Nasdaq (NDAQ) 10-Q 6 Nov 19 2019 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2019	Oct. 28, 2019
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2019
Document Transition Report	false
Entity File Number	001-38855
Entity Registrant Name	Nasdaq, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	52-1165937
Entity Address, Address Line One	151 W. 42nd Street,
Entity Address, City or Town	New York,
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10036
City Area Code	212
Local Phone Number	401 8700
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		163,915,065
Entity Central Index Key	0001120193
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	false
Common Stock, $.01 par value per share
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, $0.01 par value per share
Trading Symbol	NDAQ
Security Exchange Name	NASDAQ
1.75% Senior Notes Due 2029
Entity Information [Line Items]
Title of 12(b) Security	1.75% Senior Notes due 2029
Trading Symbol	NDAQ29
Security Exchange Name	NASDAQ
3.875% Senior Notes Due 2021
Entity Information [Line Items]
Title of 12(b) Security	3.875% Senior Notes due 2021
Trading Symbol	NDAQ21
Security Exchange Name	NASDAQ
1.75% Senior Note Due 2023
Entity Information [Line Items]
Title of 12(b) Security	1.750% Senior Notes due 2023
Trading Symbol	NDAQ23
Security Exchange Name	NASDAQ

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 304	$ 545
Restricted cash	29	41
Financial investments, at fair value	201	268
Receivables, net	399	384
Default funds and margin deposits	2,422	4,742
Other current assets	144	390
Total current assets	3,499	6,370
Property and equipment, net	361	376
Goodwill	6,232	6,363
Intangible assets, net	2,239	2,300
Operating lease assets	346	0
Other non-current assets	303	291
Total assets	12,980	15,700
Current liabilities:
Accounts payable and accrued expenses	146	198
Section 31 fees payable to SEC	34	109
Accrued personnel costs	137	199
Deferred revenue	267	194
Other current liabilities	147	253
Default funds and margin deposits	2,422	4,742
Short-term debt	539	875
Total current liabilities	3,692	6,570
Long-term debt	2,939	2,956
Deferred tax liabilities, net	525	501
Operating lease liabilities	327	0
Other non-current liabilities	170	224
Total liabilities	7,653	10,251
Commitments and contingencies
Nasdaq stockholders’ equity:
Common stock, $0.01 par value, 300,000,000 shares authorized, shares issued: 169,802,172 at September 30, 2019 and 170,709,425 at December 31, 2018; shares outstanding: 163,894,038 at September 30, 2019 and 165,165,104 at December 31, 2018	2	2
Additional paid-in capital	2,585	2,716
Common stock in treasury, at cost: 5,908,134 shares at September 30, 2019 and 5,544,321 shares at December 31, 2018	(328)	(297)
Accumulated other comprehensive loss	(1,833)	(1,530)
Retained earnings	4,901	4,558
Total Nasdaq stockholders’ equity	5,327	5,449
Total liabilities and equity	$ 12,980	$ 15,700

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	300,000,000	300,000,000
Common stock, shares issued (in shares)	169,802,172	170,709,425
Common stock, shares outstanding (in shares)	163,894,038	165,165,104
Common stock in treasury (in shares)	5,908,134	5,544,321

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues:
Total revenues	$ 1,096	$ 964	$ 3,197	$ 3,141
Transaction-based expenses:
Transaction rebates	(349)	(293)	(1,012)	(947)
Brokerage, clearance and exchange fees	(115)	(71)	(296)	(312)
Revenues less transaction-based expenses	632	600	1,889	1,882
Operating expenses:
Compensation and benefits	175	164	518	534
Professional and contract services	31	33	99	105
Computer operations and data communications	33	32	98	94
Occupancy	24	23	72	72
General, administrative and other	40	28	95	73
Marketing and advertising	8	7	29	27
Depreciation and amortization	47	53	143	159
Regulatory	8	8	23	24
Merger and strategic initiatives	10	6	25	7
Restructuring charges	30	0	30	0
Total operating expenses	406	354	1,132	1,095
Operating income	226	246	757	787
Interest income	3	3	8	8
Interest expense	(29)	(38)	(97)	(112)
Net gain (loss) on divestiture of businesses	0	(8)	27	33
Other investment income	0	0	1	7
Net income from unconsolidated investees	15	6	71	13
Income before income taxes	215	209	767	736
Income tax provision	65	46	196	234
Net income attributable to Nasdaq	$ 150	$ 163	$ 571	$ 502
Per share information:
Basic earnings per share (in dollars per share)	$ 0.91	$ 0.99	$ 3.46	$ 3.03
Diluted earnings per share (in dollars per share)	0.90	0.97	3.42	2.99
Cash dividends declared per common share (in dollars per share)	$ 0.47	$ 0.44	$ 1.38	$ 1.26
Market Services
Revenues:
Total revenues	$ 690	$ 586	$ 1,995	$ 1,968
Corporate Services
Revenues:
Total revenues	124	121	368	364
Information Services
Revenues:
Total revenues	198	179	585	528
Market Technology
Revenues:
Total revenues	84	68	239	194
Other revenues
Revenues:
Total revenues	$ 0	10	10	87
Transaction-based expenses:
Revenues less transaction-based expenses		$ 10	$ 10	$ 87

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income		$ 150	$ 163	$ 571	$ 502
Other comprehensive income (loss):
Foreign currency translation gains (losses)		(121)	22	(256)	(239)
Income tax expense	[1],[2]	(46)	(15)	(47)	(76)
Foreign currency translation, net		(167)	7	(303)	(315)
Employee benefit plan income tax expense	[1]	0	0	0	(7)
Total other comprehensive income (loss), net of tax		(167)	7	(303)	(322)
Comprehensive income (loss) attributable to Nasdaq		$ (17)	$ 170	$ 268	$ 180
[1]	Primarily includes income tax expense on Euro denominated notes.
[2]	For the nine months ended September 30, 2018, includes a reclassification of the stranded tax effects related to the Tax Cuts and Jobs Act. See “Tax Cuts and Jobs Act,” of Note 17, “Income Taxes,” for further discussion.

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Millions	Total	Common stock	Additional paid-in capital	Common stock in Treasury, at Cost	Accumulated Other Comprehensive Loss	Retained Earnings
Beginning balance (in shares) at Dec. 31, 2017		167,000,000
Beginning balance at Dec. 31, 2017		$ 2	$ 3,024	$ (247)	$ (862)	$ 3,963
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares repurchase program (in shares)			(4,000,000)
Share repurchase program	$ (394)		$ (394)
Share-based compensation (in shares)			1,000,000
Share-based compensation			$ 51
Stock option exercises, net (in shares)	99,953		0
Stock option exercises, net			$ 2
Other employee stock activity (in shares)			0	0
Other employee stock activity			$ (7)	$ (44)
Other comprehensive income (loss)					(322)	142
Net income						502
Cash dividends declared per common share						(208)
Ending balance (in shares) at Sep. 30, 2018	164,000,000
Ending balance at Sep. 30, 2018	$ 5,602		2,676	(291)	(1,184)	4,399
Beginning balance (in shares) at Jun. 30, 2018		165,000,000
Beginning balance at Jun. 30, 2018		$ 2	$ 2,712	$ (290)	(1,191)	4,309
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares repurchase program (in shares)			(1,000,000)
Share repurchase program			$ (54)
Share-based compensation (in shares)			0
Share-based compensation			$ 18
Stock option exercises, net (in shares)	11,953		0
Stock option exercises, net			$ 0
Other employee stock activity (in shares)			0	0
Other employee stock activity			$ 0	$ (1)
Other comprehensive income (loss)					7	(1)
Net income						163
Cash dividends declared per common share						(72)
Ending balance (in shares) at Sep. 30, 2018	164,000,000
Ending balance at Sep. 30, 2018	$ 5,602		2,676	(291)	(1,184)	4,399
Beginning balance (in shares) at Dec. 31, 2018		165,000,000
Beginning balance at Dec. 31, 2018		$ 2	$ 2,716	$ (297)	(1,530)	4,558
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares repurchase program (in shares)			(2,000,000)
Share repurchase program	$ (200)		$ (200)
Share-based compensation (in shares)			1,000,000
Share-based compensation			$ 57
Stock option exercises, net (in shares)	62,624		0
Stock option exercises, net			$ 1
Other employee stock activity (in shares)			0	0
Other employee stock activity			$ 11	$ (31)
Other comprehensive income (loss)					(303)	0
Net income						571
Cash dividends declared per common share	$ (228)					(228)
Ending balance (in shares) at Sep. 30, 2019	164,000,000
Ending balance at Sep. 30, 2019	$ 5,327		2,585	(328)	(1,833)	4,901
Beginning balance (in shares) at Jun. 30, 2019		165,000,000
Beginning balance at Jun. 30, 2019		$ 2	$ 2,713	$ (327)	(1,666)	4,829
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares repurchase program (in shares)			(2,000,000)
Share repurchase program			$ (150)
Share-based compensation (in shares)			1,000,000
Share-based compensation			$ 21
Stock option exercises, net (in shares)	9,216		0
Stock option exercises, net			$ 1
Other employee stock activity (in shares)			0	0
Other employee stock activity			$ 0	$ (1)
Other comprehensive income (loss)					(167)	0
Net income						150
Cash dividends declared per common share						(78)
Ending balance (in shares) at Sep. 30, 2019	164,000,000
Ending balance at Sep. 30, 2019	$ 5,327		$ 2,585	$ (328)	$ (1,833)	$ 4,901

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net income	$ 571	$ 502
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	143	159
Share-based compensation	57	51
Deferred income taxes	(21)	(12)
Reversal of certain Swedish tax benefits	0	41
Net gain on divestiture of businesses	(27)	(33)
Non-cash restructuring charges	25	0
Net income from unconsolidated investees	(71)	(13)
Other reconciling items included in net income	18	10
Net change in operating assets and liabilities, net of effects of divestiture and acquisitions:
Receivables, net	(7)	(11)
Other assets	(128)	(23)
Accounts payable and accrued expenses	(36)	6
Section 31 fees payable to SEC	(75)	(107)
Accrued personnel costs	(58)	(22)
Deferred revenue	52	74
Other liabilities	181	46
Net cash provided by operating activities	624	668
Cash flows from investing activities:
Purchases of securities	(384)	(312)
Proceeds from sales and redemptions of securities	429	331
Proceeds from divestiture of businesses, net	108	286
Proceeds from sale of investment security	11	0
Acquisition of business, net of cash and cash equivalents acquired	(193)	0
Purchases of property and equipment	(88)	(72)
Other investing activities	(14)	(6)
Net cash provided by (used in) investing activities	(131)	227
Cash flows from financing activities:
Proceeds from (repayments of) commercial paper, net	264	(170)
Repayments of debt obligations	(1,215)	(115)
Payment of debt extinguishment cost	(11)	0
Proceeds from issuances of long-term debt, net of issuance costs	680	0
Repurchases of common stock	(200)	(394)
Dividends paid	(228)	(208)
Proceeds received from employee stock activity	12	10
Payments related to employee shares withheld for taxes	(31)	(44)
Proceeds of customer funds	0	15
Net cash used in financing activities	(729)	(906)
Effect of exchange rate changes on cash and cash equivalents and restricted cash	(17)	(12)
Net decrease in cash and cash equivalents and restricted cash	(253)	(23)
Cash and cash equivalents and restricted cash at beginning of period	586	399
Cash and cash equivalents and restricted cash at end of period	333	376
Cash paid for:
Interest	97	121
Income taxes, net of refund	$ 189	$ 195

Organization and Nature of Oper

Organization and Nature of Operations	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Nature of Operations	Organization and Nature of Operations Nasdaq is a global technology company serving the capital markets and other industries. Our diverse offering of data, analytics, software and services enables clients to optimize and execute their business vision with confidence. We manage, operate and provide our products and services in four business segments: Market Services, Corporate Services, Information Services and Market Technology. Market Services Our Market Services segment includes our Equity Derivative Trading and Clearing, Cash Equity Trading, FICC and Trade Management Services businesses. We operate multiple exchanges and other marketplace facilities across several asset classes, including derivatives, commodities, cash equity, debt, structured products and ETPs. In addition, in some countries where we operate exchanges, we also provide broker services, clearing, settlement and central depository services. Our transaction-based platforms provide market participants with the ability to access, process, display and integrate orders and quotes. The platforms allow the routing and execution of buy and sell orders as well as the reporting of transactions, providing fee-based revenues. In the U.S., we operate six electronic options exchanges and three cash equity exchanges. The Nasdaq Stock Market, the largest of our cash equities exchanges, is the largest single venue of liquidity for trading U.S.-listed cash equities. We also operate an electronic platform for trading of U.S. Treasuries and NFX, a U.S. based designated contract market which lists cash-settled energy derivatives based on key energy benchmarks including oil, natural gas and U.S. power. In addition, we also operate a Canadian exchange for the trading of certain Canadian-listed securities. In Europe, we operate exchanges in Stockholm (Sweden), Copenhagen (Denmark), Helsinki (Finland), and Reykjavik (Iceland), as well as the clearing operations of Nasdaq Clearing, as Nasdaq Nordic. We also operate exchanges in Tallinn (Estonia), Riga (Latvia) and Vilnius (Lithuania) as Nasdaq Baltic. Collectively, Nasdaq Nordic and Nasdaq Baltic offer trading in cash equities, depository receipts, warrants, convertibles, rights, fund units and ETFs, as well as trading and clearing of derivatives and clearing of resale and repurchase agreements. Nasdaq Commodities is the brand name for Nasdaq’s European commodity-related products and services. Nasdaq Commodities’ offerings include derivatives in oil, power, natural gas and carbon emission markets, seafood, electricity certificates and clearing services. These products are listed on two of Nasdaq’s derivatives exchanges, Nasdaq Oslo ASA and NFX. Through our Trade Management Services business, we provide market participants with a wide variety of alternatives for connecting to and accessing our markets via a number of different protocols used for quoting, order entry, trade reporting, and connectivity to various data feeds. We also provide data center services, including co-location to market participants, whereby we offer firms cabinet space and power to house their own servers and other equipment within our data centers. Our broker services operations offer technology and customized securities administration solutions to financial participants in the Nordic market. In March 2019, we entered into an agreement to sell Nordic Fund Market, an electronic mutual fund service which is a small part of our Broker Services business. The closing of this transaction occurred on October 31, 2019. Corporate Services Our Corporate Services segment includes our Listing Services and Corporate Solutions businesses. Our Listing Services business includes our U.S. and European Listing Services businesses. We operate a variety of listing platforms around the world to provide multiple global capital raising solutions for private and public companies. Our main listing markets are The Nasdaq Stock Market and the Nasdaq Nordic and Nasdaq Baltic exchanges. Through Nasdaq First North, our Nordic and Baltic operations also offer alternative marketplaces for smaller companies and growth companies. Our Listing Services business also includes NPM, which provides liquidity solutions for private companies and private funds. In December 2018, we launched our Corporate Bond exchange for the listing and trading of corporate bonds. The new exchange operates pursuant to The Nasdaq Stock Market exchange license and is powered by NFF. As of September 30, 2019 , there were 3,091 total listings on The Nasdaq Stock Market, including 382 ETPs. The combined market capitalization was approximately $13.4 trillion . In Europe, the Nasdaq Nordic and Nasdaq Baltic exchanges, together with Nasdaq First North, were home to 1,028 listed companies with a combined market capitalization of approximately $1.4 trillion . Our Corporate Solutions business includes our Investor Relations Intelligence and Governance Solutions businesses which serve both public and private companies and organizations. Our public clients can be companies listed on our exchanges or other U.S. and global exchanges. We help organizations enhance their ability to understand and expand their global shareholder base, and improve corporate governance through our suite of advanced technology, analytics, and consultative services. In October 2019, Nasdaq acquired the Center for Board Excellence, or CBE, a privately-held provider of corporate governance and compliance solutions for boards of directors, CEOs, corporate secretaries and general counsels. Nasdaq will combine CBE with its Nasdaq Governance Solutions business, which includes board portal and collaboration technology solutions. We expect the combination will enhance Nasdaq's position as a leading provider of technology, research, insights and consultative services designed to advance governance excellence and collaboration at organizations worldwide. In March 2019, we sold our BWise enterprise governance, risk and compliance software platform and in April 2018, we sold our Public Relations Solutions and Digital Media Services businesses. See Note 5, “Acquisitions and Divestitures,” for further discussion. As of December 31, 2018, BWise was classified as held for sale. See Note 6, “Assets and Liabilities Held for Sale,” for further discussion. For segment reporting purposes, we have included the revenues and expenses of BWise and the Public Relations Solutions and Digital Media Services businesses in corporate items. These businesses were part of the Corporate Solutions business, within our Corporate Services segment, prior to the date of sale. For discussion of business segments, see Note 19, “Business Segments.” Information Services Our Information Services segment includes our Market Data, Index and Investment Data & Analytics businesses. Our Market Data business sells and distributes historical and real-time quote and trade information to the sell-side, the buy-side, retail online brokers, proprietary trading shops, other venues, internet portals and data distributors. Our market data products enhance transparency of market activity within our exchanges and provide critical information to professional and non-professional investors globally. Our Index business develops and licenses Nasdaq-branded indexes, associated derivatives, and financial products and also provides custom calculation services for third-party clients. As of September 30, 2019 , we had 325 ETPs licensed to Nasdaq’s indexes which had $207 billion in assets under management. Our Investment Data & Analytics business is a leading content and analytics cloud-based solutions provider used by asset managers, investment consultants and asset owners to help facilitate better investment decisions. Market Technology Our Market Technology segment is a leading global technology solutions provider and partner to exchanges, clearing organizations, central securities depositories, regulators, banks, brokers, buy-side firms and corporate businesses. Our Market Technology business is the sales channel for our complete global offering to other marketplaces. Market Technology provides technology solutions for trading, clearing, settlement, surveillance and information dissemination to markets with wide-ranging requirements, from the leading markets in the U.S., Europe and Asia to emerging markets in the Middle East, Latin America, and Africa. Our marketplace solutions can handle a wide array of assets, including cash equities, equity derivatives, currencies, various interest-bearing securities, commodities and energy products, and are currently powering more than 100 marketplaces in 50 countries. Market Technology also provides market surveillance services to broker-dealer firms worldwide, as well as risk management solutions.

Basis of Presentation and Princ

Basis of Presentation and Principles of Consolidation	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation The condensed consolidated financial statements are prepared in accordance with U.S. GAAP and include the accounts of Nasdaq, its wholly-owned subsidiaries and other entities in which Nasdaq has a controlling financial interest. When we do not have a controlling interest in an entity but exercise significant influence over the entity’s operating and financial policies, such investment is accounted for under the equity method of accounting. We recognize our share of earnings or losses of an equity method investee based on our ownership percentage. See “Equity Method Investments,” of Note 8, “Investments,” for further discussion of our equity method investments. The accompanying condensed consolidated financial statements reflect all adjustments which are, in the opinion of management, necessary for a fair statement of the results. These adjustments are of a normal recurring nature. All significant intercompany accounts and transactions have been eliminated in consolidation. As permitted under U.S. GAAP, certain footnotes or other financial information can be condensed or omitted in the interim condensed consolidated financial statements. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the consolidated financial statements and accompanying notes included in Nasdaq’s Form 10-K. The year-end condensed balance sheet data was derived from the audited financial statements, but does not include all disclosures required by U.S. GAAP. On January 1, 2019, we adopted ASU 2016-02, “Leases,” or ASU 2016-02. See Note 3, “Significant Accounting Policies Update,” for further discussion. Certain prior year amounts have been reclassified to conform to the current year presentation. The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts and the disclosure of contingent amounts in the condensed consolidated financial statements and accompanying notes. Actual results could differ from those estimates. Subsequent Events We have evaluated subsequent events through the issuance date of this Quarterly Report on Form 10-Q. Recent Accounting Pronouncements Accounting Standard Description Effective Date Effect on the Financial Statements or Other Significant Matters Goodwill In January 2017, the FASB issued ASU 2017-04, “Simplifying the Test for Goodwill Impairment.” This ASU simplifies how an entity is required to test goodwill for impairment and removes the second step of the goodwill impairment test, which required a hypothetical purchase price allocation if the fair value of a reporting unit is less than its carrying amount. Goodwill impairment will now be measured using the difference between the carrying amount and the fair value of the reporting unit and the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. The amendments in this ASU should be applied on a prospective basis. January 1, 2020, with early adoption permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. We will adopt this standard on January 1, 2020. We do not anticipate a material impact on our consolidated financial statements at the time of adoption of this new standard as the carrying amounts of our reporting units have been less than their corresponding fair values in recent years. However, changes in future projections, market conditions and other factors may cause a change in the excess of fair value of our reporting units over their corresponding carrying amounts. Financial Instruments - Credit Losses In June 2016, the FASB issued ASU 2016-13, “Measurement of Credit Losses on Financial Instruments.” This ASU changes the impairment model for certain financial instruments. The new model is a forward looking expected loss model and will apply to financial assets subject to credit losses and measured at amortized cost and certain off-balance sheet credit exposures. This includes loans, held-to-maturity debt securities, loan commitments, financial guarantees and net investments in leases, as well as trade receivables. For available-for-sale debt securities with unrealized losses, credit losses will be measured in a manner similar to today, except that the losses will be recognized as allowances rather than reductions in the amortized cost of the securities. January 1, 2020, with early adoption permitted as of January 1, 2019. We will adopt this standard on January 1, 2020. Any impact will be recognized as a cumulative-effect adjustment to retained earnings as of the effective date to align our credit loss methodology with the new standard. We do not expect the adoption of this new standard to have a material impact on our consolidated balance sheets or our statements of income and it will not impact our cash flows.

