State Street (STT) 10-Q 1 Nov 17 2017 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Oct. 31, 2017
Document And Entity Information [Abstract]
Entity Registrant Name	STATE STREET Corp
Entity Central Index Key	93,751
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		370,836,680

Consolidated Statement of Incom

Consolidated Statement of Income - USD ($) shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Fee revenue:
Servicing fees	$ 1,351	$ 1,303	$ 3,986	$ 3,784
Management fees	419	368	1,198	931
Trading services	259	267	823	806
Securities finance	147	136	459	426
Processing fees and other	66	5	209	155
Total fee revenue	2,242	2,079	6,675	6,102
Net interest income:
Interest income	761	647	2,111	1,896
Interest expense	158	110	423	326
Net interest income	603	537	1,688	1,570
Gains (losses) related to investment securities, net:
Gains (losses) from sales of available-for-sale securities, net	1	6	(39)	7
Losses from other-than-temporary impairment	0	(2)	0	(2)
Gains (losses) related to investment securities, net	1	4	(39)	5
Total revenue	2,846	2,620	8,324	7,677
Provision for loan losses	3	0	4	8
Expenses:
Compensation and employee benefits	1,090	1,013	3,327	3,109
Information systems and communications	296	285	866	827
Transaction processing services	215	200	619	601
Occupancy	118	107	344	331
Acquisition and restructuring costs	33	42	133	166
Professional services	71	95	262	270
Amortization of other intangible assets	54	55	160	153
Other	144	187	427	437
Total expenses	2,021	1,984	6,138	5,894
Income before income tax expense	822	636	2,182	1,775
Income tax expense (benefit)	137	72	375	226
Net income from non-controlling interest	0	(1)	0	1
Net income	685	563	1,807	1,550
Net income available to common shareholders	$ 629	$ 507	$ 1,659	$ 1,411
Earnings per common share:
Basic (in USD per share)	$ 1.69	$ 1.31	$ 4.41	$ 3.58
Diluted (in USD per share)	$ 1.66	$ 1.29	$ 4.35	$ 3.54
Average common shares outstanding (in thousands):
Basic (in shares)	372,765	388,358	376,430	393,959
Diluted (in shares)	378,518	393,212	381,779	398,413
Cash dividends declared (in USD per share)	$ 0.42	$ 0.38	$ 1.18	$ 1.06

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 685	$ 563	$ 1,807	$ 1,550
Other comprehensive income (loss), net of related taxes:
Foreign currency translation, net of related taxes of ($7) and ($14), respectively	259	38	785	132
Net unrealized gains (losses) on available-for-sale securities, net of reclassification adjustment and net of related taxes of $28 and ($11), respectively	47	(13)	519	533
Net unrealized gains (losses) on available-for-sale securities designated in fair value hedges, net of related taxes of $4 and $9, respectively	4	13	13	(9)
Other-than-temporary impairment on held-to-maturity securities related to factors other than credit, net of related taxes of $1 and $1, respectively	1	2	3	5
Net unrealized gains (losses) on cash flow hedges, net of related taxes of ($15) and ($27), respectively	(27)	(39)	(274)	(213)
Net unrealized gains (losses) on retirement plans, net of related taxes of $0 and ($1), respectively	2	3	10	1
Other comprehensive income (loss)	286	4	1,056	449
Total comprehensive income	$ 971	$ 567	$ 2,863	$ 1,999

Consolidated Statement of Comp4

Consolidated Statement of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Foreign currency translation, Taxes	$ (7)	$ (14)	$ 6	$ (24)
Change in net unrealized losses on available-for-sale securities, Taxes	28	(11)	336	347
Change in net unrealized losses on available-for-sale securities designated in fair value hedges, Taxes	4	9	9	(6)
Other-than-temporary impairment on held-to-maturity securities related to factors other than credit, Taxes	1	1	2	3
Change in net unrealized losses on cash flow hedges, Taxes	(15)	(27)	(179)	(144)
Change in unrealized losses on retirement plans, Taxes	$ 0	$ (1)	$ 2	$ 2

Consolidated Statement of Condi

Consolidated Statement of Condition - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Assets:
Cash and due from banks	$ 3,939	$ 1,314
Interest-bearing deposits with banks	60,956	70,935
Securities purchased under resale agreements	3,465	1,956
Trading account assets	1,135	1,024
Investment securities available-for-sale	56,238	61,998
Investment securities held-to-maturity (fair value of $36,836 and $34,994)	36,850	35,169
Loans and leases (less allowance for losses of $51 and $46)	23,581	19,704
Premises and equipment (net of accumulated depreciation of $3,750 and $3,333)	2,167	2,062
Accrued interest and fees receivable	3,043	2,644
Goodwill	5,997	5,814
Other intangible assets	1,658	1,750
Other assets	36,957	38,328
Total assets	235,986	242,698
Deposits:
Non-interest-bearing	49,850	59,397
Interest-bearing—U.S.	49,394	30,911
Interest-bearing—non-U.S.	80,019	96,855
Total deposits	179,263	187,163
Securities sold under repurchase agreements	3,867	4,400
Other short-term borrowings	1,253	1,585
Accrued expenses and other liabilities	17,390	16,901
Long-term debt	11,716	11,430
Total liabilities	213,489	221,479
Commitments, guarantees and contingencies (Notes 9 and 10)
Shareholders’ equity:
Common stock, $1 par: 750,000,000 shares authorized; 503,879,642 and 503,879,642 shares issued	504	504
Surplus	9,803	9,782
Retained earnings	18,675	17,459
Accumulated other comprehensive income (loss)	(984)	(2,040)
Treasury stock, at cost (133,038,955 and 121,940,502 shares)	(8,697)	(7,682)
Total shareholders’ equity	22,497	21,219
Total liabilities and shareholders' equity	235,986	242,698
Series C Preferred Stock
Shareholders’ equity:
Preferred stock, no par: 3,500,000 shares authorized; Series C, 5,000 shares issued and outstanding, Series D, 7,500 shares issued and outstanding, Series E, 7,500 shares issued and outstanding, Series F, 7,500 shares issued and outstanding, and Series G, 5,000 shares issued and outstanding	491	491
Series D Preferred Stock
Shareholders’ equity:
Preferred stock, no par: 3,500,000 shares authorized; Series C, 5,000 shares issued and outstanding, Series D, 7,500 shares issued and outstanding, Series E, 7,500 shares issued and outstanding, Series F, 7,500 shares issued and outstanding, and Series G, 5,000 shares issued and outstanding	742	742
Series E Preferred Stock
Shareholders’ equity:
Preferred stock, no par: 3,500,000 shares authorized; Series C, 5,000 shares issued and outstanding, Series D, 7,500 shares issued and outstanding, Series E, 7,500 shares issued and outstanding, Series F, 7,500 shares issued and outstanding, and Series G, 5,000 shares issued and outstanding	728	728
Series F Preferred Stock
Shareholders’ equity:
Preferred stock, no par: 3,500,000 shares authorized; Series C, 5,000 shares issued and outstanding, Series D, 7,500 shares issued and outstanding, Series E, 7,500 shares issued and outstanding, Series F, 7,500 shares issued and outstanding, and Series G, 5,000 shares issued and outstanding	742	742
Series G Preferred Stock
Shareholders’ equity:
Preferred stock, no par: 3,500,000 shares authorized; Series C, 5,000 shares issued and outstanding, Series D, 7,500 shares issued and outstanding, Series E, 7,500 shares issued and outstanding, Series F, 7,500 shares issued and outstanding, and Series G, 5,000 shares issued and outstanding	$ 493	$ 493

Consolidated Statement of Cond6

Consolidated Statement of Condition (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Current Assets:
Investment securities held-to-maturity, fair value	$ 36,836	$ 34,994
Loans and leases, allowance for losses	57	53
Premises and equipment, accumulated depreciation	$ 3,750	$ 3,333
Stockholders' Equity:
Preferred stock, no par value (in USD per share)	$ 0	$ 0
Preferred stock, shares authorized (in shares)	3,500,000	3,500,000
Common stock, par value (in USD per share)	$ 1	$ 1
Common stock, shares authorized	750,000,000	750,000,000
Common stock, shares issued	503,879,642	503,879,642
Treasury stock, shares	133,038,955	121,940,502
Series C Preferred Stock
Stockholders' Equity:
Preferred stock, shares issued	5,000	5,000
Preferred stock, shares outstanding	5,000	5,000
Series D Preferred Stock
Stockholders' Equity:
Preferred stock, shares issued	7,500	7,500
Preferred stock, shares outstanding	7,500	7,500
Series E Preferred Stock
Stockholders' Equity:
Preferred stock, shares issued	7,500	7,500
Preferred stock, shares outstanding	7,500	7,500
Series F Preferred Stock
Stockholders' Equity:
Preferred stock, shares issued	7,500	7,500
Preferred stock, shares outstanding	7,500	7,500
Series G Preferred Stock
Stockholders' Equity:
Preferred stock, shares issued	5,000	5,000
Preferred stock, shares outstanding	5,000	5,000

Consolidated Statement of Chang

Consolidated Statement of Changes In Shareholders' Equity - USD ($) shares in Thousands, $ in Millions	Total	PREFERRED STOCK	COMMON STOCK	Surplus	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	TREASURY STOCK
Beginning balance at Dec. 31, 2015	$ 21,103	$ 2,703	$ 504	$ 9,746	$ 16,049	$ (1,442)	$ (6,457)
Beginning balance (shares) at Dec. 31, 2015			503,880				104,228
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,550				1,550
Other comprehensive loss	449					449
Preferred stock issued	493	493
Cash dividends declared:
Common stock dividends	(414)				(414)
Preferred stock cash dividend	(137)				(137)
Common stock acquired	(1,040)						$ (1,040)
Common stock acquired (shares)							16,861
Common stock awards exercised	146			32			$ 114
Common stock awards and options exercised (shares)							(2,765)
Other	0				(1)		$ 1
Other (shares)							(15)
Ending balance at Sep. 30, 2016	22,150	3,196	$ 504	9,778	17,047	(993)	$ (7,382)
Ending balance (shares) at Sep. 30, 2016			503,880				118,309
Beginning balance at Dec. 31, 2016	21,219	3,196	$ 504	9,782	17,459	(2,040)	$ (7,682)
Beginning balance (shares) at Dec. 31, 2016			503,880				121,941
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,807				1,807
Other comprehensive loss	1,056					1,056
Cash dividends declared:
Common stock dividends	(442)				(442)
Preferred stock cash dividend	(146)				(146)
Common stock acquired	(1,100)						$ (1,100)
Common stock acquired (shares)							13,131
Common stock awards exercised	106			21			$ 85
Common stock awards and options exercised (shares)							(2,033)
Other	(3)				(3)
Other (shares)
Ending balance at Sep. 30, 2017	$ 22,497	$ 3,196	$ 504	$ 9,803	$ 18,675	$ (984)	$ (8,697)
Ending balance (shares) at Sep. 30, 2017			503,880				133,039

Consolidated Statement of Chan8

Consolidated Statement of Changes In Shareholders' Equity (Parenthetical) $ in Millions	9 Months Ended
	Sep. 30, 2016USD ($)$ / shares
Statement of Stockholders' Equity [Abstract]
Cash dividends declared (in USD per share) | $ / shares	$ 1.06
Common stock awards and options exercised, related taxes | $	$ 6

Consolidated Statement of Cash

Consolidated Statement of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Operating Activities:
Net income	$ 1,807	$ 1,550
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Deferred income tax (benefit)	(217)	31
Amortization of other intangible assets	160	153
Other non-cash adjustments for depreciation, amortization and accretion, net	636	517
Losses (gains) related to investment securities, net	39	(5)
Change in trading account assets, net	(111)	(214)
Change in accrued interest and fees receivable, net	(399)	(248)
Change in collateral deposits, net	(1,232)	(615)
Change in unrealized losses on foreign exchange derivatives, net	1,136	853
Change in other assets, net	(2,063)	(457)
Change in accrued expenses and other liabilities, net	1,733	399
Other, net	368	312
Net cash provided by operating activities	1,857	2,276
Investing Activities:
Net decrease in interest-bearing deposits with banks	9,979	(3,752)
Net (increase) decrease in securities purchased under resale agreements	(1,509)	962
Proceeds from sales of available-for-sale securities	7,122	424
Proceeds from maturities of available-for-sale securities	21,619	21,564
Purchases of available-for-sale securities	(20,891)	(22,625)
Proceeds from maturities of held-to-maturity securities	2,647	7,184
Purchases of held-to-maturity securities	(3,961)	(5,581)
Net (increase) in loans and leases	(3,859)	(2,678)
Business acquisitions	0	(437)
Purchases of equity investments and other long-term assets	(32)	(265)
Purchases of premises and equipment, net	(485)	(477)
Proceeds from sale of joint venture investment	172	0
Other, net	77	129
Net cash provided by (used in) investing activities	10,879	(5,552)
Financing Activities:
Net (decrease) increase in time deposits	(16,790)	9,077
Net increase (decrease) in all other deposits	8,890	(1,938)
Net (decrease) in other short-term borrowings	(865)	(476)
Proceeds from issuance of long-term debt, net of issuance costs	747	1,492
Payments for long-term debt and obligations under capital leases	(482)	(1,430)
Proceeds from issuance of preferred stock, net	0	493
Purchases of common stock	(942)	(1,029)
Excess tax benefit related to stock-based compensation	0	6
Repurchases of common stock for employee tax withholding	(101)	(95)
Payments for cash dividends	(577)	(541)
Other, net	9	0
Net cash (used in) provided by financing activities	(10,111)	5,559
Net increase	2,625	2,283
Cash and due from banks at beginning of period	1,314	1,207
Cash and due from banks at end of period	$ 3,939	$ 3,490

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The accounting and financial reporting policies of State Street Corporation conform to U.S. GAAP. State Street Corporation, the Parent Company, is a financial holding company headquartered in Boston, Massachusetts. Unless otherwise indicated or unless the context requires otherwise, all references in these notes to consolidated financial statements to “State Street,” “we,” “us,” “our” or similar references mean State Street Corporation and its subsidiaries on a consolidated basis. Our principal banking subsidiary is State Street Bank. The accompanying Consolidated Financial Statements should be read in conjunction with the financial and risk factor information included in our 2016 Form 10-K, which we previously filed with the SEC. The consolidated financial statements accompanying these condensed notes are unaudited. In the opinion of management, all adjustments, consisting only of normal recurring adjustments, which are necessary for a fair statement of the consolidated results of operations in these financial statements, have been made. Certain previously reported amounts presented in this Form 10-Q have been reclassified to conform to current-period presentation. Events occurring subsequent to the date of our consolidated statement of condition were evaluated for potential recognition or disclosure in our consolidated financial statements through the date we filed this Form 10-Q with the SEC. The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions in the application of certain of our significant accounting policies that may materially affect the reported amounts of assets, liabilities, equity, revenue, and expenses. As a result of unanticipated events or circumstances, actual results could differ from those estimates. These accounting estimates reflect the best judgment of management, but actual results could differ. Our consolidated statement of condition as of December 31, 2016 included in the accompanying consolidated financial statements was derived from the audited financial statements as of that date, but does not include all notes required by U.S. GAAP for a complete set of consolidated financial statements. Dispositions In the first quarter of 2017 , we completed the sale of our joint venture interest in IFDS U.K. for approximately $175 million in cash and the exchange of our joint venture interest in BFDS stock for $158 million in State Street's common stock. We recognized a pre-tax gain of $30 million , in the aggregate, in the nine months ended September 30, 2017 on these dispositions. Recent Accounting Developments Relevant standards that were 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. January 1, 2018 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. 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 NII, securities gains/ losses and 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. We continue to monitor industry developments and focus our assessment on areas such as costs that may require capitalization under the new standard and the impact of changes to the principal and agent guidance. The new standard modified the principal and agent guidance which we expect to result in recognition of certain expenses on a gross basis, rather than offset against revenue. We are still assessing the completeness and materiality of these changes. We continue to assess the operational and disclosure impacts of each transition method and have not yet finalized the transition method to be applied. 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 Based on our assessment, we do not 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. Relevant standards that were issued but not yet adopted Standard Description Date of Adoption Effects on the financial statements or other significant matters 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, and a significant implementation project is in place 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, assessing existing credit loss models against the new guidance and processes and identifying a complete set of data requirements and sources. We have commenced the development of new or modified credit loss models and based on our analysis to date, we expect the timing of the allowance for credit losses to accelerate under the new standard. We are continuing to assess the extent of the impact on the allowance for credit losses. 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 Based on our current presentation we do not anticipate a significant change to our presentation of the statement of cash flows. ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business The standard incorporates gating criteria to determine when an integrated set of assets and activities is not a business. When substantially all the fair value of gross assets acquired (or group of similar identifiable assets) is concentrated in a single identifiable asset, it would not represent a business. January 1, 2018, early adoption permitted We will apply this standard prospectively to transactions occurring after January 1, 2018, as applicable. ASU 2017-04, Intangibles-Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment The standard simplifies the subsequent measurement of goodwill by eliminating Step 2 from the goodwill impairment test. The ASU requires an entity to compare the fair value of a reporting unit with its carrying amount and recognize an impairment charge for the amount by which the carrying value exceeds the fair value of the reporting unit. Additionally, an entity should consider income tax effects from any tax deductible goodwill on the carrying amount of the reporting unit when measuring the goodwill impairment loss. January 1, 2020, early adoption permitted We are evaluating the impacts of early adoption, and will apply this standard prospectively upon adoption. ASU 2017-08, Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium amortization on Purchased Callable Debt Securities The standard shortens the amortization period for certain purchased callable debt securities to the earliest call date. January 1, 2019, early adoption permitted We are currently evaluating the impact of the new standard and the early adoption provisions. ASU 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities The standard amends the hedge accounting model to better portray the economics of risk management activities in the financial statements and enhances the presentation of hedge results. The amendments also make targeted changes to simplify the application of hedge accounting in certain situations. January 1, 2019, early adoption permitted We are currently evaluating the impact of the new standard and the early adoption provisions. We adopted ASU 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting , effective January 1, 2017. Starting in the quarter ended March 31, 2017, we reclassified excess tax benefits related to stock-based compensation from financing activities to other operating activities. We continued to present repurchases of common stock for employee tax withholding in financing activities in the consolidated statements of cash flows for all periods presented. As required by the transition provisions of the standard, excess tax benefits previously recognized in surplus prior to January 1, 2017 remain in surplus, and excess tax benefits recognized after January 1, 2017 are included in income tax expense. In connection with this change, we recognized a tax benefit of $18.6 million in the first nine months of 2017 . We elected to make no changes to our current policy of estimating forfeitures. Lastly, we did not make any changes to tax withholding rates.

Fair Value

Fair Value	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value	Fair Value Fair Value Measurements We carry trading account assets, AFS investment securities and various types of derivative financial instruments at fair value in our consolidated statement of condition on a recurring basis. Changes in the fair values of these financial assets and liabilities are recorded either as components of our consolidated statement of income or as components of AOCI within shareholders' equity in our consolidated statement of condition. We measure fair value for the above-described financial assets and liabilities in conformity with U.S. GAAP that governs the measurement of the fair value of financial instruments. Management believes that its valuation techniques and underlying assumptions used to measure fair value conform to the provisions of U.S. GAAP. We categorize the financial assets and liabilities that we carry at fair value based on a prescribed three-level valuation hierarchy. For information about our valuation techniques for financial assets and financial liabilities measured at fair value and the fair value hierarchy, refer to pages 135 to 142 in Note 2 to the consolidated financial statements included under Item 8, Financial Statements and Supplementary Data, in our 2016 Form 10-K. The following tables present information with respect to our financial assets and liabilities carried at fair value in our consolidated statement of condition on a recurring basis as of the dates indicated. During the nine months ended September 30, 2017 , approximately $9 million of assets were transferred between levels 1 and 2. No transfers of financial assets or liabilities between levels 1 and 2 occurred during the year ended December 31, 2016 . Fair Value Measurements on a Recurring Basis as of September 30, 2017 (In millions) Quoted Market Prices in Active Markets (Level 1) Pricing Methods with Significant Observable Market Inputs (Level 2) Pricing Methods with Significant Unobservable Market Inputs (Level 3) Impact of Netting (1) Total Net Carrying Value in Consolidated Statement of Condition Assets: Trading account assets: U.S. government securities $ 39 $ — $ — $ 39 Non-U.S. government securities 387 174 — 561 Other 20 515 — 535 Total trading account assets 446 689 — 1,135 AFS investment securities: U.S. Treasury and federal agencies: Direct obligations 231 389 — 620 Mortgage-backed securities — 10,975 25 11,000 Asset-backed securities: Student loans — 4,626 200 4,826 Credit cards — 1,548 — 1,548 Other (2) — 35 1,186 1,221 Total asset-backed securities — 6,209 1,386 7,595 Non-U.S. debt securities: Mortgage-backed securities — 6,956 118 7,074 Asset-backed securities — 2,742 97 2,839 Government securities — 6,658 — 6,658 Other (3) — 5,617 201 5,818 Total non-U.S. debt securities — 21,973 416 22,389 State and political subdivisions — 9,700 38 9,738 Collateralized mortgage obligations — 1,528 — 1,528 Other U.S. debt securities — 2,909 19 2,928 U.S. equity securities — 46 — 46 U.S. money-market mutual funds — 394 — 394 Total AFS investment securities 231 54,123 1,884 56,238 Other assets: Derivative instruments: Foreign exchange contracts — 11,735 2 $ (7,026 ) 4,711 Interest-rate contracts — 3 — (2 ) 1 Total derivative instruments — 11,738 2 (7,028 ) 4,712 Other 22 — — — 22 Total assets carried at fair value $ 699 $ 66,550 $ 1,886 $ (7,028 ) $ 62,107 Liabilities: Accrued expenses and other liabilities: Trading account liabilities: Other $ 19 $ — $ — $ — $ 19 Derivative instruments: Foreign exchange contracts — 11,581 2 (7,465 ) 4,118 Interest-rate contracts 10 97 — (1 ) 106 Other derivative contracts — 319 — — 319 Total derivative instruments 10 11,997 2 (7,466 ) 4,543 Other 22 — — — 22 Total liabilities carried at fair value $ 51 $ 11,997 $ 2 $ (7,466 ) $ 4,584 (1) Represents counterparty netting against level 2 financial assets and liabilities where a legally enforceable master netting agreement exists between State Street and the counterparty. Netting also reflects asset and liability reductions of $637 million and $1,074 million , respectively, for cash collateral received from and provided to derivative counterparties. (2) As of September 30, 2017 , the fair value of other ABS was primarily composed of $1,221 million of CLOs. (3) As of September 30, 2017 , the fair value of other non-U.S. debt securities was primarily composed of $3,600 million of covered bonds and $1,503 million of corporate bonds. Fair Value Measurements on a Recurring Basis as of December 31, 2016 (In millions) Quoted Market Prices in Active Markets (Level 1) Pricing Methods with Significant Observable Market Inputs (Level 2) Pricing Methods with Significant Unobservable Market Inputs (Level 3) Impact of Netting (1) Total Net Carrying Value in Consolidated Statement of Condition Assets: Trading account assets: U.S. government securities $ 30 $ — $ — $ 30 Non-U.S. government securities 495 174 — 669 Other — 325 — 325 Total trading account assets 525 499 — 1,024 AFS investment securities: U.S. Treasury and federal agencies: Direct obligations 3,824 439 — 4,263 Mortgage-backed securities — 13,257 — 13,257 Asset-backed securities: Student loans — 5,499 97 5,596 Credit cards — 1,351 — 1,351 Sub-prime — 272 — 272 Other (2) — — 905 905 Total asset-backed securities — 7,122 1,002 8,124 Non-U.S. debt securities: Mortgage-backed securities — 6,535 — 6,535 Asset-backed securities — 2,484 32 2,516 Government securities — 5,836 — 5,836 Other (3) — 5,365 248 5,613 Total non-U.S. debt securities — 20,220 280 20,500 State and political subdivisions — 10,283 39 10,322 Collateralized mortgage obligations — 2,577 16 2,593 Other U.S. debt securities — 2,469 — 2,469 U.S. equity securities — 42 — 42 Non-U.S. equity securities — 3 — 3 U.S. money-market mutual funds — 409 — 409 Non-U.S. money-market mutual funds — 16 — 16 Total AFS investment securities 3,824 56,837 1,337 61,998 Other assets: Derivatives instruments: Foreign exchange contracts — 16,476 8 $ (9,163 ) 7,321 Interest-rate contracts — 68 — (68 ) — Total derivative instruments — 16,544 8 (9,231 ) 7,321 Total assets carried at fair value $ 4,349 $ 73,880 $ 1,345 $ (9,231 ) $ 70,343 Liabilities: Accrued expenses and other liabilities: Derivative instruments: Foreign exchange contracts $ — $ 15,948 $ 8 $ (10,456 ) $ 5,500 Interest-rate contracts — 348 — (226 ) 122 Other derivative contracts — 380 — — 380 Total derivative instruments — 16,676 8 (10,682 ) 6,002 Total liabilities carried at fair value $ — $ 16,676 $ 8 $ (10,682 ) $ 6,002 (1) Represents counterparty netting against level 2 financial assets and liabilities where a legally enforceable master netting agreement exists between State Street and the counterparty. Netting also reflects asset and liability reductions of $906 million and $2,356 million , respectively, for cash collateral received from and provided to derivative counterparties. (2) As of December 31, 2016 , the fair value of other ABS was primarily composed of $905 million of CLOs. (3) As of December 31, 2016 , the fair value of other non-U.S. debt securities was primarily composed of $3,769 million of covered bonds and $988 million of corporate bonds. The following tables present activity related to our level 3 financial assets during the three and nine months ended September 30, 2017 and 2016 , respectively. Transfers into and out of level 3 are reported as of the beginning of the period presented. During the three and nine months ended September 30, 2017 , transfers into level 3 were mainly related to certain ABS and MBS, including non-U.S. debt securities, for which fair value was measured using information obtained from third-party sources, including non-binding broker or dealer quotes. During the nine months ended September 30, 2017 and 2016 , transfers out of level 3 were mainly related to certain MBS and ABS, including non-U.S. debt securities, for which fair value was measured using prices for which observable market information became available. Fair Value Measurements Using Significant Unobservable Inputs Three Months Ended September 30, 2017 Fair Value as of June 30, 2017 Total Realized and Purchases Sales Settlements Transfers into Level 3 Fair Value as of (2) Change in (In millions) Recorded in Revenue (1) Recorded in Other Comprehensive Income (1) Assets: AFS Investment securities: U.S. Treasury and federal agencies: Mortgage-backed securities $ — $ — $ — $ — — $ — $ 25 $ 25 Asset-backed securities: Student loans — — — 200 — — — 200 Other 951 1 1 60 — (2 ) 175 1,186 Total asset-backed securities 951 1 1 260 — (2 ) 175 1,386 Non-U.S. debt securities: Mortgage-backed securities — — — 118 — — — 118 Asset-backed securities 63 — — 29 (10 ) — 15 97 Other 274 — — — (80 ) 7 — 201 Total non-U.S. debt securities 337 — — 147 (90 ) 7 15 416 State and political subdivisions 38 — — — — — — 38 Other U.S. debt securities 19 — — — — — — 19 Total AFS investment securities 1,345 1 1 407 (90 ) 5 215 1,884 Other assets: Derivative instruments: Foreign exchange contracts 5 — — 2 — (5 ) — 2 $ (2 ) Total derivative instruments 5 — — 2 — (5 ) — 2 (2 ) Total assets carried at fair value $ 1,350 $ 1 $ 1 $ 409 $ (90 ) $ — $ 215 $ 1,886 $ (2 ) (1) Total realized and unrealized gains (losses) on AFS investment securities are included within gains (losses) related to investment securities, net. Total realized and unrealized gains (losses) on derivative instruments are included within trading services. (2) There were no transfers of assets out of level 3 during the three months ended September 30, 2017. Fair Value Measurements Using Significant Unobservable Inputs Nine Months Ended September 30, 2017 Fair Value as of Total Realized and Purchases Sales Settlements Transfers into Level 3 Transfers out of Level 3 Fair Value as of September 30, 2017 Change in (In millions) Recorded in Revenue (1) Recorded in Other Comprehensive Income (1) Assets: AFS Investment securities: U.S. Treasury and federal agencies: Mortgage-backed securities $ — $ — $ — $ — $ — $ — $ 25 $ — $ 25 Asset-backed securities: Student loans 97 — 1 200 — — — (98 ) 200 Other 905 2 — 415 — (412 ) 276 — 1,186 Total asset-backed securities 1,002 2 1 615 — (412 ) 276 (98 ) 1,386 Non-U.S. debt securities: Mortgage-backed securities — — — 118 — — — — 118 Asset-backed securities 32 1 (1 ) 60 (10 ) (21 ) 67 (31 ) 97 Other 248 — — 5 (80 ) 28 — — 201 Total non-U.S. debt securities 280 1 (1 ) 183 (90 ) 7 67 (31 ) 416 State and political subdivisions 39 — — — — (1 ) — — 38 Collateralized mortgage obligations 16 — — 23 — — — (39 ) — Other U.S. debt securities — — — 19 — — — — 19 Total AFS investment securities 1,337 3 — 840 (90 ) (406 ) 368 (168 ) 1,884 Other assets: Derivative instruments: Foreign exchange contracts 8 (6 ) — 4 — (4 ) — — 2 $ (1 ) Total derivative instruments 8 (6 ) — 4 — (4 ) — — 2 (1 ) Total assets carried at fair value $ 1,345 $ (3 ) $ — $ 844 $ (90 ) $ (410 ) $ 368 $ (168 ) $ 1,886 $ (1 ) (1) Total realized and unrealized gains (losses) on AFS investment securities are included within gains (losses) related to investment securities, net. Total realized and unrealized gains (losses) on derivative instruments are included within trading services. Fair Value Measurements Using Significant Unobservable Inputs Three Months Ended September 30, 2016 Fair Value as of Total Realized and Purchases Settlements Transfers Fair Value as of September 30, (2) Change in Unrealized Gains (Losses) Related to Financial Instruments Held as of September 30, (In millions) Recorded in Revenue (1) Recorded in Other Comprehensive Income (1) Assets: AFS Investment securities: U.S. Treasury and federal agencies, mortgage-backed securities $ 25 $ — $ — $ 25 $ — $ — $ 50 Asset-backed securities: Student loans 190 — 2 — — — 192 Other 1,710 13 (8 ) 118 (560 ) — 1,273 Total asset-backed securities 1,900 13 (6 ) 118 (560 ) — 1,465 Non-U.S. debt securities: Mortgage-backed securities — — — 90 — — 90 Asset-backed securities 111 — — 90 (9 ) (54 ) 138 Other 261 — — 194 3 — 458 Total non-U.S. debt securities 372 — — 374 (6 ) (54 ) 686 State and political subdivisions 33 — 7 — — — 40 Collateralized mortgage obligations 68 — 1 36 (3 ) — 102 Total AFS investment securities 2,398 13 2 553 (569 ) (54 ) 2,343 Total assets carried at fair value $ 2,398 $ 13 $ 2 $ 553 $ (569 ) $ (54 ) $ 2,343 $ — (1) Total realized and unrealized gains (losses) on AFS investment securities are included within gains (losses) related to investment securities, net. Total realized and unrealized gains (losses) on derivative instruments are included within trading services. (2) There were no transfers of assets into level 3 during the three months ended September 30, 2016 . Fair Value Measurements Using Significant Unobservable Inputs Nine Months Ended September 30, 2016 Fair Value as of December 31, 2015 Total Realized and Purchases Settlements Transfers Fair Value as of September 30, 2016 (2) Change in Unrealized Gains (Losses) Related to Financial Instruments Held as of September 30, (In millions) Recorded (1) Recorded (1) Assets: AFS Investment securities: U.S. Treasury and federal agencies, mortgage-backed securities $ — $ — $ — $ 325 $ — $ (275 ) $ 50 Asset-backed securities: Student loans 189 1 2 — — — 192 Other 1,764 29 (21 ) 250 (749 ) — 1,273 Total asset-backed securities 1,953 30 (19 ) 250 (749 ) — 1,465 Non-U.S. debt securities: Mortgage-backed securities — — — 90 — — 90 Asset-backed securities 174 — (1 ) 196 (43 ) (188 ) 138 Other 255 — — 223 9 (29 ) 458 Total non-U.S. debt securities 429 — (1 ) 509 (34 ) (217 ) 686 State and political subdivisions 33 — 9 — (2 ) — 40 Collateralized mortgage obligations 39 — 2 86 (25 ) — 102 Other U.S. debt securities 10 — — — (10 ) — — Total AFS investment securities 2,464 30 (9 ) 1,170 (820 ) (492 ) 2,343 Other assets: Derivative instruments: Foreign exchange contracts 5 3 — — (8 ) — — $ — Total derivative instruments 5 3 — — (8 ) — — — Total assets carried at fair value $ 2,469 $ 33 $ (9 ) $ 1,170 $ (828 ) $ (492 ) $ 2,343 $ — Fair Value Measurements Using Significant Unobservable Inputs Nine Months Ended September 30, 2016 Fair Value as of December 31, 2015 Total Realized and Settlements Fair Value as of September 30, 2016 (3) Change in Unrealized 2016 (In millions) Recorded in Revenue Liabilities: Accrued expenses and other liabilities: Derivative instruments: Foreign exchange contracts $ 5 $ 5 $ (10 ) $ — $ — Total derivative instruments 5 5 (10 ) — — Total liabilities carried at fair value $ 5 $ 5 $ (10 ) $ — $ — (1) Total realized and unrealized gains (losses) on AFS investment securities are included within gains (losses) related to investment securities, net. Total realized and unrealized gains (losses) on derivative instruments are included within trading services. (2) There were no transfers of assets into level 3 during the nine months ended September 30, 2016. (3) There were no transfers of liabilities into or out of level 3 during the nine months ended September 30, 2016. The following table presents quantitative information, as of the dates indicated, about the valuation techniques and significant unobservable inputs used in the valuation of our level 3 financial assets and liabilities measured at fair value on a recurring basis for which we use internally-developed pricing models. The significant unobservable inputs for our level 3 financial assets and liabilities whose fair value is measured using pricing information from non-binding broker or dealer quotes are not included in the table, as the specific inputs applied are not provided by the broker/dealer. Quantitative Information about Level 3 Fair Value Measurements Fair Value Weighted-Average (Dollars in millions) As of September 30, 2017 As of December 31, 2016 Valuation Technique Significant (1) As of September 30, 2017 As of December 31, 2016 Significant unobservable inputs readily available to State Street: Assets: Asset-backed securities, other $ — $ 1 Discounted cash flows Credit spread — % 0.3 % State and political subdivisions 38 39 Discounted cash flows Credit spread 1.7 1.8 Derivative instruments, foreign exchange contracts 2 8 Option model Volatility 8.3 14.4 Total $ 40 $ 48 Liabilities: Derivative instruments, foreign exchange contracts $ 2 $ 8 Option model Volatility 8.3 14.4 Total $ 2 $ 8 (1) Significant chan ges in these unobservable inputs would result in significant changes in fair value measurement. Fair Value Estimates Estimates of fair value for financial instruments not carried at fair value on a recurring basis in our consolidated statement of condition are generally subjective in nature, and are determined as of a specific point in time based on the characteristics of the financial instruments and relevant market information. The following tables present the reported amounts and estimated fair values of the financial assets and liabilities not carried at fair value on a recurring basis, as they would be categorized within the fair value hierarchy, as of the dates indicated. Fair Value Hierarchy (In millions) Reported Amount Estimated Fair Value Quoted Market Prices in Active Markets (Level 1) Pricing Methods with Significant Observable Market Inputs (Level 2) Pricing Methods with Significant Unobservable Market Inputs (Level 3) September 30, 2017 Financial Assets: Cash and due from banks $ 3,939 $ 3,939 $ 3,939 $ — $ — Interest-bearing deposits with banks 60,956 60,956 — 60,956 — Securities purchased under resale agreements 3,465 3,465 — 3,465 — Investment securities held-to-maturity 36,850 36,836 17,362 19,351 123 Net loans (excluding leases) 22,868 22,866 — 22,811 55 Financial Liabilities: Deposits: Non-interest-bearing $ 49,850 $ 49,850 $ — $ 49,850 $ — Interest-bearing - U.S. 49,394 49,394 — 49,394 — Interest-bearing - non-U.S. 80,019 80,019 — 80,019 — Securities sold under repurchase agreements 3,867 3,867 — 3,867 — Other short-term borrowings 1,253 1,253 — 1,253 — Long-term debt 11,716 12,022 — 11,725 297 Fair Value Hierarchy (In millions) Reported Amount Estimated Fair Value Quoted Market Prices in Active Markets (Level 1) Pricing Methods with Significant Observable Market Inputs (Level 2) Pricing Methods with Significant Unobservable Market Inputs (Level 3) December 31, 2016 Financial Assets: Cash and due from banks $ 1,314 $ 1,314 $ 1,314 $ — $ — Interest-bearing deposits with banks 70,935 70,935 — 70,935 — Securities purchased under resale agreements 1,956 1,956 — 1,956 — Investment securities held-to-maturity 35,169 34,994 17,400 17,439 155 Net loans (excluding leases) 18,862 18,877 — 18,781 96 Financial Liabilities: Deposits: Non-interest-bearing $ 59,397 $ 59,397 $ — $ 59,397 $ — Interest-bearing - U.S. 30,911 30,911 — 30,911 — Interest-bearing - non-U.S. 96,855 96,855 — 96,855 — Securities sold under repurchase agreements 4,400 4,400 — 4,400 — Other short-term borrowings 1,585 1,585 — 1,585 — Long-term debt 11,430 11,618 — 11,282 336

