Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2016

Accounting Policies [Abstract]

Recent Accounting Developments

Recent Accounting Developments:

Relevant standards that were recently issued but not yet adopted
Standard	Description	Date of Adoption	Effects on the financial statements or other significant matters
ASU 2014-09, Revenue from Contracts with Customers (Topic 606)	The standard, and its related amendments, will replace existing revenue recognition standards and expand the disclosure requirements for revenue arrangements with customers. Under the new standard, revenue is recognized when a customer obtains control of promised goods or services and is recognized in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. The guidance permits two methods of adoption: retrospectively to each prior reporting period presented (full retrospective method), or retrospectively with the cumulative effect of initially applying the guidance recognized at the date of initial application (the modified retrospective method).	January 1, 2018	We are currently assessing the full impact of the revenue recognition standard and its amendments on our consolidated financial statements and evaluating the alternative methods of adoption. The standard does not apply to revenue associated with financial instruments, including loans and securities, or revenue recognized under other U.S. GAAP standards. Therefore net interest revenue, securities gains/ losses, revenue related to derivative instruments are not impacted by the standard. Our implementation efforts include the scoping of material revenue streams into cohorts, analysis of underlying contracts for each cohort, business unit workshops to further assess specific contracts and products, and the development of updated disclosures. Based on our efforts to date, we expect both the timing and amount of our material revenue streams, including servicing fees, management fees, trading services, and securities finance to remain substantially unchanged as these revenues likely will continue to be recognized over time. Specifically, under the new standard we expect to recognize revenue related to these activities ratably over the term of the related agreements with customers as the customer simultaneously benefits from the services as they are performed. Due to the complexity of certain of our agreements, the actual revenue recognition treatment required under the standard will be dependent on contract-specific terms, and certain aspects may vary in some instances from recognition ratably over the contract term. While we have not yet identified any material changes, we continue to monitor industry progress and focus our assessment on areas such as any additional costs that may require capitalization under the new standard as well as assessing the impact of changes to principal and agent guidance. The new standard modified some of the principal and agent considerations which may result in changes to gross or net treatment of revenue and expenses but would not affect final net income. Although we currently expect no material changes to the timing or amount of revenue, we are still assessing the operational and disclosure impacts of each transition method.
ASU 2016-01, Financial Instruments-Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities	The standard makes limited amendments to the guidance on the classification and measurement of financial instruments. Under the new standard, all equity securities will be measured at fair value through earnings with certain exceptions, including investments accounted for under the equity method of accounting. In addition, the FASB clarified the guidance related to valuation allowance assessments when recognizing deferred tax assets on unrealized losses on available-for-sale debt securities. This standard must be applied on a retrospective basis.	January 1, 2018	We are currently assessing the impact of the standard on our consolidated financial statements. Based on our initial assessments, we do not currently anticipate this standard to have a material impact on our consolidated financial statements due to the limited number of investments on our consolidated statement of condition that are within scope of the standard.
ASU 2016-02, Leases (Topic 842)	The standard represents a wholesale change to lease accounting and requires all leases, other than short-term leases, to be reported on balance sheet through recognition of a right-of-use asset and a corresponding liability for future lease obligations. The standard also requires extensive disclosures for assets, expenses, and cash flows associated with leases, as well as a maturity analysis of lease liabilities.	January 1, 2019	We are currently assessing the impact of the standard on our consolidated financial statements, but we anticipate an increase in assets and liabilities due to the recognition of the required right-of-use asset and corresponding liability for all lease obligations that are currently classified as operating leases, primarily real estate leases for office space, as well as additional disclosure on all our lease obligations.
ASU 2016-05, Derivatives and Hedging (Topic 815): Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships (a consensus of the Emerging Issues Task Force)	The standard clarifies that the novation of a derivative contract that is part of a hedge accounting relationship does not automatically require a dedesignation of that hedge relationship. This may be applied on a prospective or modified retrospective basis.	January 1, 2017	State Street will apply this standard prospectively as applicable, but we do not anticipate a material impact on our consolidated financial statements.