Significant Accounting Policies

Significant Accounting Policies Update	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Significant Accounting Policies Update	Significant Accounting Policies Update Our significant accounting policies are detailed in Note 2, “Summary of Significant Accounting Policies,” in our Form 10-K. A significant change to our accounting policies as a result of adopting ASU 2016-02 is discussed below. We adopted ASU 2016-02 on January 1, 2019, and elected the optional transition method to initially apply the standard at the January 1, 2019 adoption date. As a result, we applied the new lease standard prospectively to our leases existing or commencing on or after January 1, 2019. Comparative periods presented were not restated upon adoption. Similarly, new disclosures under the standard were made for periods beginning January 1, 2019, and not for prior comparative periods. Prior periods will continue to be reported under guidance in effect prior to January 1, 2019. In addition, w e elected the package of practical expedients permitted under the transition guidance within the standard, which among other things, allowed us to not reassess contracts to determine if they contain leases, lease classification and initial direct costs. The standard did not impact our statements of income and had no impact on our cash flows. We have operating leases which are primarily real estate leases for our U.S. and European headquarters and for general office space. These leases have varying lease terms ranging from 3 months to 17 years. We determine if an arrangement is a lease at inception. Operating leases are included in operating lease assets, other current liabilities, and operating lease liabilities in our condensed consolidated balance sheets as of September 30, 2019 . As of September 30, 2019 , we do not have any finance leases. Operating lease assets represent our right to use an underlying asset for the lease term and lease liabilities represent our obligation to make lease payments arising from the lease. Operating lease assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. Since our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The operating lease asset also includes any lease payments made and excludes lease incentives. Our lease terms include options to extend or terminate the lease when we are reasonably certain that we will exercise that option. Lease expense for lease payments is recognized on a straight-line basis over the lease term. Certain of our lease agreements include rental payments adjusted periodically for inflation based on an index or rate. These payments are included in the initial measurement of the operating lease liability and operating lease asset. However, rental payments that are based on a change in an index or a rate are considered variable lease payments and are expensed as incurred. We have lease agreements with lease and non-lease components, which are accounted for as a single performance obligation to the extent that the timing and pattern of transfer are similar for the lease and non-lease components and the lease component qualifies as an operating lease . We do not recognize lease liabilities and operating lease assets for leases with a term of 12 months or less. We recognize these lease payments on a straight-line basis over the lease term. Our lease agreements do not contain any material residual value guarantees or material restrictions or covenants. We sublease certain real estate to third parties. Our sublease portfolio consists of operating leases. The following table provides supplemental balance sheet information related to Nasdaq's operating leases: Leases Balance Sheet Classification September 30, 2019 (in millions) Assets: Operating lease assets Operating lease assets $ 346 Liabilities: Current lease liabilities Other current liabilities $ 60 Non-current lease liabilities Operating lease liabilities 327 Total lease liabilities $ 387 The following table summarizes Nasdaq's lease cost: Three Months Ended September 30, 2019 Nine Months Ended September 30, 2019 (in millions) Operating lease cost (1) $ 19 $ 58 Variable lease cost 6 18 Sublease income (1 ) (4 ) Total lease cost $ 24 $ 72 ____________ (1) Includes short-term lease cost, which was immaterial. The following table reconciles the undiscounted cash flows for each of the first five years and total of the remaining years to the operating lease liabilities recorded in our condensed consolidated balance sheet. September 30, 2019 (in millions) 2019 (1) $ 19 2020 76 2021 66 2022 44 2023 39 Thereafter 261 Total lease payments 505 Less: interest (2) (118 ) Present value of lease liabilities (3) $ 387 ____________ (1) Represents the estimated lease payments to be made for the remaining three months of 2019. (2) Calculated using the interest rate for each lease. (3) Includes the current portion of $60 million . Total lease payments in the above table exclude $143 million of legally binding minimum lease payments for leases signed but not yet commenced primarily related to the expansion of our world headquarters. These leases will commence in 2020 with a lease term of 16 years. The following table provides information related to Nasdaq's lease term and discount rate: September 30, 2019 Weighted-average remaining lease term (in years) 10.4 Weighted-average discount rate 4.6 % The following table provides supplemental cash flow information related to Nasdaq's operating leases: Nine Months Ended September 30, 2019 (in millions) Cash paid for amounts included in the measurement of operating lease liabilities $ 59 Lease assets obtained in exchange for new operating lease liabilities $ 20

Revenue From Contracts With Cus

Revenue From Contracts With Customers	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Revenue From Contracts With Customers	Revenue From Contracts With Customers Disaggregation of Revenue The following tables summarize the disaggregation of revenue by major product and service and by segment for the three and nine months ended September 30, 2019 and 2018 : Three Months Ended September 30, 2019 Market Services Corporate Services Information Services Market Technology Consolidated (in millions) Transaction-based trading and clearing, net $ 154 $ — $ — $ — $ 154 Trade management services 72 — — — 72 Listing services — 74 — — 74 Corporate solutions — 50 — — 50 Market data — — 102 — 102 Index — — 56 — 56 Investment data & analytics — — 40 — 40 Market technology — — — 84 84 Revenues less transaction-based expenses $ 226 $ 124 $ 198 $ 84 $ 632 Three Months Ended September 30, 2018 Market Services Corporate Services Information Services Market Technology Other Revenues Consolidated (in millions) Transaction-based trading and clearing, net $ 150 $ — $ — $ — $ — $ 150 Trade management services 72 — — — — 72 Listing services — 72 — — — 72 Corporate solutions — 49 — — — 49 Market data — — 95 — — 95 Index — — 52 — — 52 Investment data & analytics — — 32 — — 32 Market technology — — — 68 — 68 Other revenues — — — — 10 10 Revenues less transaction-based expenses $ 222 $ 121 $ 179 $ 68 $ 10 $ 600 For the three months ended September 30, 2019 , approximately 65.0% of Market Services revenues were recognized at a point in time and 35.0% were recognized over time. For the three months ended September 30, 2018 , approximately 63.0% of Market Services revenues were recognized at a point in time and 37.0% were recognized over time. Substantially all revenues from the Corporate Services, Information Services and Market Technology segments were recognized over time for both the three months ended September 30, 2019 and 2018. Nine Months Ended September 30, 2019 Market Services Corporate Services Information Services Market Technology Other Revenues Consolidated (in millions) Transaction-based trading and clearing, net $ 468 $ — $ — $ — $ — $ 468 Trade management services 219 — — — — 219 Listing services — 219 — — — 219 Corporate solutions — 149 — — — 149 Market data — — 302 — — 302 Index — — 166 — — 166 Investment data & analytics — — 117 — — 117 Market technology — — — 239 — 239 Other revenues — — — — 10 10 Revenues less transaction-based expenses $ 687 $ 368 $ 585 $ 239 $ 10 $ 1,889 Nine Months Ended September 30, 2018 Market Services Corporate Services Information Services Market Technology Other Revenues Consolidated (in millions) Transaction-based trading and clearing, net $ 489 $ — $ — $ — $ — $ 489 Trade management services 220 — — — — 220 Listing services — 217 — — — 217 Corporate solutions — 147 — — — 147 Market data — — 293 — — 293 Index — — 152 — — 152 Investment data & analytics — — 83 — — 83 Market technology — — — 194 — 194 Other revenues — — — — 87 87 Revenues less transaction-based expenses $ 709 $ 364 $ 528 $ 194 $ 87 $ 1,882 For the nine months ended September 30, 2019 , approximately 65.0% of Market Services revenues were recognized at a point in time and 35.0% were recognized over time. For the nine months ended September 30, 2018, approximately 64.0% of Market Services revenues were recognized at a point in time and 36.0% were recognized over time. Substantially all revenues from the Corporate Services, Information Services and Market Technology segments were recognized over time for both the nine months ended September 30, 2019 and 2018. * * * * * * Contract Balances Substantially all of our revenues are considered to be revenues from contracts with customers. The related accounts receivable balances are recorded in our Condensed Consolidated Balance Sheets as receivables which are net of allowance for doubtful accounts of $12 million as of September 30, 2019 and $13 million as of December 31, 2018 . The changes in the balance between periods were immaterial. We do not have obligations for warranties, returns or refunds to customers. For the majority of our contracts with customers, except for our market technology and listings services contracts, our performance obligations are short-term in nature and there is no significant variable consideration. We do not have revenues recognized from performance obligations that were satisfied in prior periods. We have elected not to provide disclosures about transaction price allocated to unsatisfied performance obligations if contract durations are less than one year. Excluding our market technology contracts, for contract durations that are one-year or greater, materially all of the transaction price allocated to unsatisfied performance obligations is included in deferred revenue. For our market technology contracts, the portion of transaction price allocated to unsatisfied performance obligations is shown in the table below. Deferred revenue primarily represents our contract liabilities related to our fees for annual and initial listings, market technology, corporate solutions and information services contracts. Deferred revenue is the only significant contract asset or liability as of September 30, 2019 . See Note 9, “Deferred Revenue,” for our discussion on deferred revenue balances, activity, and expected timing of recognition. Transaction Price Allocated to Remaining Performance Obligations As stated above, for contract durations that are one-year or greater, we do not have a material portion of transaction price allocated to unsatisfied performance obligations that are not included in deferred revenue other than for our market technology contracts. For our market technology contracts, t he following table summarizes the amount of the transaction price allocated to performance obligations that are unsatisfied as of September 30, 2019 : (in millions) 2019 (1) $ 78 2020 310 2021 159 2022 85 2023 45 2024 and thereafter 85 Total $ 762 ____________ (1) Represents performance obligations to be recognized over the remaining three months of 2019. Market technology deferred revenue, as discussed in Note 9, “Deferred Revenue,” to the condensed consolidated financial statements, represents consideration received that is yet to be recognized as revenue for unsatisfied performance obligations. Deferred revenue represents consideration received that is yet to be recognized as revenue. The changes in our deferred revenue during the nine months ended September 30, 2019 are reflected in the following table: Initial Listing Revenues Annual Listings Revenues Market Technology Revenues Corporate Solutions Revenues Information Services Revenues Other (1) Total (in millions) Balance at December 31, 2018 $ 66 $ 4 $ 75 $ 36 $ 80 $ 20 $ 281 Deferred revenue billed in the current period, net of recognition 24 61 36 39 56 7 223 Revenue recognized that was included in the beginning of the period (21 ) (3 ) (36 ) (34 ) (54 ) (10 ) (158 ) Translation adjustment (1 ) (1 ) (7 ) — — — (9 ) Balance at September 30, 2019 $ 68 $ 61 $ 68 $ 41 $ 82 $ 17 $ 337 ____________ (1) Primarily includes deferred revenue from U.S. listing of additional shares fees which will continue to run-off as a result of the implementation of our all-inclusive annual fee. Listing of additional shares fees are included in our Listing Services business. The deferred revenue billed in the current period, net of recognition primarily pertains to our Market Services business. As of September 30, 2019 , we estimate that our deferred revenue will be recognized in the following years: Initial Listing Revenues Annual Listings Revenues Market Technology Revenues Corporate Solutions Revenues Information Services Revenues Other (1) Total (in millions) Fiscal year ended: 2019 (2) $ 8 $ 61 $ 26 $ 21 $ 36 $ 5 $ 157 2020 25 — 33 20 46 7 131 2021 15 — 9 — — 3 27 2022 10 — — — — 1 11 2023 7 — — — — 1 8 2024 and thereafter 3 — — — — — 3 Total $ 68 $ 61 $ 68 $ 41 $ 82 $ 17 $ 337 ____________ (1) Other primarily includes revenues from U.S. listing of additional shares fees which are included in our Listing Services business. (2) Represents the estimated amortization to be recognized for the remaining three months of 2019. The timing of recognition of our deferred market technology revenues is primarily dependent upon the completion of customization and any significant modifications made pursuant to existing market technology contracts. As such, as it relates to market technology revenues, the timing represents our best estimate.

Acquisitions and Divestiture

Acquisitions and Divestiture	9 Months Ended
	Sep. 30, 2019
Business Combinations [Abstract]
Acquisitions and Divestiture	Acquisitions and Divestitures 2019 Divestiture and Acquisition We completed the following divestiture and acquisition in 2019. Financial results of each transaction are included in our condensed consolidated financial statements from the date of each divestiture or acquisition. 2019 Divestiture In March 2019, we sold our BWise enterprise governance, risk and compliance software platform, which was part of our Corporate Solutions business within our Corporate Services segment, to SAI Global and recognized a pre-tax gain on the sale of $27 million , net of disposal costs ( $20 million after tax). The pre-tax gain is included in net gain on divestiture of businesses in the Condensed Consolidated Statements of Income for the nine months ended September 30, 2019. As of December 31, 2018, the assets and liabilities of BWise were held for sale. See Note 6, “Assets and Liabilities Held For Sale,” for further discussion. 2019 Acquisition Purchase Consideration Total Net Assets Acquired Total Net Deferred Tax Liability Acquired Goodwill (in millions) Cinnober $ 219 $ 18 $ (19 ) $ 79 $ 141 In January 2019, we acquired Cinnober, a Swedish financial technology provider to brokers, exchanges and clearinghouses worldwide for $219 million . Cinnober is part of our Market Technology segment. Nasdaq used cash on hand to fund this acquisition. As of September 30, 2019 , the allocation of the purchase price, including effects of a measurement period adjustment, which is discussed below, is included in the table above. Additional adjustments to the provisional values may result before the end of the measurement period, a period not to exceed 12 months from the acquisition date. These adjustments, which may include tax and other estimates will be recorded in the reporting period in which the adjustment amounts are determined. Changes to amounts recorded as assets and liabilities may result in a corresponding adjustment to goodwill. In the third quarter of 2019, we recorded a measurement period adjustment of $4 million which resulted in a decrease to net assets acquired and an increase in goodwill. The adjustment did not result in an impact to our Condensed Consolidated Statements of Income. See “Intangible Assets” below for further discussion of intangible assets acquired in the Cinnober acquisition. 2018 Acquisition and Divestiture We completed an acquisition in November 2018 and a divestiture in April 2018. Financial results of each transaction are included in our condensed consolidated financial statements from the date of the acquisition or divestiture. 2018 Acquisition Acquisition of Quandl In November 2018, we acquired Quandl, Inc., a provider of alternative and core financial data. Quandl is part of our Information Services segment. Nasdaq used issuances of commercial paper to fund this acquisition. 2018 Divestiture In April 2018, we sold our Public Relations Solutions and Digital Media Services businesses, which were part of our Corporate Solutions business, to West Corporation and recognized a pre-tax net gain on the sale of $33 million , net of disposal costs ( $14 million after tax). This includes a post-closing working capital adjustment of $8 million ( $5 million after tax) recorded during the three months ended September 30, 2018. The total net pre-tax gain is included in net gain on divestiture of businesses in the Condensed Consolidated Statements of Income for the nine months ended September 30, 2018. Through a multi-year agreement with West, Nasdaq will continue to provide eligible Nasdaq-listed clients with access to public relations, webcasting and webhosting products and services as part of the terms of the transaction. Intangible Assets The following table presents the details of the customer relationships intangible asset at the date of acquisition for Cinnober which was the significant acquired intangible asset for this acquisition. All acquired intangible assets with finite lives are amortized using the straight-line method. ($ in millions) Customer relationships $ 67 Discount rate used 9.5 % Estimated average useful life 13 years Customer Relationships Customer relationships represent the non-contractual and contractual relationships with customers. Methodology Customer relationships were valued using the income approach, specifically an excess earnings method. The excess earnings method examines the economic returns contributed by the identified tangible and intangible assets of a company, and then isolates the excess return that is attributable to the intangible asset being valued. Discount Rate The discount rates used reflect the amount of risk associated with the hypothetical cash flows for the customer relationships relative to the overall business. In developing a discount rate for the customer relationships, we estimated a weighted-average cost of capital for the overall business and we employed this rate when discounting the cash flows. The resulting discounted cash flows were then tax-effected at the applicable statutory rate. For our acquisition of Cinnober, a discounted tax amortization benefit was added to the fair value of the assets under the assumption that the customer relationships would be amortized for tax purposes over a period of 5 years . Estimated Useful Life We estimate the useful life based on the historical behavior of the customers and a parallel analysis of the customers using the excess earnings method. Pro Forma Results and Acquisition-Related Costs The condensed consolidated financial statements for the three and nine months ended September 30, 2019 include the financial results of the above acquisitions from the date of each acquisition. Pro forma financial results have not been presented since these acquisitions both individually and in the aggregate were not material to our financial results. Acquisition-related costs for the transactions described above were expensed as incurred and are included in merger and strategic initiatives expense in the Condensed Consolidated Statements of Income.

Assets and Liabilities Held For

Assets and Liabilities Held For Sale	9 Months Ended
	Sep. 30, 2019
Discontinued Operations and Disposal Groups [Abstract]
Assets and Liabilities Held For Sale	Assets and Liabilities Held For Sale In 2018, we decided to sell BWise, our enterprise governance, risk and compliance software platform and this business was recorded as held for sale as of December 31, 2018. BWise was part of our Corporate Solutions business within our Corporate Services segment. We determined that we met all of the criteria to classify the assets and liabilities of BWise as held for sale. The disposal of BWise did not represent a strategic shift that would have a major effect on our operations and financial results and was, therefore, not classified as discontinued operations. As a result of this classification, the assets and liabilities of this business were recorded at the lower of their carrying amount or fair value less costs to sell. In February 2019, we entered into an agreement to sell BWise and in March 2019, we completed the sale and recognized a pre-tax gain on the sale of $27 million , net of disposal costs ( $20 million after tax). See “2019 Divestiture,” of Note 5, “Acquisitions and Divestitures,” for further discussion. Major Classes of Assets and Liabilities Held For Sale The carrying amounts of the major classes of assets and liabilities that were classified as held for sale at December 31, 2018 were as follows: December 31, 2018 (in millions) Receivables, net $ 13 Property and equipment, net 10 Goodwill (1) 47 Intangible assets, net (2) 16 Other assets 3 Total assets held for sale (3) $ 89 Deferred tax liabilities $ 4 Deferred revenue 12 Other current liabilities 4 Total liabilities held for sale (4) $ 20 ____________ (1) The assignment of goodwill was based on the relative fair value of the disposal group and the portion of the remaining reporting unit. (2) Primarily represents customer relationships. (3) Included in other current assets in the Condensed Consolidated Balance Sheets as of December 31, 2018. (4) Included in other current liabilities in the Condensed Consolidated Balance Sheets as of December 31, 2018.

Goodwill and Acquired Intangibl

Goodwill and Acquired Intangible Assets	9 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Acquired Intangible Assets	Goodwill and Acquired Intangible Assets Goodwill The following table presents the changes in goodwill by business segment during the nine months ended September 30, 2019 : Market Services Corporate Services Information Services Market Technology Total (in millions) Balance at December 31, 2018 $ 3,430 $ 455 $ 2,333 $ 145 $ 6,363 Goodwill acquired — — — 137 137 Measurement period adjustment — — — 4 4 Foreign currency translation adjustment (138 ) (16 ) (95 ) (23 ) (272 ) Balance at September 30, 2019 $ 3,292 $ 439 $ 2,238 $ 263 $ 6,232 The goodwill acquired for Market Technology shown above relates to our acquisition of Cinnober. See “2019 Acquisition,” of Note 5, “Acquisitions and Divestitures,” for further discussion. For further discussion of the measurement period adjustment of $4 million shown above, see “2019 Acquisition,” of Note 5, “Acquisitions and Divestitures.” This adjustment is included in our Condensed Consolidated Balance Sheets as of September 30, 2019 . Goodwill represents the excess of purchase price over the value assigned to the net assets, including identifiable intangible assets, of a business acquired. Goodwill is allocated to our reporting units based on the assignment of the fair values of each reporting unit of the acquired company. We test goodwill for impairment at the reporting unit level annually, or in interim periods if certain events occur indicating that the carrying amount may be impaired, such as changes in the business climate, poor indicators of operating performance or the sale or disposition of a significant portion of a reporting unit. There was no impairment of goodwill for the nine months ended September 30, 2019 and 2018 ; however, events such as extended economic weakness or unexpected significant declines in operating results of a reporting unit may result in goodwill impairment charges in the future. Acquired Intangible Assets The following table presents details of our total acquired intangible assets, both finite- and indefinite-lived: September 30, 2019 December 31, 2018 Gross Amount Accumulated Amortization Net Amount Weighted-Average Useful Life (in Years) Gross Amount Accumulated Amortization Net Amount Weighted-Average Useful Life (in Years) (in millions) (in millions) Finite-Lived Intangible Assets Technology $ 62 $ (17 ) $ 45 9 $ 54 $ (15 ) $ 39 9 Customer relationships 1,599 (508 ) 1,091 18 1,532 (456 ) 1,076 18 Other 18 (4 ) 14 8 17 (2 ) 15 8 Foreign currency translation adjustment (187 ) 63 (124 ) (149 ) 64 (85 ) Total finite-lived intangible assets $ 1,492 $ (466 ) $ 1,026 $ 1,454 $ (409 ) $ 1,045 Indefinite-Lived Intangible Assets Exchange and clearing registrations $ 1,257 $ — $ 1,257 $ 1,257 $ — $ 1,257 Trade names 121 — 121 122 — 122 Licenses 52 — 52 52 — 52 Foreign currency translation adjustment (217 ) — (217 ) (176 ) — (176 ) Total indefinite-lived intangible assets $ 1,213 $ — $ 1,213 $ 1,255 $ — $ 1,255 Total intangible assets $ 2,705 $ (466 ) $ 2,239 $ 2,709 $ (409 ) $ 2,300 Amortization expense for acquired finite-lived intangible assets was $25 million for the three months ended September 30, 2019 , $27 million for the three months ended September 30, 2018 , $76 million for the nine months ended September 30, 2019 , and $83 million for the nine months ended September 30, 2018 . Amortization expense decreased in 2019 primarily due to certain assets becoming fully amortized in the fourth quarter of 2018, partially offset by additional amortization expense associated with acquired intangible assets in 2019. These amounts are included in depreciation and amortization expense in the Condensed Consolidated Statements of Income. The estimated future amortization expense (excluding the impact of foreign currency translation adjustments of $124 million as of September 30, 2019 ) of acquired finite-lived intangible assets as of September 30, 2019 is as follows: (in millions) 2019 (1) $ 27 2020 105 2021 104 2022 100 2023 98 2024 and thereafter 716 Total $ 1,150 ____________ (1) Represents the estimated amortization to be recognized for the remaining three months of 2019.