Investment Securities

Investment Securities	9 Months Ended
	Sep. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Investment Securities	Investment Securities Investment securities held by us are classified as either trading, AFS , or HTM at the time of purchase and reassessed periodically, based on management’s intent. Generally, trading assets are debt and equity securities purchased in connection with our trading activities and, as such, are expected to be sold in the near term. Our trading activities typically involve active and frequent buying and selling with the objective of generating profits on short-term movements. AFS investment securities are those securities that we intend to hold for an indefinite period of time. AFS investment securities include securities utilized as part of our asset-and-liability management activities that may be sold in response to changes in interest rates, prepayment risk, liquidity needs or other factors. HTM securities are debt securities that management has the intent and the ability to hold to maturity. Trading assets are carried at fair value. Both realized and unrealized gains and losses on trading assets are recorded in trading services revenue in our consolidated statement of income. Debt and marketable equity securities classified as AFS are carried at fair value, and after-tax net unrealized gains and losses are recorded in AOCI. Gains or losses realized on sales of AFS investment securities are computed using the specific identification method and are recorded in gains (losses) related to investment securities, net, in our consolidated statement of income. HTM investment securities are carried at cost, adjusted for amortization of premiums and accretion of discounts. The following table presents the amortized cost, fair value and associated unrealized gains and losses of investment securities as of the dates indicated: September 30, 2017 December 31, 2016 Amortized Cost Gross Unrealized Fair Value Amortized Cost Gross Unrealized Fair Value (In millions) Gains Losses Gains Losses Available-for-sale: U.S. Treasury and federal agencies: Direct obligations $ 617 $ 4 $ 1 $ 620 $ 4,265 $ 7 $ 9 $ 4,263 Mortgage-backed securities 11,044 51 95 11,000 13,340 76 159 13,257 Asset-backed securities: Student loans (1) 4,795 39 8 4,826 5,659 12 75 5,596 Credit cards 1,567 3 22 1,548 1,377 — 26 1,351 Sub-prime — — — — 289 1 18 272 Other (2) 1,213 8 — 1,221 895 10 — 905 Total asset-backed securities 7,575 50 30 7,595 8,220 23 119 8,124 Non-U.S. debt securities: Mortgage-backed securities 7,041 36 3 7,074 6,506 35 6 6,535 Asset-backed securities 2,833 6 — 2,839 2,513 4 1 2,516 Government securities 6,666 8 16 6,658 5,834 8 6 5,836 Other (3) 5,783 39 4 5,818 5,587 31 5 5,613 Total non-U.S. debt securities 22,323 89 23 22,389 20,440 78 18 20,500 State and political subdivisions 9,444 322 28 9,738 10,233 201 112 10,322 Collateralized mortgage obligations 1,522 15 9 1,528 2,610 18 35 2,593 Other U.S. debt securities 2,923 20 15 2,928 2,481 18 30 2,469 U.S. equity securities 40 8 2 46 39 6 3 42 Non-U.S. equity securities — — — — 3 — — 3 U.S. money-market mutual funds 394 — — 394 409 — — 409 Non-U.S. money-market mutual funds — — — — 16 — — 16 Total $ 55,882 $ 559 $ 203 $ 56,238 $ 62,056 $ 427 $ 485 $ 61,998 Held-to-maturity: U.S. Treasury and federal agencies: Direct obligations $ 17,456 $ 20 $ 37 $ 17,439 $ 17,527 $ 17 $ 58 $ 17,486 Mortgage-backed securities 12,375 38 169 12,244 10,334 20 221 10,133 Asset-backed securities: Student loans (1) 3,116 25 13 3,128 2,883 5 30 2,858 Credit cards 798 3 — 801 897 2 — 899 Other 1 — — 1 35 — — 35 Total asset-backed securities 3,915 28 13 3,930 3,815 7 30 3,792 Non-U.S. debt securities: Mortgage-backed securities 1,000 84 7 1,077 1,150 70 15 1,205 Asset-backed securities 325 1 — 326 531 — — 531 Government securities 483 2 — 485 286 3 — 289 Other 47 — — 47 113 1 — 114 Total non-U.S. debt securities 1,855 87 7 1,935 2,080 74 15 2,139 Collateralized mortgage obligations 1,249 44 5 1,288 1,413 42 11 1,444 Total $ 36,850 $ 217 $ 231 $ 36,836 $ 35,169 $ 160 $ 335 $ 34,994 (1) Primarily composed of securities guaranteed by the federal government with respect to at least 97% of defaulted principal and accrued interest on the underlying loans. (2) As of September 30, 2017 and December 31, 2016 , the fair value of other ABS was primarily composed of $1,221 million and $905 million , respectively, of CLOs. (3) As of September 30, 2017 and December 31, 2016 , the fair value of other non-U.S. debt securities was primarily composed of $3,600 million and $3,769 million , respectively, of covered bonds and $1,503 million and $988 million , as of September 30, 2017 and December 31, 2016 , respectively, of corporate bonds. Aggregate investment securities with carrying values of approximately $52 billion and $46 billion as of September 30, 2017 and December 31, 2016 , respectively, were designated as pledged for public and trust deposits, short-term borrowings and for other purposes as provided by law. In the first quarter of 2017 , we sold $2.7 billion of AFS, primarily Agency MBS and U.S. Treasury securities in our investment portfolio, in response to the current interest rate environment resulting in a pre-tax loss of $40 million . The following tables present the aggregate fair values of investment securities that have been in a continuous unrealized loss position for less than 12 months , and those that have been in a continuous unrealized loss position for 12 months or longer, as of the dates indicated: Less than 12 months 12 months or longer Total September 30, 2017 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses (In millions) Available-for-sale: U.S. Treasury and federal agencies: Direct obligations $ — $ — $ 153 $ 1 $ 153 $ 1 Mortgage-backed securities 4,382 51 1,880 44 6,262 95 Asset-backed securities: Student loans — — 1,191 8 1,191 8 Credit cards 499 22 — — 499 22 Total asset-backed securities 499 22 1,191 8 1,690 30 Non-U.S. debt securities: Mortgage-backed securities 780 2 569 1 1,349 3 Government securities 4,965 16 — — 4,965 16 Other 447 3 229 1 676 4 Total non-U.S. debt securities 6,192 21 798 2 6,990 23 State and political subdivisions 1,052 15 525 13 1,577 28 Collateralized mortgage obligations 550 7 56 2 606 9 Other U.S. debt securities 1,141 14 75 1 1,216 15 U.S. equity securities — — 6 2 6 2 Total $ 13,816 $ 130 $ 4,684 $ 73 $ 18,500 $ 203 Held-to-maturity: U.S. Treasury and federal agencies: Direct obligations $ 9,660 $ 36 $ 77 $ 1 $ 9,737 $ 37 Mortgage-backed securities 6,939 152 493 17 7,432 169 Asset-backed securities: Student loans 544 8 389 5 933 13 Total asset-backed securities 544 8 389 5 933 13 Non-U.S. debt securities: Mortgage-backed securities — — 259 7 259 7 Total non-U.S. debt securities — — 259 7 259 7 Collateralized mortgage obligations 245 2 176 3 421 5 Total $ 17,388 $ 198 $ 1,394 $ 33 $ 18,782 $ 231 Less than 12 months 12 months or longer Total December 31, 2016 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses (In millions) Available-for-sale: U.S. Treasury and federal agencies: Direct obligations $ 651 $ 8 $ 180 $ 1 $ 831 $ 9 Mortgage-backed securities 7,072 131 1,114 28 8,186 159 Asset-backed securities: Student loans 54 — 3,745 75 3,799 75 Credit cards 795 1 494 25 1,289 26 Sub-prime 1 — 252 18 253 18 Other 75 — — — 75 — Total asset-backed securities 925 1 4,491 118 5,416 119 Non-U.S. debt securities: Mortgage-backed securities 442 1 893 5 1,335 6 Asset-backed securities 253 — 276 1 529 1 Government securities 1,314 6 — — 1,314 6 Other 670 4 218 1 888 5 Total non-U.S. debt securities 2,679 11 1,387 7 4,066 18 State and political subdivisions 3,390 102 304 10 3,694 112 Collateralized mortgage obligations 1,259 31 162 4 1,421 35 Other U.S. debt securities 944 24 157 6 1,101 30 U.S. equity securities 8 — 5 3 13 3 Total $ 16,928 $ 308 $ 7,800 $ 177 $ 24,728 $ 485 Held-to-maturity: U.S. Treasury and federal agencies: Direct obligations $ 8,891 $ 57 $ 86 $ 1 $ 8,977 $ 58 Mortgage-backed securities 6,838 221 — — 6,838 221 Asset-backed securities: Student loans 705 9 1,235 21 1,940 30 Credit cards 33 — — — 33 — Other 18 — 9 — 27 — Total asset-backed securities 756 9 1,244 21 2,000 30 Non-U.S. debt securities: Mortgage-backed securities 54 2 330 13 384 15 Asset-backed securities 28 — 35 — 63 — Government securities 180 — — — 180 — Total non-U.S. debt securities 262 2 365 13 627 15 Collateralized mortgage obligations 537 4 204 7 741 11 Total $ 17,284 $ 293 $ 1,899 $ 42 $ 19,183 $ 335 The following table presents contractual maturities of debt investment securities by carrying amount as of September 30, 2017 . The maturities of certain ABS, MBS, and collateralized mortgage obligations are based on expected principal payments. Actual maturities may differ from these expected maturities since certain borrowers have the right to prepay obligations with or without prepayment penalties. Under 1 Year 1 to 5 Years 6 to 10 Years Over 10 Years Total (In millions) Available-for-sale: U.S. Treasury and federal agencies: Direct obligations $ 232 $ 7 $ 55 $ 326 $ 620 Mortgage-backed securities 270 1,311 3,424 5,995 11,000 Asset-backed securities: Student loans 408 1,634 1,159 1,625 4,826 Credit cards — 1,296 252 — 1,548 Other — 120 1,101 — 1,221 Total asset-backed securities 408 3,050 2,512 1,625 7,595 Non-U.S. debt securities: Mortgage-backed securities 837 4,128 1,046 1,063 7,074 Asset-backed securities 395 2,182 262 — 2,839 Government securities 3,000 2,288 1,370 — 6,658 Other 1,485 3,607 726 — 5,818 Total non-U.S. debt securities 5,717 12,205 3,404 1,063 22,389 State and political subdivisions 433 2,525 5,020 1,760 9,738 Collateralized mortgage obligations 7 148 343 1,030 1,528 Other U.S. debt securities 404 1,052 1,472 — 2,928 Total $ 7,471 $ 20,298 $ 16,230 $ 11,799 $ 55,798 Held-to-maturity: U.S. Treasury and federal agencies: Direct obligations $ 1,827 $ 15,552 $ 14 $ 63 $ 17,456 Mortgage-backed securities — 172 1,427 10,776 12,375 Asset-backed securities: Student loans 87 240 298 2,491 3,116 Credit cards 178 620 — — 798 Other — — — 1 1 Total asset-backed securities 265 860 298 2,492 3,915 Non-U.S. debt securities: Mortgage-backed securities 173 221 49 557 1,000 Asset-backed securities 84 241 — — 325 Government securities 364 119 — — 483 Other — 47 — — 47 Total non-U.S. debt securities 621 628 49 557 1,855 Collateralized mortgage obligations 9 117 373 750 1,249 Total $ 2,722 $ 17,329 $ 2,161 $ 14,638 $ 36,850 The following table presents a roll-forward with respect to net impairment losses that have been recognized in income for the periods indicated. Nine Months Ended September 30, (In millions) 2017 2016 Balance, beginning of period $ 66 $ 92 Additions: Losses for which OTTI was previously recognized — 2 Deductions: Previously recognized losses related to securities sold or matured (2 ) (26 ) Balance, end of period $ 64 $ 68 Interest income related to debt securities is recognized in our consolidated statement of income using the effective interest method, or on a basis approximating a level rate of return over the contractual or estimated life of the security. The level rate of return considers any non-refundable fees or costs, as well as purchase premiums or discounts, resulting in amortization or accretion, accordingly. For debt securities acquired for which we consider it probable as of the date of acquisition that we will be unable to collect all contractually required principal, interest and other payments, the excess of our estimate of undiscounted future cash flows from these securities over their initial recorded investment is accreted into interest income on a level-yield basis over the securities’ estimated remaining terms. Subsequent decreases in these securities’ expected future cash flows are either recognized prospectively through an adjustment of the yields on the securities over their remaining terms, or are evaluated for other-than-temporary impairment. Increases in expected future cash flows are recognized prospectively over the securities’ estimated remaining terms through the recalculation of their yields. For certain debt securities acquired which are considered to be beneficial interests in securitized financial assets, the excess of our estimate of undiscounted future cash flows from these securities over their initial recorded investment is accreted into interest income on a level-yield basis over the securities’ estimated remaining terms. Subsequent decreases in these securities’ expected future cash flows are either recognized prospectively through an adjustment of the yields on the securities over their remaining terms, or are evaluated for OTTI. Increases in expected future cash flows are recognized prospectively over the securities’ estimated remaining terms through the recalculation of their yields. Impairment We conduct periodic reviews of individual securities to assess whether OTTI exists. For additional information about the review of securities for impairment, refer to pages 149 to 152 in Note 3 to the consolidated financial statements included under Item 8, Financial Statements and Supplementary Data, in our 2016 Form 10-K. We recorded less than $1 million of OTTI in the nine months ended September 30, 2017 and $2 million of OTTI in the nine months ended September 30, 2016 , which resulted from adverse changes in the timing of expected future cash flows from the securities. After a review of the investment portfolio, taking into consideration current economic conditions, adverse situations that might affect our ability to fully collect principal and interest, the timing of future payments, the credit quality and performance of the collateral underlying MBS and ABS and other relevant factors, management considers the aggregate decline in fair value of the investment securities portfolio and the resulting gross pre-tax unrealized losses of $434 million related to 1,151 securities as of September 30, 2017 to be temporary, and not the result of any material changes in the credit characteristics of the securities.

Loans and Leases

Loans and Leases	9 Months Ended
	Sep. 30, 2017
Loans and Leases Receivable Disclosure [Abstract]
Loans and Leases	Loans and Leases We segregate our loans and leases into three segments: commercial and financial loans, commercial real estate loans, and lease financing. We further classify commercial and financial loans as loans to investment funds, senior secured bank loans, loans to municipalities, and other. These classifications reflect their risk characteristics, their initial measurement attributes and the methods we use to monitor and assess credit risk. For additional information on our loans and leases, including our internal risk-rating system used to assess our risk of credit loss for each loan or lease, refer to pages 152 to 155 in Note 4 to the consolidated financial statements included under Item 8, Financial Statements and Supplementary Data, in our 2016 Form 10-K. The following table presents our recorded investment in loans and leases, by segment, as of the dates indicated: (In millions) September 30, 2017 December 31, 2016 Domestic: Commercial and financial: Loans to investment funds $ 12,886 $ 11,734 Senior secured bank loans 3,377 3,256 Loans to municipalities 1,955 1,352 Other 55 70 Commercial real estate — 27 Lease financing 283 338 Total domestic 18,556 16,777 Non-U.S.: Commercial and financial: Loans to investment funds 4,138 2,224 Senior secured bank loans 514 252 Lease financing 430 504 Total non-U.S. 5,082 2,980 Total loans and leases 23,638 19,757 Allowance for loan and lease losses (57 ) (53 ) Loans and leases, net of allowance $ 23,581 $ 19,704 The commercial and financial segment is composed of primarily floating-rate loans to mutual fund clients, purchased senior secured bank loans, and loans to municipalities. Investment fund lending is composed of short-duration revolving credit lines providing liquidity to fund clients in support of their transaction flows associated with securities' settlement activities. Certain loans are pledged as collateral for access to the Federal Reserve's discount window. As of September 30, 2017 and December 31, 2016 , the loans pledged as collateral totaled $1.7 billion and $1.5 billion , respectively. The following tables present our recorded investment in each class of loans and leases by credit quality indicator as of the dates indicated: September 30, 2017 Commercial and Financial Commercial Real Estate Lease Financing Total Loans and Leases (In millions) Investment grade (1) $ 18,270 $ — $ 713 $ 18,983 Speculative (2) 4,655 — — 4,655 Total $ 22,925 $ — $ 713 $ 23,638 December 31, 2016 Commercial and Financial Commercial Real Estate Lease Financing Total Loans and Leases (In millions) Investment grade (1) $ 14,889 $ 27 $ 842 $ 15,758 Speculative (2) 3,984 — — 3,984 Substandard (3) 15 — — 15 Total $ 18,888 $ 27 $ 842 $ 19,757 (1) Investment-grade loans and leases consist of counterparties with strong credit quality and low expected credit risk and probability of default. Ratings apply to counterparties with a strong capacity to support the timely repayment of any financial commitment. (2) Speculative loans and leases consist of counterparties that face ongoing uncertainties or exposure to business, financial, or economic downturns. However, these counterparties may have financial flexibility or access to financial alternatives, which allow for financial commitments to be met. (3) Substandard loans and leases consist of counterparties with well-defined weakness that jeopardizes repayment with the possibility we will sustain some loss. The following table presents our recorded investment in loans and leases, disaggregated based on our impairment methodology, as of the dates indicated: September 30, 2017 December 31, 2016 (In millions) Commercial and Financial Commercial Real Estate Lease Financing Total Loans and Leases Commercial and Financial Commercial Real Estate Lease Financing Total Loans and Leases Loans and leases (1) : Individually evaluated for impairment $ — $ — $ — $ — $ 15 $ — $ — $ 15 Collectively evaluated for impairment 22,925 — 713 23,638 18,873 27 842 19,742 Total $ 22,925 $ — $ 713 $ 23,638 $ 18,888 $ 27 $ 842 $ 19,757 (1) For those portfolios where there are a small number of loans each with a large balance, we review each loan annually for indicators of impairment. For those loans where no such indicators are identified, the loans are collectively evaluated for impairment. As of September 30, 2017 , no loans were individually evaluated for impairment. As of December 31, 2016 , $0.2 million of the allowance for loan and lease loss related to commercial and financial loans were individually evaluated for impairment. As of September 30, 2017 , we had no impaired loans and leases. As of December 31, 2016 , we identified one commercial and financial loan as impaired, with both a recorded investment and unpaid principal balance of $15 million . The impaired loan had zero related interest income and an associated allowance for loan losses of $0.2 million . In certain circumstances, we restructure troubled loans by granting concessions to borrowers experiencing financial difficulty. Once restructured, the loans are generally considered impaired until their maturity, regardless of whether the borrowers perform under the modified terms of the loans. There were no loans modified in troubled debt restructurings during the nine months ended September 30, 2017 and the year ended December 31, 2016 . As of September 30, 2017 , there were no loans or leases on non-accrual status. As of December 31, 2016 , there was one commercial and financial loan on non-accrual status and no CRE loans or leases were on non-accrual status. There were no loans and leases 90 days or more contractually past due as of September 30, 2017 and December 31, 2016 . Allowance for loan and lease losses The following table presents activity in the allowance for loan and lease losses for the periods indicated: Three Months Ended September 30, 2017 2016 (In millions) Total Loans and Leases Total Loans and Leases Allowance for loan and lease losses (1) : Beginning balance $ 54 $ 51 Provision for loan and lease losses 3 — Charge-offs — — Ending balance $ 57 $ 51 Nine Months Ended September 30, 2017 2016 (In millions) Total Loans and Leases Total Loans and Leases Allowance for loan and lease losses (1) : Beginning balance $ 53 $ 46 Provision for loan and lease losses 4 8 Charge-offs — (3 ) Ending balance $ 57 $ 51 (1) The provisions and charge-offs for loans and leases were attributable to exposure to senior secured loans to non-investment grade borrowers, purchased in connection with our participation in syndicated loans. Loans and leases are reviewed on a regular basis, and any provisions for loan and lease losses that are recorded reflect management's estimate of the amount necessary to maintain the allowance for loan and lease losses at a level considered appropriate to absorb estimated incurred losses in the loan and lease portfolio.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	9 Months Ended
	Sep. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets The following table presents changes in the carrying amount of goodwill during the periods indicated: (In millions) Investment Servicing Investment Management Total Goodwill: Beginning balance January 1, 2016 $ 5,641 $ 30 $ 5,671 Acquisitions (1) — 236 236 Divestitures and other reductions (11 ) — (11 ) Foreign currency translation (80 ) (2 ) (82 ) Ending balance December 31, 2016 $ 5,550 $ 264 $ 5,814 Acquisitions 17 — 17 Divestitures and other reductions (9 ) — (9 ) Foreign currency translation 170 5 175 Ending balance September 30, 2017 $ 5,728 $ 269 $ 5,997 (1) Investment Management includes our acquisition of GEAM on July 1, 2016. The following table presents changes in the net carrying amount of other intangible assets during the periods indicated: (In millions) Investment Servicing Investment Management Total Other intangible assets: Beginning balance January 1, 2016 $ 1,753 $ 15 $ 1,768 Acquisitions (1) — 217 217 Divestitures (8 ) — (8 ) Amortization (186 ) (21 ) (207 ) Foreign currency translation and other, net (20 ) — (20 ) Ending balance December 31, 2016 $ 1,539 $ 211 $ 1,750 Acquisitions 16 — 16 Divestitures (11 ) — (11 ) Amortization (137 ) (23 ) (160 ) Foreign currency translation and other, net 63 — 63 Ending balance September 30, 2017 $ 1,470 $ 188 $ 1,658 (1) Investment Management includes our acquisition of GEAM on July 1, 2016. The following table presents the gross carrying amount, accumulated amortization and net carrying amount of other intangible assets by type as of the dates indicated: September 30, 2017 December 31, 2016 (In millions) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Other intangible assets: Client relationships $ 2,654 $ (1,418 ) $ 1,236 $ 2,620 $ (1,306 ) $ 1,314 Core deposits 683 (311 ) 372 661 (277 ) 384 Other 141 (91 ) 50 132 (80 ) 52 Total $ 3,478 $ (1,820 ) $ 1,658 $ 3,413 $ (1,663 ) $ 1,750

Other Assets

Other Assets	9 Months Ended
	Sep. 30, 2017
Other Assets [Abstract]
Other Assets	Other Assets The following table presents the components of other assets as of the dates indicated: (In millions) September 30, 2017 December 31, 2016 Receivable - securities lending (1) $ 23,628 $ 21,204 Derivative instruments, net 4,712 7,321 Bank-owned life insurance 3,219 3,158 Investments in joint ventures and other unconsolidated entities 2,099 2,363 Collateral, net 902 2,236 Accounts receivable 393 886 Prepaid expenses 422 333 Receivable for securities settlement 441 40 Income taxes receivable 368 106 Deferred tax assets, net of valuation allowance (2) 213 210 Deposits with clearing organizations 125 132 Other (3) 435 339 Total $ 36,957 $ 38,328 (1) Refer to Note 8 for further information on the impact of collateral on our financial statement presentation of securities borrowing transactions. (2) Deferred tax assets and liabilities recorded in our consolidated statement of condition are netted within the same tax jurisdiction. (3) Includes amounts held in escrow accounts at third parties related to the negotiated settlements in the transition management legal matter presented in Note 10.

Derivative Financial Instrument

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments We use derivative financial instruments to support our clients' needs and to manage our interest-rate and currency risk. In undertaking these activities, we assume positions in both the foreign exchange and interest-rate markets by buying and selling cash instruments and using derivative financial instruments, including foreign exchange forward contracts, foreign exchange options and interest-rate contracts. For information on our derivative instruments, including the related accounting policies, refer to pages 160 to 166 in Note 10 to the consolidated financial statements included under Item 8, Financial Statements and Supplementary Data, in our 2016 Form 10-K. Derivative financial instruments are also subject to credit and counterparty risk, which we manage by performing credit reviews, maintaining individual counterparty limits, entering into netting arrangements and requiring the receipt of collateral. Cash collateral received from and provided to counterparties in connection with derivative financial instruments is recorded in accrued expenses and other liabilities and other assets, respectively, in our consolidated statement of condition. As of September 30, 2017 and December 31, 2016 , we had recorded approximately $1.18 billion and $1.99 billion , respectively, of cash collateral received from counterparties and approximately $1.85 billion and $4.39 billion , respectively, of cash collateral provided to counterparties in connection with derivative financial instruments in our consolidated statement of condition. Certain of our derivative assets and liabilities as of September 30, 2017 and December 31, 2016 are subject to master netting agreements with our derivative counterparties. Certain of these agreements contain credit risk-related contingent features in which the counterparty has the right to declare us in default and accelerate cash settlement of our net derivative liabilities with the counterparty in the event that our credit rating falls below specified levels. The aggregate fair value of all derivative instruments with credit risk-related contingent features that were in a net liability position as of September 30, 2017 totaled approximately $1.94 billion , against which we provided no underlying collateral. If our credit rating were downgraded below levels specified in the agreements, the maximum additional amount of payments related to termination events that could have been required pursuant to these contingent features, assuming no change in fair value, as of September 30, 2017 was approximately $1.94 billion . Such accelerated settlement would be at fair value and therefore not affect our consolidated results of operations. Derivatives Not Designated as Hedging Instruments In connection with our trading activities, we use derivative financial instruments in our role as a financial intermediary and as both a manager and servicer of financial assets, in order to accommodate our clients' investment and risk management needs. In addition, we use derivative financial instruments for risk management purposes as economic hedges, which are not formally designated as accounting hedges, in order to contribute to our overall corporate earnings and liquidity. These activities are designed to generate trading services revenue and to manage volatility in our NII. The level of market risk that we assume is a function of our overall objectives and liquidity needs, our clients' requirements and market volatility. For additional information on derivative not designated as hedging instruments, refer to pages 161 to 162 in Note 10 to the consolidated financial statements included under Item 8, Financial Statements and Supplementary Data, in our 2016 Form 10-K. Derivatives Designated as Hedging Instruments In connection with our asset-and-liability management activities, we use derivative financial instruments to manage our interest rate risk and foreign currency risk. Interest rate risk, defined as the sensitivity of income or financial condition to variations in interest rates, is a significant non-trading market risk to which our assets and liabilities are exposed. We manage our interest rate risk by identifying, quantifying and hedging our exposures, using fixed-rate portfolio securities and a variety of derivative financial instruments, most frequently interest-rate swaps. Interest rate swap agreements alter the interest-rate characteristics of specific balance sheet assets or liabilities. We use foreign exchange forward and swap contracts to hedge foreign exchange exposure to various foreign currencies with respect to certain assets and liabilities. Our hedging relationships are formally designated, and qualify for hedge accounting, as fair value, cash flow or net investment hedges. For additional information on derivatives designated as hedging instruments, refer to pages 162 to 166 in Note 10 to the consolidated financial statements included under Item 8, Financial Statements and Supplementary Data, in our 2016 Form 10-K. Fair Value Hedges We have entered into interest rate swap agreements to modify our interest income from certain AFS investment securities from a fixed rate to a floating rate. The hedged AFS investment securities included hedged trusts that had a weighted-average life of approximately 4.4 years as of September 30, 2017 , compared to 4.5 years as of December 31, 2016 . We have entered into interest rate swap agreements to modify our interest expense on eight senior notes and one subordinated note from fixed rates to floating rates. The senior and subordinated notes are hedged with interest rate swap contracts with notional amounts, maturities and fixed-rate coupon terms that effectively hedge the fixed-rate notes. The table below summarizes the maturities and the paid fixed interest rates for the hedged senior and subordinated notes: September 30, 2017 Maturity Paid Fixed Interest Rate Senior Notes 2020 2.55% 2021 4.38 2021 1.95 2022 2.65 2023 3.70 2024 3.30 2025 3.55 2026 2.65 Subordinated Notes 2023 3.10 We have entered into foreign exchange swap contracts to hedge the change in fair value attributable to foreign exchange movements in our foreign currency denominated investment securities and deposits. These forward contracts convert the foreign currency risk to U.S. dollars, thereby mitigating our exposure to fluctuations in the fair value of the securities and deposits attributable to changes in foreign exchange rates. Cash Flow Hedges We have entered into foreign exchange contracts to hedge the change in cash flows attributable to foreign exchange movements in foreign currency denominated investment securities. These foreign exchange contracts convert the foreign currency risk to U.S. dollars, thereby mitigating our exposure to fluctuations in the cash flows of the securities attributable to changes in foreign exchange rates. We have entered into an interest rate swap agreement to hedge the forecasted cash flows associated with LIBOR-indexed floating-rate loans. The interest rate swaps synthetically convert the loan interest receipts from a variable-rate to a fixed-rate, thereby mitigating the risk attributable to changes in the LIBOR benchmark rate. As of September 30, 2017 , the maximum maturity date of the underlying loans is approximately 5.0 years . Net Investment Hedges We have entered into foreign exchange contracts to protect the net investment in our foreign operations against adverse changes in exchange rates. These forward contracts convert the foreign currency risk to U.S. dollars, thereby mitigating our exposure to fluctuations in the fair value of our net investments in our foreign operations attributable to changes in foreign exchange rates. The changes in fair value of the foreign exchange forward contracts are recorded, net of taxes, in the foreign currency translation component of other comprehensive income. Effectiveness of net investment hedges is based on the overall changes in the fair value of the forward contracts. The following table presents the aggregate contractual, or notional, amounts of derivative financial instruments entered into in connection with our trading and asset-and-liability management activities as of the dates indicated: (In millions) September 30, December 31, Derivatives not designated as hedging instruments: Interest-rate contracts: Futures $ 14,262 $ 13,455 Foreign exchange contracts: Forward, swap and spot 1,618,670 1,414,765 Options purchased 455 337 Options written 262 202 Futures — — Other: Stable value contracts 25,351 27,182 Deferred value awards (1)(2) 531 409 Derivatives designated as hedging instruments: Interest-rate contracts: Swap agreements 10,616 10,169 Foreign exchange contracts: Forward and swap 27,429 8,564 (1) Represents grants of deferred value awards to employees; refer to discussion in this note under "Derivatives Not Designated as Hedging Instruments." (2) Amount as of December 31, 2016 reflects $249 million related to the acceleration of expense associated with certain cash settled deferred incentive compensation awards. In connection with our asset-and-liability management activities, we have entered into interest-rate contracts designated as fair value and cash flow hedges to manage our interest rate risk. The following tables present the aggregate notional amounts of these interest rate contracts and the related assets or liabilities being hedged as of the dates indicated: September 30, 2017 (In millions) Fair Value Hedges Cash Total Investment securities available-for-sale $ 1,323 $ — $ 1,323 Long-term debt (1) 8,493 — 8,493 Floating-rate loans — 800 800 Total $ 9,816 $ 800 $ 10,616 December 31, 2016 (2) (In millions) Fair Value Hedges Investment securities available-for-sale $ 1,444 Long-term debt (1) 8,725 Total $ 10,169 (1) As of September 30, 2017 , these fair value hedges decreased the carrying value of LTD presented in our consolidated statement of condition by $1 million . As of December 31, 2016 , these fair value hedges decreased the carrying value of long-term debt presented in our consolidated statement of condition by $15 million . (2) As of December 31, 2016 , there were no interest-rate contracts designated as cash flow hedges. The following table presents the contractual and weighted-average interest rates for long-term debt, which include the effects of the fair value hedges presented in the table above, for the periods indicated: Three Months Ended September 30, 2017 2016 Contractual Rates Rate Including Impact of Hedges Contractual Rates Rate Including Impact of Hedges Long-term debt 3.30 % 2.67 % 3.37 % 2.27 % Nine Months Ended September 30, 2017 2016 Contractual Rate Contractual Rate Long-term debt 3.35 % 2.61 % 3.41 % 2.24 % The following tables present the fair value of derivative financial instruments, excluding the impact of master netting agreements, recorded in our consolidated statement of condition as of the dates indicated. The impact of master netting agreements is provided in Note 8 to the consolidated financial statements in this Form 10-Q. Derivative Assets (1) Fair Value (In millions) September 30, December 31, 2016 Derivatives not designated as hedging instruments: Foreign exchange contracts $ 11,667 $ 15,982 Total $ 11,667 $ 15,982 Derivatives designated as hedging instruments: Foreign exchange contracts $ 70 $ 502 Interest-rate contracts 3 68 Total $ 73 $ 570 (1) Derivative assets are included within other assets in our consolidated statement of condition. Derivative Liabilities (1) Fair Value (In millions) September 30, December 31, 2016 Derivatives not designated as hedging instruments: Foreign exchange contracts $ 11,506 $ 15,881 Other derivative contracts 319 380 Total $ 11,825 $ 16,261 Derivatives designated as hedging instruments: Foreign exchange contracts $ 77 $ 75 Interest-rate contracts 107 348 Total $ 184 $ 423 (1) Derivative liabilities are included within other liabilities in our consolidated statement of condition. The following tables present the impact of our use of derivative financial instruments on our consolidated statement of income for the periods indicated: Location of Gain (Loss) on Derivative in Consolidated Statement of Income Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income Three Months Ended September 30, Nine Months Ended September 30, (In millions) 2017 2016 2017 2016 Derivatives not designated as hedging instruments: Foreign exchange contracts Trading services revenue $ 152 $ 161 $ 485 $ 477 Interest-rate contracts Processing fees and other revenue — — — 1 Foreign exchange contracts Processing fees and other revenue (9 ) (3 ) (11 ) (13 ) Interest-rate contracts Trading services revenue (2 ) (1 ) 7 (6 ) Credit derivative contracts Trading services revenue — — — (1 ) Other derivative contracts Trading services revenue — 1 — (2 ) Other derivative contracts Compensation and employee benefits (25 ) 41 (120 ) 168 Total $ 116 $ 199 $ 361 $ 624 Location of Gain (Loss) on Derivative in Consolidated Statement of Income Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income Hedged Item in Fair Value Hedging Relationship Location of Gain (Loss) on Hedged Item in Consolidated Statement of Income Amount of Gain (Loss) on Hedged Item Recognized in Consolidated Statement of Income Three Months Ended September 30, Three Months Ended September 30, (In millions) 2017 2016 2017 2016 Derivatives designated as fair value hedges: Foreign exchange contracts Processing fees and $ 19 $ 24 Investment securities Processing fees and $ (19 ) $ (24 ) Foreign exchange contracts Processing fees and other revenue 200 1 FX deposit Processing fees and other revenue (200 ) (1 ) Interest-rate contracts Processing fees and other revenue 9 22 Available-for-sale securities Processing fees and other revenue (1) (9 ) (22 ) Interest-rate contracts Processing fees and (8 ) (79 ) Long-term debt Processing fees and 5 78 Total $ 220 $ (32 ) $ (223 ) $ 31 Location of Gain (Loss) on Derivative in Consolidated Statement of Income Amount of Gain Hedged Item in Fair Value Hedging Relationship Location of Gain (Loss) on Hedged Item in Consolidated Statement of Income Amount of Gain Nine Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Derivatives designated as fair value hedges: Foreign exchange contracts Processing fees and $ 21 $ 43 Investment securities Processing fees and $ (21 ) $ (43 ) Foreign exchange contracts Processing fees and other revenue 1,282 247 FX deposit Processing fees and other revenue (1,282 ) (247 ) Interest-rate contracts Processing fees and 23 (15 ) Available-for-sale securities Processing fees and (2) (21 ) 15 Interest-rate contracts Processing fees and 37 297 Long-term debt Processing fees and (39 ) (282 ) Total $ 1,363 $ 572 $ (1,363 ) $ (557 ) (1) In the three months ended September 30, 2017 and 2016 , $4 million and $13 million , respectively, of net unrealized (losses) gains on AFS investment securities designated in fair value hedges were recognized in OCI. (2) In the nine months ended September 30, 2017 and 2016 , $13 million and $(9) million , respectively, of net unrealized (losses) gains on AFS investment securities designated in fair value hedges were recognized in OCI. Differences between the gains (losses) on the derivative and the gains (losses) on the hedged item, excluding any amounts recorded in NII, represent hedge ineffectiveness. Amount of Gain (Loss) on Derivative Recognized in Other Comprehensive Income Location of Gain (Loss) Reclassified from OCI to Consolidated Statement of Income Amount of Gain (Loss) Reclassified from OCI to Consolidated Statement of Income Location of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income Three Months Ended September 30, Three Months Ended September 30, Three Months Ended September 30, (In millions) 2017 2016 2017 2016 2017 2016 Derivatives designated as cash flow hedges: Interest-rate contracts $ (1 ) $ — Net interest income $ — $ — Net interest income $ — $ — Foreign exchange contracts (1 ) (65 ) Net interest income — — Net interest income 5 6 Total $ (2 ) $ (65 ) $ — $ — $ 5 $ 6 Derivatives designated as net investment hedges: Foreign exchange contracts $ (47 ) $ 4 Gains (Losses) related to investment securities, net $ — $ — Gains (Losses) related to investment securities, net $ — $ — Total $ (47 ) $ 4 $ — $ — $ — $ — Amount of Gain (Loss) on Derivative Recognized in Other Comprehensive Income Location of Gain (Loss) Reclassified from OCI to Consolidated Statement of Income Amount of Gain (Loss) Reclassified from OCI to Consolidated Statement of Income Location of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income Nine Months Ended September 30, Nine Months Ended September 30, Nine Months Ended September 30, (In millions) 2017 2016 2017 2016 2017 2016 Derivatives designated as cash flow hedges: Interest-rate contracts $ (2 ) $ — Net interest income $ — $ — Net interest income $ — $ — Foreign exchange contracts (93 ) (293 ) Net interest income — — Net interest income 18 17 Total $ (95 ) $ (293 ) $ — $ — $ 18 $ 17 Derivatives designated as net investment hedges: Foreign exchange contracts $ (148 ) $ 55 Gains (Losses) related to investment securities, net $ — $ — Gains (Losses) related to investment securities, net $ — $ — Total $ (148 ) $ 55 $ — $ — $ — $ —

