on dividends paid on securities of German issuers held as collateral over dividend record dates in client lending transactions with counterparties outside of Germany. Income Taxes In determining our provision for income taxes, we make certain judgments and interpretations with respect to tax laws in jurisdictions in which we have business operations. Because of the complex nature of these laws, in the normal course of our business, we are subject to challenges from U.S. and non-U.S. income tax authorities regarding the amount of income taxes due. These challenges may result in adjustments to the timing or amount of taxable income or deductions or the allocation of taxable income among tax jurisdictions. We recognize a tax benefit when it is more likely than not that our position will result in a tax deduction or credit. Unrecognized tax benefits of approximately $237 million as of December 31, 2023 decreased from $285 million as of December 31, 2022. We are presently under audit by a number of tax authorities. The earliest tax year open to examination in jurisdictions where we have material operations is 2015. Management believes that we have sufficiently accrued liabilities as of December 31, 2023 for potential tax exposures.

The entire disclosure for loss and gain contingencies. Describes any existing condition, situation, or set of circumstances involving uncertainty as of the balance sheet date (or prior to issuance of the financial statements) as to a probable or reasonably possible loss incurred by an entity that will ultimately be resolved when one or more future events occur or fail to occur, and typically discloses the amount of loss recorded or a range of possible loss, or an assertion that no reasonable estimate can be made.