Investments

Investments	9 Months Ended
	Sep. 30, 2019
Investments, Debt and Equity Securities [Abstract]
Investments	Investments The following table presents the details of our investments: September 30, December 31, (in millions) Trading securities $ 201 $ 259 Available-for-sale investment securities — 9 Financial investments, at fair value $ 201 $ 268 Equity method investments $ 159 $ 135 Equity securities $ 49 $ 44 Financial Investments, at Fair Value Trading Securities Trading securities, which are included in financial investments, at fair value in the Condensed Consolidated Balance Sheets, are primarily comprised of highly rated European government debt securities, of which $166 million as of September 30, 2019 and December 31, 2018 , are assets primarily utilized to meet regulatory capital requirements, mainly for our clearing operations at Nasdaq Clearing. Available-for-Sale Investment Securities As of December 31, 2018, available-for-sale investment securities, which are included in financial investments, at fair value in the Condensed Consolidated Balance Sheets, were primarily comprised of commercial paper. As of September 30, 2019 and December 31, 2018, the cumulative unrealized gains and losses on these securities were immaterial. Equity Method Investments As of September 30, 2019 and December 31, 2018 , our equity method investments primarily included our equity interest in OCC. The carrying amounts of our equity method investments are included in other non-current assets in the Condensed Consolidated Balance Sheets. Net income recognized from our equity interest in the earnings and losses of these equity method investments was $15 million for the three months ended September 30, 2019 , $6 million for the three months ended September 30, 2018 , $71 million for the nine months ended September 30, 2019 , and $13 million for the nine months ended September 30, 2018 . The change for the three and nine months ended September 30, 2019 compared with the same periods in 2018 is primarily due to an increase in income recognized from our investment in OCC. Following the disapproval of the OCC capital plan in February 2019, described below, OCC suspended customer rebates and dividends to owners, including the unpaid dividend on 2018 results which Nasdaq expected to receive in March 2019. We were not able to determine the impact of the disapproval of the OCC capital plan on OCC's 2018 net income until March 2019, when OCC's 2018 financial statements were made available to us. As a result, in March 2019, we recognized an additional $36 million of income relating to our share of OCC's net income for the year ended December 31, 2018. We also recognized our share of OCC's net income of $15 million for the three months ended September 30, 2019 and $33 million for the nine months ended September 30, 2019 . OCC Capital Plan In March 2015, OCC implemented a capital plan under which the options exchanges that are OCC’s stockholders contributed $150 million of new equity capital to OCC, committed to make future replenishment capital contributions under certain circumstances, and received commitments regarding future dividend payments and related matters. Nasdaq PHLX and ISE each contributed $30 million of new equity capital under the OCC capital plan. OCC adopted specific policies with respect to fees, customer refunds and stockholder dividends, which envisioned an annual dividend equal to the portion of OCC’s after-tax income that exceeded OCC’s capital requirements after payment of refunds to OCC’s clearing members (such refunds were generally 50% of the portion of OCC’s pre-tax income that exceeded OCC’s capital requirements). In 2018, 2017 and 2016, OCC disbursed annual dividends under the capital plan and Nasdaq, as the beneficial owner of shares held by Nasdaq PHLX and ISE, received $13 million in 2018, $10 million in 2017 and $4 million in 2016. The dividend recorded by Nasdaq in 2016 did not include the dividend due to ISE because our acquisition of ISE was completed in June 2016, after that year’s dividend had been paid. In February 2016, after the SEC approved the rule change establishing the OCC capital plan, certain industry participants appealed that approval in the U.S. Court of Appeals. In February 2019, on remand from the Court of Appeals, the SEC disapproved the OCC rule change that established the capital plan. OCC began a phased return of capital contributed under the capital plan, and we received $44 million in February 2019, with the remainder to be repaid at a later date. As a result of the SEC's disapproval of the rule change, we are also released from any future capital replenishment obligations under the 2015 capital plan. Equity Securities The carrying amounts of our equity securities are included in other non-current assets in the Condensed Consolidated Balance Sheets. We elected the measurement alternative for primarily all of our equity securities as they do not have a readily determinable fair value. Under the measurement alternative, these securities are measured at cost, less any impairment, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same issuer. No material adjustments were made to the carrying value of our equity investments measured under the measurement alternative during the three and nine months ended September 30, 2019. As of September 30, 2019 , our equity securities represent various strategic investments made through our corporate venture program and investments acquired through various acquisitions. As of December 31,

Deferred Revenue

Deferred Revenue	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Deferred Revenue	Revenue From Contracts With Customers Disaggregation of Revenue The following tables summarize the disaggregation of revenue by major product and service and by segment for the three and nine months ended September 30, 2019 and 2018 : Three Months Ended September 30, 2019 Market Services Corporate Services Information Services Market Technology Consolidated (in millions) Transaction-based trading and clearing, net $ 154 $ — $ — $ — $ 154 Trade management services 72 — — — 72 Listing services — 74 — — 74 Corporate solutions — 50 — — 50 Market data — — 102 — 102 Index — — 56 — 56 Investment data & analytics — — 40 — 40 Market technology — — — 84 84 Revenues less transaction-based expenses $ 226 $ 124 $ 198 $ 84 $ 632 Three Months Ended September 30, 2018 Market Services Corporate Services Information Services Market Technology Other Revenues Consolidated (in millions) Transaction-based trading and clearing, net $ 150 $ — $ — $ — $ — $ 150 Trade management services 72 — — — — 72 Listing services — 72 — — — 72 Corporate solutions — 49 — — — 49 Market data — — 95 — — 95 Index — — 52 — — 52 Investment data & analytics — — 32 — — 32 Market technology — — — 68 — 68 Other revenues — — — — 10 10 Revenues less transaction-based expenses $ 222 $ 121 $ 179 $ 68 $ 10 $ 600 For the three months ended September 30, 2019 , approximately 65.0% of Market Services revenues were recognized at a point in time and 35.0% were recognized over time. For the three months ended September 30, 2018 , approximately 63.0% of Market Services revenues were recognized at a point in time and 37.0% were recognized over time. Substantially all revenues from the Corporate Services, Information Services and Market Technology segments were recognized over time for both the three months ended September 30, 2019 and 2018. Nine Months Ended September 30, 2019 Market Services Corporate Services Information Services Market Technology Other Revenues Consolidated (in millions) Transaction-based trading and clearing, net $ 468 $ — $ — $ — $ — $ 468 Trade management services 219 — — — — 219 Listing services — 219 — — — 219 Corporate solutions — 149 — — — 149 Market data — — 302 — — 302 Index — — 166 — — 166 Investment data & analytics — — 117 — — 117 Market technology — — — 239 — 239 Other revenues — — — — 10 10 Revenues less transaction-based expenses $ 687 $ 368 $ 585 $ 239 $ 10 $ 1,889 Nine Months Ended September 30, 2018 Market Services Corporate Services Information Services Market Technology Other Revenues Consolidated (in millions) Transaction-based trading and clearing, net $ 489 $ — $ — $ — $ — $ 489 Trade management services 220 — — — — 220 Listing services — 217 — — — 217 Corporate solutions — 147 — — — 147 Market data — — 293 — — 293 Index — — 152 — — 152 Investment data & analytics — — 83 — — 83 Market technology — — — 194 — 194 Other revenues — — — — 87 87 Revenues less transaction-based expenses $ 709 $ 364 $ 528 $ 194 $ 87 $ 1,882 For the nine months ended September 30, 2019 , approximately 65.0% of Market Services revenues were recognized at a point in time and 35.0% were recognized over time. For the nine months ended September 30, 2018, approximately 64.0% of Market Services revenues were recognized at a point in time and 36.0% were recognized over time. Substantially all revenues from the Corporate Services, Information Services and Market Technology segments were recognized over time for both the nine months ended September 30, 2019 and 2018. * * * * * * Contract Balances Substantially all of our revenues are considered to be revenues from contracts with customers. The related accounts receivable balances are recorded in our Condensed Consolidated Balance Sheets as receivables which are net of allowance for doubtful accounts of $12 million as of September 30, 2019 and $13 million as of December 31, 2018 . The changes in the balance between periods were immaterial. We do not have obligations for warranties, returns or refunds to customers. For the majority of our contracts with customers, except for our market technology and listings services contracts, our performance obligations are short-term in nature and there is no significant variable consideration. We do not have revenues recognized from performance obligations that were satisfied in prior periods. We have elected not to provide disclosures about transaction price allocated to unsatisfied performance obligations if contract durations are less than one year. Excluding our market technology contracts, for contract durations that are one-year or greater, materially all of the transaction price allocated to unsatisfied performance obligations is included in deferred revenue. For our market technology contracts, the portion of transaction price allocated to unsatisfied performance obligations is shown in the table below. Deferred revenue primarily represents our contract liabilities related to our fees for annual and initial listings, market technology, corporate solutions and information services contracts. Deferred revenue is the only significant contract asset or liability as of September 30, 2019 . See Note 9, “Deferred Revenue,” for our discussion on deferred revenue balances, activity, and expected timing of recognition. Transaction Price Allocated to Remaining Performance Obligations As stated above, for contract durations that are one-year or greater, we do not have a material portion of transaction price allocated to unsatisfied performance obligations that are not included in deferred revenue other than for our market technology contracts. For our market technology contracts, t he following table summarizes the amount of the transaction price allocated to performance obligations that are unsatisfied as of September 30, 2019 : (in millions) 2019 (1) $ 78 2020 310 2021 159 2022 85 2023 45 2024 and thereafter 85 Total $ 762 ____________ (1) Represents performance obligations to be recognized over the remaining three months of 2019. Market technology deferred revenue, as discussed in Note 9, “Deferred Revenue,” to the condensed consolidated financial statements, represents consideration received that is yet to be recognized as revenue for unsatisfied performance obligations. Deferred revenue represents consideration received that is yet to be recognized as revenue. The changes in our deferred revenue during the nine months ended September 30, 2019 are reflected in the following table: Initial Listing Revenues Annual Listings Revenues Market Technology Revenues Corporate Solutions Revenues Information Services Revenues Other (1) Total (in millions) Balance at December 31, 2018 $ 66 $ 4 $ 75 $ 36 $ 80 $ 20 $ 281 Deferred revenue billed in the current period, net of recognition 24 61 36 39 56 7 223 Revenue recognized that was included in the beginning of the period (21 ) (3 ) (36 ) (34 ) (54 ) (10 ) (158 ) Translation adjustment (1 ) (1 ) (7 ) — — — (9 ) Balance at September 30, 2019 $ 68 $ 61 $ 68 $ 41 $ 82 $ 17 $ 337 ____________ (1) Primarily includes deferred revenue from U.S. listing of additional shares fees which will continue to run-off as a result of the implementation of our all-inclusive annual fee. Listing of additional shares fees are included in our Listing Services business. The deferred revenue billed in the current period, net of recognition primarily pertains to our Market Services business. As of September 30, 2019 , we estimate that our deferred revenue will be recognized in the following years: Initial Listing Revenues Annual Listings Revenues Market Technology Revenues Corporate Solutions Revenues Information Services Revenues Other (1) Total (in millions) Fiscal year ended: 2019 (2) $ 8 $ 61 $ 26 $ 21 $ 36 $ 5 $ 157 2020 25 — 33 20 46 7 131 2021 15 — 9 — — 3 27 2022 10 — — — — 1 11 2023 7 — — — — 1 8 2024 and thereafter 3 — — — — — 3 Total $ 68 $ 61 $ 68 $ 41 $ 82 $ 17 $ 337 ____________ (1) Other primarily includes revenues from U.S. listing of additional shares fees which are included in our Listing Services business. (2) Represents the estimated amortization to be recognized for the remaining three months of 2019. The timing of recognition of our deferred market technology revenues is primarily dependent upon the completion of customization and any significant modifications made pursuant to existing market technology contracts. As such, as it relates to market technology revenues, the timing represents our best estimate.

Debt Obligations

Debt Obligations	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Debt Obligations	Debt Obligations The following table presents the changes in the carrying amount of our debt obligations during the nine months ended September 30, 2019 : December 31, 2018 Additions Payments, Accretion September 30, 2019 Short-term debt: (in millions) Commercial paper $ 275 $ 2,951 $ (2,687 ) $ 539 Senior unsecured floating rate notes repaid on March 22, 2019 500 — (500 ) — 5.55% senior unsecured notes repaid on May 1, 2019 ( 1) 599 — (599 ) — $400 million senior unsecured term loan facility repaid on June 28, 2019 (average interest rate of 4.00% for the period January 1, 2019 through June 28, 2019) 100 — (100 ) — Total short-term debt 1,474 2,951 (3,886 ) 539 Long-term debt: 3.875% senior unsecured notes due June 7, 2021 686 — (34 ) 652 4.25% senior unsecured notes due June 1, 2024 497 — — 497 1.75% senior unsecured notes due May 19, 2023 682 — (33 ) 649 3.85% senior unsecured notes due June 30, 2026 496 — 1 497 1.75% senior unsecured notes due March 28, 2029 — 665 (18 ) 647 $1 billion senior unsecured revolving credit facility due April 25, 2022 (4 ) 15 (14 ) (3 ) Total long-term debt 2,357 680 (98 ) 2,939 Total debt obligations $ 3,831 $ 3,631 $ (3,984 ) $ 3,478 ____________ (1) Balance was reclassified to short-term debt as of March 31, 2019. Commercial Paper Program Our U.S. dollar commercial paper program is supported by our 2017 Credit Facility which provides liquidity support for the repayment of commercial paper issued through the commercial paper program. See “2017 Credit Facility” below for further discussion of our 2017 Credit Facility. The effective interest rate of commercial paper issuances fluctuates as short term interest rates and demand fluctuate. The fluctuation of these rates due to market conditions may impact our interest expense. As of September 30, 2019 , commercial paper notes in the table above reflect the aggregate principal amount, less the unamortized discount which is being accreted through interest expense over the life of the applicable notes. The original maturities of these notes range from 11 days to 81 days and the weighted-average maturity is 18 days . The weighted-average effective interest rate is 2.33% per annum. Senior Unsecured Notes Our senior unsecured notes were all issued at a discount. As a result of the discount, the proceeds received from each issuance were less than the aggregate principal amount. As of September 30, 2019 , the amounts in the table above reflect the aggregate principal amount, less the unamortized debt discount and the unamortized debt issuance costs which are being accreted through interest expense over the life of the applicable notes. For our Euro denominated notes, the “Payments, Accretion and Other” column also includes the impact of foreign currency translation. Our senior unsecured notes are general unsecured obligations of ours and rank equally with all of our existing and future unsubordinated obligations and they are not guaranteed by any of our subsidiaries. The senior unsecured notes were issued under indentures that, among other things, limit our ability to consolidate, merge or sell all or substantially all of our assets, create liens, and enter into sale and leaseback transactions. Upon a change of control triggering event (as defined in the various note indentures), the terms require us to repurchase all or part of each holder’s notes for cash equal to 101% of the aggregate principal amount purchased plus accrued and unpaid interest, if any. Senior Unsecured Floating Rate Notes In March 2019, we used net proceeds from the sale of commercial paper and cash on hand and repaid all of our 2019 Notes. Nasdaq issued the 2019 Notes in September 2017. The 2019 Notes paid interest quarterly in arrears at a rate equal to the three-month U.S. dollar LIBOR as determined at the beginning of each quarterly period plus 0.39% per annum until March 22, 2019. Early Extinguishment of 5.55% Senior Unsecured Notes Due 2020 Nasdaq issued the 2020 Notes in January 2010. The 2020 Notes paid interest semiannually at a rate of 5.55% per annum. In May 2019, we primarily used the net proceeds from the 2029 Notes to repay in full and terminate our 2020 Notes. For further discussion of the 2029 Notes, see “ 1.75% Senior Unsecured Notes Due 2029” below. In connection with the early extinguishment of the 2020 Notes, we recorded a pre-tax charge of $11 million , which primarily included a make-whole redemption price premium. This charge is included in general, administrative and other expense in the Condensed Consolidated Statements of Income for the nine months ended September 30, 2019 . 3.875% Senior Unsecured Notes Due 2021 In June 2013, Nasdaq issued the 2021 Notes. The 2021 Notes pay interest annually at a rate of 3.875% per annum until June 7, 2021 and such rate may vary with Nasdaq’s debt rating up to a rate not to exceed 5.875% . The 2021 Notes have been designated as a hedge of our net investment in certain foreign subsidiaries to mitigate the foreign exchange risk associated with certain investments in these subsidiaries. The decrease in the carrying amount of $34 million noted in the “Payments, Accretion and Other” column in the table above primarily reflects the translation of the 2021 Notes into U.S. dollars and is recorded in accumulated other comprehensive loss within stockholders’ equity in the Condensed Consolidated Balance Sheets as of September 30, 2019 . 4.25% Senior Unsecured Notes Due 2024 In May 2014, Nasdaq issued the 2024 Notes. The 2024 Notes pay interest semiannually at a rate of 4.25% per annum until June 1, 2024 and such rate may vary with Nasdaq’s debt rating up to a rate not to exceed 6.25% . 1.75% Senior Unsecured Notes Due 2023 In May 2016, Nasdaq issued the 2023 Notes. The 2023 Notes pay interest annually at a rate of 1.75% per annum until May 19, 2023 and such rate may vary with Nasdaq’s debt rating up to a rate not to exceed 3.75% . The 2023 Notes have been designated as a hedge of our net investment in certain foreign subsidiaries to mitigate the foreign exchange rate risk associated with certain investments in these subsidiaries. The decrease in the carrying amount of $33 million noted in the “Payments, Accretion and Other” column in the table above primarily reflects the translation of the 2023 Notes into U.S. dollars and is recorded in accumulated other comprehensive loss within stockholders’ equity in the Condensed Consolidated Balance Sheets as of September 30, 2019 . 3.85% Senior Unsecured Notes Due 2026 In June 2016, Nasdaq issued the 2026 Notes. The 2026 Notes pay interest semiannually at a rate of 3.85% per annum until June 30, 2026 and such rate may vary with Nasdaq’s debt rating up to a rate not to exceed 5.85% . 1.75% Senior Unsecured Notes Due 2029 In April 2019, Nasdaq issued the 2029 Notes at a discount. As a result of the discount, the proceeds received from the issuance were less than the aggregate principal amount. The 2029 Notes are unsecured, pay interest annually in arrears, beginning on March 28, 2020 at a rate of 1.75% per annum until March 28, 2029 and such rate may vary with Nasdaq’s debt rating up to a rate not to exceed 3.75% . The 2029 Notes may be redeemed by Nasdaq at any time, subject to a make-whole amount. The proceeds from the 2029 Notes, approximately $665 million after deducting the underwriting discount and expenses of this offering, were primarily used to redeem the 2020 Notes. For further discussion of the 2020 Notes, see “Early Extinguishment of 5.55% Senior Unsecured Notes Due 2020” above. The 2029 Notes have been designated as a hedge of our net investment in certain foreign subsidiaries to mitigate the foreign exchange risk associated with certain investments in these subsidiaries. The decrease in the carrying amount of $18 million noted in the “Payments, Accretion and Other” column in the table above primarily reflects the translation of the 2029 Notes into U.S. dollars and is recorded in accumulated other comprehensive loss within stockholders’ equity in the Condensed Consolidated Balance Sheets as of September 30, 2019 . Credit Facilities Early Extinguishment of 2016 Credit Facility In March 2016, Nasdaq entered into the 2016 Credit Facility. Under our 2016 Credit Facility, borrowings bore interest on the principal amount outstanding at a variable interest rate based on either the LIBOR or the base rate (or other applicable rate with respect to non-dollar borrowings), plus an applicable margin that varied with Nasdaq’s debt rating. In June 2019, we used proceeds from issuances of commercial paper to repay in full and terminate our 2016 Credit Facility. 2017 Credit Facility In April 2017, Nasdaq entered into the 2017 Credit Facility. The 2017 Credit Facility consists of a $1 billion five-year revolving credit facility (with sublimits for non-dollar borrowings, swingline borrowings and letters of credit), which replaced a former credit facility. Nasdaq intends to use funds available under the 2017 Credit Facility for general corporate purposes and to provide liquidity support for the repayment of commercial paper issued through the commercial paper program. Nasdaq is permitted to repay borrowings under our 2017 Credit Facility at any time in whole or in part, without penalty. As of September 30, 2019 , no amounts were outstanding on the 2017 Credit Facility. The $3 million balance represents unamortized debt issuance costs which are being accreted through interest expense over the life of the credit facility. Of the $1 billion that is available for borrowing, $541 million provides liquidity support for the commercial paper program and for a letter of credit. As such, as of September 30, 2019 , the total remaining amount available under the 2017 Credit Facility was $459 million excluding the amounts that support the commercial paper program and letter of credit. See “Commercial Paper Program” above for further discussion of our commercial paper program. Under our 2017 Credit Facility, borrowings under the revolving credit facility and swingline borrowings bear interest on the principal amount outstanding at a variable interest rate based on either the LIBOR or the base rate (as defined in the credit agreement) (or other applicable rate with respect to non-dollar borrowings), plus an applicable margin that varies with Nasdaq’s debt rating. We are charged commitment fees of 0.125% to 0.4% , depending on our credit rating, whether or not amounts have been borrowed. These commitment fees are included in interest expense and were not material for both the three and nine months ended September 30, 2019 and 2018. The 2017 Credit Facility contains financial and operating covenants. Financial covenants include a minimum interest expense coverage ratio and a maximum leverage ratio. Operating covenants include, among other things, limitations on Nasdaq’s ability to incur additional indebtedness, grant liens on assets, dispose of assets and make certain restricted payments. The facility also contains customary affirmative covenants, including access to financial statements, notice of defaults and certain other material events, maintenance of properties and insurance, and events of default, including cross-defaults to our material indebtedness. The 2017 Credit Facility includes an option for Nasdaq to increase the available aggregate amount by up to $500 million , subject to the consent of the lenders funding the increase and certain other conditions. Other Credit Facilities We also have credit facilities primarily related to our Nasdaq Clearing operations in order to provide further liquidity. Credit facilities, which are available in multiple currencies, totaled $198 million as of September 30, 2019 and $234 million as of December 31, 2018 in available liquidity, none of which was utilized. Debt Covenants As of September 30, 2019 , we were in compliance with the covenants of all of our debt obligations.

Retirement Plans

Retirement Plans	9 Months Ended
	Sep. 30, 2019
Retirement Benefits [Abstract]
Retirement Plans	Retirement Plans Defined Contribution Savings Plan We sponsor a 401(k) Plan for U.S. employees. Employees are immediately eligible to make contributions to the plan and are also eligible for an employer contribution match at an amount equal to 100.0% of the first 6.0% of eligible employee contributions. Savings plan expense included in compensation and benefits expense in the Condensed Consolidated Statements of Income was $4 million for the three months ended September 30, 2019, $3 million for the three months ended September 30, 2018, and $10 million for both the nine months ended September 30, 2019 and 2018. Pension and Supplemental Executive Retirement Plans We maintain non-contributory, defined-benefit pension plans, non-qualified SERPs for certain senior executives and other post-retirement benefit plans for eligible employees in the U.S., collectively referred to as the Nasdaq Benefit Plans. Our pension plans and SERPs are frozen. Future service and salary for all participants do not count toward an accrual of benefits under the pension plans and SERPs. Most employees outside the U.S. are covered by local retirement plans or by applicable social laws. Benefits under social laws are generally expensed in the periods in which the costs are incurred. The total expense for these plans is included in compensation and benefits expense in the Condensed Consolidated Statements of Income and was $5 million for both the three months ended September 30, 2019 and 2018, $15 million for the nine months ended September 30, 2019 , and $17 million for the nine months ended September 30, 2018 .