Offsetting Arrangements

Offsetting Arrangements	9 Months Ended
	Sep. 30, 2017
Offsetting [Abstract]
Offsetting Arrangements	Offsetting Arrangements We manage credit and counterparty risk by entering into enforceable netting agreements and other collateral arrangements with counterparties to derivative contracts and secured financing transactions, including resale and repurchase agreements, and principal securities borrowing and lending agreements. These netting agreements mitigate our counterparty credit risk by providing for a single net settlement with a counterparty of all financial transactions covered by the agreement in an event of default as defined under such agreement. In limited cases, a netting agreement may also provide for the periodic netting of settlement payments with respect to multiple different transaction types in the normal course of business. For additional information on offsetting arrangements, refer to pages 166 to 170 in Note 11 to the consolidated financial statements included under Item 8, Financial Statements and Supplementary Data, in our 2016 Form 10-K. As of September 30, 2017 and December 31, 2016 , the fair value of securities received as collateral from third parties where we are permitted to transfer or re-pledge the securities totaled $2.96 billion and $1.77 billion , respectively, and the fair value of the portion that had been transferred or re-pledged as of the same dates was $41.2 million and $166 million , respectively. The following tables present information about the offsetting of assets related to derivative contracts and secured financing transactions, as of the dates indicated: Assets: September 30, 2017 Gross Amounts Not Offset in Statement of Condition (In millions) Gross Amounts of Recognized Assets (1)(2) Gross Amounts Offset in Statement of Condition (3) Net Amounts of Assets Presented in Statement of Condition Cash and Securities Received (4) Net Amount (5) Derivatives: Foreign exchange contracts $ 11,737 $ (6,389 ) $ 5,348 $ 5,348 Interest-rate contracts 3 (2 ) 1 1 Cash collateral and securities netting NA (637 ) (637 ) $ (106 ) (743 ) Total derivatives 11,740 (7,028 ) 4,712 (106 ) 4,606 Other financial instruments: Resale agreements and securities borrowing (6) 63,821 (36,728 ) 27,093 (27,093 ) — Total derivatives and other financial instruments $ 75,561 $ (43,756 ) $ 31,805 $ (27,199 ) $ 4,606 Assets: December 31, 2016 Gross Amounts Not Offset in Statement of Condition (In millions) Gross Amounts of Recognized Assets (1)(2) Gross Amounts Offset in Statement of Condition (3) Net Amounts of Assets Presented in Statement of Condition Cash and Securities Received (4) Net Amount (5) Derivatives: Foreign exchange contracts $ 16,484 $ (8,257 ) $ 8,227 $ 8,227 Interest-rate contracts 68 (68 ) — — Cash collateral and securities netting NA (906 ) (906 ) $ (247 ) (1,153 ) Total derivatives 16,552 (9,231 ) 7,321 (247 ) 7,074 Other financial instruments: Resale agreements and securities borrowing (6) 58,677 (35,517 ) 23,160 (22,939 ) 221 Total derivatives and other financial instruments $ 75,229 $ (44,748 ) $ 30,481 $ (23,186 ) $ 7,295 (1) Amounts include all transactions regardless of whether or not they are subject to an enforceable netting arrangement. (2) Derivative amounts are carried at fair value and securities financing amounts are carried at amortized cost, except for securities collateral which is also carried at fair value. For additional information about the measurement basis of these instruments, refer to pages 131 to 142 in Notes 1 and 2 to the consolidated financial statements included under Item 8, Financial Statements and Supplementary Data, in our 2016 Form 10-K. (3) Amounts subject to netting arrangements which have been determined to be legally enforceable and eligible for netting in the consolidated statement of condition. (4) Includes securities in connection with our securities borrowing transactions. (5) Includes amounts secured by collateral not determined to be subject to enforceable netting arrangements. (6) Included in the $27,093 million as of September 30, 2017 were $3,465 million of resale agreements and $23,628 million of collateral provided related to securities borrowing. Included in the $23,160 million as of December 31, 2016 were $1,956 million of resale agreements and $21,204 million of collateral provided related to securities borrowing. Resale agreements and collateral provided related to securities borrowing were recorded in securities purchased under resale agreements and other assets, respectively, in our consolidated statement of condition. Additional information about principal securities finance transactions is provided in Note 9 to the consolidated financial statements in this Form 10-Q. NA Not applicable The following tables present information about the offsetting of liabilities related to derivative contracts and secured financing transactions, as of the dates indicated: Liabilities: September 30, 2017 Gross Amounts Not Offset in Statement of Condition (In millions) Gross Amounts of Recognized Liabilities (1)(2) Gross Amounts Offset in Statement of Condition (3) Net Amounts of Liabilities Presented in Statement of Condition Cash and Securities Provided (4) Net Amount (5) Derivatives: Foreign exchange contracts $ 11,583 $ (6,390 ) $ 5,193 $ 5,193 Interest-rate contracts (6) 107 (1 ) 106 106 Other derivative contracts 319 — 319 319 Cash collateral and securities netting NA (1,074 ) (1,074 ) $ (262 ) (1,336 ) Total derivatives 12,009 (7,465 ) 4,544 (262 ) 4,282 Other financial instruments: Repurchase agreements and securities lending (7) 45,864 (36,728 ) 9,136 (6,564 ) 2,572 Total derivatives and other financial instruments $ 57,873 $ (44,193 ) $ 13,680 $ (6,826 ) $ 6,854 Liabilities: December 31, 2016 Gross Amounts Not Offset in Statement of Condition (In millions) Gross Amounts of Recognized Liabilities (1)(2) Gross Amounts Offset in Statement of Condition (3) Net Amounts of Liabilities Presented in Statement of Condition Cash and Securities Provided (4) Net Amount (5) Derivatives: Foreign exchange contracts $ 15,956 $ (8,253 ) $ 7,703 $ 7,703 Interest-rate contracts 348 (73 ) 275 275 Other derivative contracts 380 — 380 380 Cash collateral and securities netting NA (2,356 ) (2,356 ) $ (180 ) (2,536 ) Total derivatives 16,684 (10,682 ) 6,002 (180 ) 5,822 Other financial instruments: Resale agreements and securities lending (7) 44,933 (35,517 ) 9,416 (7,059 ) 2,357 Total derivatives and other financial instruments $ 61,617 $ (46,199 ) $ 15,418 $ (7,239 ) $ 8,179 (1) Amounts include all transactions regardless of whether or not they are subject to an enforceable netting arrangement. (2) Derivative amounts are carried at fair value and securities financing amounts are carried at amortized cost, except for securities collateral which is also carried at fair value. For additional information about the measurement basis of these instruments, refer to pages 131 to 142 in Notes 1 and 2 to the consolidated financial statements included under Item 8, Financial Statements and Supplementary Data, in our 2016 Form 10-K. (3) Amounts subject to netting arrangements which have been determined to be legally enforceable and eligible for netting in the consolidated statement of condition. (4) Includes securities provided in connection with our securities lending transactions. (5) Includes amounts secured by collateral not determined to be subject to enforceable netting arrangements. (6) Variation margin payments presented as settlements rather than collateral. (7) Included in the $9,136 million as of September 30, 2017 were $3,867 million of repurchase agreements and $5,269 million of collateral received related to securities lending. Included in the $9,416 million as of December 31, 2016 were $4,400 million of repurchase agreements and $5,016 million of collateral received related to securities lending. Repurchase agreements and collateral received related to securities lending were recorded in securities sold under repurchase agreements and accrued expenses and other liabilit ies, respectively, in our consolidated statement of condition. Additional information about principal securities finance transactions is provided in Note 9 to the consolidated financial statements in this Form 10-Q. NA Not applicable The securities transferred under resale and repurchase agreements typically are U.S. Treasury, agency and agency MBS. In our principal securities borrowing and lending arrangements, the securities transferred are predominantly equity securities and some corporate debt securities. The fair value of the securities transferred may increase in value to an amount greater than the amount received under our repurchase and securities lending arrangements, which exposes the Company with counterparty risk. We require the review of the price of the underlying securities in relation to the carrying value of the repurchase agreements and securities lending arrangements on a daily basis and when appropriate, adjust the cash or security to be obtained or returned to counterparties that is reflective of the required collateral levels. The following tables summarize our repurchase agreements and securities lending transactions by category of collateral pledged and remaining maturity of these agreements as of the periods indicated: Remaining Contractual Maturity of the Agreements As of September 30, 2017 (In millions) Overnight and Continuous Up to 30 days 30 – 90 days Total Repurchase agreements: U.S. Treasury and agency securities $ 35,009 $ 35,009 Total 35,009 — — 35,009 Securities lending transactions: Corporate debt securities 103 103 Equity securities 10,433 297 10,730 Non-U.S. sovereign debt 22 22 Total 10,558 — 297 10,855 Gross amount of recognized liabilities for repurchase agreements and securities lending $ 45,567 $ — $ 297 $ 45,864 Remaining Contractual Maturity of the Agreements As of December 31, 2016 (In millions) Overnight and Continuous Up to 30 days 30 – 90 days Total Repurchase agreements: U.S. Treasury and agency securities $ 35,509 $ — $ — $ 35,509 Total 35,509 — — 35,509 Securities lending transactions: Corporate debt securities 53 — — 53 Equity securities 8,337 — 1,034 9,371 Total 8,390 — 1,034 9,424 Gross amount of recognized liabilities for repurchase agreements and securities lending $ 43,899 $ — $ 1,034 $ 44,933

Commitments and Guarantees

Commitments and Guarantees	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Guarantees	Commitments and Guarantees For additional information about our commitments and guarantees, refer to pages 171 to 172 in Note 12 to the consolidated financial statements included under Item 8, Financial Statements and Supplementary Data, in our 2016 Form 10-K. The following table presents the aggregate gross contractual amounts of our off-balance sheet commitments and off-balance sheet guarantees as of the dates indicated. (In millions) September 30, 2017 December 31, 2016 Commitments: Unfunded credit facilities $ 27,008 $ 26,993 Guarantees (1) : Indemnified securities financing $ 379,459 $ 360,452 Stable value protection 25,351 27,182 Standby letters of credit 3,255 3,459 (1) The potential losses associated with these guarantees equal the gross contractual amounts and do not consider the value of any collateral or reflect any participations to independent third parties. Unfunded Credit Facilities Unfunded credit facilities consist of liquidity facilities for our fund and municipal lending clients and undrawn lines of credit related to senior secured bank loans. As of September 30, 2017 , approximately 73% of our unfunded commitments to extend credit expire within one year. Since many of these commitments are expected to expire or renew without being drawn upon, the gross contractual amounts do not necessarily represent our future cash requirements. Indemnified Securities Financing On behalf of our clients, we lend their securities, as agent, to brokers and other institutions. In most circumstances, we indemnify our clients for the fair market value of those securities against a failure of the borrower to return such securities. The following table summarizes the aggregate fair values of indemnified securities financing and related collateral, as well as collateral invested in indemnified repurchase agreements, as of the dates indicated: (In millions) September 30, 2017 December 31, 2016 Fair value of indemnified securities financing $ 379,459 $ 360,452 Fair value of cash and securities held by us, as agent, as collateral for indemnified securities financing 396,123 377,919 Fair value of collateral for indemnified securities financing invested in indemnified repurchase agreements 68,243 60,003 Fair value of cash and securities held by us or our agents as collateral for investments in indemnified repurchase agreements 73,157 63,959 In certain cases, we participate in securities finance transactions as a principal. As a principal, we borrow securities from the lending client and then lend such securities to the subsequent borrower, either a State Street client or a broker/dealer. Our right to receive and obligation to return collateral in connection with our securities lending transactions are recorded in other assets and accrued expenses and other liabilities, respectively, in our consolidated statement of condition. As of September 30, 2017 and December 31, 2016 , we had approximately $23.63 billion and $21.20 billion , respectively, of collateral provided and approximately $5.27 billion and $5.02 billion , respectively, of collateral received from clients in connection with our participation in principal securities finance transactions. Stable Value Protection In the normal course of our business, we offer products that provide book-value protection, primarily to plan participants in stable value funds managed by non-affiliated investment managers of post-retirement defined contribution benefit plans, particularly 401(k) plans. The book-value protection is provided on portfolios of intermediate investment grade fixed-income securities, and is intended to provide safety and stable growth of principal invested. The protection is intended to cover any shortfall in the event that a significant number of plan participants withdraw funds when book value exceeds market value and the liquidation of the assets is not sufficient to redeem the participants. The investment parameters of the underlying portfolios, combined with structural protections, are designed to provide cushion and guard against payments even under extreme stress scenarios. These contingencies are individually accounted for as derivative financial instruments. The notional amounts of the stable value contracts are presented as “derivatives not designated as hedging instruments” in the table of aggregate notional amounts of derivative financial instruments provided in Note 7 to the consolidated financial statements in this Form 10-Q. We have not made a payment under these contingencies that we consider material to our consolidated financial condition, and management believes that the probability of payment under these contingencies in the future, that we would consider material to our consolidated financial condition, is remote. Standby Letters of Credit Standby letters of credit provide credit enhancement to our municipal clients to support the issuance of capital markets financing.

Contingencies

Contingencies	9 Months Ended
	Sep. 30, 2017
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 damages, 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 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 for 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 (collectively, "factors influencing reasonable estimates"), 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. As of September 30, 2017, our aggregate accruals for loss contingencies for legal and regulatory matters totaled approximately $15 million . 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. Except where otherwise noted below, we have not established accruals with respect to the claims discussed and do not believe that potential exposure is probable and can be reasonably estimated. We have identified certain matters for which loss is reasonably possible (but not probable) in future periods, whether in excess of an accrued liability or where there is no accrued liability, and for which we are able to estimate a range of reasonably possible loss. As of September 30, 2017, our estimate of the range of reasonably possible loss for these matters is from zero to approximately $15 million in the aggregate. Our estimate with respect to the aggregate range of 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. The matters underlying the estimated range will change from time to time, and actual results may vary significantly from the current estimate. In certain other pending matters , including the Invoicing Matter, Federal Reserve/Massachusetts Division of Banks Written Agreement and Shareholder Litigation discussed below, it is not currently feasible to reasonably estimate the amount or a range of reasonably possible loss (including reasonably possible loss in excess of amounts accrued), 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, one or more considerations consistent with the factors influencing reasonable estimates described in the above discussion of probable loss accruals. These considerations are particularly prevalent in governmental and regulatory inquiries and investigations and, as a result, reasonably possible loss estimates often are not feasible until the later stages of the inquiry or investigation or of any related legal or regulatory proceeding. An adverse outcome in one or more of the matters for which we do not estimate 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 we cannot estimate reasonably possible loss for all legal and regulatory proceedings as to which we may be subject now or in the future, including matters that if adversely concluded may present material financial, regulatory and reputational risks, no conclusion as to the 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. Transition Management In January 2014, we entered into a settlement with the FCA, pursuant to which we paid a fine of £22.9 million (approximately $37.8 million ), as a result of our having charged six clients of our U.K. transition management business during 2010 and 2011 amounts in excess of the contractual terms. The SEC and the DOJ opened separate investigations into this matter. The U.S. Attorney’s office in Boston has charged three former employees in our transition management business with criminal fraud in connection with their alleged role in this matter. Two of these individuals have pled guilty to one count of criminal conspiracy. Charges remain pending against the third individual. The SEC has also commenced a parallel civil enforcement proceeding against that individual. On January 18, 2017, we announced that we had entered into a settlement agreement with the DOJ and the United States Attorney for the District of Massachusetts to resolve their investigation. Under the terms of the agreement, we, among other things, paid a fine of $32.3 million and entered into a deferred prosecution agreement. Under the deferred prosecution agreement, we agreed to retain an independent compliance and ethics monitor for a term of three years (subject to extension) which will, among other things, review and monitor the effectiveness of our compliance controls and business ethics and make related recommendations. In September 2017, we entered into a settlement with the SEC and paid a penalty of $32.3 million (equal to the fine paid to the DOJ). The SEC settlement also required us to retain an independent ethics and compliance consultant. The monitor appointed in connection with the previously announced DOJ settlement will fulfill that role. Federal Reserve/Massachusetts Division of Banks Written Agreement On June 1, 2015, we entered into a written agreement with the Federal Reserve and the Massachusetts Division of Banks relating to deficiencies identified in our compliance programs with the requirements of the Bank Secrecy Act, AML regulations and U.S. economic sanctions regulations promulgated by OFAC. As part of this enforcement action, we are required to, among other things, implement improvements to our compliance programs and to retain an independent firm to conduct a review of account and transaction activity covering a prior three-month period to evaluate whether any suspicious activity not previously reported should have been identified and reported in accordance with applicable regulatory requirements. To the extent deficiencies in our historical reporting are identified as a result of the transaction review or if we fail to comply with the terms of the written agreement, we may become subject to fines and other regulatory sanctions, which may have a material adverse effect on us. Invoicing Matter In December 2015, we announced a review of the manner in which we invoiced certain expenses to some of our Investment Servicing clients, primarily in the United States, during an 18-year period going back to 1998, and our determination that we had incorrectly invoiced clients for certain expenses. We informed our clients in December 2015 that we will pay to them the amounts we concluded were incorrectly invoiced to them, plus interest. We currently expect the cumulative total of our payments to be at least $340 million (including interest), in connection with that review, which is ongoing. We are implementing enhancements to our billing processes, and we are reviewing the conduct of our employees and have taken appropriate steps to address conduct inconsistent with our standards, including, in some cases, termination of employment. We are also evaluating other billing practices relating to our Investment Servicing clients, including calculation of asset-based fees. We have received a purported class action demand letter alleging that our invoicing practices were unfair and deceptive under Massachusetts law. A class of customers, or particular customers, may assert that we have not paid to them all amounts incorrectly invoiced, and may seek double or treble damages under Massachusetts law. In addition, in March 2017, a purported class action was commenced against us alleging that our invoicing practices violated duties owed to retirement plan customers under ERISA. We are also responding to requests for information from, and are cooperating with investigations by, governmental and regulatory authorities on these matters, including the civil and criminal divisions of the DOJ, the SEC, the DOL, the Massachusetts Attorney General, and the New Hampshire Bureau of Securities Regulation, which could result in significant fines or other sanctions, civil and criminal, against us. If these governmental or regulatory authorities were to conclude that all or a portion of the billing error merited civil or criminal sanctions, any fine or other penalty could be a significant percentage or a multiple of the portion of the overcharging serving as the basis of such a claim or of the full amount of the overcharging. The governmental and regulatory authorities have significant discretion in civil and criminal matters as to the fines and other penalties they seek to impose. The severity of such fines or other penalties could take into account factors such as the amount and duration of our incorrect invoicing, the government’s or regulator's assessment of the conduct of our employees, as well as prior conduct such as that which resulted in our January 2017 deferred prosecution agreement in connection with transition management services and our recent settlement of civil claims regarding our indirect foreign exchange business. Any governmental or regulatory proceeding or sanction or the outcome of any litigation could have a material adverse effect on our reputation or business, including the imposition of restrictions on the operation of our business or a reduction in client demand. Resolution of these matters could also have a material adverse effect on our consolidated results of operations for the period or periods in which such matters are resolved or an accrual is determined to be required. No accrual, other than a reserve for client reimbursement, is reflected on our consolidated statement of condition as of September 30, 2017. Shareholder Litigation A State Street shareholder has filed a purported class action complaint against the Company alleging that the Company’s financial statements in its annual reports for the 2011-14 period were misleading due to the inclusion of revenues associated with the Transition Management and Invoicing matters. In addition, a State Street shareholder has filed a derivative complaint against the Company's past and present officers and directors to recover alleged losses incurred by the Company relating to the Invoicing Matter and to our January 2016 settlement with the SEC concerning Ohio public retirement plans. 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 $63 million as of September 30, 2017 decreased from $71 million as of December 31, 2016. We are presently under audit by a number of tax authorities and the Internal Revenue Service is currently reviewing our U.S. income tax returns for the tax years 2014 and 2015. The earliest tax year open to examination in jurisdictions where we have material operations is 2010. Management believes that we have sufficiently accrued liabilities as of September 30, 2017 for tax exposures.

Variable Interest Entities

Variable Interest Entities	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entities	Variable Interest Entities For additional information on our VIEs, refer to pages 174 to 175 in Note 14 to the consolidated financial statements included under Item 8, Financial Statements and Supplementary Data, in our 2016 Form 10-K. Tax-Exempt Investment Program In the normal course of our business, we structure and sell certificated interests in pools of tax-exempt investment-grade assets, principally to our mutual fund clients. We structure these pools as partnership trusts, and the assets and liabilities of the trusts are recorded in our consolidated statement of condition as AFS investment securities and other short-term borrowings. As of September 30, 2017 and December 31, 2016 , we carried AFS investment securities, composed of securities related to state and political subdivisions, with a fair value of $1.29 billion and $1.35 billion , respectively, and other short-term borrowings of $1.10 billion and $1.16 billion , respectively, in our consolidated statement of condition in connection with these trusts. The interest income and interest expense generated by the investments and certificated interests, respectively, are recorded as components of NII when earned or incurred. The trusts had a weighted-average life of approximately 4.4 years as of September 30, 2017 , compared to approximately 4.5 years as of December 31, 2016 . Under separate legal agreements, we provide liquidity facilities to these trusts and, with respect to certain securities, letters of credit. As of September 30, 2017 , our commitments to the trusts under these liquidity facilities and letters of credit totaled $1.12 billion and $351 million , respectively, and none of the liquidity facilities were utilized. Interests in Investment Funds As of September 30, 2017 , the average assets and liabilities of our consolidated sponsored investment funds totaled $119.82 million and $19.44 million , respectively. As of December 31, 2016 , we had no consolidated funds. As of September 30, 2017 , our potential maximum total exposure associated with the consolidated sponsored investment funds totaled $100 million and represented the value of our economic ownership interest in the funds. As of September 30, 2017 and December 31, 2016 , we managed certain funds, considered VIEs, in which we held a variable interest but for which we were not deemed to be the primary beneficiary. Our potential maximum loss exposure related to these unconsolidated funds totaled $79 million and $121 million as of September 30, 2017 and December 31, 2016 , respectively, and represented the carrying value of our investments, which are recorded in either AFS investment securities or other assets in our consolidated statement of condition. The amount of loss we may recognize during any period is limited to the carrying amount of our investments in the unconsolidated funds.

Shareholders' Equity

Shareholders' Equity	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Shareholders' Equity	Shareholders' Equity Preferred Stock The following table summarizes selected terms of each of the series of the preferred stock issued and outstanding as of September 30, 2017 : Issuance Date Depositary Shares Issued Ownership Interest Per Depositary Share Liquidation Preference Per Share Liquidation Preference Per Depositary Share Net Proceeds of Offering (In millions) Redemption Date (1) Preferred Stock (2) : Series C August 2012 20,000,000 1/4,000th $ 100,000 $ 25 $ 488 September 15, 2017 Series D February 2014 30,000,000 1/4,000th 100,000 25 742 March 15, 2024 Series E November 2014 30,000,000 1/4,000th 100,000 25 728 December 15, 2019 Series F May 2015 750,000 1/100th 100,000 1,000 742 September 15, 2020 Series G April 2016 20,000,000 1/4,000th 100,000 25 493 March 15, 2026 (1) On the redemption date, or any dividend declaration date thereafter, the preferred stock and corresponding depositary shares may be redeemed by us, in whole or in part, at the liquidation price per share and liquidation price per depositary share plus any declared and unpaid dividends, without accumulation of any undeclared dividends. (2) The preferred stock and corresponding depositary shares may be redeemed at our option in whole, but not in part, prior to the redemption date upon the occurrence of a regulatory capital treatment event, as defined in the certificate of designation, at a redemption price equal to the liquidation price per share and liquidation price per depositary share plus any declared and unpaid dividends, without accumulation of any undeclared dividends. The following tables present the dividends declared for each of the series of preferred stock issued and outstanding for the periods indicated: Three Months Ended September 30, 2017 2016 Dividends Declared per Share Dividends Declared per Depositary Share Total (1) Dividends Declared per Share Dividends Declared per Depositary Share Total (In millions) Preferred Stock: Series C $ 1,313 $ 0.33 $ 6 $ 1,313 $ 0.33 $ 6 Series D 1,475 0.37 11 1,475 0.37 11 Series E 1,500 0.38 11 1,500 0.38 11 Series F 2,625 26.25 20 2,625 26.25 20 Series G 1,338 0.33 7 1,338 0.33 7 Total $ 55 $ 55 Nine Months Ended September 30, 2017 2016 Dividends Declared per Share Dividends Declared per Depositary Share Total (In millions) Dividends Declared per Share Dividends Declared per Depositary Share Total (In millions) Preferred Stock: Series C $ 3,939 $ 0.99 $ 19 $ 3,939 $ 0.99 $ 19 Series D 4,425 1.11 33 4,425 1.11 33 Series E 4,500 1.14 33 4,500 1.14 33 Series F 5,250 52.50 40 5,250 52.50 40 Series G 4,014 0.99 21 2,289 0.57 12 Total $ 146 $ 137 (1) Dividends were paid in September 2017. In October 2017, we declared dividends on our Series C, D, E and G preferred stock of approximately $1,313 , $1,475 , $1,500 and $1,338 , respectively, per share, or approximately $0.33 , $0.37 , $0.38 and $0.33 , respectively, per depositary share. These dividends total approximately $6 million , $11 million , $11 million and $7 million on our Series C, D, E and G preferred stock, respectively, which will be paid in December 2017. Common Stock In June 2017, our Board approved a common stock purchase program authorizing the purchase of up to $1.4 billion of our common stock through June 30, 2018 (the 2017 Program). In June 2016, our Board approved a common stock purchase program authorizing the purchase of up to $1.4 billion of our common stock through June 30, 2017 (the 2016 Program). The table below presents the activity under both the 2017 Program and 2016 Program during the periods indicated: Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 Shares Acquired Average Cost per Share Total Acquired Shares Acquired Average Cost per Share Total Acquired 2016 Program (1) — $ — $ — 9.4 $ 79.93 $ 750 2017 Program 3.7 93.39 350 3.7 93.39 350 Total 3.7 $ 93.39 $ 350 13.1 $ 83.77 $ 1,100 (1) Includes $158 million relating to shares acquired in exchange for BFDS stock during the first quarter of 2017. Additional information about the exchange is provided in Note 1 to the consolidated financial statements included in this Form 10-Q. The table below presents the dividends declared on common stock for the periods indicated: Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Dividends Declared per Share Total (In millions) Dividends Declared per Share Total (In millions) Dividends Declared per Share Total (In millions) Dividends Declared per Share Total (In millions) Common Stock $ 0.42 $ 156 $ 0.38 $ 147 $ 1.18 $ 442 $ 1.06 $ 414 Accumulated Other Comprehensive Income (Loss) The following table presents the after-tax components of AOCI as of the dates indicated: (In millions) September 30, 2017 December 31, 2016 Net unrealized gains (losses) on cash flow hedges $ (45 ) $ 229 Net unrealized gains (losses) on available-for-sale securities portfolio 301 (225 ) Net unrealized gains (losses) related to reclassified available-for-sale securities 18 25 Net unrealized gains (losses) on available-for-sale securities 319 (200 ) Net unrealized losses on available-for-sale securities designated in fair value hedges (73 ) (86 ) Net unrealized gains (losses) on hedges of net investments in non-U.S. subsidiaries (52 ) 95 Other-than-temporary impairment on held-to-maturity securities related to factors other than credit (6 ) (9 ) Net unrealized losses on retirement plans (184 ) (194 ) Foreign currency translation (943 ) (1,875 ) Total $ (984 ) $ (2,040 ) The following table presents changes in AOCI by component, net of related taxes, for the periods indicated: Nine Months Ended September 30, 2017 (In millions) Net Unrealized Gains (Losses) on Cash Flow Hedges Net Unrealized Gains (Losses) on Available-for-Sale Securities Net Unrealized Gains (Losses) on Hedges of Net Investments in Non-U.S. Subsidiaries Other-Than-Temporary Impairment on Held-to-Maturity Securities Net Unrealized Losses on Retirement Plans Foreign Currency Translation Total Balance as of December 31, 2016 $ 229 $ (286 ) $ 95 $ (9 ) $ (194 ) $ (1,875 ) $ (2,040 ) Other comprehensive income (loss) before reclassifications (274 ) 555 (147 ) 3 — 932 1,069 Amounts reclassified into (out of) earnings — (23 ) — — 10 — (13 ) Other comprehensive income (loss) (274 ) 532 (147 ) 3 10 932 1,056 Balance as of September 30, 2017 $ (45 ) $ 246 $ (52 ) $ (6 ) $ (184 ) $ (943 ) $ (984 ) Nine Months Ended September 30, 2016 (In millions) Net Unrealized Gains (Losses) on Cash Flow Hedges Net Unrealized Gains (Losses) on Available-for-Sale Securities Net Unrealized Gain (Losses) on Hedges of Net Investments in Non-U.S. Subsidiaries Other-Than-Temporary Impairment on Held-to-Maturity Securities Net Unrealized Losses on Retirement Plans Foreign Currency Translation Total Balance as of December 31, 2015 $ 293 $ (128 ) $ (14 ) $ (16 ) $ (183 ) $ (1,394 ) $ (1,442 ) Other comprehensive income (loss) before reclassifications (213 ) 520 55 6 — 77 445 Amounts reclassified into (out of) earnings — 4 — (1 ) 1 — 4 Other comprehensive income (loss) (213 ) 524 55 5 1 77 449 Balance as of September 30, 2016 $ 80 $ 396 $ 41 $ (11 ) $ (182 ) $ (1,317 ) $ (993 ) The following table presents after-tax reclassifications into earnings for the periods indicated: Three Months Ended September 30, 2017 2016 (In millions) Amounts Reclassified into (out of) Earnings Affected Line Item in Consolidated Statement of Income Available-for-sale securities: Net realized gains from sales of available-for-sale securities, net of related taxes of ($1) and ($2), respectively $ 4 $ 2 Net gains (losses) from sales of available-for-sale securities Retirement plans: Amortization of actuarial losses, net of related taxes of $0 and $1, respectively 2 (1 ) Compensation and employee benefits expenses Total reclassifications (out of) into AOCI $ 6 $ 1 Nine Months Ended September 30, 2017 2016 (In millions) Amounts Reclassified into (out of) Earnings Affected Line Item in Consolidated Statement of Income Available-for-sale securities: Net realized gains (losses) from sales of available-for-sale securities, net of related taxes of $15 and ($3), respectively $ (23 ) $ 4 Net gains (losses) from sales of available-for-sale securities Held-to-maturity securities: Other-than-temporary impairment on held-to-maturity securities related to factors other than credit, net of related taxes of $0 and $1, respectively — (1 ) Losses reclassified (from) to other comprehensive income Retirement plans: Amortization of actuarial losses, net of related taxes of ($2) and ($2), respectively 10 1 Compensation and employee benefits expenses Total reclassifications (out of) into AOCI $ (13 ) $ 4

Regulatory Capital

Regulatory Capital	9 Months Ended
	Sep. 30, 2017
Banking and Thrift [Abstract]
Regulatory Capital	Regulatory Capital We are subject to various regulatory capital requirements administered by federal banking agencies. Failure to meet minimum regulatory capital requirements can initiate certain mandatory and discretionary actions by regulators that, if undertaken, could have a direct material effect on our consolidated financial condition. Under current regulatory capital adequacy guidelines, we must meet specified capital requirements that involve quantitative measures of our consolidated assets, liabilities and off-balance sheet exposures calculated in conformity with regulatory accounting practices. Our capital components and their classifications are subject to qualitative judgments by regulators about components, risk weightings and other factors. For additional information on regulatory capital, and the requirements to which we are subject, refer to pages 179 to 180 in Note 16 to the consolidated financial statements included under Item 8, Financial Statements and Supplementary Data, in our 2016 Form 10-K. As required by the Dodd-Frank Act, State Street and State Street Bank, as advanced approaches banking organizations, are subject to a permanent "capital floor" in the calculation and assessment of their regulatory capital adequacy by U.S. banking regulators. Beginning on January 1, 2015, we were required to calculate our risk-based capital ratios using both the advanced approaches and the standardized approach. As a result, from January 1, 2015 going forward, our risk-based capital ratios for regulatory assessment purposes are the lower of each ratio calculated under the standardized approach and the advanced approaches. The methods for the calculation of our and State Street Bank's risk-based capital ratios will change as the provisions of the Basel III final rule related to the numerator (capital) and denominator (risk-weighted assets) are phased in, and as we begin calculating our risk-weighted assets using the advanced approaches. These ongoing methodological changes will result in differences in our reported capital ratios from one reporting period to the next that are independent of applicable changes to our capital base, our asset composition, our off-balance sheet exposures or our risk profile. As of September 30, 2017 , State Street and State Street Bank exceeded all regulatory capital adequacy requirements to which they were subject. As of September 30, 2017 , State Street Bank was categorized as “well capitalized” under the applicable regulatory capital adequacy framework, and exceeded all “well capitalized” ratio guidelines to which it was subject. Management believes that no conditions or events have occurred since September 30, 2017 that have changed the capital categorization of State Street Bank. The following table presents the regulatory capital structure, total risk-weighted assets, related regulatory capital ratios and the minimum required regulatory capital ratios for State Street and State Street Bank as of the dates indicated. As a result of changes in the methodologies used to calculate our regulatory capital ratios from period to period as the provisions of the Basel III final rule are phased in, the ratios presented in the table for each period-end are not directly comparable. Refer to the footnotes following the table. State Street State Street Bank (In millions) Basel III Advanced Approaches September 30, 2017 (1) Basel III Standardized Approach September 30, 2017 (2) Basel III Advanced Approaches December 31, 2016 (1) Basel III Standardized Approach December 31, 2016 (2) Basel III Advanced Approaches September 30, 2017 (1) Basel III Standardized Approach September 30, 2017 (2) Basel III Advanced Approaches December 31, 2016 (1) Basel III Standardized Approach December 31, 2016 (2) Common shareholders' equity: Common stock and related surplus $ 10,307 $ 10,307 $ 10,286 $ 10,286 $ 11,382 $ 11,382 $ 11,376 $ 11,376 Retained earnings 18,675 18,675 17,459 17,459 12,286 12,286 12,285 12,285 Accumulated other comprehensive income (loss) (985 ) (985 ) (1,936 ) (1,936 ) (808 ) (808 ) (1,648 ) (1,648 ) Treasury stock, at cost (8,697 ) (8,697 ) (7,682 ) (7,682 ) — — — — Total 19,300 19,300 18,127 18,127 22,860 22,860 22,013 22,013 Regulatory capital adjustments: Goodwill and other intangible assets, net of associated deferred tax liabilities (3) (6,739 ) (6,739 ) (6,348 ) (6,348 ) (6,447 ) (6,447 ) (6,060 ) (6,060 ) Other adjustments (122 ) (122 ) (155 ) (155 ) (90 ) (90 ) (148 ) (148 ) Common equity tier 1 capital 12,439 12,439 11,624 11,624 16,323 16,323 15,805 15,805 Preferred stock 3,196 3,196 3,196 3,196 — — — — Trust preferred capital securities subject to phase-out from tier 1 capital — — — — — — — — Other adjustments (29 ) (29 ) (103 ) (103 ) — — — — Tier 1 capital 15,606 15,606 14,717 14,717 16,323 16,323 15,805 15,805 Qualifying subordinated long-term debt 1,072 1,072 1,172 1,172 1,076 1,076 1,179 1,179 Trust preferred capital securities phased out of tier 1 capital — — — — — — — — ALLL and other 5 79 19 77 — 79 15 77 Other adjustments 1 1 1 1 — — — — Total capital $ 16,684 $ 16,758 $ 15,909 $ 15,967 $ 17,399 $ 17,478 $ 16,999 $ 17,061 Risk-weighted assets: Credit risk $ 50,197 $ 106,377 $ 50,900 $ 98,125 $ 47,282 $ 103,024 $ 47,383 $ 94,413 Operational risk (4) 45,795 NA 44,579 NA 45,270 NA 44,043 NA Market risk (5) 3,005 1,203 3,822 1,751 3,005 1,203 3,822 1,751 Total risk-weighted assets $ 98,997 $ 107,580 $ 99,301 $ 99,876 $ 95,557 $ 104,227 $ 95,248 $ 96,164 Adjusted quarterly average assets $ 211,396 $ 211,396 $ 226,310 $ 226,310 $ 208,308 $ 208,308 $ 222,584 $ 222,584 Capital Ratios: 2017 Minimum Requirements Including Capital Conservation Buffer and G-SIB Surcharge (6) 2016 Minimum Requirements Including Capital Conservation Buffer and G-SIB Surcharge (7) Common equity tier 1 capital 6.5 % 5.5 % 12.6 % 11.6 % 11.7 % 11.6 % 17.1 % 15.7 % 16.6 % 16.4 % Tier 1 capital 8.0 7.0 15.8 14.5 14.8 14.7 17.1 15.7 16.6 16.4 Total capital 10.0 9.0 16.9 15.6 16.0 16.0 18.2 16.8 17.8 17.7 Tier 1 leverage 4.0 4.0 7.4 7.4 6.5 6.5 7.8 7.8 7.1 7.1 (1) Common equity tier 1 capital, tier 1 capital and total capital ratios as of September 30, 2017 and December 31, 2016 were calculated in conformity with the advanced approaches provisions of the Basel III final rule. Tier 1 leverage ratio as of September 30, 2017 and December 31, 2016 were calculated in conformity with the Basel III final rule. (2) Common equity tier 1 capital, tier 1 capital and total capital ratios as of September 30, 2017 and December 31, 2016 were calculated in conformity with the standardized approach provisions of the Basel III final rule. Tier 1 leverage ratio as of September 30, 2017 and December 31, 2016 were calculated in conformity with the Basel III final rule. (3) Amounts for State Street and State Street Bank as of September 30, 2017 consisted of goodwill, net of associated deferred tax liabilities, and 80% of other intangible assets, net of associated deferred tax liabilities. Amounts for State Street and State Street Bank as of December 31, 2016 consisted of goodwill, net of deferred tax liabilities and 60% of other intangible assets, net of associated deferred tax liabilities. Intangible assets, net of associated deferred tax liabilities is phased in as a deduction from capital, in conformity with the Basel III final rule. (4) Under the current advanced approaches rules and regulatory guidance concerning operational risk models, RWA attributable to operational risk can vary substantially from period-to-period, without direct correlation to the effects of a particular loss event on our results of operations and financial condition and impacting dates and periods that may differ from the dates and periods as of and during which the loss event is reflected in our financial statements, with the timing and categorization dependent on the processes for model updates and, if applicable, model revalidation and regulatory review and related supervisory processes. An individual loss event can have a significant effect on the output of our operational risk RWA under the advanced approaches depending on the severity of the loss event and its categorization among the seven Basel-defined UOMs. (5) Market risk risk-weighted assets reported in conformity with the Basel III advanced approaches included a CVA which reflected the risk of potential fair value adjustments for credit risk reflected in our valuation of over-the-counter derivative contracts. The CVA was not provided for in the final market risk capital rule; however, it was required by the advanced approaches provisions of the Basel III final rule. We used a simple CVA approach in conformity with the Basel III advanced approaches. (6) Minimum requirements will be phased in up to full implementation beginning on January 1, 2019; minimum requirements listed are as of September 30, 2017 . (7) Minimum requirements will be phased in up to full implementation beginning on January 1, 2019; minimum requirements listed are as of December 31, 2016 . NA Not applicable

Net Interest Income

Net Interest Income	9 Months Ended
	Sep. 30, 2017
Banking and Thrift [Abstract]
Net Interest Income	Net Interest Income The following table presents the components of interest income and interest expense, and related NII, for the periods indicated: Three Months Ended September 30, Nine Months Ended September 30, (In millions) 2017 2016 2017 2016 Interest income: Deposits with banks $ 45 $ 29 $ 121 $ 101 Investment securities: U.S. Treasury and federal agencies 207 200 627 620 State and political subdivisions 56 55 171 162 Other investments 173 208 495 581 Securities purchased under resale agreements 74 40 189 112 Loans and leases 139 97 362 281 Other interest-earning assets 67 18 146 39 Total interest income 761 647 2,111 1,896 Interest expense: Deposits 39 20 96 73 Securities sold under repurchase agreements 1 — 2 1 Short-term borrowings 3 2 7 4 Long-term debt 78 68 227 191 Other interest-bearing liabilities 37 20 91 57 Total interest expense 158 110 423 326 Net interest income $ 603 $ 537 $ 1,688 $ 1,570

Expenses

Expenses	9 Months Ended
	Sep. 30, 2017
Other Expenses [Abstract]
Expenses	Expenses The following table presents the components of other expenses for the periods indicated: Three Months Ended September 30, Nine Months Ended September 30, (In millions) 2017 2016 2017 2016 Insurance $ 27 $ 31 $ 84 $ 74 Regulatory fees and assessments 24 28 77 65 Securities processing 4 10 20 20 Litigation 3 47 (15 ) 47 Other 86 71 261 231 Total other expenses $ 144 $ 187 $ 427 $ 437 Restructuring Charges In the third quarter and first nine months of 2017 , we recorded restructuring charges of $33 million and $112 million , respectively, compared to $10 million and $120 million in the same periods of 2016. The charges were primarily related to Beacon . The following table presents aggregate restructuring activity for the periods indicated: (In millions) Employee Real Estate Asset and Other Write-offs Total Accrual Balance at December 31, 2015 $ 9 $ 11 $ 3 $ 23 Accruals for Beacon 86 — 11 97 Payments and Other Adjustments (4 ) (1 ) (7 ) (12 ) Accrual Balance at March 31, 2016 $ 91 $ 10 $ 7 $ 108 Accruals for Beacon (1 ) 15 (1 ) 13 Payments and Other Adjustments (35 ) (3 ) (1 ) (39 ) Accrual Balance at June 30, 2016 $ 55 $ 22 $ 5 $ 82 Accruals for Beacon 8 3 (1 ) 10 Payments and Other Adjustments (14 ) (3 ) (1 ) (18 ) Accrual Balance at September 30, 2016 $ 49 $ 22 $ 3 $ 74 Accrual Balance at December 31, 2016 $ 37 $ 17 $ 2 $ 56 Accruals for Beacon 14 — 2 16 Payments and Other Adjustments (13 ) (3 ) (2 ) (18 ) Accrual Balance at March 31, 2017 $ 38 $ 14 $ 2 $ 54 Accruals for Beacon 60 — 2 62 Payments and other adjustments (11 ) (3 ) (2 ) (16 ) Accrual Balance at June 30, 2017 $ 87 $ 11 $ 2 $ 100 Accruals for Beacon 23 9 1 33 Payments and Other Adjustments (10 ) (5 ) (1 ) (16 ) Accrual Balance at September 30, 2017 $ 100 $ 15 $ 2 $ 117

Earnings Per Common Share

Earnings Per Common Share	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Earnings Per Common Share	Earnings Per Common Share Basic EPS is calculated pursuant to the “two-class” method, by dividing net income available to common shareholders by the weighted-average common shares outstanding during the period. Diluted EPS is calculated pursuant to the two-class method, by dividing net income available to common shareholders by the total weighted-average number of common shares outstanding for the period plus the shares representing the dilutive effect of equity-based awards. The effect of equity-based awards is excluded from the calculation of diluted EPS in periods in which their effect would be anti-dilutive. The two-class method requires the allocation of undistributed net income between common and participating shareholders. Net income available to common shareholders, presented separately in our consolidated statement of income, is the basis for the calculation of both basic and diluted EPS. Participating securities are composed of unvested and fully vested SERP shares and fully vested deferred director stock awards, which are equity-based awards that contain non-forfeitable rights to dividends, and are considered to participate with the common stock in undistributed earnings. The following table presents the computation of basic and diluted earnings per common share for the periods indicated: Three Months Ended September 30, (Dollars in millions, except per share amounts) 2017 2016 Net income $ 685 $ 563 Less: Preferred stock dividends (55 ) (55 ) Dividends and undistributed earnings allocated to participating securities (1) (1 ) (1 ) Net income available to common shareholders $ 629 $ 507 Average common shares outstanding (In thousands): Basic average common shares 372,765 388,358 Effect of dilutive securities: equity-based awards 5,753 4,854 Diluted average common shares 378,518 393,212 Anti-dilutive securities (2) — 2,166 Earnings per Common Share: Basic $ 1.69 $ 1.31 Diluted (3) 1.66 1.29 Nine Months Ended September 30, (Dollars in millions, except per share amounts) 2017 2016 Net income $ 1,807 $ 1,550 Less: Preferred stock dividends (146 ) (137 ) Dividends and undistributed earnings allocated to participating securities (1) (2 ) (2 ) Net income available to common shareholders $ 1,659 $ 1,411 Average common shares outstanding (In thousands): Basic average common shares 376,430 393,959 Effect of dilutive securities: equity-based awards 5,349 4,454 Diluted average common shares 381,779 398,413 Anti-dilutive securities (2) 250 3,027 Earnings per Common Share: Basic $ 4.41 $ 3.58 Diluted (3) 4.35 3.54 (1) Represents the portion of net income available to common equity allocated to participating securities, composed of unvested and fully vested SERP shares and fully vested deferred director stock awards, which are equity-based awards that contain non-forfeitable rights to dividends, and are considered to participate with the common stock in undistributed earnings. (2) Represents equity-based awards outstanding but not included in the computation of diluted average common shares, because their effect was anti-dilutive. Additional information about equity-based awards is provided in Note 18 to the consolidated financial statements included under Item 8, Financial Statements and Supplementary Data, in our 2016 Form 10-K. (3) Calculations reflect allocation of earnings to participating securities using the two-class method, as this computation is more dilutive than the treasury stock method.