Relevant standards that were recently issued but not yet adopted (continued)
Standard	Description	Date of Adoption	Effects on the financial statements or other significant matters
ASU 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting	The standard simplifies the guidance related to stock compensation, including the accounting for income taxes by eliminating the windfall pool and requiring recognition of all excess tax benefits and deficiencies within the statement of income, as well as changes in the accounting for forfeitures, classification in the statement of cash flows and tax withholding requirements.	January 1, 2017	We anticipate increased income statement volatility due to the recognition of all excess tax benefits and deficiencies within the consolidated statement of income. Income statement volatility will be driven by the number of shares vesting in any given period, and the change in share price between grant date and vesting. Directionally, increasing share prices from grant date to vesting date will result in lower income tax expense and higher net income. Upon adoption of the standard on January 1, 2017, excess tax benefits accumulated in surplus of approximately $352 million will be reversed through retained earnings.
ASU 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments	The standard requires immediate recognition of expected credit losses for financial assets carried at amortized cost, including trade and other receivables, loans and commitments, held-to-maturity debt securities, and other financial assets, held at the reporting date to be measured based on historical experience, current conditions, and reasonable supportable forecasts. Credit losses on available for sale securities will be recorded as an allowance versus a write-down of the amortized cost basis of the security and will allow for a reversal of impairment loss when the credit of the issuer improves.	January 1, 2020	We are currently assessing the impact of the standard on our consolidated financial statements, but we anticipate a significant implementation effort to ensure that expected credit losses are calculated in accordance with the standard.  We have established a steering committee to provide cross-functional governance over the project plan and key decisions, and are currently developing key accounting policies, evaluating existing credit loss models and processes and identifying a complete set of data requirements and sources.  Based on our analysis to date, we expect a significant effort to develop new or modified credit loss models and that the timing of the recognition of credit losses will accelerate under the new standard.
ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force)	The standard amends the statement of cash flow guidance to address specific cash flow issues with the objective of reducing the existing diversity in practice.	January 1, 2018	We are currently assessing the impact of the standard on our consolidated financial statements, however based on our current presentation we do not anticipate a significant change to our financial statement presentation of the statement of cash flows.

Relevant standards that were recently issued but not yet adopted
Standard	Description	Date of Adoption	Effects on the financial statements or other significant matters
ASU 2014-09, Revenue from Contracts with Customers (Topic 606)	The standard, and its related amendments, will replace existing revenue recognition standards and significantly expand the disclosure requirements for revenue arrangements with customers. It may be adopted either retrospectively or on a modified retrospective basis to new contracts and existing contracts with remaining performance obligations as of the effective date.	January 1, 2018	We are currently assessing the impact of the standard and its amendments on our consolidated financial statements and evaluating the alternative methods of adoption.
ASU 2016-01, Financial Instruments-Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities	The standard makes limited amendments to the guidance on the classification and measurement of financial instruments. Under the new standard, all equity securities will be measured at fair value through earnings with certain exceptions, including investments accounted for under the equity method of accounting. In addition, the FASB clarified the guidance related to valuation allowance assessments when recognizing deferred tax assets on unrealized losses on available-for-sale debt securities. This standard must be applied on a retrospective basis.	January 1, 2018	We are currently assessing the impact of the standard on our consolidated financial statements.
ASU 2016-02, Leases (Topic 842)	The standard represents a wholesale change to lease accounting and requires all leases, other than short-term leases, to be reported on balance sheet through recognition of a right-of-use asset and a corresponding liability for future lease obligations. The standard also requires extensive disclosures for assets, expenses, and cash flows associated with leases, as well as a maturity analysis of lease liabilities.	January 1, 2019	We are currently assessing the impact of the standard on our consolidated financial statements, but we anticipate an increase in assets and liabilities due to the recognition of the required right-of-use asset and corresponding liability for all lease obligations that are currently classified as operating leases, as well as additional disclosure on our leases.
ASU 2016-05, Derivatives and Hedging (Topic 815): Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships (a consensus of the Emerging Issues Task Force)	The standard clarifies that a change in the counterparty to a derivative instrument that is designated as a hedging instrument would result in dedesignation of the hedging relationship. This may be applied on a prospective or modified retrospective basis.	January 1, 2017	Our adoption of the standard will not have a material impact on our consolidated financial statements.
ASU 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting	The standard simplifies the guidance related to stock compensation, including the accounting for income taxes by eliminating the windfall pool and requiring recognition of all excess tax benefits and deficiencies within the statement of income, as well as changes in the accounting for forfeitures, classification in the statement of cash flows and tax withholding requirements.	January 1, 2017	We anticipate increased income statement volatility due to the recognition of all excess tax benefits and deficiencies within the statement of income. We do not anticipate early adoption of this standard.
ASU 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments	The standard requires all expected credit losses for financial assets held at the reporting date to be measured based on historical experience, current conditions, and reasonable supportable forecasts. The standard will utilize forward-looking information to determine credit loss estimates. It will require immediate recognition of the full amount of credit losses that are expected for certain financial assets.	January 1, 2020	We are currently assessing the impact of the standard on our consolidated financial statements.
ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force)	The standard amends the statement of cash flow guidance to address specific cash flow issues with the objective of reducing the existing diversity in practice.	January 1, 2018	We are currently assessing the impact of the standard on our consolidated financial statements, however based on our current presentation we do not anticipate a significant change to our financial statement presentation of the statement of cash flows.