Share-Based Compensation

Share-Based Compensation	9 Months Ended
	Sep. 30, 2019
Share-based Payment Arrangement [Abstract]
Share-Based Compensation	Share-Based Compensation We have a share-based compensation program for employees and non-employee directors. Share-based awards granted under this program include stock options, restricted stock (consisting of restricted stock units), and PSUs. For accounting purposes, we consider PSUs to be a form of restricted stock. Summary of Share-Based Compensation Expense The following table shows the total share-based compensation expense resulting from equity awards and the 15.0% discount for the ESPP for the three and nine months ended September 30, 2019 and 2018 in the Condensed Consolidated Statements of Income: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (in millions) Share-based compensation expense before income taxes $ 21 $ 18 $ 57 $ 51 Income tax benefit (6 ) (5 ) (16 ) (14 ) Share-based compensation expense after income taxes $ 15 $ 13 $ 41 $ 37 Common Shares Available Under Our Equity Plan As of September 30, 2019 , we had approximately 10.3 million shares of common stock authorized for future issuance under our Equity Plan. Restricted Stock We grant restricted stock to most active employees. The grant date fair value of restricted stock awards is based on the closing stock price at the date of grant less the present value of future cash dividends. Restricted stock awards granted generally vest 25.0% on the second anniversary of the grant date, 25.0% on the third anniversary of the grant date, and 50.0% on the fourth anniversary of the grant date. Summary of Restricted Stock Activity The following table summarizes our restricted stock activity for the nine months ended September 30, 2019 : Restricted Stock Number of Awards Weighted-Average Grant Date Fair Value Unvested balances at January 1, 2019 1,583,375 $ 68.62 Granted 587,987 $ 84.73 Vested (492,535 ) $ 59.46 Forfeited (127,501 ) $ 73.36 Unvested balances at September 30, 2019 1,551,326 $ 77.23 As of September 30, 2019 , $66 million of total unrecognized compensation cost related to restricted stock is expected to be recognized over a weighted-average period of 1.8 years . PSUs PSUs are based on performance measures that impact the amount of shares that each recipient will receive upon vesting. We have two performance-based long-term PSU programs for certain officers, a one-year performance-based program and a three-year cumulative performance-based program that focuses on TSR. One-Year PSU Program The grant date fair value of PSUs under the one-year performance-based program is based on the closing stock price at the date of grant less the present value of future cash dividends. Under this program, an eligible employee receives a target grant of PSUs, but may receive from 0.0% to 150.0% of the target amount granted, depending on the achievement of performance measures. These awards vest ratably on an annual basis over a three-year period commencing with the end of the one-year performance period. Compensation cost is recognized over the performance period and the three-year vesting period based on the probability that such performance measures will be achieved, taking into account an estimated forfeiture rate. During 2018, certain grants of PSUs with a one-year performance period exceeded the applicable performance parameters. As a result, an additional 51,914 units above target were considered granted in the first quarter of 2019 and are included in the "Summary of PSU Activity" table below. Three-Year PSU Program Under the three-year performance-based program, each eligible individual receives PSUs, subject to market conditions, with a three-year cumulative performance period that vest at the end of the performance period. Compensation cost is recognized over the three-year vesting period, taking into account an estimated forfeiture rate, regardless of whether the market condition is satisfied, provided that the requisite service period has been completed. Performance will be determined by comparing Nasdaq’s TSR to two peer groups, each weighted 50.0% . The first peer group consists of exchange companies, and the second peer group consists of all companies in the S&P 500. Nasdaq’s relative performance ranking against each of these groups will determine the final number of shares delivered to each individual under the program. The payout under this program will be between 0.0% and 200.0% of the number of PSUs granted and will be determined by Nasdaq’s overall performance against both peer groups. However, if Nasdaq’s TSR is negative for the three-year performance period, regardless of TSR ranking, the payout will not exceed 100.0% of the number of PSUs granted. We estimate the fair value of PSUs granted under the three-year PSU program using the Monte Carlo simulation model, as these awards contain a market condition. Certain grants of PSUs that were issued in 2016 with a three-year performance period exceeded the applicable performance parameters. As a result, an additional 99,622 units above target were considered granted in the first quarter of 2019 and are included in the "Summary of PSU Activity" table below. The following weighted-average assumptions were used to determine the weighted-average fair values of the PSU awards granted under the three-year PSU program for the nine months ended September 30, 2019 : Nine Months Ended September 30, 2019 2018 Weighted-average risk free interest rate (1) 2.26 % 2.36 % Expected volatility (2) 16.5 % 18.7 % Weighted-average grant date share price $89.00 $ 86.24 Weighted-average fair value at grant date $97.65 $ 116.86 ____________ (1) The risk-free interest rate for periods within the expected life of the award is based on the U.S. Treasury yield curve in effect at the time of grant. (2) We use historic volatility for PSU awards issued under the three-year PSU program, as implied volatility data could not be obtained for all the companies in the peer groups used for relative performance measurement within the program. In addition, the annual dividend assumption utilized in the Monte Carlo simulation model is based on Nasdaq’s dividend yield at the date of grant. Summary of PSU Activity The following table summarizes our PSU activity for the nine months ended September 30, 2019 : PSUs One-Year Program Three-Year Program Number of Awards Weighted-Average Grant Date Fair Value Number of Awards Weighted-Average Grant Date Fair Value Unvested balances at January 1, 2019 314,231 $ 74.01 837,750 $ 96.57 Granted (1) 179,599 $ 83.56 397,553 $ 96.55 Vested (12,733 ) $ 67.51 (431,751 ) $ 93.25 Forfeited (22,943 ) $ 75.03 (6,101 ) $ 103.29 Unvested balances at September 30, 2019 458,154 $ 77.88 797,451 $ 98.31 ____________ (1) Includes target awards granted and certain additional awards granted based on overachievement of performance parameters. As of September 30, 2019 , $14 million of total unrecognized compensation cost related to the one-year PSU program is expected to be recognized over a weighted-average period of 1.5 years . For the three-year PSU program, $37 million of total unrecognized compensation cost is expected to be recognized over a weighted-average period of 1.5 years . Stock Options In January 2017 and in connection with her appointment, our CEO received 268,817 performance-based non-qualified stock options which will vest one-third annually over a three-year period, with each vesting contingent upon the achievement of annual performance parameters. On January 29, 2019, Nasdaq's management compensation committee and board of directors determined that the performance goal for 2018 was met, resulting in the settlement of the second tranche of the grant. There were no stock option awards granted during the nine months ended September 30, 2019 . The weighted-average grant date fair value for the 2017 grant was $66.68 . We estimated the fair value of this stock option award using the Black-Scholes valuation model using the following assumptions: Expected life (in years) 6 Weighted-average risk free interest rate 2.1 % Expected volatility 25.6 % Dividend yield 1.92 % Our computation of expected life was based on an estimate of the average length of time between option grant and exercise. The interest rate for periods within the expected life of the award was based on the U.S. Treasury yield curve in effect at the time of grant. Our computation of expected volatility was an estimate of the future upward/downward fluctuations in the underlying share price. We used Nasdaq's historical volatility for the trailing 6-year period as of the grant date. Our computation of dividend yield was based on annualized dividends expressed as a percentage of share price. Summary of Stock Option Activity A summary of stock option activity for the nine months ended September 30, 2019 is as follows: Number of Stock Options Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (in millions) Outstanding at January 1, 2019 448,966 $ 49.25 5.51 $ 14 Exercised (62,624 ) 20.92 Forfeited (25 ) 20.10 Outstanding at September 30, 2019 386,317 $ 53.68 5.43 $ 18 Exercisable at September 30, 2019 296,711 $ 49.76 4.87 $ 15 The net cash proceeds from the exercise of 9,216 stock options for the three months ended September 30, 2019 was immaterial. The net cash proceeds from the exercise of 62,624 stock options for the nine months ended September 30, 2019 was $1 million . The net cash proceeds from the exercise of 11,953 stock options for the three months ended September 30, 2018 was immaterial. We received net cash proceeds of $2 million from the exercise of 99,953 stock options for the nine months ended September 30, 2018 . The aggregate intrinsic value in the above table represents the total pre-tax intrinsic value (i.e., the difference between our closing stock price on September 30, 2019 of $99.35 and the exercise price, times the number of shares) based on stock options with an exercise price less than Nasdaq’s closing price of $99.35 as of September 30, 2019 , which would have been received by the option holders had the option holders exercised their stock options on that date. This amount can change based on the fair market value of our common stock. The total number of in-the-money stock options exercisable as of September 30, 2019 was 0.3 million and the weighted-average exercise price was $49.76 . As of September 30, 2018 , 0.3 million outstanding stock options were exercisable and the weighted-average exercise price was $36.55 . The total pre-tax intrinsic value of stock options exercised was $1 million for the three months ended September 30, 2019 , $5 million for the nine months ended September 30, 2019 , $1 million for the three months ended September 30, 2018 , and $6 million for the nine months ended September 30, 2018 . ESPP We have an ESPP under which approximately 1.7 million shares of our common stock have been reserved for future issuance as of September 30, 2019 . Under our ESPP, employees may purchase shares having a value not exceeding 10.0% of their annual compensation, subject to applicable annual Internal Revenue Service limitations. We record compensation expense related to the 15.0% discount that is given to our employees which totaled $1 million for both the three months ended September 30, 2019 and 2018 and $3 million for both the nine months ended September 30, 2019

Nasdaq Stockholders_ Equity

Nasdaq Stockholders’ Equity	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Nasdaq Stockholders' Equity	Nasdaq Stockholders’ Equity Common Stock As of September 30, 2019 , 300,000,000 shares of our common stock were authorized, 169,802,172 shares were issued and 163,894,038 shares were outstanding. The holders of common stock are entitled to one vote per share, except that our certificate of incorporation limits the ability of any person to vote in excess of 5.0% of the then-outstanding shares of Nasdaq common stock. Common Stock in Treasury, at Cost We account for the purchase of treasury stock under the cost method with the shares of stock repurchased reflected as a reduction to Nasdaq stockholders’ equity and included in common stock in treasury, at cost in the Condensed Consolidated Balance Sheets. Shares repurchased under our share repurchase program are currently retired and canceled and are therefore not included in the common stock in treasury balance. When treasury shares are reissued, they are recorded at the average cost of the treasury shares acquired. We held 5,908,134 shares of common stock in treasury as of September 30, 2019 and 5,544,321 shares as of December 31, 2018, most of which are related to shares of our common stock repurchased for the settlement of employee tax withholding obligations arising from the vesting of restricted stock and PSUs. Share Repurchase Program In January 2018, our board of directors authorized an additional $500 million for the share repurchase program, increasing the aggregate authorized amount to $726 million . These purchases may be made from time to time at prevailing market prices in open market purchases, privately-negotiated transactions, block purchase techniques or otherwise, as determined by our management. The purchases are primarily funded from existing cash balances. The share repurchase program may be suspended, modified or discontinued at any time. The share repurchase program has no defined expiration date. The following is a summary of our share repurchase activity, reported based on settlement date, for the nine months ended September 30, 2019 and 2018: Nine Months Ended September 30, 2019 2018 Number of shares of common stock repurchased 2,053,855 4,508,426 Average price paid per share $ 97.37 $ 87.43 Total purchase price (in millions) $ 200 $ 394 As discussed above in “Common Stock in Treasury, at Cost,” shares repurchased under our share repurchase program are currently retired and cancelled. As of September 30, 2019 , the remaining amount authorized for share repurchases under the program was $132 million . In October 2019, the board authorized an additional $500 million under the existing share repurchase program, bringing the aggregate authorized amount to $632 million as of October 22, 2019. Other Repurchases of Common Stock During the first nine months of 2019 , we repurchased 363,813 shares of our common stock in settlement of employee tax withholding obligations arising from the vesting of restricted stock and PSUs. Preferred Stock Our certificate of incorporation authorizes the issuance of 30,000,000 shares of preferred stock, par value $0.01 per share, issuable from time to time in one or more series. As of September 30, 2019 and December 31, 2018, no shares of preferred stock were issued or outstanding. Cash Dividends on Common Stock During the first nine months of 2019, our board of directors declared the following cash dividends: Declaration Date Dividend Per Common Share Record Date Total Amount Paid Payment Date (in millions) January 29, 2019 $ 0.44 March 15, 2019 $ 73 March 29, 2019 April 23, 2019 0.47 June 14, 2019 77 June 28, 2019 July 23, 2019 0.47 September 13, 2019 78 September 27, 2019 $ 228 The total amount paid of $228 million was recorded in retained earnings in the Condensed Consolidated Balance Sheets at September 30, 2019 . In October 2019, the board of directors approved a regular quarterly cash dividend of $0.47 per share on our outstanding common stock. The dividend is payable on December 27, 2019 to shareholders of record at the close of business on December 13, 2019. The estimated amount of this dividend is $77 million . Future declarations of quarterly dividends and the establishment of future record and payment dates are subject to approval by the board of directors. Our board of directors maintains a dividend policy with the intention to provide stockholders with regular and growing dividends over the long term as earnings and cash flow grow.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share The following table sets forth the computation of basic and diluted earnings per share: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Numerator: (in millions, except share and per share amounts) Net income attributable to common shareholders $ 150 $ 163 $ 571 $ 502 Denominator: Weighted-average common shares outstanding for basic earnings per share 164,331,832 164,227,243 165,086,951 165,622,428 Weighted-average effect of dilutive securities: Employee equity awards (1) 1,705,665 2,071,426 1,611,232 1,931,307 Contingent issuance of common stock (2) 992,247 992,247 330,749 330,749 Weighted-average common shares outstanding for diluted earnings per share 167,029,744 167,290,916 167,028,932 167,884,484 Basic and diluted earnings per share: Basic earnings per share $ 0.91 $ 0.99 $ 3.46 $ 3.03 Diluted earnings per share $ 0.90 $ 0.97 $ 3.42 $ 2.99 ____________ (1) PSUs, which are considered contingently issuable, are included in the computation of dilutive earnings per share on a weighted average basis when management determines that the applicable performance criteria would have been met if the performance period ended as of the date of the relevant computation. (2) See “Non-Cash Contingent Consideration,” of Note 18, “Commitments, Contingencies and Guarantees,” for further discussion. Securities that were not included in the computation of diluted earnings per share because their effect was antidilutive were immaterial for the three and nine months ended September 30, 2019

Fair Value of Financial Instrum

Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Fair Value of Financial Instruments The following tables present our financial assets and financial liabilities that are measured at fair value on a recurring basis as of September 30, 2019 and December 31, 2018 . September 30, 2019 Total Level 1 Level 2 Level 3 Assets at Fair Value (in millions) Financial investments, at fair value $ 201 $ 152 $ 49 $ — Default fund and margin deposit investments 1,134 134 1,000 — Total assets at fair value $ 1,335 $ 286 $ 1,049 $ — December 31, 2018 Total Level 1 Level 2 Level 3 Assets at Fair Value (in millions) Financial investments, at fair value $ 268 $ 133 $ 135 $ — Default fund and margin deposit investments 1,649 327 1,322 — Total assets at fair value $ 1,917 $ 460 $ 1,457 $ — Liabilities at Fair Value Other financial instruments $ 112 $ — $ 112 $ — Total liabilities at fair value $ 112 $ — $ 112 $ — As of September 30, 2019 and December 31, 2018 , Level 1 financial investments, at fair value were primarily comprised of trading securities and principally are highly rated European government debt securities. As of September 30, 2019 and December 31, 2018 , Level 2 financial investments, at fair value were primarily comprised of trading securities, mainly European mortgage bonds and state owned enterprises. Level 2 financial investments, at fair value as of December 31, 2018 also included corporate bonds and time deposits. Of the Level 1 and Level 2 financial investments, at fair value, $166 million as of September 30, 2019 and December 31, 2018 are assets primarily utilized to meet regulatory capital requirements, mainly for our clearing operations at Nasdaq Clearing. Our Level 1 default fund and margin deposit investments were primarily comprised of highly rated European and U.S. government debt securities as of September 30, 2019 and December 31, 2018. Level 2 default fund and margin deposit investments were primarily comprised of central bank certificates and reverse repurchase agreements as of September 30, 2019 and December 31, 2018. Our Level 2 other financial instruments at December 31, 2018 include a liability associated with Nasdaq Clearing's requirement to fulfill the settlement of certain contracts of a defaulted member. The fair value of this guarantee was $112 million as of December 31, 2018 and is included in other current liabilities in the Condensed Consolidated Balance Sheets. Collateral of $112 million as of December 31, 2018 was recorded in other current assets which offsets this liability. See Note 16, “Clearing Operations,” for further discussion of default fund contributions and margin deposits. Financial Instruments Not Measured at Fair Value on a Recurring Basis Some of our financial instruments are not measured at fair value on a recurring basis but are recorded at amounts that approximate fair value due to their liquid or short-term nature. Such financial assets and financial liabilities include: cash and cash equivalents, restricted cash, receivables, net, certain other current assets, accounts payable and accrued expenses, Section 31 fees payable to SEC, accrued personnel costs, commercial paper and certain other current liabilities. Our investment in OCC is accounted for under the equity method of accounting. We have elected the measurement alternative for the majority of our equity securities, which primarily represent various strategic investments made through our corporate venture program. See “Equity Method Investments,” and “Equity Securities,” of Note 8, “Investments,” for further discussion. We also consider our debt obligations to be financial instruments. The fair value of our debt obligations, utilizing discounted cash flow analyses for our floating rate debt and prevailing market rates for our fixed rate debt, was $3.7 billion as of September 30, 2019 and $3.9 billion as of December 31, 2018 . The discounted cash flow analyses are based on borrowing rates currently available to us for debt with similar terms and maturities. The fair value of our commercial paper approximates the carrying value since the rates of interest on this short-term debt approximate market rates as of September 30, 2019 . Our commercial paper and our fixed rate and floating rate debt are categorized as Level 2 in the fair value hierarchy. For further discussion of our debt obligations, see Note 10, “Debt Obligations.” Non-Financial Assets Measured at Fair Value on a Non-Recurring Basis Our non-financial assets, which include goodwill, intangible assets, and other long-lived assets, are not required to be carried at fair value on a recurring basis. Fair value measures of non-financial assets are primarily used in the impairment analysis of these assets. Any resulting asset impairment would require that the non-financial asset be recorded at its fair value. Nasdaq uses Level 3 inputs to measure the fair value of the above assets on a non-recurring basis. As of September 30, 2019 and December 31, 2018 , there were no non-financial assets measured at fair value on a non-recurring basis.