Line of Business Information

Line of Business Information	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Line of Business Information	Line of Business Information Our operations are organized into two lines of business: Investment Servicing and Investment Management, which are defined based on products and services provided. The results of operations for these lines of business are not necessarily comparable with those of other companies, including companies in the financial services industry. For information about our two lines of business, as well as revenues, expenses and capital allocation methodologies associated with them, refer to pages 188 to 189 in Note 24 to the consolidated financial statements included under Item 8, Financial Statements and Supplementary Data, in our 2016 Form 10-K. The following is a summary of our line-of-business results for the periods indicated. The "Other" column represents costs incurred that are not allocated to a specific line of business, including certain severance and restructuring costs, acquisition costs and certain provisions for legal contingencies. Three Months Ended September 30, Investment Investment Other Total (Dollars in millions) 2017 2016 2017 2016 2017 2016 2017 2016 Servicing fees $ 1,351 $ 1,303 $ — $ — $ — $ — $ 1,351 $ 1,303 Management fees — — 419 368 — — 419 368 Trading services 239 248 20 19 — — 259 267 Securities finance 147 136 — — — — 147 136 Processing fees and other 65 12 1 (7 ) — — 66 5 Total fee revenue 1,802 1,699 440 380 — — 2,242 2,079 Net interest income 606 536 (3 ) 1 — — 603 537 Gains (losses) related to investment securities, net 1 4 — — — — 1 4 Total revenue 2,409 2,239 437 381 — — 2,846 2,620 Provision for loan losses 3 — — — — — 3 — Total expenses 1,673 1,634 314 317 34 33 2,021 1,984 Income before income tax expense $ 733 $ 605 $ 123 $ 64 $ (34 ) $ (33 ) $ 822 $ 636 Pre-tax margin 30 % 27 % 28 % 17 % 29 % 24 % Nine Months Ended September 30, Investment Investment Other Total (Dollars in millions) 2017 2016 2017 2016 2017 2016 2017 2016 Servicing fees $ 3,986 $ 3,784 $ — $ — $ — $ — $ 3,986 $ 3,784 Management fees — — 1,198 931 — — 1,198 931 Trading services 768 760 55 46 — — 823 806 Securities finance 459 426 — — — — 459 426 Processing fees and other 203 164 6 (9 ) — — 209 155 Total fee revenue 5,416 5,134 1,259 968 — — 6,675 6,102 Net interest income 1,691 1,567 (3 ) 3 — — 1,688 1,570 Gains (losses) related to investment securities, net (39 ) 5 — — — — (39 ) 5 Total revenue 7,068 6,706 1,256 971 — — 8,324 7,677 Provision for loan losses 4 8 — — — — 4 8 Total expenses 5,050 4,920 954 817 134 157 6,138 5,894 Income before income tax expense $ 2,014 $ 1,778 $ 302 $ 154 $ (134 ) $ (157 ) $ 2,182 $ 1,775 Pre-tax margin 28 % 27 % 24 % 16 % 26 % 23 %

Non-U.S. Activities

Non-U.S. Activities	9 Months Ended
	Sep. 30, 2017
Segments, Geographical Areas [Abstract]
Non-U.S. Activities	Non-U.S. Activities We define our non-U.S. activities as those revenue-producing business activities that arise from clients which are generally serviced or managed outside the U.S. Due to the integrated nature of our business, precise segregation of our U.S. and non-U.S. activities is not possible. Subjective estimates, assumptions and other judgments are applied to quantify the financial results and assets related to our non-U.S. activities, including our application of funds transfer pricing, our asset-and-liability management policies and our allocation of certain indirect corporate expenses. Management periodically reviews and updates its processes for quantifying the financial results and assets related to our non-U.S. activities. The following table presents our U.S. and non-U.S. financial results for the periods indicated: Three Months Ended September 30, 2017 Three Months Ended September 30, 2016 (In millions) Non-U.S. U.S. Total Non-U.S. U.S. Total Total revenue $ 1,219 $ 1,627 $ 2,846 $ 1,117 $ 1,503 $ 2,620 Income before income taxes 342 480 822 314 322 636 Nine Months Ended September 30, 2017 Nine Months Ended September 30, 2016 (In millions) Non-U.S. U.S. Total Non-U.S. U.S. Total Total revenue $ 3,494 $ 4,830 $ 8,324 $ 3,278 $ 4,399 $ 7,677 Income before income taxes 919 1,263 2,182 835 940 1,775 Non-U.S. assets were $81.5 billion and $86.7 billion as of September 30, 2017 and 2016 , respectively.

Summary of Significant Accoun28

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accounting and financial reporting policies of State Street Corporation conform to U.S. GAAP. State Street Corporation, the Parent Company, is a financial holding company headquartered in Boston, Massachusetts. Unless otherwise indicated or unless the context requires otherwise, all references in these notes to consolidated financial statements to “State Street,” “we,” “us,” “our” or similar references mean State Street Corporation and its subsidiaries on a consolidated basis. Our principal banking subsidiary is State Street Bank. The accompanying Consolidated Financial Statements should be read in conjunction with the financial and risk factor information included in our 2016 Form 10-K, which we previously filed with the SEC.
Consolidation	The consolidated financial statements accompanying these condensed notes are unaudited. In the opinion of management, all adjustments, consisting only of normal recurring adjustments, which are necessary for a fair statement of the consolidated results of operations in these financial statements, have been made. Certain previously reported amounts presented in this Form 10-Q have been reclassified to conform to current-period presentation. Events occurring subsequent to the date of our consolidated statement of condition were evaluated for potential recognition or disclosure in our consolidated financial statements through the date we filed this Form 10-Q with the SEC. The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions in the application of certain of our significant accounting policies that may materially affect the reported amounts of assets, liabilities, equity, revenue, and expenses. As a result of unanticipated events or circumstances, actual results could differ from those estimates. These accounting estimates reflect the best judgment of management, but actual results could differ. Our consolidated statement of condition as of December 31, 2016 included in the accompanying consolidated financial statements was derived from the audited financial statements as of that date, but does not include all notes required by U.S. GAAP for a complete set of consolidated financial statements.
Recent Accounting Developments	Recent Accounting Developments Relevant standards that were 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. January 1, 2018 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. 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 NII, securities gains/ losses and 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. We continue to monitor industry developments and focus our assessment on areas such as costs that may require capitalization under the new standard and the impact of changes to the principal and agent guidance. The new standard modified the principal and agent guidance which we expect to result in recognition of certain expenses on a gross basis, rather than offset against revenue. We are still assessing the completeness and materiality of these changes. We continue to assess the operational and disclosure impacts of each transition method and have not yet finalized the transition method to be applied. 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 Based on our assessment, we do not 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. Relevant standards that were issued but not yet adopted Standard Description Date of Adoption Effects on the financial statements or other significant matters 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, and a significant implementation project is in place 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, assessing existing credit loss models against the new guidance and processes and identifying a complete set of data requirements and sources. We have commenced the development of new or modified credit loss models and based on our analysis to date, we expect the timing of the allowance for credit losses to accelerate under the new standard. We are continuing to assess the extent of the impact on the allowance for credit losses. 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 Based on our current presentation we do not anticipate a significant change to our presentation of the statement of cash flows. ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business The standard incorporates gating criteria to determine when an integrated set of assets and activities is not a business. When substantially all the fair value of gross assets acquired (or group of similar identifiable assets) is concentrated in a single identifiable asset, it would not represent a business. January 1, 2018, early adoption permitted We will apply this standard prospectively to transactions occurring after January 1, 2018, as applicable. ASU 2017-04, Intangibles-Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment The standard simplifies the subsequent measurement of goodwill by eliminating Step 2 from the goodwill impairment test. The ASU requires an entity to compare the fair value of a reporting unit with its carrying amount and recognize an impairment charge for the amount by which the carrying value exceeds the fair value of the reporting unit. Additionally, an entity should consider income tax effects from any tax deductible goodwill on the carrying amount of the reporting unit when measuring the goodwill impairment loss. January 1, 2020, early adoption permitted We are evaluating the impacts of early adoption, and will apply this standard prospectively upon adoption. ASU 2017-08, Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium amortization on Purchased Callable Debt Securities The standard shortens the amortization period for certain purchased callable debt securities to the earliest call date. January 1, 2019, early adoption permitted We are currently evaluating the impact of the new standard and the early adoption provisions. ASU 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities The standard amends the hedge accounting model to better portray the economics of risk management activities in the financial statements and enhances the presentation of hedge results. The amendments also make targeted changes to simplify the application of hedge accounting in certain situations. January 1, 2019, early adoption permitted We are currently evaluating the impact of the new standard and the early adoption provisions. We adopted ASU 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting , effective January 1, 2017. Starting in the quarter ended March 31, 2017, we reclassified excess tax benefits related to stock-based compensation from financing activities to other operating activities. We continued to present repurchases of common stock for employee tax withholding in financing activities in the consolidated statements of cash flows for all periods presented. As required by the transition provisions of the standard, excess tax benefits previously recognized in surplus prior to January 1, 2017 remain in surplus, and excess tax benefits recognized after January 1, 2017 are included in income tax expense. In connection with this change, we recognized a tax benefit of $18.6 million in the first nine months of 2017 . We elected to make no changes to our current policy of estimating forfeitures. Lastly, we did not make any changes to tax withholding rates.

Summary of Significant Accoun29

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Recent Accounting Developments	Relevant standards that were 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. January 1, 2018 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. 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 NII, securities gains/ losses and 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. We continue to monitor industry developments and focus our assessment on areas such as costs that may require capitalization under the new standard and the impact of changes to the principal and agent guidance. The new standard modified the principal and agent guidance which we expect to result in recognition of certain expenses on a gross basis, rather than offset against revenue. We are still assessing the completeness and materiality of these changes. We continue to assess the operational and disclosure impacts of each transition method and have not yet finalized the transition method to be applied. 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 Based on our assessment, we do not 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. Relevant standards that were issued but not yet adopted Standard Description Date of Adoption Effects on the financial statements or other significant matters 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, and a significant implementation project is in place 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, assessing existing credit loss models against the new guidance and processes and identifying a complete set of data requirements and sources. We have commenced the development of new or modified credit loss models and based on our analysis to date, we expect the timing of the allowance for credit losses to accelerate under the new standard. We are continuing to assess the extent of the impact on the allowance for credit losses. 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 Based on our current presentation we do not anticipate a significant change to our presentation of the statement of cash flows. ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business The standard incorporates gating criteria to determine when an integrated set of assets and activities is not a business. When substantially all the fair value of gross assets acquired (or group of similar identifiable assets) is concentrated in a single identifiable asset, it would not represent a business. January 1, 2018, early adoption permitted We will apply this standard prospectively to transactions occurring after January 1, 2018, as applicable. ASU 2017-04, Intangibles-Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment The standard simplifies the subsequent measurement of goodwill by eliminating Step 2 from the goodwill impairment test. The ASU requires an entity to compare the fair value of a reporting unit with its carrying amount and recognize an impairment charge for the amount by which the carrying value exceeds the fair value of the reporting unit. Additionally, an entity should consider income tax effects from any tax deductible goodwill on the carrying amount of the reporting unit when measuring the goodwill impairment loss. January 1, 2020, early adoption permitted We are evaluating the impacts of early adoption, and will apply this standard prospectively upon adoption. ASU 2017-08, Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium amortization on Purchased Callable Debt Securities The standard shortens the amortization period for certain purchased callable debt securities to the earliest call date. January 1, 2019, early adoption permitted We are currently evaluating the impact of the new standard and the early adoption provisions. ASU 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities The standard amends the hedge accounting model to better portray the economics of risk management activities in the financial statements and enhances the presentation of hedge results. The amendments also make targeted changes to simplify the application of hedge accounting in certain situations. January 1, 2019, early adoption permitted We are currently evaluating the impact of the new standard and the early adoption provisions.

Fair Value (Tables)

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	Fair Value Measurements on a Recurring Basis as of September 30, 2017 (In millions) Quoted Market Prices in Active Markets (Level 1) Pricing Methods with Significant Observable Market Inputs (Level 2) Pricing Methods with Significant Unobservable Market Inputs (Level 3) Impact of Netting (1) Total Net Carrying Value in Consolidated Statement of Condition Assets: Trading account assets: U.S. government securities $ 39 $ — $ — $ 39 Non-U.S. government securities 387 174 — 561 Other 20 515 — 535 Total trading account assets 446 689 — 1,135 AFS investment securities: U.S. Treasury and federal agencies: Direct obligations 231 389 — 620 Mortgage-backed securities — 10,975 25 11,000 Asset-backed securities: Student loans — 4,626 200 4,826 Credit cards — 1,548 — 1,548 Other (2) — 35 1,186 1,221 Total asset-backed securities — 6,209 1,386 7,595 Non-U.S. debt securities: Mortgage-backed securities — 6,956 118 7,074 Asset-backed securities — 2,742 97 2,839 Government securities — 6,658 — 6,658 Other (3) — 5,617 201 5,818 Total non-U.S. debt securities — 21,973 416 22,389 State and political subdivisions — 9,700 38 9,738 Collateralized mortgage obligations — 1,528 — 1,528 Other U.S. debt securities — 2,909 19 2,928 U.S. equity securities — 46 — 46 U.S. money-market mutual funds — 394 — 394 Total AFS investment securities 231 54,123 1,884 56,238 Other assets: Derivative instruments: Foreign exchange contracts — 11,735 2 $ (7,026 ) 4,711 Interest-rate contracts — 3 — (2 ) 1 Total derivative instruments — 11,738 2 (7,028 ) 4,712 Other 22 — — — 22 Total assets carried at fair value $ 699 $ 66,550 $ 1,886 $ (7,028 ) $ 62,107 Liabilities: Accrued expenses and other liabilities: Trading account liabilities: Other $ 19 $ — $ — $ — $ 19 Derivative instruments: Foreign exchange contracts — 11,581 2 (7,465 ) 4,118 Interest-rate contracts 10 97 — (1 ) 106 Other derivative contracts — 319 — — 319 Total derivative instruments 10 11,997 2 (7,466 ) 4,543 Other 22 — — — 22 Total liabilities carried at fair value $ 51 $ 11,997 $ 2 $ (7,466 ) $ 4,584 (1) Represents counterparty netting against level 2 financial assets and liabilities where a legally enforceable master netting agreement exists between State Street and the counterparty. Netting also reflects asset and liability reductions of $637 million and $1,074 million , respectively, for cash collateral received from and provided to derivative counterparties. (2) As of September 30, 2017 , the fair value of other ABS was primarily composed of $1,221 million of CLOs. (3) As of September 30, 2017 , the fair value of other non-U.S. debt securities was primarily composed of $3,600 million of covered bonds and $1,503 million of corporate bonds. Fair Value Measurements on a Recurring Basis as of December 31, 2016 (In millions) Quoted Market Prices in Active Markets (Level 1) Pricing Methods with Significant Observable Market Inputs (Level 2) Pricing Methods with Significant Unobservable Market Inputs (Level 3) Impact of Netting (1) Total Net Carrying Value in Consolidated Statement of Condition Assets: Trading account assets: U.S. government securities $ 30 $ — $ — $ 30 Non-U.S. government securities 495 174 — 669 Other — 325 — 325 Total trading account assets 525 499 — 1,024 AFS investment securities: U.S. Treasury and federal agencies: Direct obligations 3,824 439 — 4,263 Mortgage-backed securities — 13,257 — 13,257 Asset-backed securities: Student loans — 5,499 97 5,596 Credit cards — 1,351 — 1,351 Sub-prime — 272 — 272 Other (2) — — 905 905 Total asset-backed securities — 7,122 1,002 8,124 Non-U.S. debt securities: Mortgage-backed securities — 6,535 — 6,535 Asset-backed securities — 2,484 32 2,516 Government securities — 5,836 — 5,836 Other (3) — 5,365 248 5,613 Total non-U.S. debt securities — 20,220 280 20,500 State and political subdivisions — 10,283 39 10,322 Collateralized mortgage obligations — 2,577 16 2,593 Other U.S. debt securities — 2,469 — 2,469 U.S. equity securities — 42 — 42 Non-U.S. equity securities — 3 — 3 U.S. money-market mutual funds — 409 — 409 Non-U.S. money-market mutual funds — 16 — 16 Total AFS investment securities 3,824 56,837 1,337 61,998 Other assets: Derivatives instruments: Foreign exchange contracts — 16,476 8 $ (9,163 ) 7,321 Interest-rate contracts — 68 — (68 ) — Total derivative instruments — 16,544 8 (9,231 ) 7,321 Total assets carried at fair value $ 4,349 $ 73,880 $ 1,345 $ (9,231 ) $ 70,343 Liabilities: Accrued expenses and other liabilities: Derivative instruments: Foreign exchange contracts $ — $ 15,948 $ 8 $ (10,456 ) $ 5,500 Interest-rate contracts — 348 — (226 ) 122 Other derivative contracts — 380 — — 380 Total derivative instruments — 16,676 8 (10,682 ) 6,002 Total liabilities carried at fair value $ — $ 16,676 $ 8 $ (10,682 ) $ 6,002 (1) Represents counterparty netting against level 2 financial assets and liabilities where a legally enforceable master netting agreement exists between State Street and the counterparty. Netting also reflects asset and liability reductions of $906 million and $2,356 million , respectively, for cash collateral received from and provided to derivative counterparties. (2) As of December 31, 2016 , the fair value of other ABS was primarily composed of $905 million of CLOs. (3) As of December 31, 2016 , the fair value of other non-U.S. debt securities was primarily composed of $3,769 million of covered bonds and $988 million of corporate bonds.
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation	The following tables present activity related to our level 3 financial assets during the three and nine months ended September 30, 2017 and 2016 , respectively. Transfers into and out of level 3 are reported as of the beginning of the period presented. During the three and nine months ended September 30, 2017 , transfers into level 3 were mainly related to certain ABS and MBS, including non-U.S. debt securities, for which fair value was measured using information obtained from third-party sources, including non-binding broker or dealer quotes. During the nine months ended September 30, 2017 and 2016 , transfers out of level 3 were mainly related to certain MBS and ABS, including non-U.S. debt securities, for which fair value was measured using prices for which observable market information became available. Fair Value Measurements Using Significant Unobservable Inputs Three Months Ended September 30, 2017 Fair Value as of June 30, 2017 Total Realized and Purchases Sales Settlements Transfers into Level 3 Fair Value as of (2) Change in (In millions) Recorded in Revenue (1) Recorded in Other Comprehensive Income (1) Assets: AFS Investment securities: U.S. Treasury and federal agencies: Mortgage-backed securities $ — $ — $ — $ — — $ — $ 25 $ 25 Asset-backed securities: Student loans — — — 200 — — — 200 Other 951 1 1 60 — (2 ) 175 1,186 Total asset-backed securities 951 1 1 260 — (2 ) 175 1,386 Non-U.S. debt securities: Mortgage-backed securities — — — 118 — — — 118 Asset-backed securities 63 — — 29 (10 ) — 15 97 Other 274 — — — (80 ) 7 — 201 Total non-U.S. debt securities 337 — — 147 (90 ) 7 15 416 State and political subdivisions 38 — — — — — — 38 Other U.S. debt securities 19 — — — — — — 19 Total AFS investment securities 1,345 1 1 407 (90 ) 5 215 1,884 Other assets: Derivative instruments: Foreign exchange contracts 5 — — 2 — (5 ) — 2 $ (2 ) Total derivative instruments 5 — — 2 — (5 ) — 2 (2 ) Total assets carried at fair value $ 1,350 $ 1 $ 1 $ 409 $ (90 ) $ — $ 215 $ 1,886 $ (2 ) (1) Total realized and unrealized gains (losses) on AFS investment securities are included within gains (losses) related to investment securities, net. Total realized and unrealized gains (losses) on derivative instruments are included within trading services. (2) There were no transfers of assets out of level 3 during the three months ended September 30, 2017. Fair Value Measurements Using Significant Unobservable Inputs Nine Months Ended September 30, 2017 Fair Value as of Total Realized and Purchases Sales Settlements Transfers into Level 3 Transfers out of Level 3 Fair Value as of September 30, 2017 Change in (In millions) Recorded in Revenue (1) Recorded in Other Comprehensive Income (1) Assets: AFS Investment securities: U.S. Treasury and federal agencies: Mortgage-backed securities $ — $ — $ — $ — $ — $ — $ 25 $ — $ 25 Asset-backed securities: Student loans 97 — 1 200 — — — (98 ) 200 Other 905 2 — 415 — (412 ) 276 — 1,186 Total asset-backed securities 1,002 2 1 615 — (412 ) 276 (98 ) 1,386 Non-U.S. debt securities: Mortgage-backed securities — — — 118 — — — — 118 Asset-backed securities 32 1 (1 ) 60 (10 ) (21 ) 67 (31 ) 97 Other 248 — — 5 (80 ) 28 — — 201 Total non-U.S. debt securities 280 1 (1 ) 183 (90 ) 7 67 (31 ) 416 State and political subdivisions 39 — — — — (1 ) — — 38 Collateralized mortgage obligations 16 — — 23 — — — (39 ) — Other U.S. debt securities — — — 19 — — — — 19 Total AFS investment securities 1,337 3 — 840 (90 ) (406 ) 368 (168 ) 1,884 Other assets: Derivative instruments: Foreign exchange contracts 8 (6 ) — 4 — (4 ) — — 2 $ (1 ) Total derivative instruments 8 (6 ) — 4 — (4 ) — — 2 (1 ) Total assets carried at fair value $ 1,345 $ (3 ) $ — $ 844 $ (90 ) $ (410 ) $ 368 $ (168 ) $ 1,886 $ (1 ) (1) Total realized and unrealized gains (losses) on AFS investment securities are included within gains (losses) related to investment securities, net. Total realized and unrealized gains (losses) on derivative instruments are included within trading services. Fair Value Measurements Using Significant Unobservable Inputs Three Months Ended September 30, 2016 Fair Value as of Total Realized and Purchases Settlements Transfers Fair Value as of September 30, (2) Change in Unrealized Gains (Losses) Related to Financial Instruments Held as of September 30, (In millions) Recorded in Revenue (1) Recorded in Other Comprehensive Income (1) Assets: AFS Investment securities: U.S. Treasury and federal agencies, mortgage-backed securities $ 25 $ — $ — $ 25 $ — $ — $ 50 Asset-backed securities: Student loans 190 — 2 — — — 192 Other 1,710 13 (8 ) 118 (560 ) — 1,273 Total asset-backed securities 1,900 13 (6 ) 118 (560 ) — 1,465 Non-U.S. debt securities: Mortgage-backed securities — — — 90 — — 90 Asset-backed securities 111 — — 90 (9 ) (54 ) 138 Other 261 — — 194 3 — 458 Total non-U.S. debt securities 372 — — 374 (6 ) (54 ) 686 State and political subdivisions 33 — 7 — — — 40 Collateralized mortgage obligations 68 — 1 36 (3 ) — 102 Total AFS investment securities 2,398 13 2 553 (569 ) (54 ) 2,343 Total assets carried at fair value $ 2,398 $ 13 $ 2 $ 553 $ (569 ) $ (54 ) $ 2,343 $ — (1) Total realized and unrealized gains (losses) on AFS investment securities are included within gains (losses) related to investment securities, net. Total realized and unrealized gains (losses) on derivative instruments are included within trading services. (2) There were no transfers of assets into level 3 during the three months ended September 30, 2016 . Fair Value Measurements Using Significant Unobservable Inputs Nine Months Ended September 30, 2016 Fair Value as of December 31, 2015 Total Realized and Purchases Settlements Transfers Fair Value as of September 30, 2016 (2) Change in Unrealized Gains (Losses) Related to Financial Instruments Held as of September 30, (In millions) Recorded (1) Recorded (1) Assets: AFS Investment securities: U.S. Treasury and federal agencies, mortgage-backed securities $ — $ — $ — $ 325 $ — $ (275 ) $ 50 Asset-backed securities: Student loans 189 1 2 — — — 192 Other 1,764 29 (21 ) 250 (749 ) — 1,273 Total asset-backed securities 1,953 30 (19 ) 250 (749 ) — 1,465 Non-U.S. debt securities: Mortgage-backed securities — — — 90 — — 90 Asset-backed securities 174 — (1 ) 196 (43 ) (188 ) 138 Other 255 — — 223 9 (29 ) 458 Total non-U.S. debt securities 429 — (1 ) 509 (34 ) (217 ) 686 State and political subdivisions 33 — 9 — (2 ) — 40 Collateralized mortgage obligations 39 — 2 86 (25 ) — 102 Other U.S. debt securities 10 — — — (10 ) — — Total AFS investment securities 2,464 30 (9 ) 1,170 (820 ) (492 ) 2,343 Other assets: Derivative instruments: Foreign exchange contracts 5 3 — — (8 ) — — $ — Total derivative instruments 5 3 — — (8 ) — — — Total assets carried at fair value $ 2,469 $ 33 $ (9 ) $ 1,170 $ (828 ) $ (492 ) $ 2,343 $ —
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation	Fair Value Measurements Using Significant Unobservable Inputs Nine Months Ended September 30, 2016 Fair Value as of December 31, 2015 Total Realized and Settlements Fair Value as of September 30, 2016 (3) Change in Unrealized 2016 (In millions) Recorded in Revenue Liabilities: Accrued expenses and other liabilities: Derivative instruments: Foreign exchange contracts $ 5 $ 5 $ (10 ) $ — $ — Total derivative instruments 5 5 (10 ) — — Total liabilities carried at fair value $ 5 $ 5 $ (10 ) $ — $ — (1) Total realized and unrealized gains (losses) on AFS investment securities are included within gains (losses) related to investment securities, net. Total realized and unrealized gains (losses) on derivative instruments are included within trading services. (2) There were no transfers of assets into level 3 during the nine months ended September 30, 2016. (3) There were no transfers of liabilities into or out of level 3 during the nine months ended September 30, 2016.
Fair Value Inputs, Assets, Quantitative Information	The following table presents quantitative information, as of the dates indicated, about the valuation techniques and significant unobservable inputs used in the valuation of our level 3 financial assets and liabilities measured at fair value on a recurring basis for which we use internally-developed pricing models. The significant unobservable inputs for our level 3 financial assets and liabilities whose fair value is measured using pricing information from non-binding broker or dealer quotes are not included in the table, as the specific inputs applied are not provided by the broker/dealer. Quantitative Information about Level 3 Fair Value Measurements Fair Value Weighted-Average (Dollars in millions) As of September 30, 2017 As of December 31, 2016 Valuation Technique Significant (1) As of September 30, 2017 As of December 31, 2016 Significant unobservable inputs readily available to State Street: Assets: Asset-backed securities, other $ — $ 1 Discounted cash flows Credit spread — % 0.3 % State and political subdivisions 38 39 Discounted cash flows Credit spread 1.7 1.8 Derivative instruments, foreign exchange contracts 2 8 Option model Volatility 8.3 14.4 Total $ 40 $ 48 Liabilities: Derivative instruments, foreign exchange contracts $ 2 $ 8 Option model Volatility 8.3 14.4 Total $ 2 $ 8 (1) Significant chan ges in these unobservable inputs would result in significant changes in fair value measurement.
Fair Value Inputs, Liabilities, Quantitative Information	The following table presents quantitative information, as of the dates indicated, about the valuation techniques and significant unobservable inputs used in the valuation of our level 3 financial assets and liabilities measured at fair value on a recurring basis for which we use internally-developed pricing models. The significant unobservable inputs for our level 3 financial assets and liabilities whose fair value is measured using pricing information from non-binding broker or dealer quotes are not included in the table, as the specific inputs applied are not provided by the broker/dealer. Quantitative Information about Level 3 Fair Value Measurements Fair Value Weighted-Average (Dollars in millions) As of September 30, 2017 As of December 31, 2016 Valuation Technique Significant (1) As of September 30, 2017 As of December 31, 2016 Significant unobservable inputs readily available to State Street: Assets: Asset-backed securities, other $ — $ 1 Discounted cash flows Credit spread — % 0.3 % State and political subdivisions 38 39 Discounted cash flows Credit spread 1.7 1.8 Derivative instruments, foreign exchange contracts 2 8 Option model Volatility 8.3 14.4 Total $ 40 $ 48 Liabilities: Derivative instruments, foreign exchange contracts $ 2 $ 8 Option model Volatility 8.3 14.4 Total $ 2 $ 8 (1) Significant chan ges in these unobservable inputs would result in significant changes in fair value measurement.
Carrying Value and Estimated Fair Value of Financial Instruments by Fair Value Hierarchy	The following tables present the reported amounts and estimated fair values of the financial assets and liabilities not carried at fair value on a recurring basis, as they would be categorized within the fair value hierarchy, as of the dates indicated. Fair Value Hierarchy (In millions) Reported Amount Estimated Fair Value Quoted Market Prices in Active Markets (Level 1) Pricing Methods with Significant Observable Market Inputs (Level 2) Pricing Methods with Significant Unobservable Market Inputs (Level 3) September 30, 2017 Financial Assets: Cash and due from banks $ 3,939 $ 3,939 $ 3,939 $ — $ — Interest-bearing deposits with banks 60,956 60,956 — 60,956 — Securities purchased under resale agreements 3,465 3,465 — 3,465 — Investment securities held-to-maturity 36,850 36,836 17,362 19,351 123 Net loans (excluding leases) 22,868 22,866 — 22,811 55 Financial Liabilities: Deposits: Non-interest-bearing $ 49,850 $ 49,850 $ — $ 49,850 $ — Interest-bearing - U.S. 49,394 49,394 — 49,394 — Interest-bearing - non-U.S. 80,019 80,019 — 80,019 — Securities sold under repurchase agreements 3,867 3,867 — 3,867 — Other short-term borrowings 1,253 1,253 — 1,253 — Long-term debt 11,716 12,022 — 11,725 297 Fair Value Hierarchy (In millions) Reported Amount Estimated Fair Value Quoted Market Prices in Active Markets (Level 1) Pricing Methods with Significant Observable Market Inputs (Level 2) Pricing Methods with Significant Unobservable Market Inputs (Level 3) December 31, 2016 Financial Assets: Cash and due from banks $ 1,314 $ 1,314 $ 1,314 $ — $ — Interest-bearing deposits with banks 70,935 70,935 — 70,935 — Securities purchased under resale agreements 1,956 1,956 — 1,956 — Investment securities held-to-maturity 35,169 34,994 17,400 17,439 155 Net loans (excluding leases) 18,862 18,877 — 18,781 96 Financial Liabilities: Deposits: Non-interest-bearing $ 59,397 $ 59,397 $ — $ 59,397 $ — Interest-bearing - U.S. 30,911 30,911 — 30,911 — Interest-bearing - non-U.S. 96,855 96,855 — 96,855 — Securities sold under repurchase agreements 4,400 4,400 — 4,400 — Other short-term borrowings 1,585 1,585 — 1,585 — Long-term debt 11,430 11,618 — 11,282 336

Investment Securities (Tables)