Clearing Operations

Clearing Operations	9 Months Ended
	Sep. 30, 2019
Due to and from Broker-Dealers and Clearing Organizations [Abstract]
Clearing Operations	Clearing Operations Nasdaq Clearing Nasdaq Clearing is authorized and supervised under EMIR as a multi-asset clearinghouse by the SFSA. Such authorization is effective for all member states of the European Union and certain other non-member states that are part of the European Economic Area, including Norway. The clearinghouse acts as the CCP for exchange and OTC trades in equity derivatives, fixed income derivatives, resale and repurchase contracts, power derivatives, emission allowance derivatives, fuel oil derivatives, and seafood derivatives. Through our clearing operations in the financial markets, which include the resale and repurchase market, the commodities markets, and the seafood market, Nasdaq Clearing is the legal counterparty for, and guarantees the fulfillment of, each contract cleared. These contracts are not used by Nasdaq Clearing for the purpose of trading on its own behalf. As the legal counterparty of each transaction, Nasdaq Clearing bears the counterparty risk between the purchaser and seller in the contract. In its guarantor role, Nasdaq Clearing has precisely equal and offsetting claims to and from clearing members on opposite sides of each contract, standing as the CCP on every contract cleared. In accordance with the rules and regulations of Nasdaq Clearing, default fund and margin collateral requirements are calculated for each clearing member’s positions in accounts with the CCP. See “Default Fund Contributions and Margin Deposits” below for further discussion of Nasdaq Clearing’s default fund and margin requirements. Nasdaq Clearing maintains four member sponsored default funds: one related to financial markets, one related to commodities markets, one related to the seafood market, and a mutualized fund. Under this structure, Nasdaq Clearing and its clearing members must contribute to the total regulatory capital related to the clearing operations of Nasdaq Clearing. This structure applies an initial separation of default fund contributions for the financial, commodities and seafood markets in order to create a buffer for each market’s counterparty risks. Simultaneously, a mutualized default fund provides capital efficiencies to Nasdaq Clearing’s members with regard to total regulatory capital required. See “Default Fund Contributions” below for further discussion of Nasdaq Clearing’s default fund. Power of assessment and a liability waterfall also have been implemented. See “Power of Assessment” and “Liability Waterfall” below for further discussion. These requirements align risk between Nasdaq Clearing and its clearing members. Nasdaq Commodities Clearing Default In September 2018, a member of the Nasdaq Clearing commodities market defaulted due to inability to post sufficient collateral to cover increased margin requirements for the positions of the relevant member, which had experienced losses due to sharp adverse movements in the Nordic - German power market spread. Nasdaq Clearing followed default procedures and offset the future market risk on the defaulting member’s positions. The default resulted in an initial loss of $133 million . In accordance with the liability waterfall, the first $8 million of the loss was allocated to Nasdaq Clearing’s junior capital and the remainder was allocated on a pro-rata basis to the commodities clearing members’ default funds. In September 2018, these funds were replenished . In December 2018, we initiated a capital relief program. The capital relief program was a voluntary program open to each commodities default fund participant; each such participant who agreed to the capital relief program received a proportion of the funds made available under the capital relief program as reflected by their proportionate share of the aggregate of the clearing members' default fund replenishments. As of September 30, 2019, we have disbursed substantially all of the $23 million offered through the program. In addition to the capital relief program, we are pursuing recovery of assets from the defaulted member which will be allocated back to default fund participants. As a result of the default, a liability of $112 million as of December 31, 2018 was recorded in other current liabilities and collateral of $112 million as of December 31, 2018 was recorded in other current assets in the Condensed Consolidated Balance Sheets in order to allow Nasdaq Clearing to fulfill the settlement of certain contracts of the defaulted member arising from the default management process. We had established mitigating positions. As of September 30, 2019, these contracts and mitigating positions have either expired or were sold to a third party together with associated collateral. The collateral and liability were previously included in default funds and margin deposits. Default Fund Contributions and Margin Deposits As of September 30, 2019 , clearing member default fund contributions and margin deposits were as follows: September 30, 2019 Cash Contributions Non-Cash Contributions Total Contributions (in millions) Default fund contributions $ 406 $ 119 $ 525 Margin deposits 2,016 3,757 5,773 Total $ 2,422 $ 3,876 $ 6,298 In accordance with its investment policy, of the total cash contributions of $2,422 million , Nasdaq Clearing has invested $856 million in highly rated European and U.S. government debt securities or central bank certificates with maturity dates primarily 90 days or less and $278 million in reverse repurchase agreements secured with highly rated government securities with maturity dates that range from 2 days to 18 days . The carrying value of these securities approximates their fair value due to the short-term nature of the instruments and reverse repurchase agreements. The remainder of this balance was held in cash in demand deposit accounts at central banks and large, highly rated financial institutions. Of the total default fund contributions of $525 million , Nasdaq Clearing can utilize $422 million as capital resources in the event of a counterparty default. The remaining balance of $103 million pertains to member posted surplus balances. In the investment activity related to default fund and margin contributions, we are exposed to counterparty risk related to reverse repurchase agreement transactions, which reflect the risk that the counterparty might become insolvent and, thus, fail to meet its obligations to Nasdaq Clearing. We mitigate this risk by only engaging in transactions with high credit quality reverse repurchase agreement counterparties and by limiting the acceptable collateral under the reverse repurchase agreement to high quality issuers, primarily government securities and other securities explicitly guaranteed by a government. The value of the underlying security is monitored during the lifetime of the contract, and in the event the market value of the underlying security falls below the reverse repurchase amount, our clearinghouse may require additional collateral or a reset of the contract. Default Fund Contributions Required contributions to the default funds are proportional to the exposures of each clearing member. When a clearing member is active in more than one market, contributions must be made to all markets’ default funds in which the member is active. Clearing members’ eligible contributions may include cash and non-cash contributions. Cash contributions received are held in cash or invested by Nasdaq Clearing, in accordance with its investment policy, either in highly rated government debt securities, time deposits, central bank certificates or reverse repurchase agreements with highly rated government debt securities as collateral. Nasdaq Clearing maintains and manages all cash deposits related to margin collateral. All risks and rewards of collateral ownership, including interest, belong to Nasdaq Clearing. Clearing members’ cash contributions are included in default funds and margin deposits in the Condensed Consolidated Balance Sheets as both a current asset and a current liability. Non-cash contributions include highly rated government debt securities that must meet specific criteria approved by Nasdaq Clearing. Non-cash contributions are pledged assets that are not recorded in the Condensed Consolidated Balance Sheets as Nasdaq Clearing does not take legal ownership of these assets and the risks and rewards remain with the clearing members. These balances may fluctuate over time due to changes in the amount of deposits required and whether members choose to provide cash or non-cash contributions. Assets pledged are held at a nominee account in Nasdaq Clearing’s name for the benefit of the clearing members and are immediately accessible by Nasdaq Clearing in the event of a default. In addition to clearing members’ required contributions to the liability waterfall, Nasdaq Clearing is also required to contribute capital to the liability waterfall and overall regulatory capital as specified under its clearinghouse rules. As of September 30, 2019 , Nasdaq Clearing committed capital totaling $140 million to the liability waterfall and overall regulatory capital, in the form of government debt securities, which are recorded as financial investments, at fair value in the Condensed Consolidated Balance Sheets. The combined regulatory capital of the clearing members and Nasdaq Clearing is intended to secure the obligations of a clearing member exceeding such member’s own margin and default fund deposits and may be used to cover losses sustained by a clearing member in the event of a default. Margin Deposits Nasdaq Clearing requires all clearing members to provide collateral, which may consist of cash and non-cash contributions, to guarantee performance on the clearing members’ open positions, or initial margin. In addition, clearing members must also provide collateral to cover the daily margin call if needed. See “Default Fund Contributions” above for further discussion of cash and non-cash contributions. Similar to default fund contributions, Nasdaq Clearing maintains and manages all cash deposits related to margin collateral. All risks and rewards of collateral ownership, including interest, belong to Nasdaq Clearing and are recorded in revenues. These cash deposits are recorded in default funds and margin deposits in the Condensed Consolidated Balance Sheets as both a current asset and a current liability. Pledged margin collateral is not recorded in our Condensed Consolidated Balance Sheets as all risks and rewards of collateral ownership, including interest, belong to the counterparty. Assets pledged are held at a nominee account in Nasdaq Clearing’s name for the benefit of the clearing members and are immediately accessible by Nasdaq Clearing in the event of a default. Nasdaq Clearing marks to market all outstanding contracts and requires payment from clearing members whose positions have lost value. The mark-to-market process helps identify any clearing members that may not be able to satisfy their financial obligations in a timely manner allowing Nasdaq Clearing the ability to mitigate the risk of a clearing member defaulting due to exceptionally large losses. In the event of a default, Nasdaq Clearing can access the defaulting member’s margin and default fund deposits to cover the defaulting member’s losses. Regulatory Capital and Risk Management Calculations Nasdaq Clearing manages risk through a comprehensive counterparty risk management framework, which is comprised of policies, procedures, standards and financial resources. The level of regulatory capital is determined in accordance with Nasdaq Clearing’s regulatory capital policy, as approved by the SFSA. Regulatory capital calculations are continuously updated through a proprietary capital-at-risk calculation model that establishes the appropriate level of capital. As mentioned above, Nasdaq Clearing is the legal counterparty for each contract cleared and thereby guarantees the fulfillment of each contract. Nasdaq Clearing accounts for this guarantee as a performance guarantee. We determine the fair value of the performance guarantee by considering daily settlement of contracts and other margining and default fund requirements, the risk management program, historical evidence of default payments, and the estimated probability of potential default payouts. The calculation is determined using proprietary risk management software that simulates gains and losses based on historical market prices, extreme but plausible market scenarios, volatility and other factors present at that point in time for those particular unsettled contracts. Based on this analysis, excluding any liability related to the Nasdaq commodities clearing default (see discussion above), the estimated liability was nominal and no liability was recorded as of September 30, 2019 . Power of Assessment To further strengthen the contingent financial resources of the clearinghouse, Nasdaq Clearing has power of assessment that provides the ability to collect additional funds from its clearing members to cover a defaulting member’s remaining obligations up to the limits established under the terms of the clearinghouse rules. The power of assessment corresponds to 100.0% of the clearing member’s aggregate contribution to the financial, commodities and seafood markets’ default funds. Liability Waterfall The liability waterfall is the priority order in which the capital resources would be utilized in the event of a default where the defaulting clearing member’s collateral would not be sufficient to cover the cost to settle its portfolio. If a default occurs and the defaulting clearing member’s collateral, including cash deposits and pledged assets, is depleted, then capital is utilized in the following amount and order: • junior capital contributed by Nasdaq Clearing, which totaled $32 million as of September 30, 2019 ; • a loss sharing pool related only to the financial market that is contributed to by clearing members and only applies if the defaulting member’s portfolio includes interest rate swap products; • specific market default fund where the loss occurred (i.e., the financial, commodities, or seafood market), which includes capital contributions of the clearing members on a pro-rata basis; • senior capital contributed to each specific market by Nasdaq Clearing, calculated in accordance with clearinghouse rules, which totaled $20 million as of September 30, 2019 ; and • mutualized default fund, which includes capital contributions of the clearing members on a pro-rata basis. If additional funds are needed after utilization of the liability waterfall, then Nasdaq Clearing will utilize its power of assessment and additional capital contributions will be required by non-defaulting members up to the limits established under the terms of the clearinghouse rules. In addition to the capital held to withstand counterparty defaults described above, Nasdaq Clearing also has committed capital of $88 million to ensure that it can handle an orderly wind-down of its operation, and that it is adequately protected against investment, operational, legal, and business risks. Market Value of Derivative Contracts Outstanding The following table includes the market value of derivative contracts outstanding prior to netting: September 30, 2019 (in millions) Commodity and seafood options, futures and forwards (1)(2)(3) $ 359 Fixed-income options and futures (1)(2) 925 Stock options and futures (1)(2) 120 Index options and futures (1)(2) 81 Total $ 1,485 ____________ (1) We determined the fair value of our option contracts using standard valuation models that were based on market-based observable inputs including implied volatility, interest rates and the spot price of the underlying instrument. (2) We determined the fair value of our futures contracts based upon quoted market prices and average quoted market yields. (3) We determined the fair value of our forward contracts using standard valuation models that were based on market-based observable inputs including LIBOR rates and the spot price of the underlying instrument. Derivative Contracts Cleared The following table includes the total number of derivative contracts cleared through Nasdaq Clearing for the nine months ended September 30, 2019 and 2018 : September 30, 2019 September 30, 2018 Commodity and seafood options, futures and forwards (1)(2) 393,153 1,506,560 Fixed-income options and futures 15,780,707 16,833,278 Stock options and futures 18,030,431 17,735,228 Index options and futures 35,752,600 35,569,046 Total 69,956,891 71,644,112 ____________ (1) The total volume in cleared power related to commodity contracts was 614 Terawatt hours (TWh) for the nine months ended September 30, 2019 and 853 TWh for the nine months ended September 30, 2018 . (2) In July 2018, the Nasdaq freight product offering was migrated to NFX, our U.S.-based futures exchange. The outstanding contract value of resale and repurchase agreements was $2.1 billion as of September 30, 2019 and $4.1 billion as of September 30, 2018 . The total number of contracts cleared was 5,580,836 for the nine months ended September 30, 2019 and was 6,835,634 for the nine months ended September 30, 2018 .

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Income Tax Provision The following table shows our income tax provision and effective tax rate: Three Months Ended September 30, Percentage Change 2019 2018 (in millions) Income tax provision $ 65 $ 46 41.3 % Effective tax rate 30.2 % 22.0 % Nine Months Ended September 30, Percentage Change 2019 2018 (in millions) Income tax provision $ 196 $ 234 (16.2 )% Effective tax rate 25.6 % 31.8 % The higher effective tax rate in the third quarter of 2019 is primarily due to a tax benefit recorded in the third quarter of 2018 for accelerated tax deductions taken on the 2017 return and a change in uncertain tax positions recorded in the third quarter of 2019. The lower effective tax rate in the first nine months of 2019 is primarily due to the 2018 reversal of certain Swedish tax benefits recorded in prior years, 2019 tax benefits from a dividends received deduction related to capital distributions from the OCC, and the reversal of a previously accrued tax penalty in Finland, partially offset by uncertain tax positions recorded in third quarter of 2019. The effective tax rate may vary from period to period depending on, among other factors, the geographic and business mix of earnings and losses. These same and other factors, including history of pre-tax earnings and losses, are taken into account in assessing the ability to realize deferred tax assets. Tax Audits Nasdaq and its eligible subsidiaries file a consolidated U.S. federal income tax return and applicable state and local income tax returns and non-U.S. income tax returns. Federal income tax returns for the years 2008 through 2016 are currently under examination by the Internal Revenue Service and we are subject to examination by the Internal Revenue Service for 2017 and 2018. Several state tax returns are currently under examination by the respective tax authorities for the years 2007 through 2017. Non-U.S. tax returns are subject to examination by the respective tax authorities for the years 2009 through 2018. Although the results of such examinations may have an impact on our unrecognized tax benefits, we do not anticipate that such impact will be material to our consolidated financial position or results of operations. In addition, other than the Swedish tax matter described below, we do not expect to settle any material tax audits in the next twelve months. The Swedish Tax Agency disallowed certain interest expense deductions for the years 2013 - 2017. We appealed this decision to the Lower Administrative Court which denied our appeal in 2018. During 2018, we further appealed to the Administrative Court of Appeal, however, we were no longer able to assert that we were more than likely to be successful and, as such, we recorded a related tax expense. In November 2019, the Administrative Court of Appeal upheld the disallowance of these deductions. As we have not recognized any benefits related to the disallowed deductions and we have paid the related assessments from the Swedish Tax Agency, the decision of the Administrative Court of Appeal does not impact our consolidated financial statements. We are subject to examination by federal, state and local, and foreign tax authorities. We regularly assess the likelihood of additional assessments by each jurisdiction and have established tax reserves that we believe are adequate in relation to the potential for additional assessments. We believe that the resolution of tax matters will not have a material effect on our financial condition but may be material to our operating results for a particular period and the effective tax rate for that period. Tax Cuts and Jobs Act On January 1, 2018, we adopted ASU 2018-02, “Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income (Topic 220).” As a result of the adoption of this standard, we recorded a reclassification of $142 million for stranded tax effects related to the Tax Cuts and Jobs Act from accumulated other comprehensive loss to retained earnings within stockholders’ equity in the Condensed Consolidated Balance Sheets as of September 30, 2018 . Of the $142 million of stranded tax effects, $135 million relates to the effect on net foreign currency translation gains and losses and $7 million relates to the effect on employee benefit plan adjustment gains and losses. These provisional amounts were finalized in the fourth quarter of 2018.

Commitments, Contingencies and

Commitments, Contingencies and Guarantees	9 Months Ended
	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments, Contingencies and Guarantees	Commitments, Contingencies and Guarantees Guarantees Issued and Credit Facilities Available In addition to the default fund contributions and margin collateral pledged by clearing members discussed in Note 16, “Clearing Operations,” we have obtained financial guarantees and credit facilities which are guaranteed by us through counter indemnities, to provide further liquidity related to our clearing businesses. Financial guarantees issued to us totaled $11 million as of September 30, 2019 and $12 million as of December 31, 2018 . As discussed in “Other Credit Facilities,” of Note 10, “Debt Obligations,” we also have credit facilities primarily related to our Nasdaq Clearing operations, which are available in multiple currencies, and totaled $198 million as of September 30, 2019 and $234 million as of December 31, 2018 , in available liquidity, none of which was utilized. Execution Access is an introducing broker which operates the trading platform for our Fixed Income business to trade in U.S. Treasury securities. Execution Access has a clearing arrangement with Industrial and Commercial Bank of China Financial Services LLC, or ICBC. As of September 30, 2019 , we have contributed $15 million of clearing deposits to ICBC in connection with this clearing arrangement. These deposits are recorded in other current assets in our Condensed Consolidated Balance Sheets. Some of the trading activity in Execution Access is cleared by ICBC through the Fixed Income Clearing Corporation, with ICBC acting as agent. Execution Access assumes the counterparty risk of clients that do not clear through the Fixed Income Clearing Corporation. Counterparty risk of clients exists for Execution Access between the trade date and the settlement date of the individual transactions, which is at least one business day (or more, if specified by the U.S. Treasury issuance calendar). Counterparties that do not clear through the Fixed Income Clearing Corporation are subject to a credit due diligence process and may be required to post collateral, provide principal letters, or provide other forms of credit enhancement to Execution Access for the purpose of mitigating counterparty risk. Daily position trading limits are also enforced for such counterparties. We believe that the potential for us to be required to make payments under these arrangements is mitigated through the pledged collateral and our risk management policies. Accordingly, no contingent liability is recorded in the Condensed Consolidated Balance Sheets for these arrangements. However, no guarantee can be provided that these arrangements will at all times be sufficient. Other Guarantees Through our clearing operations in the financial markets, Nasdaq Clearing is the legal counterparty for, and guarantees the performance of, its clearing members. See Note 16, “Clearing Operations,” for further discussion of Nasdaq Clearing performance guarantees. We have provided a guarantee related to lease obligations for The Nasdaq Entrepreneurial Center, Inc., which is a not-for-profit organization designed to convene, connect and engage aspiring and current entrepreneurs. This entity is not included in the condensed consolidated financial statements of Nasdaq. We believe that the potential for us to be required to make payments under these arrangements is unlikely. Accordingly, no contingent liability is recorded in the Condensed Consolidated Balance Sheets for the above guarantees. Non-Cash Contingent Consideration As part of the purchase price consideration of a prior acquisition, we have agreed to future annual issuances of 992,247 shares of Nasdaq common stock which approximated certain tax benefits associated with the transaction. Such contingent future issuances of Nasdaq common stock will be paid ratably through 2027 if Nasdaq’s total gross revenues equal or exceed $25 million in each such year. The contingent future issuances of Nasdaq common stock are subject to anti-dilution protections and acceleration upon certain events. Escrow Agreements In connection with prior acquisitions, we entered into escrow agreements to secure the payment of post-closing adjustments and to ensure other closing conditions. As of September 30, 2019 , these escrow agreements provide for future payment by us of up to an aggregate of $12 million which is included in other current liabilities in the Condensed Consolidated Balance Sheets. Routing Brokerage Activities One of our broker-dealer subsidiaries, Nasdaq Execution Services, provides a guarantee to securities clearinghouses and exchanges under its standard membership agreements, which require members to guarantee the performance of other members. If a member becomes unable to satisfy its obligations to a clearinghouse or exchange, other members would be required to meet its shortfalls. To mitigate these performance risks, the exchanges and clearinghouses often require members to post collateral, as well as meet certain minimum financial standards. Nasdaq Execution Services’ maximum potential liability under these arrangements cannot be quantified. However, we believe that the potential for Nasdaq Execution Services to be required to make payments under these arrangements is unlikely. Accordingly, no contingent liability is recorded in the Condensed Consolidated Balance Sheets for these arrangements. Legal and Regulatory Matters Litigation As previously disclosed, we are named as one of many defendants in City of Providence v. BATS Global Markets, Inc., et al., 14 Civ. 2811 (S.D.N.Y.), which was filed on April 18, 2014 in the United States District Court for the Southern District of New York. The district court appointed lead counsel, who filed an amended complaint on September 2, 2014. The amended complaint names as defendants seven national exchanges, as well as Barclays PLC, which operated a private alternative trading system. On behalf of a putative class of securities traders, the plaintiffs allege that the defendants engaged in a scheme to manipulate the markets through high-frequency trading; the amended complaint asserts claims against us under Section 10(b) of the Exchange Act and Rule 10b-5, as well as under Section 6(b) of the Exchange Act. The plaintiffs seek injunctive and monetary relief of an unspecified amount. We filed a motion to dismiss the amended complaint on November 3, 2014. In response, the plaintiffs filed a second amended complaint on November 24, 2014, which names the same defendants and alleges essentially the same violations. We then filed a motion to dismiss the second amended complaint on January 23, 2015. On August 26, 2015, the district court entered an order dismissing the second amended complaint in its entirety. The plaintiffs appealed the judgment of dismissal to the United States Court of Appeals for the Second Circuit (although opting not to appeal the dismissal with respect to Barclays PLC or the dismissal of claims under Section 6(b) of the Exchange Act). On December 19, 2017, the Second Circuit issued an opinion vacating the district court’s judgment of dismissal and remanding to the district court for further proceedings. On May 18, 2018, the exchanges filed a motion to dismiss the amended complaint, raising issues not addressed in the proceedings to date. On May 28, 2019, the district court denied the exchanges’ renewed motion to dismiss. On June 17, 2019, the exchanges filed a motion to certify the district court’s order for immediate review by the Second Circuit and on July 16, 2019, the district court denied the motion. Given the preliminary nature of the proceedings, we are unable to estimate what, if any, liability may result from this litigation. However, we believe that the claims are without merit and will continue to litigate vigorously. Nasdaq Commodities Clearing Default During September 2018, a clearing member of Nasdaq Clearing's commodities market was declared in default. We are responding to requests for information and are cooperating fully with the SFSA in the associated regulatory audits. While we are currently unable to predict the outcome of this matter, we do not believe it will have a material impact on our consolidated financial statements. See “Nasdaq Commodities Clearing Default,” of Note 16, “Clearing Operations,” for further information on this event. SEC Decisions In recent years, certain industry groups have challenged the level of fees that U.S. exchanges charge for market data and connectivity. We have defeated two challenges in federal appeals court pertaining to market data and an additional challenge at the administrative level within the SEC. However, in October 2018, the SEC reversed that administrative decision and found that Nasdaq had not met a burden of demonstrating that certain challenged fees were fair and reasonable; we estimate that this decision will reduce our annual revenues by approximately $1 million . Nasdaq has appealed this decision to the U.S. Court of Appeals for the District of Columbia Circuit. In addition, the SEC remanded a series of additional challenges to market data and connectivity fees back to Nasdaq for further consideration. Nasdaq has also appealed this decision to the U.S. Court of Appeals for the District of Columbia Circuit. We are unable to predict the outcome or the timing of the ultimate resolution of these matters. Other Matters Except as disclosed above and in prior reports filed under the Exchange Act, we are not currently a party to any litigation or proceeding that we believe could have a material adverse effect on our business, consolidated financial condition, or operating results. However, from time to time, we have been threatened with, or named as a defendant in, lawsuits or involved in regulatory proceedings. In the normal course of business, Nasdaq discusses matters with its regulators raised during regulatory examinations or otherwise subject to their inquiries. Management believes that censures, fines, penalties or other sanctions that could result from any ongoing examinations or inquiries will not have a material impact on its consolidated financial position or results of operations. However, we are unable to predict the outcome or the timing of the ultimate resolution of these matters, or the potential fines, penalties or injunctive or other equitable relief, if any, that may result from these matters. Tax Audits We are engaged in ongoing discussions and audits with taxing authorities on various tax matters, the resolutions of which are uncertain. Currently, there are matters that may lead to assessments, some of which may not be resolved for several years. Based on currently available information, we believe we have adequately provided for any assessments that could result from those proceedings where it is more likely than not that we will be assessed. We review our positions on these matters as they progress. See “Tax Audits,” of Note 17, “Income Taxes,” for further discussion.

Business Segments

Business Segments	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Business Segments	Business Segments We manage, operate and provide our products and services in four business segments: Market Services, Corporate Services, Information Services and Market Technology. See Note 1, “Organization and Nature of Operations,” for further discussion of our reportable segments. Our management allocates resources, assesses performance and manages these businesses as four separate segments. We evaluate the performance of our segments based on several factors, of which the primary financial measure is operating income. Results of individual businesses are presented based on our management accounting practices and structure. The following table presents certain information regarding our business segments for the three and nine months ended September 30, 2019 and 2018 : Market Services Corporate Services Information Services Market Technology Corporate Items Consolidated (in millions) Three Months Ended September 30, 2019 Total revenues $ 690 $ 124 $ 198 $ 84 $ — $ 1,096 Transaction-based expenses (464 ) — — — — (464 ) Revenues less transaction-based expenses 226 124 198 84 — 632 Operating income (loss) $ 129 $ 45 $ 126 $ 15 $ (89 ) $ 226 Three Months Ended September 30, 2018 Total revenues $ 586 $ 121 $ 179 $ 68 $ 10 $ 964 Transaction-based expenses (364 ) — — — — (364 ) Revenues less transaction-based expenses 222 121 179 68 10 600 Operating income (loss) $ 121 $ 40 $ 117 $ 9 $ (41 ) $ 246 Nine Months Ended September 30, 2019 Total revenues $ 1,995 $ 368 $ 585 $ 239 $ 10 $ 3,197 Transaction-based expenses (1,308 ) — — — — (1,308 ) Revenues less transaction-based expenses 687 368 585 239 10 1,889 Operating income (loss) 392 134 372 29 (170 ) 757 Nine Months Ended September 30, 2018 Total revenues $ 1,968 $ 364 $ 528 $ 194 $ 87 $ 3,141 Transaction-based expenses (1,259 ) — — — — (1,259 ) Revenues less transaction-based expenses 709 364 528 194 87 1,882 Operating income (loss) 402 117 342 20 (94 ) 787 Certain amounts are allocated to corporate items in our management reports as we believe they do not contribute to a meaningful evaluation of a particular segment's ongoing operating performance. These items, which are shown in the table below, include the following: Amortization expense of acquired intangible assets: We amortize intangible assets acquired in connection with various acquisitions. Intangible asset amortization expense can vary from period to period due to episodic acquisitions completed, rather than from our ongoing business operations. As such, if intangible asset amortization is included in performance measures, it is more difficult to assess the day-to-day operating performance of the segments, and the relative operating performance of the segments between periods. Management does not consider intangible asset amortization expense for the purpose of evaluating the performance of our segments or their managers or when making decisions to allocate resources. Therefore, we believe performance measures excluding intangible asset amortization expense provide management with a more useful representation of our segments' ongoing activity in each period. Merger and strategic initiatives expense: We have pursued various strategic initiatives and completed acquisitions and divestitures in recent years that have resulted in expenses which would not have otherwise been incurred. These expenses generally include integration costs, as well as legal, due diligence and other third party transaction costs. The frequency and the amount of such expenses vary significantly based on the size, timing and complexity of the transaction. Restructuring charges: In September 2019, we initiated a restructuring plan. See Note 20, “Restructuring Charges,” for a discussion of the plan. We believe performance measures excluding restructuring charges provide management with a more useful representation of our segments' ongoing activity in each period. Clearing default loss: In September 2018, we recorded an $8 million loss related to a default of a Nasdaq Clearing commodities member. See “Nasdaq Commodities Clearing Default,” of Note 16, “Clearing Operations,” for further discussion of the default. We have included the loss related to the default in corporate items as we believe it is non-recurring, as there has never been a loss due to member default in our clearinghouse, and should be excluded when evaluating the ongoing operating performance of the Market Services segment. Any expenses associated with the evaluation and enhancement of processes and procedures will be reflected within the Market Services segment. 2019 and 2018 divestitures: We have included in corporate items the revenues and expenses of BWise and the Public Relations Solutions and Digital Media Services businesses which were part of the Corporate Solutions business within our Corporate Services segment as BWise was sold in March 2019 and the Public Relations Solutions and Digital Media Services businesses were sold in April 2018. See “2019 Divestiture,” and “2018 Divestiture,” of Note 5, “Acquisitions and Divestitures,” for further discussion. Other significant items: We have included certain other charges or gains in corporate items, to the extent we believe they should be excluded when evaluating the ongoing operating performance of each individual segment. For the three and nine months ended September 30, 2019 , other significant items included a provision for notes receivable associated with the funding of technology development for the CAT, litigation costs, and out of period tax charges. The provision for notes receivable is a consequence of changes to the CAT project, and particularly, the decision by Nasdaq and the other exchanges to impair the value of the technology built by the original vendor, who has been replaced. For the nine months ended September 30, 2019, other significant items also included loss on extinguishment of debt which is recorded in general, administrative and other expense in our Condensed Consolidated Statements of Income. For the three and nine months ended September 30, 2018 , other significant items included litigation costs and for the nine months ended September 30, 2018 , out of period tax charges. Accordingly, we do not allocate these costs for purposes of disclosing segment results because they do not contribute to a meaningful evaluation of a particular segment’s ongoing operating performance. * * * * * * A summary of our corporate items is as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (in millions) Revenues - divested businesses $ — $ 10 $ 10 $ 87 Expenses: Amortization expense of acquired intangible assets 25 27 76 83 Merger and strategic initiatives expense 10 6 25 7 Restructuring charges 30 — 30 — Provision for notes receivable 20 — 20 — Clearing default loss — 8 — 8 Extinguishment of debt — — 11 — Expenses - divested businesses — 8 8 75 Other 4 2 10 8 Total expenses 89 51 180 181 Operating loss $ (89 ) $ (41 ) $ (170 ) $ (94 )

Restructuring Charges

Restructuring Charges	9 Months Ended
	Sep. 30, 2019
Restructuring and Related Activities [Abstract]
Restructuring Charges	Restructuring Charges In September 2019, we initiated the transition of certain technology platforms to advance the company's strategic opportunities as a technology and analytics provider and continue the re-alignment of certain business areas. In connection with these restructuring efforts, we are retiring certain elements of our marketplace infrastructure and technology product offerings as we implement NFF and other technologies internally and externally. As a result of these actions, we expect to incur $65 million to $75 million in pre-tax charges over a two year period related primarily to non-cash items such as asset impairments, accelerated depreciation as well as third-party consulting costs. Restructuring charges are recorded on restructuring plans that have been committed to by management and are, in part, based upon management’s best estimates of future events. The following table presents a summary of the 2019 restructuring plan charges in the Condensed Consolidated Statements of Income for the three and nine months ended September 30, 2019 which primarily consisted of asset impairment charges mainly related to capitalized software. Three and Nine Months Ended September 30, 2019 (in millions) Asset impairments $ 23 Accelerated depreciation 2 Severance and employee-related costs 3 Other 2 Total restructuring charges $ 30

Significant Accounting Polici_2

Significant Accounting Policies Update (Policies)	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Basis of Presentation	The condensed consolidated financial statements are prepared in accordance with U.S. GAAP and include the accounts of Nasdaq, its wholly-owned subsidiaries and other entities in which Nasdaq has a controlling financial interest. When we do not have a controlling interest in an entity but exercise significant influence over the entity’s operating and financial policies, such investment is accounted for under the equity method of accounting. We recognize our share of earnings or losses of an equity method investee based on our ownership percentage. See “Equity Method Investments,” of Note 8, “Investments,” for further discussion of our equity method investments.
Consolidation	The accompanying condensed consolidated financial statements reflect all adjustments which are, in the opinion of management, necessary for a fair statement of the results. These adjustments are of a normal recurring nature. All significant intercompany accounts and transactions have been eliminated in consolidation. As permitted under U.S. GAAP, certain footnotes or other financial information can be condensed or omitted in the interim condensed consolidated financial statements. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the consolidated financial statements and accompanying notes included in Nasdaq’s Form 10-K. The year-end condensed balance sheet data was derived from the audited financial statements, but does not include all disclosures required by U.S. GAAP. On January 1, 2019, we adopted ASU 2016-02, “Leases,” or ASU 2016-02. See Note 3, “Significant Accounting Policies Update,” for further discussion.
Reclassification	Certain prior year amounts have been reclassified to conform to the current year presentation.
Use of Estimates	The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts and the disclosure of contingent amounts in the condensed consolidated financial statements and accompanying notes. Actual results could differ from those estimates.
Subsequent Events	Subsequent Events We have evaluated subsequent events through the issuance date of this Quarterly Report on Form 10-Q.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Accounting Standard Description Effective Date Effect on the Financial Statements or Other Significant Matters Goodwill In January 2017, the FASB issued ASU 2017-04, “Simplifying the Test for Goodwill Impairment.” This ASU simplifies how an entity is required to test goodwill for impairment and removes the second step of the goodwill impairment test, which required a hypothetical purchase price allocation if the fair value of a reporting unit is less than its carrying amount. Goodwill impairment will now be measured using the difference between the carrying amount and the fair value of the reporting unit and the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. The amendments in this ASU should be applied on a prospective basis. January 1, 2020, with early adoption permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. We will adopt this standard on January 1, 2020. We do not anticipate a material impact on our consolidated financial statements at the time of adoption of this new standard as the carrying amounts of our reporting units have been less than their corresponding fair values in recent years. However, changes in future projections, market conditions and other factors may cause a change in the excess of fair value of our reporting units over their corresponding carrying amounts. Financial Instruments - Credit Losses In June 2016, the FASB issued ASU 2016-13, “Measurement of Credit Losses on Financial Instruments.” This ASU changes the impairment model for certain financial instruments. The new model is a forward looking expected loss model and will apply to financial assets subject to credit losses and measured at amortized cost and certain off-balance sheet credit exposures. This includes loans, held-to-maturity debt securities, loan commitments, financial guarantees and net investments in leases, as well as trade receivables. For available-for-sale debt securities with unrealized losses, credit losses will be measured in a manner similar to today, except that the losses will be recognized as allowances rather than reductions in the amortized cost of the securities. January 1, 2020, with early adoption permitted as of January 1, 2019. We will adopt this standard on January 1, 2020. Any impact will be recognized as a cumulative-effect adjustment to retained earnings as of the effective date to align our credit loss methodology with the new standard. We do not expect the adoption of this new standard to have a material impact on our consolidated balance sheets or our statements of income and it will not impact our cash flows.
Leases	We adopted ASU 2016-02 on January 1, 2019, and elected the optional transition method to initially apply the standard at the January 1, 2019 adoption date. As a result, we applied the new lease standard prospectively to our leases existing or commencing on or after January 1, 2019. Comparative periods presented were not restated upon adoption. Similarly, new disclosures under the standard were made for periods beginning January 1, 2019, and not for prior comparative periods. Prior periods will continue to be reported under guidance in effect prior to January 1, 2019. In addition, w e elected the package of practical expedients permitted under the transition guidance within the standard, which among other things, allowed us to not reassess contracts to determine if they contain leases, lease classification and initial direct costs. The standard did not impact our statements of income and had no impact on our cash flows. We have operating leases which are primarily real estate leases for our U.S. and European headquarters and for general office space. These leases have varying lease terms ranging from 3 months to 17 years. We determine if an arrangement is a lease at inception. Operating leases are included in operating lease assets, other current liabilities, and operating lease liabilities in our condensed consolidated balance sheets as of September 30, 2019 . As of September 30, 2019 , we do not have any finance leases. Operating lease assets represent our right to use an underlying asset for the lease term and lease liabilities represent our obligation to make lease payments arising from the lease. Operating lease assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. Since our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The operating lease asset also includes any lease payments made and excludes lease incentives. Our lease terms include options to extend or terminate the lease when we are reasonably certain that we will exercise that option. Lease expense for lease payments is recognized on a straight-line basis over the lease term. Certain of our lease agreements include rental payments adjusted periodically for inflation based on an index or rate. These payments are included in the initial measurement of the operating lease liability and operating lease asset. However, rental payments that are based on a change in an index or a rate are considered variable lease payments and are expensed as incurred. We have lease agreements with lease and non-lease components, which are accounted for as a single performance obligation to the extent that the timing and pattern of transfer are similar for the lease and non-lease components and the lease component qualifies as an operating lease . We do not recognize lease liabilities and operating lease assets for leases with a term of 12 months or less. We recognize these lease payments on a straight-line basis over the lease term. Our lease agreements do not contain any material residual value guarantees or material restrictions or covenants. We sublease certain real estate to third parties. Our sublease portfolio consists of operating leases.

Basis of Presentation and Pri_2

Basis of Presentation and Principles of Consolidation (Tables)	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of the Recent Accounting Pronouncements	Recent Accounting Pronouncements Accounting Standard Description Effective Date Effect on the Financial Statements or Other Significant Matters Goodwill In January 2017, the FASB issued ASU 2017-04, “Simplifying the Test for Goodwill Impairment.” This ASU simplifies how an entity is required to test goodwill for impairment and removes the second step of the goodwill impairment test, which required a hypothetical purchase price allocation if the fair value of a reporting unit is less than its carrying amount. Goodwill impairment will now be measured using the difference between the carrying amount and the fair value of the reporting unit and the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. The amendments in this ASU should be applied on a prospective basis. January 1, 2020, with early adoption permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. We will adopt this standard on January 1, 2020. We do not anticipate a material impact on our consolidated financial statements at the time of adoption of this new standard as the carrying amounts of our reporting units have been less than their corresponding fair values in recent years. However, changes in future projections, market conditions and other factors may cause a change in the excess of fair value of our reporting units over their corresponding carrying amounts. Financial Instruments - Credit Losses In June 2016, the FASB issued ASU 2016-13, “Measurement of Credit Losses on Financial Instruments.” This ASU changes the impairment model for certain financial instruments. The new model is a forward looking expected loss model and will apply to financial assets subject to credit losses and measured at amortized cost and certain off-balance sheet credit exposures. This includes loans, held-to-maturity debt securities, loan commitments, financial guarantees and net investments in leases, as well as trade receivables. For available-for-sale debt securities with unrealized losses, credit losses will be measured in a manner similar to today, except that the losses will be recognized as allowances rather than reductions in the amortized cost of the securities. January 1, 2020, with early adoption permitted as of January 1, 2019. We will adopt this standard on January 1, 2020. Any impact will be recognized as a cumulative-effect adjustment to retained earnings as of the effective date to align our credit loss methodology with the new standard. We do not expect the adoption of this new standard to have a material impact on our consolidated balance sheets or our statements of income and it will not impact our cash flows.

Significant Accounting Polici_3

Significant Accounting Policies Update (Tables)	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Supplemental Balance Sheet Information Related to Operating Leases	The following table provides supplemental balance sheet information related to Nasdaq's operating leases: Leases Balance Sheet Classification September 30, 2019 (in millions) Assets: Operating lease assets Operating lease assets $ 346 Liabilities: Current lease liabilities Other current liabilities $ 60 Non-current lease liabilities Operating lease liabilities 327 Total lease liabilities $ 387
Lease Cost and Supplemental Cash Flow Information	The following table provides information related to Nasdaq's lease term and discount rate: September 30, 2019 Weighted-average remaining lease term (in years) 10.4 Weighted-average discount rate 4.6 % The following table provides supplemental cash flow information related to Nasdaq's operating leases: Nine Months Ended September 30, 2019 (in millions) Cash paid for amounts included in the measurement of operating lease liabilities $ 59 Lease assets obtained in exchange for new operating lease liabilities $ 20 The following table summarizes Nasdaq's lease cost: Three Months Ended September 30, 2019 Nine Months Ended September 30, 2019 (in millions) Operating lease cost (1) $ 19 $ 58 Variable lease cost 6 18 Sublease income (1 ) (4 ) Total lease cost $ 24 $ 72 ____________ (1) Includes short-term lease cost, which was immaterial.
Operating Lease Maturity	The following table reconciles the undiscounted cash flows for each of the first five years and total of the remaining years to the operating lease liabilities recorded in our condensed consolidated balance sheet. September 30, 2019 (in millions) 2019 (1) $ 19 2020 76 2021 66 2022 44 2023 39 Thereafter 261 Total lease payments 505 Less: interest (2) (118 ) Present value of lease liabilities (3) $ 387 ____________ (1) Represents the estimated lease payments to be made for the remaining three months of 2019. (2) Calculated using the interest rate for each lease. (3) Includes the current portion of $60 million .

Revenue From Contracts With C_2

Revenue From Contracts With Customers (Tables)	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	Nine Months Ended September 30, 2019 Market Services Corporate Services Information Services Market Technology Other Revenues Consolidated (in millions) Transaction-based trading and clearing, net $ 468 $ — $ — $ — $ — $ 468 Trade management services 219 — — — — 219 Listing services — 219 — — — 219 Corporate solutions — 149 — — — 149 Market data — — 302 — — 302 Index — — 166 — — 166 Investment data & analytics — — 117 — — 117 Market technology — — — 239 — 239 Other revenues — — — — 10 10 Revenues less transaction-based expenses $ 687 $ 368 $ 585 $ 239 $ 10 $ 1,889 Nine Months Ended September 30, 2018 Market Services Corporate Services Information Services Market Technology Other Revenues Consolidated (in millions) Transaction-based trading and clearing, net $ 489 $ — $ — $ — $ — $ 489 Trade management services 220 — — — — 220 Listing services — 217 — — — 217 Corporate solutions — 147 — — — 147 Market data — — 293 — — 293 Index — — 152 — — 152 Investment data & analytics — — 83 — — 83 Market technology — — — 194 — 194 Other revenues — — — — 87 87 Revenues less transaction-based expenses $ 709 $ 364 $ 528 $ 194 $ 87 $ 1,882 The following tables summarize the disaggregation of revenue by major product and service and by segment for the three and nine months ended September 30, 2019 and 2018 : Three Months Ended September 30, 2019 Market Services Corporate Services Information Services Market Technology Consolidated (in millions) Transaction-based trading and clearing, net $ 154 $ — $ — $ — $ 154 Trade management services 72 — — — 72 Listing services — 74 — — 74 Corporate solutions — 50 — — 50 Market data — — 102 — 102 Index — — 56 — 56 Investment data & analytics — — 40 — 40 Market technology — — — 84 84 Revenues less transaction-based expenses $ 226 $ 124 $ 198 $ 84 $ 632 Three Months Ended September 30, 2018 Market Services Corporate Services Information Services Market Technology Other Revenues Consolidated (in millions) Transaction-based trading and clearing, net $ 150 $ — $ — $ — $ — $ 150 Trade management services 72 — — — — 72 Listing services — 72 — — — 72 Corporate solutions — 49 — — — 49 Market data — — 95 — — 95 Index — — 52 — — 52 Investment data & analytics — — 32 — — 32 Market technology — — — 68 — 68 Other revenues — — — — 10 10 Revenues less transaction-based expenses $ 222 $ 121 $ 179 $ 68 $ 10 $ 600
Remaining Performance Obligation, Expected Timing of Satisfaction	For our market technology contracts, t he following table summarizes the amount of the transaction price allocated to performance obligations that are unsatisfied as of September 30, 2019 : (in millions) 2019 (1) $ 78 2020 310 2021 159 2022 85 2023 45 2024 and thereafter 85 Total $ 762 ____________ (1) Represents performance obligations to be recognized over the remaining three months of 2019.

Acquisitions and Divestiture (T

Acquisitions and Divestiture (Tables)	9 Months Ended
	Sep. 30, 2019
Business Combinations [Abstract]
Schedule of Business Acquisitions, by Acquisition	2019 Acquisition Purchase Consideration Total Net Assets Acquired Total Net Deferred Tax Liability Acquired Goodwill (in millions) Cinnober $ 219 $ 18 $ (19 ) $ 79 $ 141
Acquired Finite Lived Intangible Assets in Acquisition	The following table presents the details of the customer relationships intangible asset at the date of acquisition for Cinnober which was the significant acquired intangible asset for this acquisition. All acquired intangible assets with finite lives are amortized using the straight-line method. ($ in millions) Customer relationships $ 67 Discount rate used 9.5 % Estimated average useful life 13 years

Assets and Liabilities Held F_2

Assets and Liabilities Held For Sale (Tables)	9 Months Ended
	Sep. 30, 2019
Discontinued Operations and Disposal Groups [Abstract]
Schedule of Carrying Amounts of Assets and Liabilities Classified as Held for Sale	The carrying amounts of the major classes of assets and liabilities that were classified as held for sale at December 31, 2018 were as follows: December 31, 2018 (in millions) Receivables, net $ 13 Property and equipment, net 10 Goodwill (1) 47 Intangible assets, net (2) 16 Other assets 3 Total assets held for sale (3) $ 89 Deferred tax liabilities $ 4 Deferred revenue 12 Other current liabilities 4 Total liabilities held for sale (4) $ 20 ____________ (1) The assignment of goodwill was based on the relative fair value of the disposal group and the portion of the remaining reporting unit. (2) Primarily represents customer relationships. (3) Included in other current assets in the Condensed Consolidated Balance Sheets as of December 31, 2018. (4) Included in other current liabilities in the Condensed Consolidated Balance Sheets as of December 31, 2018.

Goodwill and Acquired Intangi_2

Goodwill and Acquired Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Changes in Goodwill	The following table presents the changes in goodwill by business segment during the nine months ended September 30, 2019 : Market Services Corporate Services Information Services Market Technology Total (in millions) Balance at December 31, 2018 $ 3,430 $ 455 $ 2,333 $ 145 $ 6,363 Goodwill acquired — — — 137 137 Measurement period adjustment — — — 4 4 Foreign currency translation adjustment (138 ) (16 ) (95 ) (23 ) (272 ) Balance at September 30, 2019 $ 3,292 $ 439 $ 2,238 $ 263 $ 6,232
Schedule of Acquired Finite-Lived Intangible Assets	The following table presents details of our total acquired intangible assets, both finite- and indefinite-lived: September 30, 2019 December 31, 2018 Gross Amount Accumulated Amortization Net Amount Weighted-Average Useful Life (in Years) Gross Amount Accumulated Amortization Net Amount Weighted-Average Useful Life (in Years) (in millions) (in millions) Finite-Lived Intangible Assets Technology $ 62 $ (17 ) $ 45 9 $ 54 $ (15 ) $ 39 9 Customer relationships 1,599 (508 ) 1,091 18 1,532 (456 ) 1,076 18 Other 18 (4 ) 14 8 17 (2 ) 15 8 Foreign currency translation adjustment (187 ) 63 (124 ) (149 ) 64 (85 ) Total finite-lived intangible assets $ 1,492 $ (466 ) $ 1,026 $ 1,454 $ (409 ) $ 1,045 Indefinite-Lived Intangible Assets Exchange and clearing registrations $ 1,257 $ — $ 1,257 $ 1,257 $ — $ 1,257 Trade names 121 — 121 122 — 122 Licenses 52 — 52 52 — 52 Foreign currency translation adjustment (217 ) — (217 ) (176 ) — (176 ) Total indefinite-lived intangible assets $ 1,213 $ — $ 1,213 $ 1,255 $ — $ 1,255 Total intangible assets $ 2,705 $ (466 ) $ 2,239 $ 2,709 $ (409 ) $ 2,300
Schedule of Acquired Indefinite-lived Intangible Assets	The following table presents details of our total acquired intangible assets, both finite- and indefinite-lived: September 30, 2019 December 31, 2018 Gross Amount Accumulated Amortization Net Amount Weighted-Average Useful Life (in Years) Gross Amount Accumulated Amortization Net Amount Weighted-Average Useful Life (in Years) (in millions) (in millions) Finite-Lived Intangible Assets Technology $ 62 $ (17 ) $ 45 9 $ 54 $ (15 ) $ 39 9 Customer relationships 1,599 (508 ) 1,091 18 1,532 (456 ) 1,076 18 Other 18 (4 ) 14 8 17 (2 ) 15 8 Foreign currency translation adjustment (187 ) 63 (124 ) (149 ) 64 (85 ) Total finite-lived intangible assets $ 1,492 $ (466 ) $ 1,026 $ 1,454 $ (409 ) $ 1,045 Indefinite-Lived Intangible Assets Exchange and clearing registrations $ 1,257 $ — $ 1,257 $ 1,257 $ — $ 1,257 Trade names 121 — 121 122 — 122 Licenses 52 — 52 52 — 52 Foreign currency translation adjustment (217 ) — (217 ) (176 ) — (176 ) Total indefinite-lived intangible assets $ 1,213 $ — $ 1,213 $ 1,255 $ — $ 1,255 Total intangible assets $ 2,705 $ (466 ) $ 2,239 $ 2,709 $ (409 ) $ 2,300
Estimated Future Amortization Expense	The estimated future amortization expense (excluding the impact of foreign currency translation adjustments of $124 million as of September 30, 2019 ) of acquired finite-lived intangible assets as of September 30, 2019 is as follows: (in millions) 2019 (1) $ 27 2020 105 2021 104 2022 100 2023 98 2024 and thereafter 716 Total $ 1,150 ____________ (1) Represents the estimated amortization to be recognized for the remaining three months of 2019.