Investment Securities (Tables)	9 Months Ended
	Sep. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Schedule of Marketable Securities	The following table presents the amortized cost, fair value and associated unrealized gains and losses of investment securities as of the dates indicated: September 30, 2017 December 31, 2016 Amortized Cost Gross Unrealized Fair Value Amortized Cost Gross Unrealized Fair Value (In millions) Gains Losses Gains Losses Available-for-sale: U.S. Treasury and federal agencies: Direct obligations $ 617 $ 4 $ 1 $ 620 $ 4,265 $ 7 $ 9 $ 4,263 Mortgage-backed securities 11,044 51 95 11,000 13,340 76 159 13,257 Asset-backed securities: Student loans (1) 4,795 39 8 4,826 5,659 12 75 5,596 Credit cards 1,567 3 22 1,548 1,377 — 26 1,351 Sub-prime — — — — 289 1 18 272 Other (2) 1,213 8 — 1,221 895 10 — 905 Total asset-backed securities 7,575 50 30 7,595 8,220 23 119 8,124 Non-U.S. debt securities: Mortgage-backed securities 7,041 36 3 7,074 6,506 35 6 6,535 Asset-backed securities 2,833 6 — 2,839 2,513 4 1 2,516 Government securities 6,666 8 16 6,658 5,834 8 6 5,836 Other (3) 5,783 39 4 5,818 5,587 31 5 5,613 Total non-U.S. debt securities 22,323 89 23 22,389 20,440 78 18 20,500 State and political subdivisions 9,444 322 28 9,738 10,233 201 112 10,322 Collateralized mortgage obligations 1,522 15 9 1,528 2,610 18 35 2,593 Other U.S. debt securities 2,923 20 15 2,928 2,481 18 30 2,469 U.S. equity securities 40 8 2 46 39 6 3 42 Non-U.S. equity securities — — — — 3 — — 3 U.S. money-market mutual funds 394 — — 394 409 — — 409 Non-U.S. money-market mutual funds — — — — 16 — — 16 Total $ 55,882 $ 559 $ 203 $ 56,238 $ 62,056 $ 427 $ 485 $ 61,998 Held-to-maturity: U.S. Treasury and federal agencies: Direct obligations $ 17,456 $ 20 $ 37 $ 17,439 $ 17,527 $ 17 $ 58 $ 17,486 Mortgage-backed securities 12,375 38 169 12,244 10,334 20 221 10,133 Asset-backed securities: Student loans (1) 3,116 25 13 3,128 2,883 5 30 2,858 Credit cards 798 3 — 801 897 2 — 899 Other 1 — — 1 35 — — 35 Total asset-backed securities 3,915 28 13 3,930 3,815 7 30 3,792 Non-U.S. debt securities: Mortgage-backed securities 1,000 84 7 1,077 1,150 70 15 1,205 Asset-backed securities 325 1 — 326 531 — — 531 Government securities 483 2 — 485 286 3 — 289 Other 47 — — 47 113 1 — 114 Total non-U.S. debt securities 1,855 87 7 1,935 2,080 74 15 2,139 Collateralized mortgage obligations 1,249 44 5 1,288 1,413 42 11 1,444 Total $ 36,850 $ 217 $ 231 $ 36,836 $ 35,169 $ 160 $ 335 $ 34,994 (1) Primarily composed of securities guaranteed by the federal government with respect to at least 97% of defaulted principal and accrued interest on the underlying loans. (2) As of September 30, 2017 and December 31, 2016 , the fair value of other ABS was primarily composed of $1,221 million and $905 million , respectively, of CLOs. (3) As of September 30, 2017 and December 31, 2016 , the fair value of other non-U.S. debt securities was primarily composed of $3,600 million and $3,769 million , respectively, of covered bonds and $1,503 million and $988 million , as of September 30, 2017 and December 31, 2016 , respectively, of corporate bonds.
Schedule of Gross Pre-tax Unrealized Losses on Investment Securities	The following tables present the aggregate fair values of investment securities that have been in a continuous unrealized loss position for less than 12 months , and those that have been in a continuous unrealized loss position for 12 months or longer, as of the dates indicated: Less than 12 months 12 months or longer Total September 30, 2017 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses (In millions) Available-for-sale: U.S. Treasury and federal agencies: Direct obligations $ — $ — $ 153 $ 1 $ 153 $ 1 Mortgage-backed securities 4,382 51 1,880 44 6,262 95 Asset-backed securities: Student loans — — 1,191 8 1,191 8 Credit cards 499 22 — — 499 22 Total asset-backed securities 499 22 1,191 8 1,690 30 Non-U.S. debt securities: Mortgage-backed securities 780 2 569 1 1,349 3 Government securities 4,965 16 — — 4,965 16 Other 447 3 229 1 676 4 Total non-U.S. debt securities 6,192 21 798 2 6,990 23 State and political subdivisions 1,052 15 525 13 1,577 28 Collateralized mortgage obligations 550 7 56 2 606 9 Other U.S. debt securities 1,141 14 75 1 1,216 15 U.S. equity securities — — 6 2 6 2 Total $ 13,816 $ 130 $ 4,684 $ 73 $ 18,500 $ 203 Held-to-maturity: U.S. Treasury and federal agencies: Direct obligations $ 9,660 $ 36 $ 77 $ 1 $ 9,737 $ 37 Mortgage-backed securities 6,939 152 493 17 7,432 169 Asset-backed securities: Student loans 544 8 389 5 933 13 Total asset-backed securities 544 8 389 5 933 13 Non-U.S. debt securities: Mortgage-backed securities — — 259 7 259 7 Total non-U.S. debt securities — — 259 7 259 7 Collateralized mortgage obligations 245 2 176 3 421 5 Total $ 17,388 $ 198 $ 1,394 $ 33 $ 18,782 $ 231 Less than 12 months 12 months or longer Total December 31, 2016 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses (In millions) Available-for-sale: U.S. Treasury and federal agencies: Direct obligations $ 651 $ 8 $ 180 $ 1 $ 831 $ 9 Mortgage-backed securities 7,072 131 1,114 28 8,186 159 Asset-backed securities: Student loans 54 — 3,745 75 3,799 75 Credit cards 795 1 494 25 1,289 26 Sub-prime 1 — 252 18 253 18 Other 75 — — — 75 — Total asset-backed securities 925 1 4,491 118 5,416 119 Non-U.S. debt securities: Mortgage-backed securities 442 1 893 5 1,335 6 Asset-backed securities 253 — 276 1 529 1 Government securities 1,314 6 — — 1,314 6 Other 670 4 218 1 888 5 Total non-U.S. debt securities 2,679 11 1,387 7 4,066 18 State and political subdivisions 3,390 102 304 10 3,694 112 Collateralized mortgage obligations 1,259 31 162 4 1,421 35 Other U.S. debt securities 944 24 157 6 1,101 30 U.S. equity securities 8 — 5 3 13 3 Total $ 16,928 $ 308 $ 7,800 $ 177 $ 24,728 $ 485 Held-to-maturity: U.S. Treasury and federal agencies: Direct obligations $ 8,891 $ 57 $ 86 $ 1 $ 8,977 $ 58 Mortgage-backed securities 6,838 221 — — 6,838 221 Asset-backed securities: Student loans 705 9 1,235 21 1,940 30 Credit cards 33 — — — 33 — Other 18 — 9 — 27 — Total asset-backed securities 756 9 1,244 21 2,000 30 Non-U.S. debt securities: Mortgage-backed securities 54 2 330 13 384 15 Asset-backed securities 28 — 35 — 63 — Government securities 180 — — — 180 — Total non-U.S. debt securities 262 2 365 13 627 15 Collateralized mortgage obligations 537 4 204 7 741 11 Total $ 17,284 $ 293 $ 1,899 $ 42 $ 19,183 $ 335
Investments Classified by Contractual Maturity Date	The following table presents contractual maturities of debt investment securities by carrying amount as of September 30, 2017 . The maturities of certain ABS, MBS, and collateralized mortgage obligations are based on expected principal payments. Actual maturities may differ from these expected maturities since certain borrowers have the right to prepay obligations with or without prepayment penalties. Under 1 Year 1 to 5 Years 6 to 10 Years Over 10 Years Total (In millions) Available-for-sale: U.S. Treasury and federal agencies: Direct obligations $ 232 $ 7 $ 55 $ 326 $ 620 Mortgage-backed securities 270 1,311 3,424 5,995 11,000 Asset-backed securities: Student loans 408 1,634 1,159 1,625 4,826 Credit cards — 1,296 252 — 1,548 Other — 120 1,101 — 1,221 Total asset-backed securities 408 3,050 2,512 1,625 7,595 Non-U.S. debt securities: Mortgage-backed securities 837 4,128 1,046 1,063 7,074 Asset-backed securities 395 2,182 262 — 2,839 Government securities 3,000 2,288 1,370 — 6,658 Other 1,485 3,607 726 — 5,818 Total non-U.S. debt securities 5,717 12,205 3,404 1,063 22,389 State and political subdivisions 433 2,525 5,020 1,760 9,738 Collateralized mortgage obligations 7 148 343 1,030 1,528 Other U.S. debt securities 404 1,052 1,472 — 2,928 Total $ 7,471 $ 20,298 $ 16,230 $ 11,799 $ 55,798 Held-to-maturity: U.S. Treasury and federal agencies: Direct obligations $ 1,827 $ 15,552 $ 14 $ 63 $ 17,456 Mortgage-backed securities — 172 1,427 10,776 12,375 Asset-backed securities: Student loans 87 240 298 2,491 3,116 Credit cards 178 620 — — 798 Other — — — 1 1 Total asset-backed securities 265 860 298 2,492 3,915 Non-U.S. debt securities: Mortgage-backed securities 173 221 49 557 1,000 Asset-backed securities 84 241 — — 325 Government securities 364 119 — — 483 Other — 47 — — 47 Total non-U.S. debt securities 621 628 49 557 1,855 Collateralized mortgage obligations 9 117 373 750 1,249 Total $ 2,722 $ 17,329 $ 2,161 $ 14,638 $ 36,850
Schedule of Credit-Related Loss Activity Recognized in Earnings	The following table presents a roll-forward with respect to net impairment losses that have been recognized in income for the periods indicated. Nine Months Ended September 30, (In millions) 2017 2016 Balance, beginning of period $ 66 $ 92 Additions: Losses for which OTTI was previously recognized — 2 Deductions: Previously recognized losses related to securities sold or matured (2 ) (26 ) Balance, end of period $ 64 $ 68

Loans and Leases (Tables)

Loans and Leases (Tables)	9 Months Ended
	Sep. 30, 2017
Loans and Leases Receivable Disclosure [Abstract]
Net Loans	The following table presents our recorded investment in loans and leases, by segment, as of the dates indicated: (In millions) September 30, 2017 December 31, 2016 Domestic: Commercial and financial: Loans to investment funds $ 12,886 $ 11,734 Senior secured bank loans 3,377 3,256 Loans to municipalities 1,955 1,352 Other 55 70 Commercial real estate — 27 Lease financing 283 338 Total domestic 18,556 16,777 Non-U.S.: Commercial and financial: Loans to investment funds 4,138 2,224 Senior secured bank loans 514 252 Lease financing 430 504 Total non-U.S. 5,082 2,980 Total loans and leases 23,638 19,757 Allowance for loan and lease losses (57 ) (53 ) Loans and leases, net of allowance $ 23,581 $ 19,704
Recorded Investment in Each Class of Total Loans and Leases by Credit Quality Indicator	The following tables present our recorded investment in each class of loans and leases by credit quality indicator as of the dates indicated: September 30, 2017 Commercial and Financial Commercial Real Estate Lease Financing Total Loans and Leases (In millions) Investment grade (1) $ 18,270 $ — $ 713 $ 18,983 Speculative (2) 4,655 — — 4,655 Total $ 22,925 $ — $ 713 $ 23,638 December 31, 2016 Commercial and Financial Commercial Real Estate Lease Financing Total Loans and Leases (In millions) Investment grade (1) $ 14,889 $ 27 $ 842 $ 15,758 Speculative (2) 3,984 — — 3,984 Substandard (3) 15 — — 15 Total $ 18,888 $ 27 $ 842 $ 19,757 (1) Investment-grade loans and leases consist of counterparties with strong credit quality and low expected credit risk and probability of default. Ratings apply to counterparties with a strong capacity to support the timely repayment of any financial commitment. (2) Speculative loans and leases consist of counterparties that face ongoing uncertainties or exposure to business, financial, or economic downturns. However, these counterparties may have financial flexibility or access to financial alternatives, which allow for financial commitments to be met. (3) Substandard loans and leases consist of counterparties with well-defined weakness that jeopardizes repayment with the possibility we will sustain some loss.
Schedule of Loans and Leases Receivable by Impairment Methodology	The following table presents our recorded investment in loans and leases, disaggregated based on our impairment methodology, as of the dates indicated: September 30, 2017 December 31, 2016 (In millions) Commercial and Financial Commercial Real Estate Lease Financing Total Loans and Leases Commercial and Financial Commercial Real Estate Lease Financing Total Loans and Leases Loans and leases (1) : Individually evaluated for impairment $ — $ — $ — $ — $ 15 $ — $ — $ 15 Collectively evaluated for impairment 22,925 — 713 23,638 18,873 27 842 19,742 Total $ 22,925 $ — $ 713 $ 23,638 $ 18,888 $ 27 $ 842 $ 19,757 (1) For those portfolios where there are a small number of loans each with a large balance, we review each loan annually for indicators of impairment. For those loans where no such indicators are identified, the loans are collectively evaluated for impairment. As of September 30, 2017 , no loans were individually evaluated for impairment. As of December 31, 2016 , $0.2 million of the allowance for loan and lease loss related to commercial and financial loans were individually evaluated for impairment.
Schedule of Activity in the Allowance for Loan Losses	The following table presents activity in the allowance for loan and lease losses for the periods indicated: Three Months Ended September 30, 2017 2016 (In millions) Total Loans and Leases Total Loans and Leases Allowance for loan and lease losses (1) : Beginning balance $ 54 $ 51 Provision for loan and lease losses 3 — Charge-offs — — Ending balance $ 57 $ 51 Nine Months Ended September 30, 2017 2016 (In millions) Total Loans and Leases Total Loans and Leases Allowance for loan and lease losses (1) : Beginning balance $ 53 $ 46 Provision for loan and lease losses 4 8 Charge-offs — (3 ) Ending balance $ 57 $ 51 (1) The provisions and charge-offs for loans and leases were attributable to exposure to senior secured loans to non-investment grade borrowers, purchased in connection with our participation in syndicated loans.

Goodwill and Other Intangible33

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Changes In The Carrying Amount Of Goodwill	The following table presents changes in the carrying amount of goodwill during the periods indicated: (In millions) Investment Servicing Investment Management Total Goodwill: Beginning balance January 1, 2016 $ 5,641 $ 30 $ 5,671 Acquisitions (1) — 236 236 Divestitures and other reductions (11 ) — (11 ) Foreign currency translation (80 ) (2 ) (82 ) Ending balance December 31, 2016 $ 5,550 $ 264 $ 5,814 Acquisitions 17 — 17 Divestitures and other reductions (9 ) — (9 ) Foreign currency translation 170 5 175 Ending balance September 30, 2017 $ 5,728 $ 269 $ 5,997 (1) Investment Management includes our acquisition of GEAM on July 1, 2016.
Schedule of Finite-Lived Intangible Assets	The following table presents changes in the net carrying amount of other intangible assets during the periods indicated: (In millions) Investment Servicing Investment Management Total Other intangible assets: Beginning balance January 1, 2016 $ 1,753 $ 15 $ 1,768 Acquisitions (1) — 217 217 Divestitures (8 ) — (8 ) Amortization (186 ) (21 ) (207 ) Foreign currency translation and other, net (20 ) — (20 ) Ending balance December 31, 2016 $ 1,539 $ 211 $ 1,750 Acquisitions 16 — 16 Divestitures (11 ) — (11 ) Amortization (137 ) (23 ) (160 ) Foreign currency translation and other, net 63 — 63 Ending balance September 30, 2017 $ 1,470 $ 188 $ 1,658 (1) Investment Management includes our acquisition of GEAM on July 1, 2016. The following table presents the gross carrying amount, accumulated amortization and net carrying amount of other intangible assets by type as of the dates indicated: September 30, 2017 December 31, 2016 (In millions) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Other intangible assets: Client relationships $ 2,654 $ (1,418 ) $ 1,236 $ 2,620 $ (1,306 ) $ 1,314 Core deposits 683 (311 ) 372 661 (277 ) 384 Other 141 (91 ) 50 132 (80 ) 52 Total $ 3,478 $ (1,820 ) $ 1,658 $ 3,413 $ (1,663 ) $ 1,750

Other Assets (Tables)

Other Assets (Tables)	9 Months Ended
	Sep. 30, 2017
Other Assets [Abstract]
Components of Other Assets	The following table presents the components of other assets as of the dates indicated: (In millions) September 30, 2017 December 31, 2016 Receivable - securities lending (1) $ 23,628 $ 21,204 Derivative instruments, net 4,712 7,321 Bank-owned life insurance 3,219 3,158 Investments in joint ventures and other unconsolidated entities 2,099 2,363 Collateral, net 902 2,236 Accounts receivable 393 886 Prepaid expenses 422 333 Receivable for securities settlement 441 40 Income taxes receivable 368 106 Deferred tax assets, net of valuation allowance (2) 213 210 Deposits with clearing organizations 125 132 Other (3) 435 339 Total $ 36,957 $ 38,328 (1) Refer to Note 8 for further information on the impact of collateral on our financial statement presentation of securities borrowing transactions. (2) Deferred tax assets and liabilities recorded in our consolidated statement of condition are netted within the same tax jurisdiction. (3) Includes amounts held in escrow accounts at third parties related to the negotiated settlements in the transition management legal matter presented in Note 10.

Derivative Financial Instrume35

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Interest Rate Derivatives	The table below summarizes the maturities and the paid fixed interest rates for the hedged senior and subordinated notes: September 30, 2017 Maturity Paid Fixed Interest Rate Senior Notes 2020 2.55% 2021 4.38 2021 1.95 2022 2.65 2023 3.70 2024 3.30 2025 3.55 2026 2.65 Subordinated Notes 2023 3.10
Schedule of Outstanding Hedges: (Notional Amount)	The following table presents the aggregate contractual, or notional, amounts of derivative financial instruments entered into in connection with our trading and asset-and-liability management activities as of the dates indicated: (In millions) September 30, December 31, Derivatives not designated as hedging instruments: Interest-rate contracts: Futures $ 14,262 $ 13,455 Foreign exchange contracts: Forward, swap and spot 1,618,670 1,414,765 Options purchased 455 337 Options written 262 202 Futures — — Other: Stable value contracts 25,351 27,182 Deferred value awards (1)(2) 531 409 Derivatives designated as hedging instruments: Interest-rate contracts: Swap agreements 10,616 10,169 Foreign exchange contracts: Forward and swap 27,429 8,564 (1) Represents grants of deferred value awards to employees; refer to discussion in this note under "Derivatives Not Designated as Hedging Instruments." (2) Amount as of December 31, 2016 reflects $249 million related to the acceleration of expense associated with certain cash settled deferred incentive compensation awards.
Notional Amount of Interest Rate Swap Agreements Designated as Fair Value and Cash Flow Hedges	The following tables present the aggregate notional amounts of these interest rate contracts and the related assets or liabilities being hedged as of the dates indicated: September 30, 2017 (In millions) Fair Value Hedges Cash Total Investment securities available-for-sale $ 1,323 $ — $ 1,323 Long-term debt (1) 8,493 — 8,493 Floating-rate loans — 800 800 Total $ 9,816 $ 800 $ 10,616 December 31, 2016 (2) (In millions) Fair Value Hedges Investment securities available-for-sale $ 1,444 Long-term debt (1) 8,725 Total $ 10,169 (1) As of September 30, 2017 , these fair value hedges decreased the carrying value of LTD presented in our consolidated statement of condition by $1 million . As of December 31, 2016 , these fair value hedges decreased the carrying value of long-term debt presented in our consolidated statement of condition by $15 million . (2)
Contractual and Weighted-Average Interest Rates, Which Include the Effects of Hedges Related to Financial Instruments	The following table presents the contractual and weighted-average interest rates for long-term debt, which include the effects of the fair value hedges presented in the table above, for the periods indicated: Three Months Ended September 30, 2017 2016 Contractual Rates Rate Including Impact of Hedges Contractual Rates Rate Including Impact of Hedges Long-term debt 3.30 % 2.67 % 3.37 % 2.27 % Nine Months Ended September 30, 2017 2016 Contractual Rate Contractual Rate Long-term debt 3.35 % 2.61 % 3.41 % 2.24 %
Schedule of the Fair Values of Derivative Financial Instruments	The following tables present the fair value of derivative financial instruments, excluding the impact of master netting agreements, recorded in our consolidated statement of condition as of the dates indicated. The impact of master netting agreements is provided in Note 8 to the consolidated financial statements in this Form 10-Q. Derivative Assets (1) Fair Value (In millions) September 30, December 31, 2016 Derivatives not designated as hedging instruments: Foreign exchange contracts $ 11,667 $ 15,982 Total $ 11,667 $ 15,982 Derivatives designated as hedging instruments: Foreign exchange contracts $ 70 $ 502 Interest-rate contracts 3 68 Total $ 73 $ 570 (1) Derivative assets are included within other assets in our consolidated statement of condition. Derivative Liabilities (1) Fair Value (In millions) September 30, December 31, 2016 Derivatives not designated as hedging instruments: Foreign exchange contracts $ 11,506 $ 15,881 Other derivative contracts 319 380 Total $ 11,825 $ 16,261 Derivatives designated as hedging instruments: Foreign exchange contracts $ 77 $ 75 Interest-rate contracts 107 348 Total $ 184 $ 423 (1) Derivative liabilities are included within other liabilities in our consolidated statement of condition.
Impact of Derivatives on Consolidated Statement of Income	The following tables present the impact of our use of derivative financial instruments on our consolidated statement of income for the periods indicated: Location of Gain (Loss) on Derivative in Consolidated Statement of Income Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income Three Months Ended September 30, Nine Months Ended September 30, (In millions) 2017 2016 2017 2016 Derivatives not designated as hedging instruments: Foreign exchange contracts Trading services revenue $ 152 $ 161 $ 485 $ 477 Interest-rate contracts Processing fees and other revenue — — — 1 Foreign exchange contracts Processing fees and other revenue (9 ) (3 ) (11 ) (13 ) Interest-rate contracts Trading services revenue (2 ) (1 ) 7 (6 ) Credit derivative contracts Trading services revenue — — — (1 ) Other derivative contracts Trading services revenue — 1 — (2 ) Other derivative contracts Compensation and employee benefits (25 ) 41 (120 ) 168 Total $ 116 $ 199 $ 361 $ 624 Location of Gain (Loss) on Derivative in Consolidated Statement of Income Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income Hedged Item in Fair Value Hedging Relationship Location of Gain (Loss) on Hedged Item in Consolidated Statement of Income Amount of Gain (Loss) on Hedged Item Recognized in Consolidated Statement of Income Three Months Ended September 30, Three Months Ended September 30, (In millions) 2017 2016 2017 2016 Derivatives designated as fair value hedges: Foreign exchange contracts Processing fees and $ 19 $ 24 Investment securities Processing fees and $ (19 ) $ (24 ) Foreign exchange contracts Processing fees and other revenue 200 1 FX deposit Processing fees and other revenue (200 ) (1 ) Interest-rate contracts Processing fees and other revenue 9 22 Available-for-sale securities Processing fees and other revenue (1) (9 ) (22 ) Interest-rate contracts Processing fees and (8 ) (79 ) Long-term debt Processing fees and 5 78 Total $ 220 $ (32 ) $ (223 ) $ 31 Location of Gain (Loss) on Derivative in Consolidated Statement of Income Amount of Gain Hedged Item in Fair Value Hedging Relationship Location of Gain (Loss) on Hedged Item in Consolidated Statement of Income Amount of Gain Nine Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Derivatives designated as fair value hedges: Foreign exchange contracts Processing fees and $ 21 $ 43 Investment securities Processing fees and $ (21 ) $ (43 ) Foreign exchange contracts Processing fees and other revenue 1,282 247 FX deposit Processing fees and other revenue (1,282 ) (247 ) Interest-rate contracts Processing fees and 23 (15 ) Available-for-sale securities Processing fees and (2) (21 ) 15 Interest-rate contracts Processing fees and 37 297 Long-term debt Processing fees and (39 ) (282 ) Total $ 1,363 $ 572 $ (1,363 ) $ (557 )
Schedule of Differences Between the Gains (Losses) on the Derivative and the Gains (Losses) on the Hedged Item	Location of Gain (Loss) on Derivative in Consolidated Statement of Income Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income Hedged Item in Fair Value Hedging Relationship Location of Gain (Loss) on Hedged Item in Consolidated Statement of Income Amount of Gain (Loss) on Hedged Item Recognized in Consolidated Statement of Income Three Months Ended September 30, Three Months Ended September 30, (In millions) 2017 2016 2017 2016 Derivatives designated as fair value hedges: Foreign exchange contracts Processing fees and $ 19 $ 24 Investment securities Processing fees and $ (19 ) $ (24 ) Foreign exchange contracts Processing fees and other revenue 200 1 FX deposit Processing fees and other revenue (200 ) (1 ) Interest-rate contracts Processing fees and other revenue 9 22 Available-for-sale securities Processing fees and other revenue (1) (9 ) (22 ) Interest-rate contracts Processing fees and (8 ) (79 ) Long-term debt Processing fees and 5 78 Total $ 220 $ (32 ) $ (223 ) $ 31 Location of Gain (Loss) on Derivative in Consolidated Statement of Income Amount of Gain Hedged Item in Fair Value Hedging Relationship Location of Gain (Loss) on Hedged Item in Consolidated Statement of Income Amount of Gain Nine Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Derivatives designated as fair value hedges: Foreign exchange contracts Processing fees and $ 21 $ 43 Investment securities Processing fees and $ (21 ) $ (43 ) Foreign exchange contracts Processing fees and other revenue 1,282 247 FX deposit Processing fees and other revenue (1,282 ) (247 ) Interest-rate contracts Processing fees and 23 (15 ) Available-for-sale securities Processing fees and (2) (21 ) 15 Interest-rate contracts Processing fees and 37 297 Long-term debt Processing fees and (39 ) (282 ) Total $ 1,363 $ 572 $ (1,363 ) $ (557 ) (1) In the three months ended September 30, 2017 and 2016 , $4 million and $13 million , respectively, of net unrealized (losses) gains on AFS investment securities designated in fair value hedges were recognized in OCI. (2) In the nine months ended September 30, 2017 and 2016 , $13 million and $(9) million , respectively, of net unrealized (losses) gains on AFS investment securities designated in fair value hedges were recognized in OCI. Differences between the gains (losses) on the derivative and the gains (losses) on the hedged item, excluding any amounts recorded in NII, represent hedge ineffectiveness. Amount of Gain (Loss) on Derivative Recognized in Other Comprehensive Income Location of Gain (Loss) Reclassified from OCI to Consolidated Statement of Income Amount of Gain (Loss) Reclassified from OCI to Consolidated Statement of Income Location of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income Three Months Ended September 30, Three Months Ended September 30, Three Months Ended September 30, (In millions) 2017 2016 2017 2016 2017 2016 Derivatives designated as cash flow hedges: Interest-rate contracts $ (1 ) $ — Net interest income $ — $ — Net interest income $ — $ — Foreign exchange contracts (1 ) (65 ) Net interest income — — Net interest income 5 6 Total $ (2 ) $ (65 ) $ — $ — $ 5 $ 6 Derivatives designated as net investment hedges: Foreign exchange contracts $ (47 ) $ 4 Gains (Losses) related to investment securities, net $ — $ — Gains (Losses) related to investment securities, net $ — $ — Total $ (47 ) $ 4 $ — $ — $ — $ — Amount of Gain (Loss) on Derivative Recognized in Other Comprehensive Income Location of Gain (Loss) Reclassified from OCI to Consolidated Statement of Income Amount of Gain (Loss) Reclassified from OCI to Consolidated Statement of Income Location of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income Nine Months Ended September 30, Nine Months Ended September 30, Nine Months Ended September 30, (In millions) 2017 2016 2017 2016 2017 2016 Derivatives designated as cash flow hedges: Interest-rate contracts $ (2 ) $ — Net interest income $ — $ — Net interest income $ — $ — Foreign exchange contracts (93 ) (293 ) Net interest income — — Net interest income 18 17 Total $ (95 ) $ (293 ) $ — $ — $ 18 $ 17 Derivatives designated as net investment hedges: Foreign exchange contracts $ (148 ) $ 55 Gains (Losses) related to investment securities, net $ — $ — Gains (Losses) related to investment securities, net $ — $ — Total $ (148 ) $ 55 $ — $ — $ — $ —

Offsetting Arrangements (Tables

Offsetting Arrangements (Tables)	9 Months Ended
	Sep. 30, 2017
Offsetting [Abstract]
Offsetting Assets	The following tables present information about the offsetting of assets related to derivative contracts and secured financing transactions, as of the dates indicated: Assets: September 30, 2017 Gross Amounts Not Offset in Statement of Condition (In millions) Gross Amounts of Recognized Assets (1)(2) Gross Amounts Offset in Statement of Condition (3) Net Amounts of Assets Presented in Statement of Condition Cash and Securities Received (4) Net Amount (5) Derivatives: Foreign exchange contracts $ 11,737 $ (6,389 ) $ 5,348 $ 5,348 Interest-rate contracts 3 (2 ) 1 1 Cash collateral and securities netting NA (637 ) (637 ) $ (106 ) (743 ) Total derivatives 11,740 (7,028 ) 4,712 (106 ) 4,606 Other financial instruments: Resale agreements and securities borrowing (6) 63,821 (36,728 ) 27,093 (27,093 ) — Total derivatives and other financial instruments $ 75,561 $ (43,756 ) $ 31,805 $ (27,199 ) $ 4,606 Assets: December 31, 2016 Gross Amounts Not Offset in Statement of Condition (In millions) Gross Amounts of Recognized Assets (1)(2) Gross Amounts Offset in Statement of Condition (3) Net Amounts of Assets Presented in Statement of Condition Cash and Securities Received (4) Net Amount (5) Derivatives: Foreign exchange contracts $ 16,484 $ (8,257 ) $ 8,227 $ 8,227 Interest-rate contracts 68 (68 ) — — Cash collateral and securities netting NA (906 ) (906 ) $ (247 ) (1,153 ) Total derivatives 16,552 (9,231 ) 7,321 (247 ) 7,074 Other financial instruments: Resale agreements and securities borrowing (6) 58,677 (35,517 ) 23,160 (22,939 ) 221 Total derivatives and other financial instruments $ 75,229 $ (44,748 ) $ 30,481 $ (23,186 ) $ 7,295 (1) Amounts include all transactions regardless of whether or not they are subject to an enforceable netting arrangement. (2) Derivative amounts are carried at fair value and securities financing amounts are carried at amortized cost, except for securities collateral which is also carried at fair value. For additional information about the measurement basis of these instruments, refer to pages 131 to 142 in Notes 1 and 2 to the consolidated financial statements included under Item 8, Financial Statements and Supplementary Data, in our 2016 Form 10-K. (3) Amounts subject to netting arrangements which have been determined to be legally enforceable and eligible for netting in the consolidated statement of condition. (4) Includes securities in connection with our securities borrowing transactions. (5) Includes amounts secured by collateral not determined to be subject to enforceable netting arrangements. (6) Included in the $27,093 million as of September 30, 2017 were $3,465 million of resale agreements and $23,628 million of collateral provided related to securities borrowing. Included in the $23,160 million as of December 31, 2016 were $1,956 million of resale agreements and $21,204 million of collateral provided related to securities borrowing. Resale agreements and collateral provided related to securities borrowing were recorded in securities purchased under resale agreements and other assets, respectively, in our consolidated statement of condition. Additional information about principal securities finance transactions is provided in Note 9 to the consolidated financial statements in this Form 10-Q. NA Not applicable
Offsetting Liabilities	The following tables present information about the offsetting of liabilities related to derivative contracts and secured financing transactions, as of the dates indicated: Liabilities: September 30, 2017 Gross Amounts Not Offset in Statement of Condition (In millions) Gross Amounts of Recognized Liabilities (1)(2) Gross Amounts Offset in Statement of Condition (3) Net Amounts of Liabilities Presented in Statement of Condition Cash and Securities Provided (4) Net Amount (5) Derivatives: Foreign exchange contracts $ 11,583 $ (6,390 ) $ 5,193 $ 5,193 Interest-rate contracts (6) 107 (1 ) 106 106 Other derivative contracts 319 — 319 319 Cash collateral and securities netting NA (1,074 ) (1,074 ) $ (262 ) (1,336 ) Total derivatives 12,009 (7,465 ) 4,544 (262 ) 4,282 Other financial instruments: Repurchase agreements and securities lending (7) 45,864 (36,728 ) 9,136 (6,564 ) 2,572 Total derivatives and other financial instruments $ 57,873 $ (44,193 ) $ 13,680 $ (6,826 ) $ 6,854 Liabilities: December 31, 2016 Gross Amounts Not Offset in Statement of Condition (In millions) Gross Amounts of Recognized Liabilities (1)(2) Gross Amounts Offset in Statement of Condition (3) Net Amounts of Liabilities Presented in Statement of Condition Cash and Securities Provided (4) Net Amount (5) Derivatives: Foreign exchange contracts $ 15,956 $ (8,253 ) $ 7,703 $ 7,703 Interest-rate contracts 348 (73 ) 275 275 Other derivative contracts 380 — 380 380 Cash collateral and securities netting NA (2,356 ) (2,356 ) $ (180 ) (2,536 ) Total derivatives 16,684 (10,682 ) 6,002 (180 ) 5,822 Other financial instruments: Resale agreements and securities lending (7) 44,933 (35,517 ) 9,416 (7,059 ) 2,357 Total derivatives and other financial instruments $ 61,617 $ (46,199 ) $ 15,418 $ (7,239 ) $ 8,179 (1) Amounts include all transactions regardless of whether or not they are subject to an enforceable netting arrangement. (2) Derivative amounts are carried at fair value and securities financing amounts are carried at amortized cost, except for securities collateral which is also carried at fair value. For additional information about the measurement basis of these instruments, refer to pages 131 to 142 in Notes 1 and 2 to the consolidated financial statements included under Item 8, Financial Statements and Supplementary Data, in our 2016 Form 10-K. (3) Amounts subject to netting arrangements which have been determined to be legally enforceable and eligible for netting in the consolidated statement of condition. (4) Includes securities provided in connection with our securities lending transactions. (5) Includes amounts secured by collateral not determined to be subject to enforceable netting arrangements. (6) Variation margin payments presented as settlements rather than collateral. (7) Included in the $9,136 million as of September 30, 2017 were $3,867 million of repurchase agreements and $5,269 million of collateral received related to securities lending. Included in the $9,416 million as of December 31, 2016 were $4,400 million of repurchase agreements and $5,016 million of collateral received related to securities lending. Repurchase agreements and collateral received related to securities lending were recorded in securities sold under repurchase agreements and accrued expenses and other liabilit ies, respectively, in our consolidated statement of condition. Additional information about principal securities finance transactions is provided in Note 9 to the consolidated financial statements in this Form 10-Q. NA Not applicable
Securities Sold and Securities Loaned Under Repurchase Agreements	The following tables summarize our repurchase agreements and securities lending transactions by category of collateral pledged and remaining maturity of these agreements as of the periods indicated: Remaining Contractual Maturity of the Agreements As of September 30, 2017 (In millions) Overnight and Continuous Up to 30 days 30 – 90 days Total Repurchase agreements: U.S. Treasury and agency securities $ 35,009 $ 35,009 Total 35,009 — — 35,009 Securities lending transactions: Corporate debt securities 103 103 Equity securities 10,433 297 10,730 Non-U.S. sovereign debt 22 22 Total 10,558 — 297 10,855 Gross amount of recognized liabilities for repurchase agreements and securities lending $ 45,567 $ — $ 297 $ 45,864 Remaining Contractual Maturity of the Agreements As of December 31, 2016 (In millions) Overnight and Continuous Up to 30 days 30 – 90 days Total Repurchase agreements: U.S. Treasury and agency securities $ 35,509 $ — $ — $ 35,509 Total 35,509 — — 35,509 Securities lending transactions: Corporate debt securities 53 — — 53 Equity securities 8,337 — 1,034 9,371 Total 8,390 — 1,034 9,424 Gross amount of recognized liabilities for repurchase agreements and securities lending $ 43,899 $ — $ 1,034 $ 44,933

Commitments and Guarantees (Tab

Commitments and Guarantees (Tables)	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Schedule of Guarantor Obligations	The following table presents the aggregate gross contractual amounts of our off-balance sheet commitments and off-balance sheet guarantees as of the dates indicated. (In millions) September 30, 2017 December 31, 2016 Commitments: Unfunded credit facilities $ 27,008 $ 26,993 Guarantees (1) : Indemnified securities financing $ 379,459 $ 360,452 Stable value protection 25,351 27,182 Standby letters of credit 3,255 3,459 (1) The potential losses associated with these guarantees equal the gross contractual amounts and do not consider the value of any collateral or reflect any participations to independent third parties.
Schedule of Repurchase Agreements	The following table summarizes the aggregate fair values of indemnified securities financing and related collateral, as well as collateral invested in indemnified repurchase agreements, as of the dates indicated: (In millions) September 30, 2017 December 31, 2016 Fair value of indemnified securities financing $ 379,459 $ 360,452 Fair value of cash and securities held by us, as agent, as collateral for indemnified securities financing 396,123 377,919 Fair value of collateral for indemnified securities financing invested in indemnified repurchase agreements 68,243 60,003 Fair value of cash and securities held by us or our agents as collateral for investments in indemnified repurchase agreements 73,157 63,959