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2019
Investments, Debt and Equity Securities [Abstract]
Schedule of Investments	The following table presents the details of our investments: September 30, December 31, (in millions) Trading securities $ 201 $ 259 Available-for-sale investment securities — 9 Financial investments, at fair value $ 201 $ 268 Equity method investments $ 159 $ 135 Equity securities $ 49 $ 44

Deferred Revenue (Tables)

Deferred Revenue (Tables)	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Changes in Deferred Revenue	The changes in our deferred revenue during the nine months ended September 30, 2019 are reflected in the following table: Initial Listing Revenues Annual Listings Revenues Market Technology Revenues Corporate Solutions Revenues Information Services Revenues Other (1) Total (in millions) Balance at December 31, 2018 $ 66 $ 4 $ 75 $ 36 $ 80 $ 20 $ 281 Deferred revenue billed in the current period, net of recognition 24 61 36 39 56 7 223 Revenue recognized that was included in the beginning of the period (21 ) (3 ) (36 ) (34 ) (54 ) (10 ) (158 ) Translation adjustment (1 ) (1 ) (7 ) — — — (9 ) Balance at September 30, 2019 $ 68 $ 61 $ 68 $ 41 $ 82 $ 17 $ 337 ____________ (1) Primarily includes deferred revenue from U.S. listing of additional shares fees which will continue to run-off as a result of the implementation of our all-inclusive annual fee. Listing of additional shares fees are included in our Listing Services business. The deferred revenue billed in the current period, net of recognition primarily pertains to our Market Services business.
Estimated Deferred Revenue	As of September 30, 2019 , we estimate that our deferred revenue will be recognized in the following years: Initial Listing Revenues Annual Listings Revenues Market Technology Revenues Corporate Solutions Revenues Information Services Revenues Other (1) Total (in millions) Fiscal year ended: 2019 (2) $ 8 $ 61 $ 26 $ 21 $ 36 $ 5 $ 157 2020 25 — 33 20 46 7 131 2021 15 — 9 — — 3 27 2022 10 — — — — 1 11 2023 7 — — — — 1 8 2024 and thereafter 3 — — — — — 3 Total $ 68 $ 61 $ 68 $ 41 $ 82 $ 17 $ 337 ____________ (1) Other primarily includes revenues from U.S. listing of additional shares fees which are included in our Listing Services business. (2) Represents the estimated amortization to be recognized for the remaining three months of 2019.

Debt Obligations (Tables)

Debt Obligations (Tables)	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Changes in Debt Obligations	The following table presents the changes in the carrying amount of our debt obligations during the nine months ended September 30, 2019 : December 31, 2018 Additions Payments, Accretion September 30, 2019 Short-term debt: (in millions) Commercial paper $ 275 $ 2,951 $ (2,687 ) $ 539 Senior unsecured floating rate notes repaid on March 22, 2019 500 — (500 ) — 5.55% senior unsecured notes repaid on May 1, 2019 ( 1) 599 — (599 ) — $400 million senior unsecured term loan facility repaid on June 28, 2019 (average interest rate of 4.00% for the period January 1, 2019 through June 28, 2019) 100 — (100 ) — Total short-term debt 1,474 2,951 (3,886 ) 539 Long-term debt: 3.875% senior unsecured notes due June 7, 2021 686 — (34 ) 652 4.25% senior unsecured notes due June 1, 2024 497 — — 497 1.75% senior unsecured notes due May 19, 2023 682 — (33 ) 649 3.85% senior unsecured notes due June 30, 2026 496 — 1 497 1.75% senior unsecured notes due March 28, 2029 — 665 (18 ) 647 $1 billion senior unsecured revolving credit facility due April 25, 2022 (4 ) 15 (14 ) (3 ) Total long-term debt 2,357 680 (98 ) 2,939 Total debt obligations $ 3,831 $ 3,631 $ (3,984 ) $ 3,478 ____________ (1) Balance was reclassified to short-term debt as of March 31, 2019.

Share-Based Compensation (Table

Share-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2019
Share-based Payment Arrangement [Abstract]
Summary of Share-Based Compensation Expense	The following table shows the total share-based compensation expense resulting from equity awards and the 15.0% discount for the ESPP for the three and nine months ended September 30, 2019 and 2018 in the Condensed Consolidated Statements of Income: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (in millions) Share-based compensation expense before income taxes $ 21 $ 18 $ 57 $ 51 Income tax benefit (6 ) (5 ) (16 ) (14 ) Share-based compensation expense after income taxes $ 15 $ 13 $ 41 $ 37
Summary of Restricted Stock Activity	The following table summarizes our restricted stock activity for the nine months ended September 30, 2019 : Restricted Stock Number of Awards Weighted-Average Grant Date Fair Value Unvested balances at January 1, 2019 1,583,375 $ 68.62 Granted 587,987 $ 84.73 Vested (492,535 ) $ 59.46 Forfeited (127,501 ) $ 73.36 Unvested balances at September 30, 2019 1,551,326 $ 77.23
Schedule of Weighted-Average Assumptions Used to Determine the Weighted-Average Fair Values	The following weighted-average assumptions were used to determine the weighted-average fair values of the PSU awards granted under the three-year PSU program for the nine months ended September 30, 2019 : Nine Months Ended September 30, 2019 2018 Weighted-average risk free interest rate (1) 2.26 % 2.36 % Expected volatility (2) 16.5 % 18.7 % Weighted-average grant date share price $89.00 $ 86.24 Weighted-average fair value at grant date $97.65 $ 116.86 ____________ (1) The risk-free interest rate for periods within the expected life of the award is based on the U.S. Treasury yield curve in effect at the time of grant. (2) We use historic volatility for PSU awards issued under the three-year PSU program, as implied volatility data could not be obtained for all the companies in the peer groups used for relative performance measurement within the program.
Summary of PSU Activity	The following table summarizes our PSU activity for the nine months ended September 30, 2019 : PSUs One-Year Program Three-Year Program Number of Awards Weighted-Average Grant Date Fair Value Number of Awards Weighted-Average Grant Date Fair Value Unvested balances at January 1, 2019 314,231 $ 74.01 837,750 $ 96.57 Granted (1) 179,599 $ 83.56 397,553 $ 96.55 Vested (12,733 ) $ 67.51 (431,751 ) $ 93.25 Forfeited (22,943 ) $ 75.03 (6,101 ) $ 103.29 Unvested balances at September 30, 2019 458,154 $ 77.88 797,451 $ 98.31 ____________ (1) Includes target awards granted and certain additional awards granted based on overachievement of performance parameters.
Summary of Stock Options, Valuation Assumptions	We estimated the fair value of this stock option award using the Black-Scholes valuation model using the following assumptions: Expected life (in years) 6 Weighted-average risk free interest rate 2.1 % Expected volatility 25.6 % Dividend yield 1.92 %
Summary of Stock Option Activity	A summary of stock option activity for the nine months ended September 30, 2019 is as follows: Number of Stock Options Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (in millions) Outstanding at January 1, 2019 448,966 $ 49.25 5.51 $ 14 Exercised (62,624 ) 20.92 Forfeited (25 ) 20.10 Outstanding at September 30, 2019 386,317 $ 53.68 5.43 $ 18 Exercisable at September 30, 2019 296,711 $ 49.76 4.87 $ 15

Nasdaq Stockholders_ Equity (Ta

Nasdaq Stockholders’ Equity (Tables)	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Common Stock in Treasury, at Cost	The following is a summary of our share repurchase activity, reported based on settlement date, for the nine months ended September 30, 2019 and 2018: Nine Months Ended September 30, 2019 2018 Number of shares of common stock repurchased 2,053,855 4,508,426 Average price paid per share $ 97.37 $ 87.43 Total purchase price (in millions) $ 200 $ 394
Schedule of Dividends Declared	During the first nine months of 2019, our board of directors declared the following cash dividends: Declaration Date Dividend Per Common Share Record Date Total Amount Paid Payment Date (in millions) January 29, 2019 $ 0.44 March 15, 2019 $ 73 March 29, 2019 April 23, 2019 0.47 June 14, 2019 77 June 28, 2019 July 23, 2019 0.47 September 13, 2019 78 September 27, 2019 $ 228

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Summary of Computation of Basic and Diluted Earnings Per Share	The following table sets forth the computation of basic and diluted earnings per share: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Numerator: (in millions, except share and per share amounts) Net income attributable to common shareholders $ 150 $ 163 $ 571 $ 502 Denominator: Weighted-average common shares outstanding for basic earnings per share 164,331,832 164,227,243 165,086,951 165,622,428 Weighted-average effect of dilutive securities: Employee equity awards (1) 1,705,665 2,071,426 1,611,232 1,931,307 Contingent issuance of common stock (2) 992,247 992,247 330,749 330,749 Weighted-average common shares outstanding for diluted earnings per share 167,029,744 167,290,916 167,028,932 167,884,484 Basic and diluted earnings per share: Basic earnings per share $ 0.91 $ 0.99 $ 3.46 $ 3.03 Diluted earnings per share $ 0.90 $ 0.97 $ 3.42 $ 2.99 ____________ (1) PSUs, which are considered contingently issuable, are included in the computation of dilutive earnings per share on a weighted average basis when management determines that the applicable performance criteria would have been met if the performance period ended as of the date of the relevant computation. (2) See “Non-Cash Contingent Consideration,” of Note 18, “Commitments, Contingencies and Guarantees,” for further discussion.

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Schedule of Financial Assets Measured at Fair Value on Recurring Basis	The following tables present our financial assets and financial liabilities that are measured at fair value on a recurring basis as of September 30, 2019 and December 31, 2018 . September 30, 2019 Total Level 1 Level 2 Level 3 Assets at Fair Value (in millions) Financial investments, at fair value $ 201 $ 152 $ 49 $ — Default fund and margin deposit investments 1,134 134 1,000 — Total assets at fair value $ 1,335 $ 286 $ 1,049 $ — December 31, 2018 Total Level 1 Level 2 Level 3 Assets at Fair Value (in millions) Financial investments, at fair value $ 268 $ 133 $ 135 $ — Default fund and margin deposit investments 1,649 327 1,322 — Total assets at fair value $ 1,917 $ 460 $ 1,457 $ — Liabilities at Fair Value Other financial instruments $ 112 $ — $ 112 $ — Total liabilities at fair value $ 112 $ — $ 112 $ —

Clearing Operations (Tables)

Clearing Operations (Tables)	9 Months Ended
	Sep. 30, 2019
Due to and from Broker-Dealers and Clearing Organizations [Abstract]
Schedule of Clearing Member Default Fund Contributions	As of September 30, 2019 , clearing member default fund contributions and margin deposits were as follows: September 30, 2019 Cash Contributions Non-Cash Contributions Total Contributions (in millions) Default fund contributions $ 406 $ 119 $ 525 Margin deposits 2,016 3,757 5,773 Total $ 2,422 $ 3,876 $ 6,298
Schedule of Derivative Contracts Outstanding	The following table includes the market value of derivative contracts outstanding prior to netting: September 30, 2019 (in millions) Commodity and seafood options, futures and forwards (1)(2)(3) $ 359 Fixed-income options and futures (1)(2) 925 Stock options and futures (1)(2) 120 Index options and futures (1)(2) 81 Total $ 1,485 ____________ (1) We determined the fair value of our option contracts using standard valuation models that were based on market-based observable inputs including implied volatility, interest rates and the spot price of the underlying instrument. (2) We determined the fair value of our futures contracts based upon quoted market prices and average quoted market yields. (3) We determined the fair value of our forward contracts using standard valuation models that were based on market-based observable inputs including LIBOR rates and the spot price of the underlying instrument.
Schedule of Derivative Contracts Cleared	The following table includes the total number of derivative contracts cleared through Nasdaq Clearing for the nine months ended September 30, 2019 and 2018 : September 30, 2019 September 30, 2018 Commodity and seafood options, futures and forwards (1)(2) 393,153 1,506,560 Fixed-income options and futures 15,780,707 16,833,278 Stock options and futures 18,030,431 17,735,228 Index options and futures 35,752,600 35,569,046 Total 69,956,891 71,644,112 ____________ (1) The total volume in cleared power related to commodity contracts was 614 Terawatt hours (TWh) for the nine months ended September 30, 2019 and 853 TWh for the nine months ended September 30, 2018 . (2) In July 2018, the Nasdaq freight product offering was migrated to NFX, our U.S.-based futures exchange.

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	The following table shows our income tax provision and effective tax rate: Three Months Ended September 30, Percentage Change 2019 2018 (in millions) Income tax provision $ 65 $ 46 41.3 % Effective tax rate 30.2 % 22.0 % Nine Months Ended September 30, Percentage Change 2019 2018 (in millions) Income tax provision $ 196 $ 234 (16.2 )% Effective tax rate 25.6 % 31.8 %

Business Segments (Tables)

Business Segments (Tables)	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Schedule of Operating Segments	The following table presents certain information regarding our business segments for the three and nine months ended September 30, 2019 and 2018 : Market Services Corporate Services Information Services Market Technology Corporate Items Consolidated (in millions) Three Months Ended September 30, 2019 Total revenues $ 690 $ 124 $ 198 $ 84 $ — $ 1,096 Transaction-based expenses (464 ) — — — — (464 ) Revenues less transaction-based expenses 226 124 198 84 — 632 Operating income (loss) $ 129 $ 45 $ 126 $ 15 $ (89 ) $ 226 Three Months Ended September 30, 2018 Total revenues $ 586 $ 121 $ 179 $ 68 $ 10 $ 964 Transaction-based expenses (364 ) — — — — (364 ) Revenues less transaction-based expenses 222 121 179 68 10 600 Operating income (loss) $ 121 $ 40 $ 117 $ 9 $ (41 ) $ 246 Nine Months Ended September 30, 2019 Total revenues $ 1,995 $ 368 $ 585 $ 239 $ 10 $ 3,197 Transaction-based expenses (1,308 ) — — — — (1,308 ) Revenues less transaction-based expenses 687 368 585 239 10 1,889 Operating income (loss) 392 134 372 29 (170 ) 757 Nine Months Ended September 30, 2018 Total revenues $ 1,968 $ 364 $ 528 $ 194 $ 87 $ 3,141 Transaction-based expenses (1,259 ) — — — — (1,259 ) Revenues less transaction-based expenses 709 364 528 194 87 1,882 Operating income (loss) 402 117 342 20 (94 ) 787
Schedule of Corporate Items	A summary of our corporate items is as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (in millions) Revenues - divested businesses $ — $ 10 $ 10 $ 87 Expenses: Amortization expense of acquired intangible assets 25 27 76 83 Merger and strategic initiatives expense 10 6 25 7 Restructuring charges 30 — 30 — Provision for notes receivable 20 — 20 — Clearing default loss — 8 — 8 Extinguishment of debt — — 11 — Expenses - divested businesses — 8 8 75 Other 4 2 10 8 Total expenses 89 51 180 181 Operating loss $ (89 ) $ (41 ) $ (170 ) $ (94 )

Restructuring Charges (Tables)

Restructuring Charges (Tables)	9 Months Ended
	Sep. 30, 2019
Restructuring and Related Activities [Abstract]
Summary of Restructuring Charges	The following table presents a summary of the 2019 restructuring plan charges in the Condensed Consolidated Statements of Income for the three and nine months ended September 30, 2019 which primarily consisted of asset impairment charges mainly related to capitalized software. Three and Nine Months Ended September 30, 2019 (in millions) Asset impairments $ 23 Accelerated depreciation 2 Severance and employee-related costs 3 Other 2 Total restructuring charges $ 30

Organization and Nature of Op_2

Organization and Nature of Operations (Details) $ in Billions	9 Months Ended
	Sep. 30, 2019USD ($)marketplacesegmentcompanyexchangeexchange_traded_productcountry
Organization And Basis Of Presentation [Line Items]
Number of operating segments | segment	4
Market Services
Organization And Basis Of Presentation [Line Items]
Number of derivative exchanges listing commodities offerings | exchange	2
Market Services | United States | Options Markets
Organization And Basis Of Presentation [Line Items]
Number of exchanges | exchange	6
Market Services | United States | Cash Equities Trading Markets
Organization And Basis Of Presentation [Line Items]
Number of exchanges | exchange	3
Corporate Services | United States
Organization And Basis Of Presentation [Line Items]
Total number of listings on The Nasdaq Stock Market | company	3,091
ETPs and other listings listed on Nasdaq Stock Market | company	382
Approximate combined market capitalization | $	$ 13,400
Corporate Services | Europe
Organization And Basis Of Presentation [Line Items]
Approximate combined market capitalization | $	$ 1,400
Total number of listed companies within Nordic and Baltic exchanges | company	1,028
Information Services
Organization And Basis Of Presentation [Line Items]
Number of exchange traded products licensed to Nasdaq's Indexes | exchange_traded_product	325
Assets management value | $	$ 207
Market Technology
Organization And Basis Of Presentation [Line Items]
Number of exchanges | marketplace	100
Number of countries services are provided | country	50

Significant Accounting Polici_4

Significant Accounting Policies Update (Narrative) (Details) $ in Millions	Sep. 30, 2019USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future minimum payments on lease not yet commenced	$ 143
Terms of lease not yet commenced	16 years
Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease terms of contract	3 months
Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease terms of contract	17 years

Significant Accounting Polici_5

Significant Accounting Policies Update (Summary of Supplemental Balance Sheet Information Related to Operating Leases) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Assets:
Operating lease assets	$ 346	$ 0
Liabilities:
Current lease liabilities	60
Non-current lease liabilities	327	$ 0
Total lease liabilities	$ 387

Significant Accounting Polici_6

Significant Accounting Policies Update (Lease Cost) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Accounting Policies [Abstract]
Operating lease cost	$ 19	$ 58
Variable lease cost	6	18
Sublease income	(1)	(4)
Total lease cost	$ 24	$ 72

Significant Accounting Polici_7

Significant Accounting Policies Update (Operating Lease Maturity) (Details) $ in Millions	Sep. 30, 2019USD ($)
Accounting Policies [Abstract]
2019	$ 19
2020	76
2021	66
2022	44
2023	39
Thereafter	261
Total lease payments	505
Less: interest	(118)
Total lease liabilities	387
Current lease liabilities	$ 60

Significant Accounting Polici_8

Significant Accounting Policies Update (Lease Terms and Discount Rate) (Details)	Sep. 30, 2019
Accounting Policies [Abstract]
Weighted-average remaining lease term (in years)	10 years 4 months 24 days
Weighted-average discount rate	4.60%

Significant Accounting Polici_9

Significant Accounting Policies Update (Supplemental Cash Flow Information) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2019USD ($)
Accounting Policies [Abstract]
Cash paid for amounts included in the measurement of operating lease liabilities	$ 59
Lease assets obtained in exchange for new operating lease liabilities	$ 20

Revenue From Contracts With C_3

Revenue From Contracts With Customers (Revenue by Product, Service and Segment) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	$ 632	$ 600	$ 1,889	$ 1,882
Transaction-based trading and clearing, net
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	154	150	468	489
Trade management services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	72	72	219	220
Listing services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	74	72	219	217
Corporate solutions
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	50	49	149	147
Market data
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	102	95	302	293
Index
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	56	52	166	152
Investment data & analytics
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	40	32	117	83
Market technology
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	84	68	239	194
Other revenues
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses		10	10	87
Operating Segments | Market Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	226	222	687	709
Operating Segments | Corporate Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	124	121	368	364
Operating Segments | Information Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	198	179	585	528
Operating Segments | Market Technology
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	84	68	239	194
Operating Segments | Transaction-based trading and clearing, net | Market Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	154	150	468	489
Operating Segments | Transaction-based trading and clearing, net | Corporate Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	0	0	0	0
Operating Segments | Transaction-based trading and clearing, net | Information Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	0	0	0	0
Operating Segments | Transaction-based trading and clearing, net | Market Technology
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	0	0	0	0
Operating Segments | Trade management services | Market Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	72	72	219	220
Operating Segments | Trade management services | Corporate Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	0	0	0	0
Operating Segments | Trade management services | Information Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	0	0	0	0
Operating Segments | Trade management services | Market Technology
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	0	0	0	0
Operating Segments | Listing services | Market Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	0	0	0	0
Operating Segments | Listing services | Corporate Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	74	72	219	217
Operating Segments | Listing services | Information Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	0	0	0	0
Operating Segments | Listing services | Market Technology
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	0	0	0	0
Operating Segments | Corporate solutions | Market Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	0	0	0	0
Operating Segments | Corporate solutions | Corporate Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	50	49	149	147
Operating Segments | Corporate solutions | Information Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	0	0	0	0
Operating Segments | Corporate solutions | Market Technology
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	0	0	0	0
Operating Segments | Market data | Market Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	0	0	0	0
Operating Segments | Market data | Corporate Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	0	0	0	0
Operating Segments | Market data | Information Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	102	95	302	293
Operating Segments | Market data | Market Technology
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	0	0	0	0
Operating Segments | Index | Market Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	0	0	0	0
Operating Segments | Index | Corporate Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	0	0	0	0
Operating Segments | Index | Information Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	56	52	166	152
Operating Segments | Index | Market Technology
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	0	0	0	0
Operating Segments | Investment data & analytics | Market Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	0	0	0	0
Operating Segments | Investment data & analytics | Corporate Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	0	0	0	0
Operating Segments | Investment data & analytics | Information Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	40	32	117	83
Operating Segments | Investment data & analytics | Market Technology
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	0	0	0	0
Operating Segments | Market technology | Market Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	0	0	0	0
Operating Segments | Market technology | Corporate Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	0	0	0	0
Operating Segments | Market technology | Information Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	0	0	0	0
Operating Segments | Market technology | Market Technology
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses	$ 84	68	239	194
Operating Segments | Other revenues | Market Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses		0	0	0
Operating Segments | Other revenues | Corporate Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses		0	0	0
Operating Segments | Other revenues | Information Services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses		0	0	0
Operating Segments | Other revenues | Market Technology
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses		0	0	0
Other Revenues
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses		10	10	87
Other Revenues | Transaction-based trading and clearing, net
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses		0	0	0
Other Revenues | Trade management services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses		0	0	0
Other Revenues | Listing services
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses		0	0	0
Other Revenues | Corporate solutions
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses		0	0	0
Other Revenues | Market data
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses		0	0	0
Other Revenues | Index
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses		0	0	0
Other Revenues | Investment data & analytics
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses		0	0	0
Other Revenues | Market technology
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses		0	0	0
Other Revenues | Other revenues
Disaggregation of Revenue [Line Items]
Revenues less transaction-based expenses		$ 10	$ 10	$ 87