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Schedule of Preferred Shares	The following table summarizes selected terms of each of the series of the preferred stock issued and outstanding as of September 30, 2017 : Issuance Date Depositary Shares Issued Ownership Interest Per Depositary Share Liquidation Preference Per Share Liquidation Preference Per Depositary Share Net Proceeds of Offering (In millions) Redemption Date (1) Preferred Stock (2) : Series C August 2012 20,000,000 1/4,000th $ 100,000 $ 25 $ 488 September 15, 2017 Series D February 2014 30,000,000 1/4,000th 100,000 25 742 March 15, 2024 Series E November 2014 30,000,000 1/4,000th 100,000 25 728 December 15, 2019 Series F May 2015 750,000 1/100th 100,000 1,000 742 September 15, 2020 Series G April 2016 20,000,000 1/4,000th 100,000 25 493 March 15, 2026 (1) On the redemption date, or any dividend declaration date thereafter, the preferred stock and corresponding depositary shares may be redeemed by us, in whole or in part, at the liquidation price per share and liquidation price per depositary share plus any declared and unpaid dividends, without accumulation of any undeclared dividends. (2) The preferred stock and corresponding depositary shares may be redeemed at our option in whole, but not in part, prior to the redemption date upon the occurrence of a regulatory capital treatment event, as defined in the certificate of designation, at a redemption price equal to the liquidation price per share and liquidation price per depositary share plus any declared and unpaid dividends, without accumulation of any undeclared dividends.
Dividends Declared	The following tables present the dividends declared for each of the series of preferred stock issued and outstanding for the periods indicated: Three Months Ended September 30, 2017 2016 Dividends Declared per Share Dividends Declared per Depositary Share Total (1) Dividends Declared per Share Dividends Declared per Depositary Share Total (In millions) Preferred Stock: Series C $ 1,313 $ 0.33 $ 6 $ 1,313 $ 0.33 $ 6 Series D 1,475 0.37 11 1,475 0.37 11 Series E 1,500 0.38 11 1,500 0.38 11 Series F 2,625 26.25 20 2,625 26.25 20 Series G 1,338 0.33 7 1,338 0.33 7 Total $ 55 $ 55 Nine Months Ended September 30, 2017 2016 Dividends Declared per Share Dividends Declared per Depositary Share Total (In millions) Dividends Declared per Share Dividends Declared per Depositary Share Total (In millions) Preferred Stock: Series C $ 3,939 $ 0.99 $ 19 $ 3,939 $ 0.99 $ 19 Series D 4,425 1.11 33 4,425 1.11 33 Series E 4,500 1.14 33 4,500 1.14 33 Series F 5,250 52.50 40 5,250 52.50 40 Series G 4,014 0.99 21 2,289 0.57 12 Total $ 146 $ 137 (1) Dividends were paid in September 2017. The table below presents the dividends declared on common stock for the periods indicated: Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Dividends Declared per Share Total (In millions) Dividends Declared per Share Total (In millions) Dividends Declared per Share Total (In millions) Dividends Declared per Share Total (In millions) Common Stock $ 0.42 $ 156 $ 0.38 $ 147 $ 1.18 $ 442 $ 1.06 $ 414
Stock Repurchase Program	Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 Shares Acquired Average Cost per Share Total Acquired Shares Acquired Average Cost per Share Total Acquired 2016 Program (1) — $ — $ — 9.4 $ 79.93 $ 750 2017 Program 3.7 93.39 350 3.7 93.39 350 Total 3.7 $ 93.39 $ 350 13.1 $ 83.77 $ 1,100 (1) Includes $158 million relating to shares acquired in exchange for BFDS stock during the first quarter of 2017. Additional information about the exchange is provided in Note 1 to the consolidated financial statements included in this Form 10-Q.
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table presents the after-tax components of AOCI as of the dates indicated: (In millions) September 30, 2017 December 31, 2016 Net unrealized gains (losses) on cash flow hedges $ (45 ) $ 229 Net unrealized gains (losses) on available-for-sale securities portfolio 301 (225 ) Net unrealized gains (losses) related to reclassified available-for-sale securities 18 25 Net unrealized gains (losses) on available-for-sale securities 319 (200 ) Net unrealized losses on available-for-sale securities designated in fair value hedges (73 ) (86 ) Net unrealized gains (losses) on hedges of net investments in non-U.S. subsidiaries (52 ) 95 Other-than-temporary impairment on held-to-maturity securities related to factors other than credit (6 ) (9 ) Net unrealized losses on retirement plans (184 ) (194 ) Foreign currency translation (943 ) (1,875 ) Total $ (984 ) $ (2,040 ) The following table presents changes in AOCI by component, net of related taxes, for the periods indicated: Nine Months Ended September 30, 2017 (In millions) Net Unrealized Gains (Losses) on Cash Flow Hedges Net Unrealized Gains (Losses) on Available-for-Sale Securities Net Unrealized Gains (Losses) on Hedges of Net Investments in Non-U.S. Subsidiaries Other-Than-Temporary Impairment on Held-to-Maturity Securities Net Unrealized Losses on Retirement Plans Foreign Currency Translation Total Balance as of December 31, 2016 $ 229 $ (286 ) $ 95 $ (9 ) $ (194 ) $ (1,875 ) $ (2,040 ) Other comprehensive income (loss) before reclassifications (274 ) 555 (147 ) 3 — 932 1,069 Amounts reclassified into (out of) earnings — (23 ) — — 10 — (13 ) Other comprehensive income (loss) (274 ) 532 (147 ) 3 10 932 1,056 Balance as of September 30, 2017 $ (45 ) $ 246 $ (52 ) $ (6 ) $ (184 ) $ (943 ) $ (984 ) Nine Months Ended September 30, 2016 (In millions) Net Unrealized Gains (Losses) on Cash Flow Hedges Net Unrealized Gains (Losses) on Available-for-Sale Securities Net Unrealized Gain (Losses) on Hedges of Net Investments in Non-U.S. Subsidiaries Other-Than-Temporary Impairment on Held-to-Maturity Securities Net Unrealized Losses on Retirement Plans Foreign Currency Translation Total Balance as of December 31, 2015 $ 293 $ (128 ) $ (14 ) $ (16 ) $ (183 ) $ (1,394 ) $ (1,442 ) Other comprehensive income (loss) before reclassifications (213 ) 520 55 6 — 77 445 Amounts reclassified into (out of) earnings — 4 — (1 ) 1 — 4 Other comprehensive income (loss) (213 ) 524 55 5 1 77 449 Balance as of September 30, 2016 $ 80 $ 396 $ 41 $ (11 ) $ (182 ) $ (1,317 ) $ (993 )
Schedule of Reclassifications Out of AOCI	The following table presents after-tax reclassifications into earnings for the periods indicated: Three Months Ended September 30, 2017 2016 (In millions) Amounts Reclassified into (out of) Earnings Affected Line Item in Consolidated Statement of Income Available-for-sale securities: Net realized gains from sales of available-for-sale securities, net of related taxes of ($1) and ($2), respectively $ 4 $ 2 Net gains (losses) from sales of available-for-sale securities Retirement plans: Amortization of actuarial losses, net of related taxes of $0 and $1, respectively 2 (1 ) Compensation and employee benefits expenses Total reclassifications (out of) into AOCI $ 6 $ 1 Nine Months Ended September 30, 2017 2016 (In millions) Amounts Reclassified into (out of) Earnings Affected Line Item in Consolidated Statement of Income Available-for-sale securities: Net realized gains (losses) from sales of available-for-sale securities, net of related taxes of $15 and ($3), respectively $ (23 ) $ 4 Net gains (losses) from sales of available-for-sale securities Held-to-maturity securities: Other-than-temporary impairment on held-to-maturity securities related to factors other than credit, net of related taxes of $0 and $1, respectively — (1 ) Losses reclassified (from) to other comprehensive income Retirement plans: Amortization of actuarial losses, net of related taxes of ($2) and ($2), respectively 10 1 Compensation and employee benefits expenses Total reclassifications (out of) into AOCI $ (13 ) $ 4

Regulatory Capital (Tables)

Regulatory Capital (Tables)	9 Months Ended
	Sep. 30, 2017
Banking and Thrift [Abstract]
Schedule of Regulatory Capital	The following table presents the regulatory capital structure, total risk-weighted assets, related regulatory capital ratios and the minimum required regulatory capital ratios for State Street and State Street Bank as of the dates indicated. As a result of changes in the methodologies used to calculate our regulatory capital ratios from period to period as the provisions of the Basel III final rule are phased in, the ratios presented in the table for each period-end are not directly comparable. Refer to the footnotes following the table. State Street State Street Bank (In millions) Basel III Advanced Approaches September 30, 2017 (1) Basel III Standardized Approach September 30, 2017 (2) Basel III Advanced Approaches December 31, 2016 (1) Basel III Standardized Approach December 31, 2016 (2) Basel III Advanced Approaches September 30, 2017 (1) Basel III Standardized Approach September 30, 2017 (2) Basel III Advanced Approaches December 31, 2016 (1) Basel III Standardized Approach December 31, 2016 (2) Common shareholders' equity: Common stock and related surplus $ 10,307 $ 10,307 $ 10,286 $ 10,286 $ 11,382 $ 11,382 $ 11,376 $ 11,376 Retained earnings 18,675 18,675 17,459 17,459 12,286 12,286 12,285 12,285 Accumulated other comprehensive income (loss) (985 ) (985 ) (1,936 ) (1,936 ) (808 ) (808 ) (1,648 ) (1,648 ) Treasury stock, at cost (8,697 ) (8,697 ) (7,682 ) (7,682 ) — — — — Total 19,300 19,300 18,127 18,127 22,860 22,860 22,013 22,013 Regulatory capital adjustments: Goodwill and other intangible assets, net of associated deferred tax liabilities (3) (6,739 ) (6,739 ) (6,348 ) (6,348 ) (6,447 ) (6,447 ) (6,060 ) (6,060 ) Other adjustments (122 ) (122 ) (155 ) (155 ) (90 ) (90 ) (148 ) (148 ) Common equity tier 1 capital 12,439 12,439 11,624 11,624 16,323 16,323 15,805 15,805 Preferred stock 3,196 3,196 3,196 3,196 — — — — Trust preferred capital securities subject to phase-out from tier 1 capital — — — — — — — — Other adjustments (29 ) (29 ) (103 ) (103 ) — — — — Tier 1 capital 15,606 15,606 14,717 14,717 16,323 16,323 15,805 15,805 Qualifying subordinated long-term debt 1,072 1,072 1,172 1,172 1,076 1,076 1,179 1,179 Trust preferred capital securities phased out of tier 1 capital — — — — — — — — ALLL and other 5 79 19 77 — 79 15 77 Other adjustments 1 1 1 1 — — — — Total capital $ 16,684 $ 16,758 $ 15,909 $ 15,967 $ 17,399 $ 17,478 $ 16,999 $ 17,061 Risk-weighted assets: Credit risk $ 50,197 $ 106,377 $ 50,900 $ 98,125 $ 47,282 $ 103,024 $ 47,383 $ 94,413 Operational risk (4) 45,795 NA 44,579 NA 45,270 NA 44,043 NA Market risk (5) 3,005 1,203 3,822 1,751 3,005 1,203 3,822 1,751 Total risk-weighted assets $ 98,997 $ 107,580 $ 99,301 $ 99,876 $ 95,557 $ 104,227 $ 95,248 $ 96,164 Adjusted quarterly average assets $ 211,396 $ 211,396 $ 226,310 $ 226,310 $ 208,308 $ 208,308 $ 222,584 $ 222,584 Capital Ratios: 2017 Minimum Requirements Including Capital Conservation Buffer and G-SIB Surcharge (6) 2016 Minimum Requirements Including Capital Conservation Buffer and G-SIB Surcharge (7) Common equity tier 1 capital 6.5 % 5.5 % 12.6 % 11.6 % 11.7 % 11.6 % 17.1 % 15.7 % 16.6 % 16.4 % Tier 1 capital 8.0 7.0 15.8 14.5 14.8 14.7 17.1 15.7 16.6 16.4 Total capital 10.0 9.0 16.9 15.6 16.0 16.0 18.2 16.8 17.8 17.7 Tier 1 leverage 4.0 4.0 7.4 7.4 6.5 6.5 7.8 7.8 7.1 7.1 (1) Common equity tier 1 capital, tier 1 capital and total capital ratios as of September 30, 2017 and December 31, 2016 were calculated in conformity with the advanced approaches provisions of the Basel III final rule. Tier 1 leverage ratio as of September 30, 2017 and December 31, 2016 were calculated in conformity with the Basel III final rule. (2) Common equity tier 1 capital, tier 1 capital and total capital ratios as of September 30, 2017 and December 31, 2016 were calculated in conformity with the standardized approach provisions of the Basel III final rule. Tier 1 leverage ratio as of September 30, 2017 and December 31, 2016 were calculated in conformity with the Basel III final rule. (3) Amounts for State Street and State Street Bank as of September 30, 2017 consisted of goodwill, net of associated deferred tax liabilities, and 80% of other intangible assets, net of associated deferred tax liabilities. Amounts for State Street and State Street Bank as of December 31, 2016 consisted of goodwill, net of deferred tax liabilities and 60% of other intangible assets, net of associated deferred tax liabilities. Intangible assets, net of associated deferred tax liabilities is phased in as a deduction from capital, in conformity with the Basel III final rule. (4) Under the current advanced approaches rules and regulatory guidance concerning operational risk models, RWA attributable to operational risk can vary substantially from period-to-period, without direct correlation to the effects of a particular loss event on our results of operations and financial condition and impacting dates and periods that may differ from the dates and periods as of and during which the loss event is reflected in our financial statements, with the timing and categorization dependent on the processes for model updates and, if applicable, model revalidation and regulatory review and related supervisory processes. An individual loss event can have a significant effect on the output of our operational risk RWA under the advanced approaches depending on the severity of the loss event and its categorization among the seven Basel-defined UOMs. (5) Market risk risk-weighted assets reported in conformity with the Basel III advanced approaches included a CVA which reflected the risk of potential fair value adjustments for credit risk reflected in our valuation of over-the-counter derivative contracts. The CVA was not provided for in the final market risk capital rule; however, it was required by the advanced approaches provisions of the Basel III final rule. We used a simple CVA approach in conformity with the Basel III advanced approaches. (6) Minimum requirements will be phased in up to full implementation beginning on January 1, 2019; minimum requirements listed are as of September 30, 2017 . (7) Minimum requirements will be phased in up to full implementation beginning on January 1, 2019; minimum requirements listed are as of December 31, 2016 . NA Not applicable

Net Interest Income (Tables)

Net Interest Income (Tables)	9 Months Ended
	Sep. 30, 2017
Banking and Thrift [Abstract]
Components of Interest Revenue and Interest Expense	The following table presents the components of interest income and interest expense, and related NII, for the periods indicated: Three Months Ended September 30, Nine Months Ended September 30, (In millions) 2017 2016 2017 2016 Interest income: Deposits with banks $ 45 $ 29 $ 121 $ 101 Investment securities: U.S. Treasury and federal agencies 207 200 627 620 State and political subdivisions 56 55 171 162 Other investments 173 208 495 581 Securities purchased under resale agreements 74 40 189 112 Loans and leases 139 97 362 281 Other interest-earning assets 67 18 146 39 Total interest income 761 647 2,111 1,896 Interest expense: Deposits 39 20 96 73 Securities sold under repurchase agreements 1 — 2 1 Short-term borrowings 3 2 7 4 Long-term debt 78 68 227 191 Other interest-bearing liabilities 37 20 91 57 Total interest expense 158 110 423 326 Net interest income $ 603 $ 537 $ 1,688 $ 1,570

Expenses (Tables)

Expenses (Tables)	9 Months Ended
	Sep. 30, 2017
Other Expenses [Abstract]
Schedule of Expenses	The following table presents the components of other expenses for the periods indicated: Three Months Ended September 30, Nine Months Ended September 30, (In millions) 2017 2016 2017 2016 Insurance $ 27 $ 31 $ 84 $ 74 Regulatory fees and assessments 24 28 77 65 Securities processing 4 10 20 20 Litigation 3 47 (15 ) 47 Other 86 71 261 231 Total other expenses $ 144 $ 187 $ 427 $ 437
Restructuring and Related Costs	The following table presents aggregate restructuring activity for the periods indicated: (In millions) Employee Real Estate Asset and Other Write-offs Total Accrual Balance at December 31, 2015 $ 9 $ 11 $ 3 $ 23 Accruals for Beacon 86 — 11 97 Payments and Other Adjustments (4 ) (1 ) (7 ) (12 ) Accrual Balance at March 31, 2016 $ 91 $ 10 $ 7 $ 108 Accruals for Beacon (1 ) 15 (1 ) 13 Payments and Other Adjustments (35 ) (3 ) (1 ) (39 ) Accrual Balance at June 30, 2016 $ 55 $ 22 $ 5 $ 82 Accruals for Beacon 8 3 (1 ) 10 Payments and Other Adjustments (14 ) (3 ) (1 ) (18 ) Accrual Balance at September 30, 2016 $ 49 $ 22 $ 3 $ 74 Accrual Balance at December 31, 2016 $ 37 $ 17 $ 2 $ 56 Accruals for Beacon 14 — 2 16 Payments and Other Adjustments (13 ) (3 ) (2 ) (18 ) Accrual Balance at March 31, 2017 $ 38 $ 14 $ 2 $ 54 Accruals for Beacon 60 — 2 62 Payments and other adjustments (11 ) (3 ) (2 ) (16 ) Accrual Balance at June 30, 2017 $ 87 $ 11 $ 2 $ 100 Accruals for Beacon 23 9 1 33 Payments and Other Adjustments (10 ) (5 ) (1 ) (16 ) Accrual Balance at September 30, 2017 $ 100 $ 15 $ 2 $ 117

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Computation of Basic and Diluted Earnings Per Share	The following table presents the computation of basic and diluted earnings per common share for the periods indicated: Three Months Ended September 30, (Dollars in millions, except per share amounts) 2017 2016 Net income $ 685 $ 563 Less: Preferred stock dividends (55 ) (55 ) Dividends and undistributed earnings allocated to participating securities (1) (1 ) (1 ) Net income available to common shareholders $ 629 $ 507 Average common shares outstanding (In thousands): Basic average common shares 372,765 388,358 Effect of dilutive securities: equity-based awards 5,753 4,854 Diluted average common shares 378,518 393,212 Anti-dilutive securities (2) — 2,166 Earnings per Common Share: Basic $ 1.69 $ 1.31 Diluted (3) 1.66 1.29 Nine Months Ended September 30, (Dollars in millions, except per share amounts) 2017 2016 Net income $ 1,807 $ 1,550 Less: Preferred stock dividends (146 ) (137 ) Dividends and undistributed earnings allocated to participating securities (1) (2 ) (2 ) Net income available to common shareholders $ 1,659 $ 1,411 Average common shares outstanding (In thousands): Basic average common shares 376,430 393,959 Effect of dilutive securities: equity-based awards 5,349 4,454 Diluted average common shares 381,779 398,413 Anti-dilutive securities (2) 250 3,027 Earnings per Common Share: Basic $ 4.41 $ 3.58 Diluted (3) 4.35 3.54 (1) Represents the portion of net income available to common equity allocated to participating securities, composed of unvested and fully vested SERP shares and fully vested deferred director stock awards, which are equity-based awards that contain non-forfeitable rights to dividends, and are considered to participate with the common stock in undistributed earnings. (2) Represents equity-based awards outstanding but not included in the computation of diluted average common shares, because their effect was anti-dilutive. Additional information about equity-based awards is provided in Note 18 to the consolidated financial statements included under Item 8, Financial Statements and Supplementary Data, in our 2016 Form 10-K. (3) Calculations reflect allocation of earnings to participating securities using the two-class method, as this computation is more dilutive than the treasury stock method.

Line of Business Information (T

Line of Business Information (Tables)	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Summary of Line of Business Results	The following is a summary of our line-of-business results for the periods indicated. The "Other" column represents costs incurred that are not allocated to a specific line of business, including certain severance and restructuring costs, acquisition costs and certain provisions for legal contingencies. Three Months Ended September 30, Investment Investment Other Total (Dollars in millions) 2017 2016 2017 2016 2017 2016 2017 2016 Servicing fees $ 1,351 $ 1,303 $ — $ — $ — $ — $ 1,351 $ 1,303 Management fees — — 419 368 — — 419 368 Trading services 239 248 20 19 — — 259 267 Securities finance 147 136 — — — — 147 136 Processing fees and other 65 12 1 (7 ) — — 66 5 Total fee revenue 1,802 1,699 440 380 — — 2,242 2,079 Net interest income 606 536 (3 ) 1 — — 603 537 Gains (losses) related to investment securities, net 1 4 — — — — 1 4 Total revenue 2,409 2,239 437 381 — — 2,846 2,620 Provision for loan losses 3 — — — — — 3 — Total expenses 1,673 1,634 314 317 34 33 2,021 1,984 Income before income tax expense $ 733 $ 605 $ 123 $ 64 $ (34 ) $ (33 ) $ 822 $ 636 Pre-tax margin 30 % 27 % 28 % 17 % 29 % 24 % Nine Months Ended September 30, Investment Investment Other Total (Dollars in millions) 2017 2016 2017 2016 2017 2016 2017 2016 Servicing fees $ 3,986 $ 3,784 $ — $ — $ — $ — $ 3,986 $ 3,784 Management fees — — 1,198 931 — — 1,198 931 Trading services 768 760 55 46 — — 823 806 Securities finance 459 426 — — — — 459 426 Processing fees and other 203 164 6 (9 ) — — 209 155 Total fee revenue 5,416 5,134 1,259 968 — — 6,675 6,102 Net interest income 1,691 1,567 (3 ) 3 — — 1,688 1,570 Gains (losses) related to investment securities, net (39 ) 5 — — — — (39 ) 5 Total revenue 7,068 6,706 1,256 971 — — 8,324 7,677 Provision for loan losses 4 8 — — — — 4 8 Total expenses 5,050 4,920 954 817 134 157 6,138 5,894 Income before income tax expense $ 2,014 $ 1,778 $ 302 $ 154 $ (134 ) $ (157 ) $ 2,182 $ 1,775 Pre-tax margin 28 % 27 % 24 % 16 % 26 % 23 %

Non-U.S. Activities (Tables)

Non-U.S. Activities (Tables)	9 Months Ended
	Sep. 30, 2017
Segments, Geographical Areas [Abstract]
Schedule of Results from Non-U.S. Operations	The following table presents our U.S. and non-U.S. financial results for the periods indicated: Three Months Ended September 30, 2017 Three Months Ended September 30, 2016 (In millions) Non-U.S. U.S. Total Non-U.S. U.S. Total Total revenue $ 1,219 $ 1,627 $ 2,846 $ 1,117 $ 1,503 $ 2,620 Income before income taxes 342 480 822 314 322 636 Nine Months Ended September 30, 2017 Nine Months Ended September 30, 2016 (In millions) Non-U.S. U.S. Total Non-U.S. U.S. Total Total revenue $ 3,494 $ 4,830 $ 8,324 $ 3,278 $ 4,399 $ 7,677 Income before income taxes 919 1,263 2,182 835 940 1,775

Summary of Significant Accoun45

Summary of Significant Accounting Policies - Basis of Presentation (Details) - Boston Financial Data Services, Inc. and International Financial Data Services - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Mar. 31, 2017	Sep. 30, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash received	$ 175
Common stock received	$ 158
Gain on sale		$ 30

Summary of Significant Accoun46

Summary of Significant Accounting Policies - New Accounting Pronouncement (Details) $ in Millions	9 Months Ended
	Sep. 30, 2017USD ($)
Accounting Standards Update 2016-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Tax benefit	$ 18.6

Fair Value - Narrative (Details

Fair Value - Narrative (Details) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Assets, level 1 to level 2 transfers	$ 0	$ 0
Assets, level 2 to level 1 transfers	9,000,000	0
Liabilities, level 1 to level 2 transfers	0	0
Liabilities, level 2 to level 1 transfers	$ 0	$ 0

Fair Value - Schedule of Fair V

Fair Value - Schedule of Fair Value Measurements on a Recurring Basis (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	$ 1,135	$ 1,024
Investment securities available-for-sale	56,238	61,998
Derivative asset, collateral, cash offset	(637)	(906)
Derivative liability, collateral, cash offset	(1,074)	(2,356)
Collateralized loan obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	1,221	905
Non-US debt securities, covered bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	3,600	3,769
Non-U.S. debt securities, other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	1,503	988
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	1,135	1,024
Investment securities available-for-sale	56,238	61,998
Derivative asset, Impact of Netting	(7,028)	(9,231)
Derivative assets	4,712	7,321
Other	22
Other impact of netting	0
Total	62,107	70,343
Derivative liability, Impact of Netting	(7,466)	(10,682)
Derivative liabilities	4,543	6,002
Other	22
Other, impact of netting	0
Total liabilities carried at fair value	4,584	6,002
Recurring | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset, Impact of Netting	(7,026)	(9,163)
Derivative assets	4,711	7,321
Derivative liability, Impact of Netting	(7,465)	(10,456)
Derivative liabilities	4,118	5,500
Recurring | Interest-rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset, Impact of Netting	(2)	(68)
Derivative assets	1	0
Derivative liability, Impact of Netting	(1)	(226)
Derivative liabilities	106	122
Recurring | Other derivative contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, Impact of Netting	0	0
Derivative liabilities	319	380
Recurring | U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	39	30
Recurring | Non-U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	561	669
Recurring | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	535	325
Investment securities available-for-sale	2,928	2,469
Recurring | US Treasury and federal agencies, direct obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	620	4,263
Recurring | US Treasury and federal agencies, mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	11,000	13,257
Recurring | Asset-backed securities, student loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	4,826	5,596
Recurring | Asset-backed securities, credit cards
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	1,548	1,351
Recurring | Asset-backed securities, sub-prime
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		272
Recurring | Asset-backed securities, other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	1,221	905
Recurring | Total asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	7,595	8,124
Recurring | Non-U.S. debt securities, mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	7,074	6,535
Recurring | Non-U.S. debt securities, asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	2,839	2,516
Recurring | Non-U.S. debt securities, Government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	6,658	5,836
Recurring | Non-U.S. debt securities, other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	5,818	5,613
Recurring | Total non-U.S. debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	22,389	20,500
Recurring | State and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	9,738	10,322
Recurring | Collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	1,528	2,593
Recurring | U.S. equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	46	42
Recurring | Non-U.S. equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		3
Recurring | U.S. money-market mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	394	409
Recurring | Non-U.S. money-market mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		16
Quoted Market Prices in Active Markets (Level 1) | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	446	525
Investment securities available-for-sale	231	3,824
Derivative asset	0	0
Other	22
Total	699	4,349
Derivative liability	10	0
Other	22
Total liabilities carried at fair value	51	0
Quoted Market Prices in Active Markets (Level 1) | Recurring | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	0
Derivative liability	0	0
Quoted Market Prices in Active Markets (Level 1) | Recurring | Interest-rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	0
Derivative liability	10	0
Quoted Market Prices in Active Markets (Level 1) | Recurring | Other derivative contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability	0	0
Quoted Market Prices in Active Markets (Level 1) | Recurring | U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	39	30
Quoted Market Prices in Active Markets (Level 1) | Recurring | Non-U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	387	495
Quoted Market Prices in Active Markets (Level 1) | Recurring | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	20	0
Investment securities available-for-sale	0	0
Quoted Market Prices in Active Markets (Level 1) | Recurring | US Treasury and federal agencies, direct obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	231	3,824
Quoted Market Prices in Active Markets (Level 1) | Recurring | US Treasury and federal agencies, mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0	0
Quoted Market Prices in Active Markets (Level 1) | Recurring | Asset-backed securities, student loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0	0
Quoted Market Prices in Active Markets (Level 1) | Recurring | Asset-backed securities, credit cards
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0	0
Quoted Market Prices in Active Markets (Level 1) | Recurring | Asset-backed securities, sub-prime
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		0
Quoted Market Prices in Active Markets (Level 1) | Recurring | Asset-backed securities, other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0	0
Quoted Market Prices in Active Markets (Level 1) | Recurring | Total asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0	0
Quoted Market Prices in Active Markets (Level 1) | Recurring | Non-U.S. debt securities, mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0	0
Quoted Market Prices in Active Markets (Level 1) | Recurring | Non-U.S. debt securities, asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0	0
Quoted Market Prices in Active Markets (Level 1) | Recurring | Non-U.S. debt securities, Government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0	0
Quoted Market Prices in Active Markets (Level 1) | Recurring | Non-U.S. debt securities, other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0	0
Quoted Market Prices in Active Markets (Level 1) | Recurring | Total non-U.S. debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0	0
Quoted Market Prices in Active Markets (Level 1) | Recurring | State and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0	0
Quoted Market Prices in Active Markets (Level 1) | Recurring | Collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0	0
Quoted Market Prices in Active Markets (Level 1) | Recurring | U.S. equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0	0
Quoted Market Prices in Active Markets (Level 1) | Recurring | Non-U.S. equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		0
Quoted Market Prices in Active Markets (Level 1) | Recurring | U.S. money-market mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0	0
Quoted Market Prices in Active Markets (Level 1) | Recurring | Non-U.S. money-market mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		0
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	689	499
Investment securities available-for-sale	54,123	56,837
Derivative asset	11,738	16,544
Other	0
Total	66,550	73,880
Derivative liability	11,997	16,676
Other	0
Total liabilities carried at fair value	11,997	16,676
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	11,735	16,476
Derivative liability	11,581	15,948
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring | Interest-rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	3	68
Derivative liability	97	348
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring | Other derivative contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability	319	380
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring | U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	0	0
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring | Non-U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	174	174
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	515	325
Investment securities available-for-sale	2,909	2,469
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring | US Treasury and federal agencies, direct obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	389	439
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring | US Treasury and federal agencies, mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	10,975	13,257
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring | Asset-backed securities, student loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	4,626	5,499
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring | Asset-backed securities, credit cards
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	1,548	1,351
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring | Asset-backed securities, sub-prime
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		272
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring | Asset-backed securities, other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	35	0
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring | Total asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	6,209	7,122
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring | Non-U.S. debt securities, mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	6,956	6,535
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring | Non-U.S. debt securities, asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	2,742	2,484
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring | Non-U.S. debt securities, Government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	6,658	5,836
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring | Non-U.S. debt securities, other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	5,617	5,365
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring | Total non-U.S. debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	21,973	20,220
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring | State and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	9,700	10,283
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring | Collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	1,528	2,577
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring | U.S. equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	46	42
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring | Non-U.S. equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		3
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring | U.S. money-market mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	394	409
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring | Non-U.S. money-market mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		16
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	0	0
Investment securities available-for-sale	1,884	1,337
Derivative asset	2	8
Other	0
Total	1,886	1,345
Derivative liability	2	8
Other	0
Total liabilities carried at fair value	2	8
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	2	8
Derivative liability	2	8
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring | Interest-rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	0
Derivative liability	0	0
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring | Other derivative contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability	0	0
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring | U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	0	0
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring | Non-U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	0	0
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	0	0
Investment securities available-for-sale	19	0
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring | US Treasury and federal agencies, direct obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0	0
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring | US Treasury and federal agencies, mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	25	0
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring | Asset-backed securities, student loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	200	97
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring | Asset-backed securities, credit cards
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0	0
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring | Asset-backed securities, sub-prime
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		0
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring | Asset-backed securities, other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	1,186	905
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring | Total asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	1,386	1,002
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring | Non-U.S. debt securities, mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	118	0
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring | Non-U.S. debt securities, asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	97	32
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring | Non-U.S. debt securities, Government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0	0
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring | Non-U.S. debt securities, other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	201	248
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring | Total non-U.S. debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	416	280
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring | State and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	38	39
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring | Collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0	16
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring | U.S. equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0	0
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring | Non-U.S. equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		0
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring | U.S. money-market mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0	0
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring | Non-U.S. money-market mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		$ 0
Other | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account liabilities	19
Other | Quoted Market Prices in Active Markets (Level 1) | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account liabilities	19
Other | Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account liabilities	0
Other | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account liabilities	0
Trading account liabilities, impact of netting	$ 0

Fair Value - Schedule of Fair49

Fair Value - Schedule of Fair Value Measurements, Assets, Using Significant Unobservable Inputs (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning of period	$ 1,350	$ 2,398	$ 1,345	$ 2,469
Total realized and unrealized gain (losses) recorded in revenue	1	13	(3)	33
Total realized and unrealized gain (losses) recorded in other comprehensive income	1	2	0	(9)
Purchases	409	553	844	1,170
Settlements	0	(569)	(410)	(828)
Transfers into Level 3	215		368
Transfers out of Level 3		(54)	(168)	(492)
Fair value, end of period	1,886	2,343	1,886	2,343
Change in unrealized gains (losses) related to financial instruments held	(2)	0	(1)	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	(90)		(90)
Derivative instruments, assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning of period	5		8	5
Total realized and unrealized gain (losses) recorded in revenue	0		(6)	3
Total realized and unrealized gain (losses) recorded in other comprehensive income	0		0	0
Purchases	2		4	0
Settlements	(5)		(4)	(8)
Transfers into Level 3	0		0
Transfers out of Level 3			0	0
Fair value, end of period	2	0	2	0
Change in unrealized gains (losses) related to financial instruments held	(2)		(1)	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	0		0
Foreign exchange contracts
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning of period	5		8	5
Total realized and unrealized gain (losses) recorded in revenue	0		(6)	3
Total realized and unrealized gain (losses) recorded in other comprehensive income	0		0	0
Purchases	2		4	0
Settlements	(5)		(4)	(8)
Transfers into Level 3	0		0
Transfers out of Level 3			0	0
Fair value, end of period	2	0	2	0
Change in unrealized gains (losses) related to financial instruments held	(2)		(1)	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	0		0
Investment securities available-for-sale
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning of period	1,345	2,398	1,337	2,464
Total realized and unrealized gain (losses) recorded in revenue	1	13	3	30
Total realized and unrealized gain (losses) recorded in other comprehensive income	1	2	0	(9)
Purchases	407	553	840	1,170
Settlements	5	(569)	(406)	(820)
Transfers into Level 3	215		368
Transfers out of Level 3		(54)	(168)	(492)
Fair value, end of period	1,884	2,343	1,884	2,343
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	(90)		(90)
US Treasury and federal agencies, mortgage-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning of period	0	25	0	0
Total realized and unrealized gain (losses) recorded in revenue	0	0	0	0
Total realized and unrealized gain (losses) recorded in other comprehensive income	0	0	0	0
Purchases	0	25	0	325
Settlements	0	0	0	0
Transfers into Level 3	25		25
Transfers out of Level 3		0	0	(275)
Fair value, end of period	25	50	25	50
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	0		0
Asset-backed securities, student loans
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning of period	0	190	97	189
Total realized and unrealized gain (losses) recorded in revenue	0	0	0	1
Total realized and unrealized gain (losses) recorded in other comprehensive income	0	2	1	2
Purchases	200	0	200	0
Settlements	0	0	0	0
Transfers into Level 3	0		0
Transfers out of Level 3		0	(98)	0
Fair value, end of period	200	192	200	192
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	0		0
Asset-backed securities, other
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning of period	951	1,710	905	1,764
Total realized and unrealized gain (losses) recorded in revenue	1	13	2	29
Total realized and unrealized gain (losses) recorded in other comprehensive income	1	(8)	0	(21)
Purchases	60	118	415	250
Settlements	(2)	(560)	(412)	(749)
Transfers into Level 3	175		276
Transfers out of Level 3		0	0	0
Fair value, end of period	1,186	1,273	1,186	1,273
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	0		0
Total asset-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning of period	951	1,900	1,002	1,953
Total realized and unrealized gain (losses) recorded in revenue	1	13	2	30
Total realized and unrealized gain (losses) recorded in other comprehensive income	1	(6)	1	(19)
Purchases	260	118	615	250
Settlements	(2)	(560)	(412)	(749)
Transfers into Level 3	175		276
Transfers out of Level 3		0	(98)	0
Fair value, end of period	1,386	1,465	1,386	1,465
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	0		0
Non-U.S. debt securities, mortgage-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning of period	0		0	0
Total realized and unrealized gain (losses) recorded in revenue	0	0	0	0
Total realized and unrealized gain (losses) recorded in other comprehensive income	0	0	0	0
Purchases	118	90	118	90
Settlements	0	0	0	0
Transfers into Level 3	0		0
Transfers out of Level 3		0	0	0
Fair value, end of period	118	90	118	90
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	0		0
Non-U.S. debt securities, asset-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning of period	63	111	32	174
Total realized and unrealized gain (losses) recorded in revenue	0	0	1	0
Total realized and unrealized gain (losses) recorded in other comprehensive income	0	0	(1)	(1)
Purchases	29	90	60	196
Settlements	0	(9)	(21)	(43)
Transfers into Level 3	15		67
Transfers out of Level 3		(54)	(31)	(188)
Fair value, end of period	97	138	97	138
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	(10)		(10)
Non-U.S. debt securities, other
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning of period	274	261	248	255
Total realized and unrealized gain (losses) recorded in revenue	0	0	0	0
Total realized and unrealized gain (losses) recorded in other comprehensive income	0	0	0	0
Purchases	0	194	5	223
Settlements	7	3	28	9
Transfers into Level 3	0		0
Transfers out of Level 3		0	0	(29)
Fair value, end of period	201	458	201	458
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	(80)		(80)
Total non-U.S. debt securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning of period	337	372	280	429
Total realized and unrealized gain (losses) recorded in revenue	0	0	1	0
Total realized and unrealized gain (losses) recorded in other comprehensive income	0	0	(1)	(1)
Purchases	147	374	183	509
Settlements	7	(6)	7	(34)
Transfers into Level 3	15		67
Transfers out of Level 3		(54)	(31)	(217)
Fair value, end of period	416	686	416	686
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	(90)		(90)
State and political subdivisions
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning of period	38	33	39	33
Total realized and unrealized gain (losses) recorded in revenue	0	0	0	0
Total realized and unrealized gain (losses) recorded in other comprehensive income	0	7	0	9
Purchases	0	0	0	0
Settlements	0	0	(1)	(2)
Transfers into Level 3	0		0
Transfers out of Level 3		0	0	0
Fair value, end of period	38	40	38	40
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	0		0
Collateralized mortgage obligations
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning of period		68	16	39
Total realized and unrealized gain (losses) recorded in revenue		0	0	0
Total realized and unrealized gain (losses) recorded in other comprehensive income		1	0	2
Purchases		36	23	86
Settlements		(3)	0	(25)
Transfers into Level 3			0
Transfers out of Level 3		0	(39)	0
Fair value, end of period	0	102	0	102
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales			0
Other U.S. debt securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning of period	19		0	10
Total realized and unrealized gain (losses) recorded in revenue	0		0	0
Total realized and unrealized gain (losses) recorded in other comprehensive income	0		0	0
Purchases	0		19	0
Settlements	0		0	(10)
Transfers into Level 3	0		0
Transfers out of Level 3			0	0
Fair value, end of period	19	$ 0	19	$ 0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	0		0
Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	7,466		7,466		$ 10,682
Derivative Liability	4,543		4,543		6,002
Recurring | Foreign exchange contracts
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	7,465		7,465		10,456
Derivative Liability	4,118		4,118		5,500
Recurring | Interest-rate contracts
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	1		1		226
Derivative Liability	106		106		122
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative liability	11,997		11,997		16,676
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring | Foreign exchange contracts
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative liability	11,581		11,581		15,948
Pricing Methods with Significant Observable Market Inputs (Level 2) | Recurring | Interest-rate contracts
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative liability	97		97		348
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative liability	2		2		8
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring | Foreign exchange contracts
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative liability	2		2		8
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Recurring | Interest-rate contracts
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative liability	0		0		0
Quoted Market Prices in Active Markets (Level 1) | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative liability	10		10		0
Quoted Market Prices in Active Markets (Level 1) | Recurring | Foreign exchange contracts
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative liability	0		0		0
Quoted Market Prices in Active Markets (Level 1) | Recurring | Interest-rate contracts
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative liability	$ 10		$ 10		$ 0

Fair Value - Schedule of Fair50

Fair Value - Schedule of Fair Value Measurements, Liabilities, Using Significant Unobservable Input (Details) - Accrued expenses and other liabilities $ in Millions	9 Months Ended
	Sep. 30, 2016USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value as of December 31, 2015	$ 5
Total Realized and Unrealized (Gains) Losses Recorded in Revenue	5
Settlements	(10)
Fair Value as of June 30, 2016	0
Change in Unrealized (Gains) Losses Related to Financial Instruments Held as of September 30, 2016	0
Foreign exchange contracts
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value as of December 31, 2015	5
Total Realized and Unrealized (Gains) Losses Recorded in Revenue	5
Settlements	(10)
Fair Value as of June 30, 2016	0
Change in Unrealized (Gains) Losses Related to Financial Instruments Held as of September 30, 2016	0
Total derivative instruments
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value as of December 31, 2015	5
Total Realized and Unrealized (Gains) Losses Recorded in Revenue	5
Settlements	(10)
Fair Value as of June 30, 2016	0
Change in Unrealized (Gains) Losses Related to Financial Instruments Held as of September 30, 2016	$ 0

Fair Value - Fair Value Inputs,

Fair Value - Fair Value Inputs, Assets and Liabilities, Quantitative Information (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Investment securities available-for-sale	$ 56,238	$ 61,998
Asset-backed securities, other
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Investment securities available-for-sale	1,221	905
State and political subdivisions
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Investment securities available-for-sale	$ 9,738	$ 10,322
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Discounted cash flows | Asset-backed securities, other | Weighted average
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Credit spread	0.00%	0.30%
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Discounted cash flows | State and political subdivisions | Weighted average
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Credit spread	1.70%	1.80%
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Option model | Derivative instruments, liabilities | Weighted average
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Volatility	8.30%	14.40%
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Option model | Derivative instruments, assets | Weighted average
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Volatility	8.30%	14.40%
Significant Unobservable Inputs Readily Available | Pricing Methods with Significant Unobservable Market Inputs (Level 3)
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Total	$ 40	$ 48
Total	2	8
Significant Unobservable Inputs Readily Available | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Derivative instruments, liabilities
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Derivative instruments, foreign exchange contracts	2	8
Significant Unobservable Inputs Readily Available | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Derivative instruments, assets
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Derivative instruments, foreign exchange contracts	2	8
Significant Unobservable Inputs Readily Available | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Asset-backed securities, other
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Investment securities available-for-sale	0	1
Significant Unobservable Inputs Readily Available | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | State and political subdivisions
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Investment securities available-for-sale	$ 38	$ 39

Fair Value - Carrying Value and

Fair Value - Carrying Value and Estimated Fair Value of Financial Instruments (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Financial Assets:
Cash and due from banks	$ 3,939	$ 1,314	$ 3,490	$ 1,207
Interest-bearing deposits with banks	60,956	70,935
Securities purchased under resale agreements	3,465	1,956
Investment securities held-to-maturity	36,836	34,994
Financial Liabilities:
Non-interest-bearing	49,850	59,397
Interest-bearing—U.S.	49,394	30,911
Interest-bearing—non-U.S.	80,019	96,855
Securities sold under repurchase agreements	3,867	4,400
Other short-term borrowings	1,253	1,585
Reported Amount
Financial Assets:
Cash and due from banks	3,939	1,314
Interest-bearing deposits with banks	60,956	70,935
Securities purchased under resale agreements	3,465	1,956
Investment securities held-to-maturity	36,850	35,169
Net loans (excluding leases)	22,868	18,862
Financial Liabilities:
Non-interest-bearing	49,850	59,397
Interest-bearing—U.S.	49,394	30,911
Interest-bearing—non-U.S.	80,019	96,855
Securities sold under repurchase agreements	3,867	4,400
Other short-term borrowings	1,253	1,585
Long-term debt	11,716	11,430
Estimated Fair Value
Financial Assets:
Cash and due from banks	3,939	1,314
Interest-bearing deposits with banks	60,956	70,935
Securities purchased under resale agreements	3,465	1,956
Investment securities held-to-maturity	36,836	34,994
Net loans (excluding leases)	22,866	18,877
Financial Liabilities:
Non-interest-bearing	49,850	59,397
Interest-bearing—U.S.	49,394	30,911
Interest-bearing—non-U.S.	80,019	96,855
Securities sold under repurchase agreements	3,867	4,400
Other short-term borrowings	1,253	1,585
Long-term debt	12,022	11,618
Estimated Fair Value | Quoted Market Prices in Active Markets (Level 1)
Financial Assets:
Cash and due from banks	3,939	1,314
Interest-bearing deposits with banks	0	0
Securities purchased under resale agreements	0	0
Investment securities held-to-maturity	17,362	17,400
Net loans (excluding leases)	0	0
Financial Liabilities:
Non-interest-bearing	0	0
Interest-bearing—U.S.	0	0
Interest-bearing—non-U.S.	0	0
Securities sold under repurchase agreements	0	0
Other short-term borrowings	0	0
Long-term debt	0	0
Estimated Fair Value | Pricing Methods with Significant Observable Market Inputs (Level 2)
Financial Assets:
Cash and due from banks	0	0
Interest-bearing deposits with banks	60,956	70,935
Securities purchased under resale agreements	3,465	1,956
Investment securities held-to-maturity	19,351	17,439
Net loans (excluding leases)	22,811	18,781
Financial Liabilities:
Non-interest-bearing	49,850	59,397
Interest-bearing—U.S.	49,394	30,911
Interest-bearing—non-U.S.	80,019	96,855
Securities sold under repurchase agreements	3,867	4,400
Other short-term borrowings	1,253	1,585
Long-term debt	11,725	11,282
Estimated Fair Value | Pricing Methods with Significant Unobservable Market Inputs (Level 3)
Financial Assets:
Cash and due from banks	0	0
Interest-bearing deposits with banks	0	0
Securities purchased under resale agreements	0	0
Investment securities held-to-maturity	123	155
Net loans (excluding leases)	55	96
Financial Liabilities:
Non-interest-bearing	0	0
Interest-bearing—U.S.	0	0
Interest-bearing—non-U.S.	0	0
Securities sold under repurchase agreements	0	0
Other short-term borrowings	0	0
Long-term debt	$ 297	$ 336

Investment Securities - Narrati

Investment Securities - Narrative (Details) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)security	Sep. 30, 2016USD ($)	Dec. 31, 2016USD ($)
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Pledged securities not separately reported	$ 52,000			$ 52,000		$ 46,000
Net impairment losses	$ 1		$ 1		$ 2
MBS and U.S. Treasury Securities
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Securities sold		$ 2,700
Loss on sale		$ 40
U.S. Non-Agency Commercial Mortgage Backed Securities [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Gross pre-tax unrealized losses				$ 434
Number of securities in loss position | security				1,151

Investment Securities - Schedul

Investment Securities - Schedule of Marketable Securities (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	$ 55,882	$ 62,056
Available for sale, gross unrealized gains	559	427
Available for sale, gross unrealized losses	203	485
Investment securities available-for-sale	56,238	61,998
Held to maturity, amortized cost	36,850	35,169
Held to maturity, gross unrealized gains	217	160
Held to maturity, gross unrealized losses	231	335
Investment securities held-to-maturity	36,836	34,994
US Treasury and federal agencies, direct obligations
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	617	4,265
Available for sale, gross unrealized gains	4	7
Available for sale, gross unrealized losses	1	9
Investment securities available-for-sale	620	4,263
Held to maturity, amortized cost	17,456	17,527
Held to maturity, gross unrealized gains	20	17
Held to maturity, gross unrealized losses	37	58
Investment securities held-to-maturity	17,439	17,486
US Treasury and federal agencies, mortgage-backed securities
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	11,044	13,340
Available for sale, gross unrealized gains	51	76
Available for sale, gross unrealized losses	95	159
Investment securities available-for-sale	11,000	13,257
Held to maturity, amortized cost	12,375	10,334
Held to maturity, gross unrealized gains	38	20
Held to maturity, gross unrealized losses	169	221
Investment securities held-to-maturity	12,244	10,133
Asset-backed securities, student loans
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	4,795	5,659
Available for sale, gross unrealized gains	39	12
Available for sale, gross unrealized losses	8	75
Investment securities available-for-sale	4,826	5,596
Held to maturity, amortized cost	3,116	2,883
Held to maturity, gross unrealized gains	25	5
Held to maturity, gross unrealized losses	13	30
Investment securities held-to-maturity	3,128	2,858
Asset-backed securities, credit cards
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	1,567	1,377
Available for sale, gross unrealized gains	3	0
Available for sale, gross unrealized losses	22	26
Investment securities available-for-sale	1,548	1,351
Held to maturity, amortized cost	798	897
Held to maturity, gross unrealized gains	3	2
Held to maturity, gross unrealized losses	0	0
Investment securities held-to-maturity	801	899
Asset-backed securities, sub-prime
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	0	289
Available for sale, gross unrealized gains	0	1
Available for sale, gross unrealized losses	0	18
Investment securities available-for-sale	0	272
Asset-backed securities, other
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	1,213	895
Available for sale, gross unrealized gains	8	10
Available for sale, gross unrealized losses	0	0
Investment securities available-for-sale	1,221	905
Held to maturity, amortized cost	1	35
Held to maturity, gross unrealized gains	0	0
Held to maturity, gross unrealized losses	0	0
Investment securities held-to-maturity	1	35
Total asset-backed securities
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	7,575	8,220
Available for sale, gross unrealized gains	50	23
Available for sale, gross unrealized losses	30	119
Investment securities available-for-sale	7,595	8,124
Held to maturity, amortized cost	3,915	3,815
Held to maturity, gross unrealized gains	28	7
Held to maturity, gross unrealized losses	13	30
Investment securities held-to-maturity	3,930	3,792
Non-U.S. debt securities, mortgage-backed securities
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	7,041	6,506
Available for sale, gross unrealized gains	36	35
Available for sale, gross unrealized losses	3	6
Investment securities available-for-sale	7,074	6,535
Held to maturity, amortized cost	1,000	1,150
Held to maturity, gross unrealized gains	84	70
Held to maturity, gross unrealized losses	7	15
Investment securities held-to-maturity	1,077	1,205
Non-U.S. debt securities, asset-backed securities
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	2,833	2,513
Available for sale, gross unrealized gains	6	4
Available for sale, gross unrealized losses	0	1
Investment securities available-for-sale	2,839	2,516
Held to maturity, amortized cost	325	531
Held to maturity, gross unrealized gains	1	0
Held to maturity, gross unrealized losses	0	0
Investment securities held-to-maturity	326	531
Non-U.S. debt securities, Government securities
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	6,666	5,834
Available for sale, gross unrealized gains	8	8
Available for sale, gross unrealized losses	16	6
Investment securities available-for-sale	6,658	5,836
Held to maturity, amortized cost	483	286
Held to maturity, gross unrealized gains	2	3
Held to maturity, gross unrealized losses	0	0
Investment securities held-to-maturity	485	289
Non-U.S. debt securities, other
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	5,783	5,587
Available for sale, gross unrealized gains	39	31
Available for sale, gross unrealized losses	4	5
Investment securities available-for-sale	5,818	5,613
Held to maturity, amortized cost	47	113
Held to maturity, gross unrealized gains	0	1
Held to maturity, gross unrealized losses	0	0
Investment securities held-to-maturity	47	114
Total non-U.S. debt securities
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	22,323	20,440
Available for sale, gross unrealized gains	89	78
Available for sale, gross unrealized losses	23	18
Investment securities available-for-sale	22,389	20,500
Held to maturity, amortized cost	1,855	2,080
Held to maturity, gross unrealized gains	87	74
Held to maturity, gross unrealized losses	7	15
Investment securities held-to-maturity	1,935	2,139
State and political subdivisions
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	9,444	10,233
Available for sale, gross unrealized gains	322	201
Available for sale, gross unrealized losses	28	112
Investment securities available-for-sale	9,738	10,322
Collateralized mortgage obligations
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	1,522	2,610
Available for sale, gross unrealized gains	15	18
Available for sale, gross unrealized losses	9	35
Investment securities available-for-sale	1,528	2,593
Held to maturity, amortized cost	1,249	1,413
Held to maturity, gross unrealized gains	44	42
Held to maturity, gross unrealized losses	5	11
Investment securities held-to-maturity	1,288	1,444
Other U.S. debt securities
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	2,923	2,481
Available for sale, gross unrealized gains	20	18
Available for sale, gross unrealized losses	15	30
Investment securities available-for-sale	2,928	2,469
U.S. equity securities
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	40	39
Available for sale, gross unrealized gains	8	6
Available for sale, gross unrealized losses	2	3
Investment securities available-for-sale	46	42
Non-U.S. equity securities
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	0	3
Available for sale, gross unrealized gains	0	0
Available for sale, gross unrealized losses	0	0
Investment securities available-for-sale	0	3
U.S. money-market mutual funds
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	394	409
Available for sale, gross unrealized gains	0	0
Available for sale, gross unrealized losses	0	0
Investment securities available-for-sale	394	409
Non-U.S. money-market mutual funds
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	0	16
Available for sale, gross unrealized gains	0	0
Available for sale, gross unrealized losses	0	0
Investment securities available-for-sale	$ 0	16
Federal family education loan program
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Federal government credit support guarantee, percentage minimum	97.00%
Collateralized loan obligations
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Investment securities available-for-sale	$ 1,221	905
Non-US debt securities, covered bonds
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Investment securities available-for-sale	3,600	3,769
Non-U.S. debt securities, other
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Investment securities available-for-sale	$ 1,503	$ 988

Investment Securities - Sched55

Investment Securities - Schedule of Gross Pre-Tax Unrealized Losses on Investment Securities (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	$ 13,816	$ 16,928
Available for sale, gross unrealized losses less than 12 months	130	308
Available for sale, fair value 12 months or longer	4,684	7,800
Available for sale, gross unrealized losses 12 months or longer	73	177
Available for sale, fair value total	18,500	24,728
Available for sale, gross unrealized losses total	203	485
Held to maturity, fair value less than 12 months	17,388	17,284
Held-to-maturity, gross, less than 12 months	198	293
Held to maturity, fair value 12 months or longer	1,394	1,899
Held to maturity, gross unrealized losses 12 months or longer	33	42
Held to maturity, fair value total	18,782	19,183
Held to maturity, gross unrealized losses total	231	335
US Treasury and federal agencies, direct obligations
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	0	651
Available for sale, gross unrealized losses less than 12 months	0	8
Available for sale, fair value 12 months or longer	153	180
Available for sale, gross unrealized losses 12 months or longer	1	1
Available for sale, fair value total	153	831
Available for sale, gross unrealized losses total	1	9
Held to maturity, fair value less than 12 months	9,660	8,891
Held-to-maturity, gross, less than 12 months	36	57
Held to maturity, fair value 12 months or longer	77	86
Held to maturity, gross unrealized losses 12 months or longer	1	1
Held to maturity, fair value total	9,737	8,977
Held to maturity, gross unrealized losses total	37	58
US Treasury and federal agencies, mortgage-backed securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	4,382	7,072
Available for sale, gross unrealized losses less than 12 months	51	131
Available for sale, fair value 12 months or longer	1,880	1,114
Available for sale, gross unrealized losses 12 months or longer	44	28
Available for sale, fair value total	6,262	8,186
Available for sale, gross unrealized losses total	95	159
Held to maturity, fair value less than 12 months	6,939	6,838
Held-to-maturity, gross, less than 12 months	152	221
Held to maturity, fair value 12 months or longer	493	0
Held to maturity, gross unrealized losses 12 months or longer	17	0
Held to maturity, fair value total	7,432	6,838
Held to maturity, gross unrealized losses total	169	221
Asset-backed securities, student loans
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	0	54
Available for sale, gross unrealized losses less than 12 months	0	0
Available for sale, fair value 12 months or longer	1,191	3,745
Available for sale, gross unrealized losses 12 months or longer	8	75
Available for sale, fair value total	1,191	3,799
Available for sale, gross unrealized losses total	8	75
Held to maturity, fair value less than 12 months	544	705
Held-to-maturity, gross, less than 12 months	8	9
Held to maturity, fair value 12 months or longer	389	1,235
Held to maturity, gross unrealized losses 12 months or longer	5	21
Held to maturity, fair value total	933	1,940
Held to maturity, gross unrealized losses total	13	30
Asset-backed securities, credit cards
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	499	795
Available for sale, gross unrealized losses less than 12 months	22	1
Available for sale, fair value 12 months or longer	0	494
Available for sale, gross unrealized losses 12 months or longer	0	25
Available for sale, fair value total	499	1,289
Available for sale, gross unrealized losses total	22	26
Held to maturity, fair value less than 12 months		33
Held-to-maturity, gross, less than 12 months		0
Held to maturity, fair value 12 months or longer		0
Held to maturity, gross unrealized losses 12 months or longer		0
Held to maturity, fair value total		33
Held to maturity, gross unrealized losses total		0
Asset-backed securities, sub-prime
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months		1
Available for sale, gross unrealized losses less than 12 months		0
Available for sale, fair value 12 months or longer		252
Available for sale, gross unrealized losses 12 months or longer		18
Available for sale, fair value total		253
Available for sale, gross unrealized losses total		18
Asset-backed securities, other
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months		75
Available for sale, gross unrealized losses less than 12 months		0
Available for sale, fair value 12 months or longer		0
Available for sale, gross unrealized losses 12 months or longer		0
Available for sale, fair value total		75
Available for sale, gross unrealized losses total		0
Held to maturity, fair value less than 12 months		18
Held-to-maturity, gross, less than 12 months		0
Held to maturity, fair value 12 months or longer		9
Held to maturity, gross unrealized losses 12 months or longer		0
Held to maturity, fair value total		27
Held to maturity, gross unrealized losses total		0
Asset-backed securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	499	925
Available for sale, gross unrealized losses less than 12 months	22	1
Available for sale, fair value 12 months or longer	1,191	4,491
Available for sale, gross unrealized losses 12 months or longer	8	118
Available for sale, fair value total	1,690	5,416
Available for sale, gross unrealized losses total	30	119
Held to maturity, fair value less than 12 months	544	756
Held-to-maturity, gross, less than 12 months	8	9
Held to maturity, fair value 12 months or longer	389	1,244
Held to maturity, gross unrealized losses 12 months or longer	5	21
Held to maturity, fair value total	933	2,000
Held to maturity, gross unrealized losses total	13	30
Non-U.S. debt securities, mortgage-backed securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	780	442
Available for sale, gross unrealized losses less than 12 months	2	1
Available for sale, fair value 12 months or longer	569	893
Available for sale, gross unrealized losses 12 months or longer	1	5
Available for sale, fair value total	1,349	1,335
Available for sale, gross unrealized losses total	3	6
Held to maturity, fair value less than 12 months	0	54
Held-to-maturity, gross, less than 12 months	0	2
Held to maturity, fair value 12 months or longer	259	330
Held to maturity, gross unrealized losses 12 months or longer	7	13
Held to maturity, fair value total	259	384
Held to maturity, gross unrealized losses total	7	15
Non-U.S. debt securities, asset-backed securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months		253
Available for sale, gross unrealized losses less than 12 months		0
Available for sale, fair value 12 months or longer		276
Available for sale, gross unrealized losses 12 months or longer		1
Available for sale, fair value total		529
Available for sale, gross unrealized losses total		1
Held to maturity, fair value less than 12 months		28
Held-to-maturity, gross, less than 12 months		0
Held to maturity, fair value 12 months or longer		35
Held to maturity, gross unrealized losses 12 months or longer		0
Held to maturity, fair value total		63
Held to maturity, gross unrealized losses total		0
Government securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	4,965	1,314
Available for sale, gross unrealized losses less than 12 months	16	6
Available for sale, fair value 12 months or longer	0	0
Available for sale, gross unrealized losses 12 months or longer	0	0
Available for sale, fair value total	4,965	1,314
Available for sale, gross unrealized losses total	16	6
Held to maturity, fair value less than 12 months		180
Held-to-maturity, gross, less than 12 months		0
Held to maturity, fair value 12 months or longer		0
Held to maturity, gross unrealized losses 12 months or longer		0
Held to maturity, fair value total		180
Held to maturity, gross unrealized losses total		0
Non-U.S. debt securities, other
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	447	670
Available for sale, gross unrealized losses less than 12 months	3	4
Available for sale, fair value 12 months or longer	229	218
Available for sale, gross unrealized losses 12 months or longer	1	1
Available for sale, fair value total	676	888
Available for sale, gross unrealized losses total	4	5
Total non-U.S. debt securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	6,192	2,679
Available for sale, gross unrealized losses less than 12 months	21	11
Available for sale, fair value 12 months or longer	798	1,387
Available for sale, gross unrealized losses 12 months or longer	2	7
Available for sale, fair value total	6,990	4,066
Available for sale, gross unrealized losses total	23	18
Held to maturity, fair value less than 12 months	0	262
Held-to-maturity, gross, less than 12 months	0	2
Held to maturity, fair value 12 months or longer	259	365
Held to maturity, gross unrealized losses 12 months or longer	7	13
Held to maturity, fair value total	259	627
Held to maturity, gross unrealized losses total	7	15
State and political subdivisions
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	1,052	3,390
Available for sale, gross unrealized losses less than 12 months	15	102
Available for sale, fair value 12 months or longer	525	304
Available for sale, gross unrealized losses 12 months or longer	13	10
Available for sale, fair value total	1,577	3,694
Available for sale, gross unrealized losses total	28	112
Collateralized mortgage obligations
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	550	1,259
Available for sale, gross unrealized losses less than 12 months	7	31
Available for sale, fair value 12 months or longer	56	162
Available for sale, gross unrealized losses 12 months or longer	2	4
Available for sale, fair value total	606	1,421
Available for sale, gross unrealized losses total	9	35
Held to maturity, fair value less than 12 months	245	537
Held-to-maturity, gross, less than 12 months	2	4
Held to maturity, fair value 12 months or longer	176	204
Held to maturity, gross unrealized losses 12 months or longer	3	7
Held to maturity, fair value total	421	741
Held to maturity, gross unrealized losses total	5	11
Other U.S. debt securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	1,141	944
Available for sale, gross unrealized losses less than 12 months	14	24
Available for sale, fair value 12 months or longer	75	157
Available for sale, gross unrealized losses 12 months or longer	1	6
Available for sale, fair value total	1,216	1,101
Available for sale, gross unrealized losses total	15	30
U.S. equity securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	0	8
Available for sale, gross unrealized losses less than 12 months	0	0
Available for sale, fair value 12 months or longer	6	5
Available for sale, gross unrealized losses 12 months or longer	2	3
Available for sale, fair value total	6	13
Available for sale, gross unrealized losses total	$ 2	$ 3

Investment Securities - Sched56

Investment Securities - Schedule of Contractual Maturities of Debt Securities (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 Year	$ 7,471
Available for sale, 1 to 5 Years	20,298
Available for sale, 6 to 10 Years	16,230
Available for sale, over 10 Years	11,799
Available-for-sale, fair value	55,798
Held to maturity, under 1 Year	2,722
Held to maturity, 1 to 5 Years	17,329
Held to maturity, 6 to 10 Years	2,161
Held to maturity, over 10 Years	14,638
Held to maturity, amortized cost	36,850	$ 35,169
US Treasury and federal agencies, direct obligations
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 Year	232
Available for sale, 1 to 5 Years	7
Available for sale, 6 to 10 Years	55
Available for sale, over 10 Years	326
Available-for-sale, fair value	620
Held to maturity, under 1 Year	1,827
Held to maturity, 1 to 5 Years	15,552
Held to maturity, 6 to 10 Years	14
Held to maturity, over 10 Years	63
Held to maturity, amortized cost	17,456	17,527
US Treasury and federal agencies, mortgage-backed securities
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 Year	270
Available for sale, 1 to 5 Years	1,311
Available for sale, 6 to 10 Years	3,424
Available for sale, over 10 Years	5,995
Available-for-sale, fair value	11,000
Held to maturity, under 1 Year	0
Held to maturity, 1 to 5 Years	172
Held to maturity, 6 to 10 Years	1,427
Held to maturity, over 10 Years	10,776
Held to maturity, amortized cost	12,375	10,334
Asset-backed securities, student loans
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 Year	408
Available for sale, 1 to 5 Years	1,634
Available for sale, 6 to 10 Years	1,159
Available for sale, over 10 Years	1,625
Available-for-sale, fair value	4,826
Held to maturity, under 1 Year	87
Held to maturity, 1 to 5 Years	240
Held to maturity, 6 to 10 Years	298
Held to maturity, over 10 Years	2,491
Held to maturity, amortized cost	3,116	2,883
Asset-backed securities, credit cards
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 Year	0
Available for sale, 1 to 5 Years	1,296
Available for sale, 6 to 10 Years	252
Available for sale, over 10 Years	0
Available-for-sale, fair value	1,548
Held to maturity, under 1 Year	178
Held to maturity, 1 to 5 Years	620
Held to maturity, 6 to 10 Years	0
Held to maturity, over 10 Years	0
Held to maturity, amortized cost	798	897
Asset-backed securities, other
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 Year	0
Available for sale, 1 to 5 Years	120
Available for sale, 6 to 10 Years	1,101
Available for sale, over 10 Years	0
Available-for-sale, fair value	1,221
Held to maturity, under 1 Year	0
Held to maturity, 1 to 5 Years	0
Held to maturity, 6 to 10 Years	0
Held to maturity, over 10 Years	1
Held to maturity, amortized cost	1	35
Total asset-backed securities
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 Year	408
Available for sale, 1 to 5 Years	3,050
Available for sale, 6 to 10 Years	2,512
Available for sale, over 10 Years	1,625
Available-for-sale, fair value	7,595
Held to maturity, under 1 Year	265
Held to maturity, 1 to 5 Years	860
Held to maturity, 6 to 10 Years	298
Held to maturity, over 10 Years	2,492
Held to maturity, amortized cost	3,915	3,815
Non-U.S. debt securities, mortgage-backed securities
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 Year	837
Available for sale, 1 to 5 Years	4,128
Available for sale, 6 to 10 Years	1,046
Available for sale, over 10 Years	1,063
Available-for-sale, fair value	7,074
Held to maturity, under 1 Year	173
Held to maturity, 1 to 5 Years	221
Held to maturity, 6 to 10 Years	49
Held to maturity, over 10 Years	557
Held to maturity, amortized cost	1,000	1,150
Non-U.S. debt securities, asset-backed securities
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 Year	395
Available for sale, 1 to 5 Years	2,182
Available for sale, 6 to 10 Years	262
Available for sale, over 10 Years	0
Available-for-sale, fair value	2,839
Held to maturity, under 1 Year	84
Held to maturity, 1 to 5 Years	241
Held to maturity, 6 to 10 Years	0
Held to maturity, over 10 Years	0
Held to maturity, amortized cost	325	531
Government securities
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 Year	3,000
Available for sale, 1 to 5 Years	2,288
Available for sale, 6 to 10 Years	1,370
Available for sale, over 10 Years	0
Available-for-sale, fair value	6,658
Held to maturity, under 1 Year	364
Held to maturity, 1 to 5 Years	119
Held to maturity, 6 to 10 Years	0
Held to maturity, over 10 Years	0
Held to maturity, amortized cost	483	286
Non-U.S. debt securities, other
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 Year	1,485
Available for sale, 1 to 5 Years	3,607
Available for sale, 6 to 10 Years	726
Available for sale, over 10 Years	0
Available-for-sale, fair value	5,818
Held to maturity, under 1 Year	0
Held to maturity, 1 to 5 Years	47
Held to maturity, 6 to 10 Years	0
Held to maturity, over 10 Years	0
Held to maturity, amortized cost	47	113
Total non-U.S. debt securities
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 Year	5,717
Available for sale, 1 to 5 Years	12,205
Available for sale, 6 to 10 Years	3,404
Available for sale, over 10 Years	1,063
Available-for-sale, fair value	22,389
Held to maturity, under 1 Year	621
Held to maturity, 1 to 5 Years	628
Held to maturity, 6 to 10 Years	49
Held to maturity, over 10 Years	557
Held to maturity, amortized cost	1,855	2,080
State and political subdivisions
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 Year	433
Available for sale, 1 to 5 Years	2,525
Available for sale, 6 to 10 Years	5,020
Available for sale, over 10 Years	1,760
Available-for-sale, fair value	9,738
Collateralized mortgage obligations
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 Year	7
Available for sale, 1 to 5 Years	148
Available for sale, 6 to 10 Years	343
Available for sale, over 10 Years	1,030
Available-for-sale, fair value	1,528
Held to maturity, under 1 Year	9
Held to maturity, 1 to 5 Years	117
Held to maturity, 6 to 10 Years	373
Held to maturity, over 10 Years	750
Held to maturity, amortized cost	1,249	$ 1,413
Other U.S. debt securities
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 Year	404
Available for sale, 1 to 5 Years	1,052
Available for sale, 6 to 10 Years	1,472
Available for sale, over 10 Years	0
Available-for-sale, fair value	$ 2,928

Investment Securities - Sched57

Investment Securities - Schedule of Credit-Related Loss Activity Recognized In Earnings (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Balance, beginning of period	$ 66	$ 92
Losses for which OTTI was previously recognized	0	2
Previously recognized losses related to securities sold or matured	(2)	(26)
Balance, end of period	$ 64	$ 68

Loans and Leases - Narrative (D

Loans and Leases - Narrative (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2017USD ($)loan	Dec. 31, 2016USD ($)loan
Financing Receivable, Recorded Investment [Line Items]
Loans and leases pledged as collateral | $	$ 1,700,000,000	$ 1,500,000,000
Allowance for loan and lease losses | $	$ 57,000,000	$ 53,000,000
Loans modified in troubled debt restructurings | loan	0	0
Number of loans on non-accrual status | loan	0
Loans more than 90 days past due | loan	0	0
Commercial and Financial
Financing Receivable, Recorded Investment [Line Items]
Number of loans on non-accrual status | loan		1
Commercial and Financial | Senior Secured Bank Loans
Financing Receivable, Recorded Investment [Line Items]
Number of impaired loans and leases | loan	0	1
Recorded Investment | $		$ 15,000,000
Unpaid Principal Balance | $		15,000,000
Interest Income Recognized | $		0
Allowance for loan and lease losses | $	$ 0	$ 195,000
Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Number of loans on non-accrual status | loan		0

Loans and Leases - Net Loans (D

Loans and Leases - Net Loans (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	$ 23,638	$ 19,757
Allowance for loan and lease losses	(57)	(53)
Loans and leases, net of allowance	23,581	19,704
Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to investment funds	12,886	11,734
Senior secured bank loans	3,377	3,256
Loans to municipalities	1,955	1,352
Other	55	70
Commercial real estate	0	27
Lease financing	283	338
Total loans and leases	18,556	16,777
Non-U.S.
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to investment funds	4,138	2,224
Senior secured bank loans	514	252
Lease financing	430	504
Total loans and leases	$ 5,082	$ 2,980

Loans and Leases - Recorded Inv

Loans and Leases - Recorded Investment in Each Class of Total Loans and Leases by Credit Quality Indicator (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	$ 23,638	$ 19,757
Commercial and Financial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	22,925	18,888
Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	27
Lease Financing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	713	842
Investment grade
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	18,983	15,758
Investment grade | Commercial and Financial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	18,270	14,889
Investment grade | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	27
Investment grade | Lease Financing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	713	842
Speculative
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	4,655	3,984
Speculative | Commercial and Financial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	4,655	3,984
Speculative | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
Speculative | Lease Financing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	$ 0	0
Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases		15
Substandard | Commercial and Financial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases		15
Substandard | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases		0
Substandard | Lease Financing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases		$ 0

Loans and Leases - Schedule of

Loans and Leases - Schedule of Allowance for Loan Losses (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	$ 23,638,000	$ 19,757,000
Loans and leases, allowance for losses	57,000	53,000
Commercial and Financial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	22,925,000	18,888,000
Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	27,000
Lease Financing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	713,000	842,000
Individually evaluated for impairment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	15,000
Individually evaluated for impairment | Commercial and Financial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	15,000
Individually evaluated for impairment | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
Individually evaluated for impairment | Lease Financing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
Collectively evaluated for impairment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	23,638,000	19,742,000
Collectively evaluated for impairment | Commercial and Financial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	22,925,000	18,873,000
Collectively evaluated for impairment | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	27,000
Collectively evaluated for impairment | Lease Financing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	713,000	842,000
Senior Secured Bank Loans | Commercial and Financial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, allowance for losses	$ 0	$ 195

Loans and Leases - Schedule o62

Loans and Leases - Schedule of Activity In The Allowance For Loan Losses (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$ 54	$ 51	$ 53	$ 46
Provision for loan and lease losses	3	0	4	8
Charge-offs	0	0	0	(3)
Ending balance	$ 57	$ 51	$ 57	$ 51

Goodwill and Other Intangible63

Goodwill and Other Intangible Assets - Changes In The Carrying Amount Of Goodwill (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Goodwill [Roll Forward]
Beginning balance January 1, 2016	$ 5,814	$ 5,671
Acquisitions	17	236
Divestitures and other reductions	(9)	(11)
Foreign currency translation	175	(82)
Ending balance December 31, 2016	5,997	5,814
Investment Servicing
Goodwill [Roll Forward]
Beginning balance January 1, 2016	5,550	5,641
Acquisitions	17	0
Divestitures and other reductions	(9)	(11)
Foreign currency translation	170	(80)
Ending balance December 31, 2016	5,728	5,550
Investment Management
Goodwill [Roll Forward]
Beginning balance January 1, 2016	264	30
Acquisitions	0	236
Divestitures and other reductions	0	0
Foreign currency translation	5	(2)
Ending balance December 31, 2016	$ 269	$ 264

Goodwill and Other Intangible64

Goodwill and Other Intangible Assets - Changes In The Carrying Amount Of Other Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Finite-lived Intangible Assets [Roll Forward]
Beginning balance			$ 1,750	$ 1,768	$ 1,768
Acquisitions			16		217
Divestitures			(11)		(8)
Amortization	$ (54)	$ (55)	(160)	(153)	(207)
Foreign currency translation and other, net			63		(20)
Ending balance	1,658		1,658		1,750
Investment Servicing
Finite-lived Intangible Assets [Roll Forward]
Beginning balance			1,539	1,753	1,753
Acquisitions			16		0
Divestitures			(11)		(8)
Amortization			(137)		(186)
Foreign currency translation and other, net			63		(20)
Ending balance	1,470		1,470		1,539
Investment Management
Finite-lived Intangible Assets [Roll Forward]
Beginning balance			211	$ 15	15
Acquisitions			0		217
Divestitures			0		0
Amortization			(23)		(21)
Foreign currency translation and other, net			0		0
Ending balance	$ 188		$ 188		$ 211

Goodwill and Other Intangible65

Goodwill and Other Intangible Assets - Gross Carrying Amount, Accumulated Amortization And Net Carrying Amount Of Other Intangible Assets (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 3,478	$ 3,413
Accumulated Amortization	(1,820)	(1,663)
Net Carrying Amount	1,658	1,750	$ 1,768
Client relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	2,654	2,620
Accumulated Amortization	(1,418)	(1,306)
Net Carrying Amount	1,236	1,314
Core deposits
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	683	661
Accumulated Amortization	(311)	(277)
Net Carrying Amount	372	384
Other
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	141	132
Accumulated Amortization	(91)	(80)
Net Carrying Amount	$ 50	$ 52

Other Assets (Details)

Other Assets (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Other Assets [Abstract]
Receivable - securities lending	$ 23,628	$ 21,204
Derivative instruments, net	4,712	7,321
Bank-owned life insurance	3,219	3,158
Investments in joint ventures and other unconsolidated entities	2,099	2,363
Collateral, net	902	2,236
Accounts receivable	393	886
Prepaid expenses	422	333
Receivable for securities settlement	441	40
Income taxes receivable	368	106
Deferred tax assets, net of valuation allowance	213	210
Deposits with clearing organizations	125	132
Other	435	339
Total	$ 36,957	$ 38,328

Derivative Financial Instrume67

Derivative Financial Instruments - Narrative (Details) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2017USD ($)security	Dec. 31, 2016USD ($)
Derivative [Line Items]
Cash collateral received for derivative instruments	$ 1,180	$ 1,990
Cash collateral provided for derivative instruments	1,850	4,390
Fair value of derivative liabilities	$ 12,009	$ 16,684
Weighted average life of trusts	4 years 4 months 17 days	4 years 6 months
LIBOR Indexed Floating Rate Loans
Derivative [Line Items]
Debt Instrument, Term	5 years
Credit swap agreements
Derivative [Line Items]
Fair value of derivative liabilities	$ 1,940
Fair value of collateral posted	0
Maximum additional amount of payments related to termination events	$ 1,940
Interest rate swap | Fair Value Hedges | Senior notes
Derivative [Line Items]
Number of securities | security	8
Interest rate swap | Fair Value Hedges | Subordinated note
Derivative [Line Items]
Number of securities | security	1

Derivative Financial Instrume68

Derivative Financial Instruments - Schedule of Interest Rate Derivatives (Details) - Interest rate swap - Fair Value Hedges	Sep. 30, 2017
Senior notes | 1.35% notes due 2018
Derivative [Line Items]
Fixed interest rate	2.55%
Senior notes | 2.55% notes due 2020
Derivative [Line Items]
Fixed interest rate	4.375%
Senior notes | 1.95% Notes Due 2021
Derivative [Line Items]
Fixed interest rate	1.95%
Senior notes | 4.38% note due 2021
Derivative [Line Items]
Fixed interest rate	2.653%
Senior notes | 3.70% notes due in 2023
Derivative [Line Items]
Fixed interest rate	3.70%
Senior notes | 3.30% notes due 2024
Derivative [Line Items]
Fixed interest rate	3.30%
Senior notes | 3.55% notes due 2025
Derivative [Line Items]
Fixed interest rate	3.55%
Senior notes | 2.65% notes due 2026
Derivative [Line Items]
Fixed interest rate	2.65%
Subordinated note | 3.10% subordinated note due 2023
Derivative [Line Items]
Fixed interest rate	3.10%

Derivative Financial Instrume69

Derivative Financial Instruments - Schedule of Outstanding Hedges: (Notional Amount) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Sep. 30, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of derivatives		$ 10,616
Additional compensation and employee benefits expense due to accelerated vesting	$ 249
Derivatives not designated as hedging instruments | Interest-rate contracts | Futures
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of derivatives	13,455	14,262
Derivatives not designated as hedging instruments | Foreign exchange contracts | Futures
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of derivatives	0	0
Derivatives not designated as hedging instruments | Foreign exchange contracts | Forward, swap and spot
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of derivatives	1,414,765	1,618,670
Derivatives not designated as hedging instruments | Foreign exchange contracts | Options purchased
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of derivatives	337	455
Derivatives not designated as hedging instruments | Foreign exchange contracts | Options written
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of derivatives	202	262
Derivatives not designated as hedging instruments | Other contracts | Stable value contracts
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of derivatives	27,182	25,351
Derivatives not designated as hedging instruments | Other contracts | Deferred value awards
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of derivatives	409	531
Derivatives designated as hedging instruments | Interest-rate contracts | Swap agreements
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of derivatives	10,169	10,616
Derivatives designated as hedging instruments | Foreign exchange contracts | Forward and swap
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of derivatives	$ 8,564	$ 27,429

Derivative Financial Instrume70

Derivative Financial Instruments - Notional Amount of Interest Rate Swap Agreements Designated as Fair Value and Cash Flow Hedges (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Derivative [Line Items]
Total	$ 10,616
Investment securities available-for-sale
Derivative [Line Items]
Investment securities available-for-sale	1,323
Long-term debt
Derivative [Line Items]
Long-term debt	8,493
Floating-rate loans
Derivative [Line Items]
Long-term debt	800
Fair Value Hedges
Derivative [Line Items]
Total	9,816	$ 10,169
Increase in carrying value of long-term debt	(1)	(15)
Fair Value Hedges | Investment securities available-for-sale
Derivative [Line Items]
Investment securities available-for-sale	1,323	1,444
Fair Value Hedges | Long-term debt
Derivative [Line Items]
Long-term debt	8,493	$ 8,725
Fair Value Hedges | Floating-rate loans
Derivative [Line Items]
Long-term debt	0
Cash Flow Hedges
Derivative [Line Items]
Total	800
Cash Flow Hedges | Investment securities available-for-sale
Derivative [Line Items]
Investment securities available-for-sale	0
Cash Flow Hedges | Long-term debt
Derivative [Line Items]
Long-term debt	0
Cash Flow Hedges | Floating-rate loans
Derivative [Line Items]
Long-term debt	$ 800

Derivative Financial Instrume71

Derivative Financial Instruments - Contractual and Weighted-Average Interest Rates, Which Include the Effects of Hedges Related to Financial Instruments (Details) - Long-term debt	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Derivative [Line Items]
Contractual rates	3.30%	3.37%	3.353%	3.41%
Rate including impact of hedges	2.67%	2.27%	2.61%	2.24%

Derivative Financial Instrume72

Derivative Financial Instruments - Schedule of The Fair Values of Derivative Financial Instruments (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	$ 11,740	$ 16,552
Fair value of derivative liabilities	12,009	16,684
Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	11,737	16,484
Fair value of derivative liabilities	11,583	15,956
Interest-rate contracts
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	3	68
Fair value of derivative liabilities	107	348
Derivatives not designated as hedging instruments | Other Assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	11,667	15,982
Derivatives not designated as hedging instruments | Other liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	11,825	16,261
Derivatives not designated as hedging instruments | Foreign exchange contracts | Other Assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	11,667	15,982
Derivatives not designated as hedging instruments | Foreign exchange contracts | Other liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	11,506	15,881
Derivatives not designated as hedging instruments | Other derivative contracts | Other liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	319	380
Derivatives designated as hedging instruments | Other Assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	73	570
Derivatives designated as hedging instruments | Other liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	184	423
Derivatives designated as hedging instruments | Foreign exchange contracts | Other Assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	70	502
Derivatives designated as hedging instruments | Foreign exchange contracts | Other liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	77	75
Derivatives designated as hedging instruments | Interest-rate contracts | Other Assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	3	68
Derivatives designated as hedging instruments | Interest-rate contracts | Other liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	$ 107	$ 348

Derivative Financial Instrume73

Derivative Financial Instruments - Impact of Derivatives on Consolidated Statement of Income (Details) - Derivatives not designated as hedging instruments - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	$ 116	$ 199	$ 361	$ 624
Foreign exchange contracts | Trading services
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	152	161	485	477
Foreign exchange contracts | Processing fees and other revenue
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	(9)	(3)	(11)	(13)
Interest-rate contracts | Trading services
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	(2)	(1)	7	(6)
Interest-rate contracts | Processing fees and other revenue
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	0	0	0	1
Credit derivative contracts | Trading services
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	0	0	0	(1)
Other derivative contracts | Trading services
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	0	1	0	(2)
Other derivative contracts | Compensation and employee benefits
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	$ (25)	$ 41	$ (120)	$ 168

Derivative Financial Instrume74

Derivative Financial Instruments - Schedule of Differences Between the Gains (Losses) on the Derivative and The Gains (Losses) on the Hedged Item (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Derivative [Line Items]
Net unrealized gains (losses) on available-for-sale securities designated in fair value hedges, net of related taxes	$ (4)	$ (13)	$ (13)	$ 9
Derivatives designated as hedging instruments | Fair Value Hedges
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	220	(32)	1,363	572
Gain (loss) on fair value hedges recognized in earnings	(223)	31	(1,363)	(557)
Derivatives designated as hedging instruments | Fair Value Hedges | Investment securities available-for-sale | Foreign exchange contracts | Processing fees and other revenue
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	19	24	21	43
Gain (loss) on fair value hedges recognized in earnings	(19)	(24)	(21)	(43)
Derivatives designated as hedging instruments | Fair Value Hedges | Investment securities available-for-sale | Interest-rate contracts | Processing fees and other revenue
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	9	22	23	(15)
Gain (loss) on fair value hedges recognized in earnings	(9)	(22)	(21)	15
Derivatives designated as hedging instruments | Fair Value Hedges | Deposits | Foreign exchange contracts | Processing fees and other revenue
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	200	1	1,282	247
Gain (loss) on fair value hedges recognized in earnings	(200)	(1)	(1,282)	(247)
Derivatives designated as hedging instruments | Fair Value Hedges | Long-term debt | Interest-rate contracts | Processing fees and other revenue
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	(8)	(79)	37	297
Gain (loss) on fair value hedges recognized in earnings	5	78	(39)	(282)
Derivatives designated as hedging instruments | Cash Flow Hedges
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	5	6	18	17
Gain (loss) on derivative recognized in OCI	(2)	(65)	(95)	(293)
Gain (loss) on hedges reclassified to income	0	0	0	0
Derivatives designated as hedging instruments | Cash Flow Hedges | Foreign exchange contracts
Derivative [Line Items]
Gain (loss) on derivative recognized in OCI	(1)	(65)	(93)	(293)
Derivatives designated as hedging instruments | Cash Flow Hedges | Foreign exchange contracts | Net interest revenue
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	5	6	18	17
Gain (loss) on hedges reclassified to income	0	0	0	0
Derivatives designated as hedging instruments | Cash Flow Hedges | Interest-rate contracts
Derivative [Line Items]
Gain (loss) on derivative recognized in OCI	(1)	0	(2)	0
Derivatives designated as hedging instruments | Cash Flow Hedges | Interest-rate contracts | Net interest revenue
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	0	0	0	0
Gain (loss) on hedges reclassified to income	0	0	0	0
Derivatives designated as hedging instruments | Investment Hedges
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	0	0	0	0
Gain (loss) on derivative recognized in OCI	(47)	4	(148)	55
Gain (loss) on hedges reclassified to income	0	0	0	0
Derivatives designated as hedging instruments | Investment Hedges | Foreign exchange contracts
Derivative [Line Items]
Gain (loss) on derivative recognized in OCI	(47)	4	(148)	55
Derivatives designated as hedging instruments | Investment Hedges | Foreign exchange contracts | Gains (Losses) related to investment securities, net
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	0	0	0	0
Gain (loss) on hedges reclassified to income	$ 0	$ 0	$ 0	$ 0

Offsetting Arrangements - Narra

Offsetting Arrangements - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Offsetting [Abstract]
Fair Value of securities received as collateral that can be resold or repledged	$ 2,960	$ 1,770
Fair Value of securities received as collateral that have been resold or repledged	$ 41.2	$ 166

Offsetting Arrangements - Asset

Offsetting Arrangements - Assets With Offsetting Arrangements (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Offsetting Assets [Line Items]
Derivatives, Gross Amounts of Recognized Assets	$ 11,740	$ 16,552
Derivatives, Gross Amounts Offset in Statement of Condition	(7,028)	(9,231)
Derivatives, Net Amounts of Assets Presented in Statement of Condition	4,712	7,321
Derivatives, Net Amount	4,606	7,074
Derivatives, Cash collateral and securities netting, offset	(637)	(906)
Derivatives, Cash collateral and securities netting, Cash and Securities Received	(106)	(247)
Derivatives, Cash collateral and securities netting, Net	(743)	(1,153)
Resale agreements and securities borrowing, Gross Amounts of Recognized Assets	63,821	58,677
Resale agreements and securities borrowing, Gross Amounts Offset in Statement of Condition	(36,728)	(35,517)
Resale agreements and securities borrowing, Net Amounts of Assets Presented in Statement of Condition	27,093	23,160
Resale agreements and securities borrowing, Cash and Securities Received	(27,093)	(22,939)
Resale agreements and securities borrowing, Net Amount	0	221
Total derivatives and other financial instruments, Gross Amounts of Recognized Assets	75,561	75,229
Total derivatives and other financial instruments, Gross Amounts Offset in Statement of Condition	(43,756)	(44,748)
Total derivatives and other financial instruments, Net Amounts of Assets Presented in Statement of Condition	31,805	30,481
Total derivatives and other financial instruments, Cash and Securities Received(5)	(27,199)	(23,186)
Total derivatives and other financial instruments, Net Amount	4,606	7,295
Securities purchased under resale agreements	3,465	1,956
Securities borrowed subject to master netting arrangements	(23,628)	(21,204)
Foreign exchange contracts
Offsetting Assets [Line Items]
Derivatives, Gross Amounts of Recognized Assets	11,737	16,484
Derivatives, Gross Amounts Offset in Statement of Condition	(6,389)	(8,257)
Derivatives, Net Amounts of Assets Presented in Statement of Condition	5,348	8,227
Derivatives, Net Amount	5,348	8,227
Interest-rate contracts
Offsetting Assets [Line Items]
Derivatives, Gross Amounts of Recognized Assets	3	68
Derivatives, Gross Amounts Offset in Statement of Condition	(2)	(68)
Derivatives, Net Amounts of Assets Presented in Statement of Condition	1	0
Derivatives, Net Amount	$ 1	$ 0

Offsetting Arrangements - Liabi

Offsetting Arrangements - Liabilities With Offsetting Arrangements (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Offsetting Liabilities [Line Items]
Derivatives, Gross amounts of recognized liabilities	$ 12,009	$ 16,684
Derivatives, Gross amounts offset in statement of condition	(7,465)	(10,682)
Derivatives, Net Amounts of Liabilities Presented in Statement of Condition	4,544	6,002
Derivative, Net Amount	4,282	5,822
Derivatives, Cash and collateral securities netting, offset	(1,074)	(2,356)
Derivatives, Cash and collateral securities netting, Cash and Securities Provided	(262)	(180)
Derivatives, Cash and collateral securities netting, Net	(1,336)	(2,536)
Resale agreements and securities lending, Gross Amounts of Recognized Liabilities(1)(2)	45,864	44,933
Resale agreements and securities lending, Gross Amounts Offset in Statement of Condition(3)	(36,728)	(35,517)
Resale agreements and securities lending, Net Amounts of Liabilities Presented in Statement of Condition	9,136	9,416
Resale agreements and securities lending, Cash and Securities Provided	(6,564)	(7,059)
Resale agreements and securities lending, Net Amount	2,572	2,357
Total derivatives and other financial instruments, Gross Amounts of Recognized Liabilities	57,873	61,617
Total derivatives and other financial instruments, Gross Amounts Offset in Statement of Condition	(44,193)	(46,199)
Total derivatives and other financial instruments, Net Amounts of Liabilities Presented in Statement of Condition	13,680	15,418
Total derivatives and other financial instruments, Cash and Securities Provided	(6,826)	(7,239)
Total derivatives and other financial instruments, Net Amount	6,854	8,179
Securities sold under repurchase agreements	3,867	4,400
Securities lending, fair value, amount not offset against collateral	5,269	5,016
Foreign exchange contracts
Offsetting Liabilities [Line Items]
Derivatives, Gross amounts of recognized liabilities	11,583	15,956
Derivatives, Gross amounts offset in statement of condition	(6,390)	(8,253)
Derivatives, Net Amounts of Liabilities Presented in Statement of Condition	5,193	7,703
Derivative, Net Amount	5,193	7,703
Interest-rate contracts
Offsetting Liabilities [Line Items]
Derivatives, Gross amounts of recognized liabilities	107	348
Derivatives, Gross amounts offset in statement of condition	(1)	(73)
Derivatives, Net Amounts of Liabilities Presented in Statement of Condition	106	275
Derivative, Net Amount	106	275
Other derivative contracts
Offsetting Liabilities [Line Items]
Derivatives, Gross amounts of recognized liabilities	319	380
Derivatives, Gross amounts offset in statement of condition	0	0
Derivatives, Net Amounts of Liabilities Presented in Statement of Condition	319	380
Derivative, Net Amount	$ 319	$ 380

Offsetting Arrangements - Repo,

Offsetting Arrangements - Repo, Sec Lending Transactions Maturity By Category (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements	$ 35,009	$ 35,509
Securities lending transactions	10,855	9,424
Gross amount of recognized liabilities for repurchase agreements and securities lending	45,864	44,933
Overnight and Continuous
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements	35,009	35,509
Securities lending transactions	10,558	8,390
Gross amount of recognized liabilities for repurchase agreements and securities lending	45,567	43,899
Up to 30 days
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements	0	0
Securities lending transactions	0	0
Gross amount of recognized liabilities for repurchase agreements and securities lending	0	0
30 – 90 days
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements	0	0
Securities lending transactions	297	1,034
Gross amount of recognized liabilities for repurchase agreements and securities lending	297	1,034
U.S. Treasury and agency securities
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements	35,009	35,509
U.S. Treasury and agency securities | Overnight and Continuous
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements	35,009	35,509
U.S. Treasury and agency securities | Up to 30 days
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements		0
U.S. Treasury and agency securities | 30 – 90 days
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements		0
Corporate debt securities
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions	103	53
Corporate debt securities | Overnight and Continuous
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions	103	53
Corporate debt securities | Up to 30 days
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions		0
Corporate debt securities | 30 – 90 days
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions		0
Equity securities
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions	10,730	9,371
Equity securities | Overnight and Continuous
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions	10,433	8,337
Equity securities | Up to 30 days
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions		0
Equity securities | 30 – 90 days
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions	297	$ 1,034
Non-U.S. sovereign debt
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions	22
Non-U.S. sovereign debt | Overnight and Continuous
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions	22
Non-U.S. sovereign debt | Up to 30 days
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions
Non-U.S. sovereign debt | 30 – 90 days
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions

Commitments and Guarantees - Na

Commitments and Guarantees - Narrative (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Loss Contingencies [Line Items]
Unfunded commitments to extend credit, short term	73.00%
Term of unfunded commitment	1 year
Cash collateral provided for securities lending	$ 23,630	$ 21,200
Accrued expenses and other liabilities
Loss Contingencies [Line Items]
Cash collateral received in connection to securities finance activities	$ 5,270	$ 5,020

Commitments and Guarantees - Co

Commitments and Guarantees - Contractual Amounts of Credit-Related Off-Balance Sheet Financial Instruments (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Unfunded commitments to extend credit	$ 27,008	$ 26,993
Indemnified securities financing	379,459	360,452
Stable value protection	25,351	27,182
Standby letters of credit	$ 3,255	$ 3,459

Commitments and Guarantees - Sc

Commitments and Guarantees - Schedule Of Repurchase Agreements (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Fair value of indemnified securities financing	$ 379,459	$ 360,452
Fair value of cash and securities held by us, as agent, as collateral for indemnified securities financing	396,123	377,919
Fair value of collateral for indemnified securities financing invested in indemnified repurchase agreements	68,243	60,003
Fair value of cash and securities held by us or our agents as collateral for investments in indemnified repurchase agreements	$ 73,157	$ 63,959

Contingencies - Narrative (Deta

Contingencies - Narrative (Details) £ in Millions	Jan. 18, 2017USD ($)	Sep. 30, 2017USD ($)	Jan. 31, 2014USD ($)	Jan. 31, 2014GBP (£)	Dec. 31, 2016USD ($)
Loss Contingencies [Line Items]
Unrecognized tax benefits		$ 63,000,000			$ 71,000,000
Minimum
Loss Contingencies [Line Items]
Estimate of possible loss		0
Maximum
Loss Contingencies [Line Items]
Estimate of possible loss		15,000,000
Legal Reserve | Invoicing Matter
Loss Contingencies [Line Items]
Estimate of possible loss		340,000,000
U.K. FCA | Regulatory Matter | Transition Management
Loss Contingencies [Line Items]
Settlement, amount			$ 37,800,000	£ 22.9
Department of Justice | Regulatory Matter | Transition Management
Loss Contingencies [Line Items]
Settlement, amount	$ 32,300,000
SEC | Regulatory Matter | Transition Management
Loss Contingencies [Line Items]
Settlement, amount		$ 32,300,000

Variable Interest Entities (Det

Variable Interest Entities (Details) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Investment securities related to state and political subdivisions	$ 1,290,000,000	$ 1,350,000,000
Variable interest entity, other short-term borrowings	$ 1,100,000,000	$ 1,160,000,000
Weighted average life of trusts	4 years 4 months 17 days	4 years 6 months
Total standby bond-purchase agreement committed to trusts	$ 1,120,000,000
Total letters of credit committed to trusts	351,000,000
Standby purchase agreements and letters of credit commitments utilized	0
VIE - primary beneficiary
Variable Interest Entity [Line Items]
Assets	119,820,000	$ 0
Liabilities	19,440,000
Potential maximum loss exposure of unconsolidated funds	100,000,000
VIE - not primary beneficiary
Variable Interest Entity [Line Items]
Potential maximum loss exposure of unconsolidated funds	$ 79,000,000	$ 121,000,000

Shareholders' Equity - Schedule

Shareholders' Equity - Schedule of Preferred Shares Outstanding (Details) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Class of Stock [Line Items]
Proceeds from issuance of preferred stock, net	$ 0	$ 493
Series C Preferred Stock, Depository Share
Class of Stock [Line Items]
Depositary shares issued (shares)	20,000,000
Liquidation preference per share (USD per share)	$ 25
Series C Preferred Stock
Class of Stock [Line Items]
Ownership Interest Per Depositary Share	0.025%
Liquidation preference per share (USD per share)	$ 100,000
Proceeds from issuance of preferred stock, net	$ 488
Series D Preferred Stock, Depository Share
Class of Stock [Line Items]
Depositary shares issued (shares)	30,000,000
Liquidation preference per share (USD per share)	$ 25
Series D Preferred Stock
Class of Stock [Line Items]
Ownership Interest Per Depositary Share	0.025%
Liquidation preference per share (USD per share)	$ 100,000
Proceeds from issuance of preferred stock, net	$ 742
Series E Preferred Stock, Depository Share
Class of Stock [Line Items]
Depositary shares issued (shares)	30,000,000
Liquidation preference per share (USD per share)	$ 25
Series E Preferred Stock
Class of Stock [Line Items]
Ownership Interest Per Depositary Share	0.025%
Liquidation preference per share (USD per share)	$ 100,000
Proceeds from issuance of preferred stock, net	$ 728
Series F Preferred Stock, Depository Share
Class of Stock [Line Items]
Depositary shares issued (shares)	750,000
Liquidation preference per share (USD per share)	$ 1,000
Series F Preferred Stock
Class of Stock [Line Items]
Ownership Interest Per Depositary Share	1.00%
Liquidation preference per share (USD per share)	$ 100,000
Proceeds from issuance of preferred stock, net	$ 742
Series G Preferred Stock, Depository Share
Class of Stock [Line Items]
Depositary shares issued (shares)	20,000,000
Liquidation preference per share (USD per share)	$ 25
Series G Preferred Stock
Class of Stock [Line Items]
Ownership Interest Per Depositary Share	0.025%
Liquidation preference per share (USD per share)	$ 100,000
Proceeds from issuance of preferred stock, net	$ 493

Shareholders' Equity - Schedu85

Shareholders' Equity - Schedule of Dividends Declared (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Oct. 31, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Dividends Payable [Line Items]
Preferred stock cash dividend		$ 55	$ 55	$ 146	$ 137
Common Stock Dividends Declared (in USD per share)		$ 0.42	$ 0.38	$ 1.18	$ 1.06
Common Stock Dividends		$ 156	$ 147	$ 442	$ 414
Series C Preferred Stock
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)		$ 1,313	$ 1,313	$ 3,939	$ 3,939
Preferred stock cash dividend		$ 6	$ 6	$ 19	$ 19
Series C Preferred Stock, Depository Share
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)		$ 0.33	$ 0.33	$ 0.99	$ 0.99
Series D Preferred Stock
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)		$ 1,475	$ 1,475	$ 4,425	$ 4,425
Preferred stock cash dividend		$ 11	$ 11	$ 33	$ 33
Series D Preferred Stock, Depository Share
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)		$ 0.37	$ 0.37	$ 1.11	$ 1.11
Series E Preferred Stock
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)		$ 1,500	$ 1,500	$ 4,500	$ 4,500
Preferred stock cash dividend		$ 11	$ 11	$ 33	$ 33
Series E Preferred Stock, Depository Share
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)		$ 0.38	$ 0.38	$ 1.14	$ 1.14
Series F Preferred Stock
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)		$ 2,625	$ 2,625	$ 5,250	$ 5,250
Preferred stock cash dividend		$ 20	$ 20	$ 40	$ 40
Series F Preferred Stock, Depository Share
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)		$ 26.25	$ 26.25	$ 52.5	$ 52.50
Series G Preferred Stock
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)		$ 1,338	$ 1,338	$ 4,014	$ 2,289
Preferred stock cash dividend		$ 7	$ 7	$ 21	$ 12
Series G Preferred Stock, Depository Share
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)		$ 0.33	$ 0.33	$ 0.99	$ 0.57
Subsequent Event | Series C Preferred Stock
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)	$ 1,313
Preferred stock cash dividend	$ 6
Subsequent Event | Series C Preferred Stock, Depository Share
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)	$ 0.33
Subsequent Event | Series D Preferred Stock
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)	$ 1,475
Preferred stock cash dividend	$ 11
Subsequent Event | Series D Preferred Stock, Depository Share
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)	$ 0.37
Subsequent Event | Series E Preferred Stock
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)	$ 1,500
Preferred stock cash dividend	$ 11
Subsequent Event | Series E Preferred Stock, Depository Share
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)	$ 0.38
Subsequent Event | Series G Preferred Stock
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)	$ 1,338
Preferred stock cash dividend	$ 7
Subsequent Event | Series G Preferred Stock, Depository Share
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)	$ 0.33

Shareholders' Equity - Schedu86

Shareholders' Equity - Schedule of Shares Repurchase Plans (Details) - USD ($) $ / shares in Units, shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Mar. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Jun. 30, 2016
Equity, Class of Treasury Stock [Line Items]
Shares Purchased	3.7		13.1
Average Cost per Share (USD per share)	$ 93.39		$ 83.77
Total Purchased	$ 350,000,000		$ 1,100,000,000
2017 Program
Equity, Class of Treasury Stock [Line Items]
Amount of common stock authorized for repurchase				$ 1,400,000,000
Shares Purchased	3.7		3.7
Average Cost per Share (USD per share)	$ 93.39		$ 93.39
Total Purchased	$ 350,000,000		$ 350,000,000
2016 Program
Equity, Class of Treasury Stock [Line Items]
Amount of common stock authorized for repurchase					$ 1,400,000,000
Shares Purchased	0		9.4
Average Cost per Share (USD per share)	$ 0		$ 79.93
Total Purchased	$ 0		$ 750,000,000
Boston Financial Data Services, Inc. and International Financial Data Services
Equity, Class of Treasury Stock [Line Items]
Common stock received in acquisition		$ 158,000,000

Shareholders' Equity - Schedu87

Shareholders' Equity - Schedule of Accumulated Other Comprehensive (Loss) Income (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Equity [Abstract]
Net unrealized gains (losses) on cash flow hedges	$ (45)	$ 229
Net unrealized gains (losses) on available-for-sale securities portfolio	301	(225)
Net unrealized gains (losses) related to reclassified available-for-sale securities	18	25
Net unrealized gains (losses) on available-for-sale securities	319	(200)
Net unrealized losses on available-for-sale securities designated in fair value hedges	(73)	(86)
Net unrealized gains (losses) on hedges of net investments in non-U.S. subsidiaries	(52)	95
Other-than-temporary impairment on held-to-maturity securities related to factors other than credit	(6)	(9)
Net unrealized losses on retirement plans	(184)	(194)
Foreign currency translation	(943)	(1,875)
Total	$ (984)	$ (2,040)

Shareholders' Equity - Accumula

Shareholders' Equity - Accumulated Other Comprehensive Income by Component (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 21,219	$ 21,103
Ending balance	22,497	22,150
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(2,040)	(1,442)
Other comprehensive income (loss) before reclassifications	1,069	445
Amounts reclassified into (out of) earnings	(13)	4
Other comprehensive income (loss)	1,056	449
Ending balance	(984)	(993)
Net Unrealized Gains (Losses) on Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	229	293
Other comprehensive income (loss) before reclassifications	(274)	(213)
Amounts reclassified into (out of) earnings	0	0
Other comprehensive income (loss)	(274)	(213)
Ending balance	(45)	80
Net Unrealized Gains (Losses) on Available-for-Sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(286)	(128)
Other comprehensive income (loss) before reclassifications	555	520
Amounts reclassified into (out of) earnings	(23)	4
Other comprehensive income (loss)	532	524
Ending balance	246	396
Net Unrealized Losses on Hedges of Net Investments in Non-U.S. Subsidiaries
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	95	(14)
Other comprehensive income (loss) before reclassifications	(147)	55
Amounts reclassified into (out of) earnings	0	0
Other comprehensive income (loss)	(147)	55
Ending balance	(52)	41
Other-Than-Temporary Impairment on Held-to-Maturity Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(9)	(16)
Other comprehensive income (loss) before reclassifications	3	6
Amounts reclassified into (out of) earnings	0	(1)
Other comprehensive income (loss)	3	5
Ending balance	(6)	(11)
Net Unrealized Losses on Retirement Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(194)	(183)
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassified into (out of) earnings	10	1
Other comprehensive income (loss)	10	1
Ending balance	(184)	(182)
Foreign Currency Translation
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(1,875)	(1,394)
Other comprehensive income (loss) before reclassifications	932	77
Amounts reclassified into (out of) earnings	0	0
Other comprehensive income (loss)	932	77
Ending balance	$ (943)	$ (1,317)

Shareholders' Equity - Adjustme

Shareholders' Equity - Adjustments to Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Class of Stock [Line Items]
Total reclassifications (out of) into AOCI	$ 6	$ 1	$ (13)	$ 4
Reclassification out of Accumulated Other Comprehensive Income | Net Unrealized Gains (Losses) on Available-for-Sale Securities
Class of Stock [Line Items]
Net realized gains (losses) from sales of available-for-sale securities, net of related taxes	4	2	(23)	4
Net realized gains from sales of available-for-sale securities, taxes	(1)	(2)	15	(3)
Reclassification out of Accumulated Other Comprehensive Income | Other-Than-Temporary Impairment on Securities
Class of Stock [Line Items]
Other-than-temporary impairment on held-to-maturity securities related to factors other than credit			0	(1)
Other-than-temporary impairment on held-to-maturity securities related to factors other than credit, taxes			0	1
Reclassification out of Accumulated Other Comprehensive Income | Amortization of Actuarial Losses
Class of Stock [Line Items]
Amortization of actuarial losses, net of related taxes	2	(1)	10	1
Amortization of actuarial losses, taxes	$ 0	$ 1	$ (2)	$ (2)

Regulatory Capital (Details)

Regulatory Capital (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Retained earnings	$ 18,675	$ 17,459
Capital ratio: required common equity tier 1 capital	6.50%	5.50%
Capital ratio: required tier 1 capital	8.00%	7.00%
Capital ratio: required total capital	10.00%	9.00%
Capital ratio: required tier 1 leverage	4.00%	4.00%
Percentage of goodwill and other intangible assets net of associated deferred tax liabilities allocated to other intangible assets	80.00%	60.00%
Basel III Advanced Approaches
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common stock and related surplus	$ 10,307	$ 10,286
Retained earnings	18,675	17,459
Accumulated other comprehensive income (loss)	(985)	(1,936)
Treasury stock, at cost	(8,697)	(7,682)
Total	19,300	18,127
Goodwill and other intangible assets, net of associated deferred tax liabilities	(6,739)	(6,348)
Other adjustments	(122)	(155)
Common equity tier 1 capital	12,439	11,624
Preferred stock	3,196	3,196
Trust preferred capital securities subject to phase-out from tier 1 capital	0	0
Other adjustments	(29)	(103)
Tier 1 capital	15,606	14,717
Qualifying subordinated long-term debt	1,072	1,172
Trust preferred capital securities phased out of tier 1 capital	0	0
ALLL and other	5	19
Other adjustments	1	1
Total capital	16,684	15,909
Credit risk	50,197	50,900
Operational risk(4)	45,795	44,579
Market risk	3,005	3,822
Total risk-weighted assets	98,997	99,301
Adjusted quarterly average assets	$ 211,396	$ 226,310
Common equity tier 1 capital	12.60%	11.70%
Tier 1 capital	15.80%	14.80%
Total capital	16.90%	16.00%
Tier 1 leveraged	7.40%	6.50%
Basel III Standardized Approach
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common stock and related surplus	$ 10,307	$ 10,286
Retained earnings	18,675	17,459
Accumulated other comprehensive income (loss)	(985)	(1,936)
Treasury stock, at cost	(8,697)	(7,682)
Total	19,300	18,127
Goodwill and other intangible assets, net of associated deferred tax liabilities	(6,739)	(6,348)
Other adjustments	(122)	(155)
Common equity tier 1 capital	12,439	11,624
Preferred stock	3,196	3,196
Trust preferred capital securities subject to phase-out from tier 1 capital	0	0
Other adjustments	(29)	(103)
Tier 1 capital	15,606	14,717
Qualifying subordinated long-term debt	1,072	1,172
Trust preferred capital securities phased out of tier 1 capital	0	0
ALLL and other	79	77
Other adjustments	1	1
Total capital	16,758	15,967
Credit risk	106,377	98,125
Market risk	1,203	1,751
Total risk-weighted assets	107,580	99,876
Adjusted quarterly average assets	$ 211,396	$ 226,310
Common equity tier 1 capital	11.60%	11.60%
Tier 1 capital	14.50%	14.70%
Total capital	15.60%	16.00%
Tier 1 leveraged	7.40%	6.50%
State Street Bank | Basel III Advanced Approaches
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common stock and related surplus	$ 11,382	$ 11,376
Retained earnings	12,286	12,285
Accumulated other comprehensive income (loss)	(808)	(1,648)
Treasury stock, at cost	0	0
Total	22,860	22,013
Goodwill and other intangible assets, net of associated deferred tax liabilities	(6,447)	(6,060)
Other adjustments	(90)	(148)
Common equity tier 1 capital	16,323	15,805
Preferred stock	0	0
Trust preferred capital securities subject to phase-out from tier 1 capital	0	0
Other adjustments	0	0
Tier 1 capital	16,323	15,805
Qualifying subordinated long-term debt	1,076	1,179
Trust preferred capital securities phased out of tier 1 capital	0	0
ALLL and other	0	15
Other adjustments	0	0
Total capital	17,399	16,999
Credit risk	47,282	47,383
Operational risk(4)	45,270	44,043
Market risk	3,005	3,822
Total risk-weighted assets	95,557	95,248
Adjusted quarterly average assets	$ 208,308	$ 222,584
Common equity tier 1 capital	17.10%	16.60%
Tier 1 capital	17.10%	16.60%
Total capital	18.20%	17.80%
Tier 1 leveraged	7.80%	7.10%
State Street Bank | Basel III Standardized Approach
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common stock and related surplus	$ 11,382	$ 11,376
Retained earnings	12,286	12,285
Accumulated other comprehensive income (loss)	(808)	(1,648)
Treasury stock, at cost	0	0
Total	22,860	22,013
Goodwill and other intangible assets, net of associated deferred tax liabilities	(6,447)	(6,060)
Other adjustments	(90)	(148)
Common equity tier 1 capital	16,323	15,805
Preferred stock	0	0
Trust preferred capital securities subject to phase-out from tier 1 capital	0	0
Other adjustments	0	0
Tier 1 capital	16,323	15,805
Qualifying subordinated long-term debt	1,076	1,179
Trust preferred capital securities phased out of tier 1 capital	0	0
ALLL and other	79	77
Other adjustments	0	0
Total capital	17,478	17,061
Credit risk	103,024	94,413
Market risk	1,203	1,751
Total risk-weighted assets	104,227	96,164
Adjusted quarterly average assets	$ 208,308	$ 222,584
Common equity tier 1 capital	15.70%	16.40%
Tier 1 capital	15.70%	16.40%
Total capital	16.80%	17.70%
Tier 1 leveraged	7.80%	7.10%

Net Interest Income - Component

Net Interest Income - Components of Interest Revenue and Interest Expenses (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Banking and Thrift [Abstract]
Deposits with banks	$ 45	$ 29	$ 121	$ 101
U.S. Treasury and federal agencies	207	200	627	620
State and political subdivisions	56	55	171	162
Other investments	173	208	495	581
Securities purchased under resale agreements	74	40	189	112
Loans and leases	139	97	362	281
Other interest-earning assets	67	18	146	39
Total interest income	761	647	2,111	1,896
Deposits	39	20	96	73
Securities sold under repurchase agreements	1	0	2	1
Short-term borrowings	3	2	7	4
Long-term debt	78	68	227	191
Other interest-bearing liabilities	37	20	91	57
Total interest expense	158	110	423	326
Net interest income	$ 603	$ 537	$ 1,688	$ 1,570

Expenses - Schedule of Expenses

Expenses - Schedule of Expenses (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Other Expenses [Abstract]
Insurance	$ 27	$ 31	$ 84	$ 74
Regulatory fees and assessments	24	28	77	65
Securities processing	4	10	20	20
Litigation	3	47	(15)	47
Other	86	71	261	231
Total other expenses	$ 144	$ 187	$ 427	$ 437

Expenses - Narrative (Details)

Expenses - Narrative (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2017	Sep. 30, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 33			$ 10			$ 112	$ 120
State Street Beacon
Restructuring Cost and Reserve [Line Items]
Restructuring charges	33	$ 62	$ 16	10	$ 13	$ 97
State Street Beacon | Severance and Benefit Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 23	$ 60	$ 14	$ 8	$ (1)	$ 86

Expenses - Restructuring Reserv

Expenses - Restructuring Reserve (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2017	Sep. 30, 2016
Restructuring Reserve [Roll Forward]
Accruals for Beacon	$ 33			$ 10			$ 112	$ 120
State Street Beacon
Restructuring Reserve [Roll Forward]
Beginning balance	100	$ 54	$ 56	82	$ 108	$ 23	56	23
Accruals for Beacon	33	62	16	10	13	97
Payments and Other Adjustments	(16)	(16)	(18)	(18)	(39)	(12)
Ending balance	117	100	54	74	82	108	117	74
State Street Beacon | Employee Related Costs
Restructuring Reserve [Roll Forward]
Beginning balance	87	38	37	55	91	9	37	9
Accruals for Beacon	23	60	14	8	(1)	86
Payments and Other Adjustments	(10)	(11)	(13)	(14)	(35)	(4)
Ending balance	100	87	38	49	55	91	100	49
State Street Beacon | Real Estate Actions
Restructuring Reserve [Roll Forward]
Beginning balance	11	14	17	22	10	11	17	11
Accruals for Beacon	9	0	0	3	15	0
Payments and Other Adjustments	(5)	(3)	(3)	(3)	(3)	(1)
Ending balance	15	11	14	22	22	10	15	22
State Street Beacon | Asset and Other Write-offs
Restructuring Reserve [Roll Forward]
Beginning balance	2	2	2	5	7	3	2	3
Accruals for Beacon	1	2	2	(1)	(1)	11
Payments and Other Adjustments	(1)	(2)	(2)	(1)	(1)	(7)
Ending balance	$ 2	$ 2	$ 2	$ 3	$ 5	$ 7	$ 2	$ 3

Earnings Per Common Share (Deta

Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share [Abstract]
Net income	$ 685	$ 563	$ 1,807	$ 1,550
Preferred stock dividends	(55)	(55)	(146)	(137)
Dividends and undistributed earnings allocated to participating securities	(1)	(1)	(2)	(2)
Net income available to common shareholders	$ 629	$ 507	$ 1,659	$ 1,411
Basic average common shares	372,765	388,358	376,430	393,959
Effect of dilutive securities: common stock options and common stock awards (in shares)	5,753	4,854	5,349	4,454
Diluted average common shares	378,518	393,212	381,779	398,413
Anti-dilutive securities (in shares)	0	2,166	250	3,027
Earnings per Common Share:
Basic (in USD per share)	$ 1.69	$ 1.31	$ 4.41	$ 3.58
Diluted (in USD per share)	$ 1.66	$ 1.29	$ 4.35	$ 3.54

Line of Business Information -

Line of Business Information - Narrative (Details)	9 Months Ended
	Sep. 30, 2017line_of_business
Segment Reporting [Abstract]
Number of lines of business	2

Line of Business Information 97

Line of Business Information - Summary of Line of Business (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Servicing fees	$ 1,351	$ 1,303	$ 3,986	$ 3,784
Management fees	419	368	1,198	931
Trading services	259	267	823	806
Securities finance	147	136	459	426
Processing fees and other	66	5	209	155
Total fee revenue	2,242	2,079	6,675	6,102
Net interest income	603	537	1,688	1,570
Gains (losses) related to investment securities, net	1	4	(39)	5
Total revenue	2,846	2,620	8,324	7,677
Provision for loan losses	3	0	4	8
Total expenses	2,021	1,984	6,138	5,894
Income before income tax expense	$ 822	$ 636	$ 2,182	$ 1,775
Pre-tax margin	29.00%	24.00%	26.00%	23.00%
Operating Segments | Investment Servicing
Segment Reporting Information [Line Items]
Servicing fees	$ 1,351	$ 1,303	$ 3,986	$ 3,784
Management fees	0	0	0	0
Trading services	239	248	768	760
Securities finance	147	136	459	426
Processing fees and other	65	12	203	164
Total fee revenue	1,802	1,699	5,416	5,134
Net interest income	606	536	1,691	1,567
Gains (losses) related to investment securities, net	1	4	(39)	5
Total revenue	2,409	2,239	7,068	6,706
Provision for loan losses	3	0	4	8
Total expenses	1,673	1,634	5,050	4,920
Income before income tax expense	$ 733	$ 605	$ 2,014	$ 1,778
Pre-tax margin	30.00%	27.00%	28.00%	27.00%
Operating Segments | Investment Management
Segment Reporting Information [Line Items]
Servicing fees	$ 0	$ 0	$ 0	$ 0
Management fees	419	368	1,198	931
Trading services	20	19	55	46
Securities finance	0	0	0	0
Processing fees and other	1	(7)	6	(9)
Total fee revenue	440	380	1,259	968
Net interest income	(3)	1	(3)	3
Gains (losses) related to investment securities, net	0	0	0	0
Total revenue	437	381	1,256	971
Provision for loan losses	0	0	0	0
Total expenses	314	317	954	817
Income before income tax expense	$ 123	$ 64	$ 302	$ 154
Pre-tax margin	28.00%	17.00%	24.00%	16.00%
Other
Segment Reporting Information [Line Items]
Servicing fees	$ 0	$ 0	$ 0	$ 0
Management fees	0	0	0	0
Trading services	0	0	0	0
Securities finance	0	0	0	0
Processing fees and other	0	0	0	0
Total fee revenue	0	0	0	0
Net interest income	0	0	0	0
Gains (losses) related to investment securities, net	0	0	0	0
Total revenue	0	0	0	0
Provision for loan losses	0	0	0	0
Total expenses	34	33	134	157
Income before income tax expense	$ (34)	$ (33)	$ (134)	$ (157)

Non-U.S. Activities - Narrative

Non-U.S. Activities - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Segment Reporting Information [Line Items]
Assets	$ 235,986	$ 242,698
Non-U.S.
Segment Reporting Information [Line Items]
Assets	$ 81,500		$ 86,700

Non-U.S. Activities - Schedule

Non-U.S. Activities - Schedule Of Results From Non-U.S. Operations (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Total revenue	$ 2,846	$ 2,620	$ 8,324	$ 7,677
Income before income taxes	822	636	2,182	1,775
Non-U.S.
Segment Reporting Information [Line Items]
Total revenue	1,219	1,117	3,494	3,278
Income before income taxes	342	314	919	835
U.S.
Segment Reporting Information [Line Items]
Total revenue	1,627	1,503	4,830	4,399
Income before income taxes	$ 480	$ 322	$ 1,263	$ 940