Revenue From Contracts With C_4

Revenue From Contracts With Customers Revenue From Contracts With Customers (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Receivables net of allowance for doubtful accounts	$ 12		$ 12		$ 13
Market Services | Services transferred at a point in time
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue recognized (percentage)	65.00%	63.00%	65.00%	64.00%
Market Services | Services transferred over time
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue recognized (percentage)	35.00%	37.00%	35.00%	36.00%

Revenue From Contracts With C_5

Revenue From Contracts With Customers (Remaining Performance Obligation) (Details) - Market Technology $ in Millions	Sep. 30, 2019USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 78
Revenue, remaining performance obligation, period	3 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 310
Revenue, remaining performance obligation, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 159
Revenue, remaining performance obligation, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 85
Revenue, remaining performance obligation, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 45
Revenue, remaining performance obligation, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 762
Revenue, remaining performance obligation, period

Acquisitions and Divestiture (2

Acquisitions and Divestiture (2019 Divestiture and Acquisition) (Details) - USD ($) $ in Millions	1 Months Ended		3 Months Ended	9 Months Ended
	Mar. 31, 2019	Jan. 31, 2019	Sep. 30, 2019	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
2019 Divestiture [Abstract]
Proceeds from divestiture of businesses				$ 108	$ 286
2019 Acquisition [Abstract]
Purchase Consideration				193	$ 0
Goodwill			$ 6,232	6,232		$ 6,363
Adjustment in goodwill				$ 4
Cinnober
2019 Acquisition [Abstract]
Purchase Consideration		$ 219
Total Net Assets Acquired		18
Total Net Deferred Tax Liability		(19)
Acquired Intangible Assets		79
Goodwill		$ 141
Measurement period, net assets acquired			4
Adjustment in goodwill			$ 4
Disposal Group, Disposed of by Sale, Not Discontinued Operations | BWise
2019 Divestiture [Abstract]
Proceeds from divestiture of businesses	$ 27
Gain on divestiture of business, after tax	$ 20

Acquisitions and Divestiture _2

Acquisitions and Divestiture (2018 Divestiture) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Apr. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net gain on divestiture of businesses		$ 0	$ (8)	$ 27	$ 33
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Public Relations Solutions and Digital Media Services
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net gain on divestiture of businesses	$ 33
Gain on divestiture of business, after tax	$ 14
Working capital adjustment			8
Working capital adjustment, after tax			$ 5

Acquisitions and Divestiture (I

Acquisitions and Divestiture (Intangible Assets) (Details) - Cinnober $ in Millions	Jan. 30, 2019USD ($)	Jan. 31, 2019USD ($)
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Intangible assets, finite-lived		$ 79
Customer relationships
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Intangible assets, finite-lived	$ 67
Estimated average useful life	13 years
Amortization period of intangible assets for tax purposes	5 years
Customer relationships | Discount rate used
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Discount rate used	0.095

Assets and Liabilities Held F_3

Assets and Liabilities Held For Sale (Details) - USD ($) $ in Millions	1 Months Ended		9 Months Ended
	Mar. 31, 2019	Apr. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from divestiture of businesses			$ 108	$ 286
Carrying Amount of Assets and Liabilities Held for Sale [Abstract]
Deferred revenue			$ 267		$ 194
BWise | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from divestiture of businesses	$ 27
Gain on divestiture of business, after tax	$ 20
Public Relations Solutions and Digital Media Services | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on divestiture of business, after tax		$ 14
Public Relations Solutions and Digital Media Services | Disposal Group, Not Discontinued Operations
Carrying Amount of Assets and Liabilities Held for Sale [Abstract]
Receivables, net					13
Property and equipment, net					10
Goodwill					47
Intangible assets, net					16
Other assets					3
Total assets held for sale					89
Deferred tax liabilities					4
Deferred revenue					12
Other current liabilities					4
Total liabilities held for sale					$ 20

Goodwill and Acquired Intangi_3

Goodwill and Acquired Intangible Assets (Schedule of Changes in Goodwill) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2019USD ($)
Goodwill [Roll Forward]
Balance at beginning of period	$ 6,363
Goodwill acquired	137
Measurement period adjustment	4
Foreign currency translation adjustment	(272)
Balance at end of period	6,232
Market Services
Goodwill [Roll Forward]
Balance at beginning of period	3,430
Goodwill acquired	0
Measurement period adjustment	0
Foreign currency translation adjustment	(138)
Balance at end of period	3,292
Corporate Services
Goodwill [Roll Forward]
Balance at beginning of period	455
Goodwill acquired	0
Measurement period adjustment	0
Foreign currency translation adjustment	(16)
Balance at end of period	439
Information Services
Goodwill [Roll Forward]
Balance at beginning of period	2,333
Goodwill acquired	0
Measurement period adjustment	0
Foreign currency translation adjustment	(95)
Balance at end of period	2,238
Market Technology
Goodwill [Roll Forward]
Balance at beginning of period	145
Goodwill acquired	137
Measurement period adjustment	4
Foreign currency translation adjustment	(23)
Balance at end of period	$ 263

Goodwill and Acquired Intangi_4

Goodwill and Acquired Intangible Assets (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Indefinite-lived Intangible Assets [Line Items]
Measurement period adjustment			$ 4,000,000
Goodwill, impairment loss			0	$ 0
Amortization expense of acquired intangible assets	$ 25,000,000	$ 27,000,000	76,000,000	$ 83,000,000
Net future amortization expense	1,026,000,000		1,026,000,000		$ 1,045,000,000
Foreign currency translation adjustment
Indefinite-lived Intangible Assets [Line Items]
Net future amortization expense	$ (124,000,000)		(124,000,000)		$ (85,000,000)
Market Technology
Indefinite-lived Intangible Assets [Line Items]
Measurement period adjustment			$ 4,000,000

Goodwill and Acquired Intangi_5

Goodwill and Acquired Intangible Assets (Finite-Lived and Indefinite-Lived Intangible Assets) (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Amount	$ 1,492	$ 1,454
Accumulated Amortization	(466)	(409)
Net Amount	1,026	1,045
Indefinite-lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	1,213	1,255
Total intangible assets	2,705	2,709
Intangible assets, net	2,239	2,300
Exchange and clearing registrations
Indefinite-lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	1,257	1,257
Trade names
Indefinite-lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	121	122
Licenses
Indefinite-lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	52	52
Foreign currency translation adjustment
Indefinite-lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	(217)	(176)
Technology
Finite-Lived Intangible Assets [Line Items]
Gross Amount	62	54
Accumulated Amortization	(17)	(15)
Net Amount	$ 45	$ 39
Weighted-Average Useful Life (in Years)	9 years	9 years
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Amount	$ 1,599	$ 1,532
Accumulated Amortization	(508)	(456)
Net Amount	$ 1,091	$ 1,076
Weighted-Average Useful Life (in Years)	18 years	18 years
Other
Finite-Lived Intangible Assets [Line Items]
Gross Amount	$ 18	$ 17
Accumulated Amortization	(4)	(2)
Net Amount	$ 14	$ 15
Weighted-Average Useful Life (in Years)	8 years	8 years
Foreign currency translation adjustment
Finite-Lived Intangible Assets [Line Items]
Gross Amount	$ (187)	$ (149)
Accumulated Amortization	63	64
Net Amount	$ (124)	$ (85)

Goodwill and Acquired Intangi_6

Goodwill and Acquired Intangible Assets (Estimated Future Amortization Expense) (Details) $ in Millions	Sep. 30, 2019USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2019	$ 27
2020	105
2021	104
2022	100
2023	98
2024 and thereafter	716
Total	$ 1,150

Investments (Schedule of Invest

Investments (Schedule of Investments) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Trading securities	$ 201	$ 259
Available-for-sale investment securities	0	9
Financial investments, at fair value	201	268
Equity method investments	159	135
Equity securities	$ 49	$ 44

Investments (Narrative) (Detail

Investments (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended			3 Months Ended		9 Months Ended		12 Months Ended
	Mar. 31, 2019	Feb. 28, 2019	Mar. 31, 2015	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Investments, Debt and Securities [Line Items]
Trading securities				$ 201		$ 201		$ 259
Net income from unconsolidated investees				15	$ 6	71	$ 13
OCC
Investments, Debt and Securities [Line Items]
Committed equity contribution			$ 150
Capital contribution			$ 30
Annual dividend from shareholders percentage			50.00%
Annual dividend received								13	$ 10	$ 4
Proceeds from contributed capital		$ 44
OCC, Prior Period Results
Investments, Debt and Securities [Line Items]
Net income from unconsolidated investees	$ 36
OCC, Current Period Results
Investments, Debt and Securities [Line Items]
Net income from unconsolidated investees				15		33
Foreign Government Debt Securities
Investments, Debt and Securities [Line Items]
Trading securities				$ 166		$ 166		$ 166

Deferred Revenue (Changes in De

Deferred Revenue (Changes in Deferred Revenue) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2019USD ($)
Change in Contract with Customer Liability [Roll Forward]
Beginning balance	$ 281
Deferred revenue billed in the current period, net of recognition	223
Revenue recognized that was included in the beginning of the period	(158)
Translation adjustment	(9)
Ending balance	337
Initial Listing Revenues
Change in Contract with Customer Liability [Roll Forward]
Beginning balance	66
Deferred revenue billed in the current period, net of recognition	24
Revenue recognized that was included in the beginning of the period	(21)
Translation adjustment	(1)
Ending balance	68
Annual Listings Revenues
Change in Contract with Customer Liability [Roll Forward]
Beginning balance	4
Deferred revenue billed in the current period, net of recognition	61
Revenue recognized that was included in the beginning of the period	(3)
Translation adjustment	(1)
Ending balance	61
Market Technology Revenues
Change in Contract with Customer Liability [Roll Forward]
Beginning balance	75
Deferred revenue billed in the current period, net of recognition	36
Revenue recognized that was included in the beginning of the period	(36)
Translation adjustment	(7)
Ending balance	68
Corporate Solutions Revenues
Change in Contract with Customer Liability [Roll Forward]
Beginning balance	36
Deferred revenue billed in the current period, net of recognition	39
Revenue recognized that was included in the beginning of the period	(34)
Translation adjustment	0
Ending balance	41
Information Services Revenues
Change in Contract with Customer Liability [Roll Forward]
Beginning balance	80
Deferred revenue billed in the current period, net of recognition	56
Revenue recognized that was included in the beginning of the period	(54)
Translation adjustment	0
Ending balance	82
Other
Change in Contract with Customer Liability [Roll Forward]
Beginning balance	20
Deferred revenue billed in the current period, net of recognition	7
Revenue recognized that was included in the beginning of the period	(10)
Translation adjustment	0
Ending balance	$ 17

Deferred Revenue (Estimated Def

Deferred Revenue (Estimated Deferred Revenue) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Fiscal year ended:
2019	$ 157
2020	131
2021	27
2022	11
2023	8
2024 and thereafter	3
Total	337	$ 281
Initial Listing Revenues
Fiscal year ended:
2019	8
2020	25
2021	15
2022	10
2023	7
2024 and thereafter	3
Total	68	66
Annual Listings Revenues
Fiscal year ended:
2019	61
2020	0
2021	0
2022	0
2023	0
2024 and thereafter	0
Total	61	4
Market Technology Revenues
Fiscal year ended:
2019	26
2020	33
2021	9
2022	0
2023	0
2024 and thereafter	0
Total	68	75
Corporate Solutions Revenues
Fiscal year ended:
2019	21
2020	20
2021	0
2022	0
2023	0
2024 and thereafter	0
Total	41	36
Information Services Revenues
Fiscal year ended:
2019	36
2020	46
2021	0
2022	0
2023	0
2024 and thereafter	0
Total	82	80
Other
Fiscal year ended:
2019	5
2020	7
2021	3
2022	1
2023	1
2024 and thereafter	0
Total	$ 17	$ 20

Debt Obligations (Changes in De

Debt Obligations (Changes in Debt Obligations) (Details) - USD ($)	6 Months Ended	9 Months Ended
	Jun. 30, 2019	Sep. 30, 2019	Apr. 30, 2019	Dec. 31, 2018	Apr. 30, 2017	Jun. 30, 2016	May 31, 2016	May 31, 2014	Jun. 30, 2013
Changes In Short-Term Debt Obligations [Roll Forward]
Short-term debt - commercial paper beginning balance	$ 1,474,000,000	$ 1,474,000,000
Additions		2,951,000,000
Payments, Accretion and Other		(3,886,000,000)
Short-term debt - commercial paper ending balance		539,000,000
Changes in Long-Term Debt Obligations [Roll Forward]
Long-term debt obligations at beginning of period	2,357,000,000	2,357,000,000
Additions		680,000,000
Payments, Accretion and Other		(98,000,000)
Long-term debt obligations at end of period		2,939,000,000
Changes In Debt Obligations [Roll Forward]
Total debt obligations at beginning of period	3,831,000,000	3,831,000,000
Additions		3,631,000,000
Payments, Accretion and Other		(3,984,000,000)
Total debt obligations at end of period		$ 3,478,000,000
Senior Notes | 3.875% senior unsecured notes due June 7, 2021
Schedule of Debt [Line Items]
Stated rate		3.875%							3.875%
Changes in Long-Term Debt Obligations [Roll Forward]
Long-term debt obligations at beginning of period	686,000,000	$ 686,000,000
Additions		0
Payments, Accretion and Other		(34,000,000)
Long-term debt obligations at end of period		$ 652,000,000
Senior Notes | 4.25% senior unsecured notes due June 1, 2024
Schedule of Debt [Line Items]
Stated rate		4.25%						4.25%
Changes in Long-Term Debt Obligations [Roll Forward]
Long-term debt obligations at beginning of period	497,000,000	$ 497,000,000
Additions		0
Payments, Accretion and Other		0
Long-term debt obligations at end of period		$ 497,000,000
Senior Notes | 1.75% senior unsecured notes due May 19, 2023
Schedule of Debt [Line Items]
Stated rate		1.75%					1.75%
Changes in Long-Term Debt Obligations [Roll Forward]
Long-term debt obligations at beginning of period	682,000,000	$ 682,000,000
Additions		0
Payments, Accretion and Other		(33,000,000)
Long-term debt obligations at end of period		$ 649,000,000
Senior Notes | 3.85% senior unsecured notes due June 30, 2026
Schedule of Debt [Line Items]
Stated rate		3.85%				3.85%
Changes in Long-Term Debt Obligations [Roll Forward]
Long-term debt obligations at beginning of period	496,000,000	$ 496,000,000
Additions		0
Payments, Accretion and Other		1,000,000
Long-term debt obligations at end of period		$ 497,000,000
Senior Notes | 1.75% senior unsecured notes due March 28, 2029
Schedule of Debt [Line Items]
Stated rate		1.75%	1.75%
Changes in Long-Term Debt Obligations [Roll Forward]
Long-term debt obligations at beginning of period	0	$ 0
Additions		665,000,000
Payments, Accretion and Other		(18,000,000)
Long-term debt obligations at end of period		647,000,000
Revolving Credit Facility | $1 billion senior unsecured revolving credit facility due April 25, 2022
Schedule of Debt [Line Items]
Facility borrowing capacity		1,000,000,000			$ 1,000,000,000
Changes in Long-Term Debt Obligations [Roll Forward]
Long-term debt obligations at beginning of period	(4,000,000)	(4,000,000)
Additions		15,000,000
Payments, Accretion and Other		(14,000,000)
Long-term debt obligations at end of period		(3,000,000)
Commercial paper
Changes In Short-Term Debt Obligations [Roll Forward]
Short-term debt - commercial paper beginning balance	275,000,000	275,000,000
Additions		2,951,000,000
Payments, Accretion and Other		(2,687,000,000)
Short-term debt - commercial paper ending balance		539,000,000
Senior unsecured floating rate notes repaid on March 22, 2019
Changes In Short-Term Debt Obligations [Roll Forward]
Short-term debt - commercial paper beginning balance	500,000,000	500,000,000
Additions		0
Payments, Accretion and Other		(500,000,000)
Short-term debt - commercial paper ending balance		0
5.55% senior unsecured notes repaid on May 1, 2019
Changes In Short-Term Debt Obligations [Roll Forward]
Short-term debt - commercial paper beginning balance	$ 599,000,000	599,000,000
Additions		0
Payments, Accretion and Other		(599,000,000)
Short-term debt - commercial paper ending balance		0
$400 million senior unsecured term loan facility repaid on June 28, 2019 (average interest rate of 4.00% for the period January 1, 2019 through June 28, 2019)
Schedule of Debt [Line Items]
Facility borrowing capacity				$ 400,000,000
Interest rate	4.00%
Changes In Short-Term Debt Obligations [Roll Forward]
Short-term debt - commercial paper beginning balance	$ 100,000,000	100,000,000
Additions		0
Payments, Accretion and Other		(100,000,000)
Short-term debt - commercial paper ending balance		$ 0

Debt Obligations (Commercial Pa

Debt Obligations (Commercial Paper) (Details) - Commercial paper	9 Months Ended
	Sep. 30, 2019
Short-term Debt [Line Items]
Weighted average interest rate	2.33%
Minimum
Short-term Debt [Line Items]
Maturity period	11 days
Maximum
Short-term Debt [Line Items]
Maturity period	81 days
Weighted Average
Short-term Debt [Line Items]
Maturity period	18 days

Debt Obligations (Senior Unsecu

Debt Obligations (Senior Unsecured Notes) (Details)	9 Months Ended
	Sep. 30, 2019
Senior Notes | Senior Notes Excluding 2020 Notes
Debt Instrument [Line Items]
Aggregate principal amount purchased plus accrued and unpaid interest	101.00%

Debt Obligations (Senior Unse_2

Debt Obligations (Senior Unsecured Floating Rate Notes) (Details)	1 Months Ended
	Sep. 30, 2017
Senior unsecured floating rate notes repaid on March 22, 2019 | Senior Notes | LIBOR
Debt Instrument [Line Items]
Spread on variable rate	0.39%

Debt Obligations (Early Extingu

Debt Obligations (Early Extinguishment of 5.55% Senior Unsecured Notes) (Details) - Senior Notes - USD ($) $ in Millions	1 Months Ended
	May 31, 2019	Sep. 30, 2019	Apr. 30, 2019	Dec. 31, 2018	Jan. 31, 2010
5.55% senior unsecured notes repaid on May 1, 2019
Debt Instrument [Line Items]
Stated rate				5.55%	5.55%
Early extinguishment of senior notes	$ 11
1.75% senior unsecured notes due March 28, 2029
Debt Instrument [Line Items]
Stated rate		1.75%	1.75%

Debt Obligations (3.875% Senior

Debt Obligations (3.875% Senior Unsecured Notes) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Jun. 30, 2013
Debt Instrument [Line Items]
Decrease in carrying amount	$ 98
Senior Notes | 3.875% senior unsecured notes due June 7, 2021
Debt Instrument [Line Items]
Stated rate	3.875%	3.875%
Decrease in carrying amount	$ 34
Senior Notes | 3.875% senior unsecured notes due June 7, 2021 | Maximum
Debt Instrument [Line Items]
Maximum interest rate on debt instrument		5.875%

Debt Obligations (4.25% Senior

Debt Obligations (4.25% Senior Unsecured Notes) (Details) - Senior Notes - 4.25% senior unsecured notes due June 1, 2024	Sep. 30, 2019	May 31, 2014
Debt Instrument [Line Items]
Stated rate	4.25%	4.25%
Maximum
Debt Instrument [Line Items]
Maximum interest rate on debt instrument		6.25%

Debt Obligations (1.75% Senior

Debt Obligations (1.75% Senior Unsecured Notes Due 2023) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	May 31, 2016
Debt Instrument [Line Items]
Decrease in carrying amount	$ 98
Senior Notes | 1.75% senior unsecured notes due May 19, 2023
Debt Instrument [Line Items]
Stated rate	1.75%	1.75%
Decrease in carrying amount	$ 33
Senior Notes | 1.75% senior unsecured notes due May 19, 2023 | Maximum
Debt Instrument [Line Items]
Maximum interest rate on debt instrument		3.75%

Debt Obligations (3.85% Senior

Debt Obligations (3.85% Senior Unsecured Notes) (Details) - Senior Notes - 3.85% senior unsecured notes due June 30, 2026	Sep. 30, 2019	Jun. 30, 2016
Debt Instrument [Line Items]
Stated rate	3.85%	3.85%
Maximum
Debt Instrument [Line Items]
Maximum interest rate on debt instrument		5.85%

Debt Obligations Debt Obligatio

Debt Obligations Debt Obligations (1.75% Senior Unsecured Notes Due 2029) (Details) - USD ($) $ in Millions	1 Months Ended	9 Months Ended
	Apr. 30, 2019	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Jan. 31, 2010
Debt Instrument [Line Items]
Proceeds from issuances of long-term debt, net of issuance costs		$ 680	$ 0
Decrease in carrying amount		$ 98
Senior Notes | 1.75% senior unsecured notes due March 28, 2029
Debt Instrument [Line Items]
Stated rate	1.75%	1.75%
Decrease in carrying amount		$ 18
Senior Notes | 1.75% senior unsecured notes due March 28, 2029 | Maximum
Debt Instrument [Line Items]
Maximum interest rate on debt instrument	3.75%
Proceeds from issuances of long-term debt, net of issuance costs	$ 665
Senior Notes | 5.55% senior unsecured notes repaid on May 1, 2019
Debt Instrument [Line Items]
Stated rate				5.55%	5.55%

Debt Obligations (2017 Credit F

Debt Obligations (2017 Credit Facility) (Details) - Revolving Credit Facility - $1 billion senior unsecured revolving credit facility due April 25, 2022 - USD ($)	1 Months Ended	9 Months Ended
	Apr. 30, 2017	Sep. 30, 2019
Debt Instrument [Line Items]
Credit facility, borrowing capacity	$ 1,000,000,000	$ 1,000,000,000
Credit facility term	5 years
Line of credit facility, fair value of amount outstanding		0
Unamortized debt issuance expense		3,000,000
Remaining amount available		459,000,000
Option to increase available aggregate amount		$ 500,000,000
Minimum
Debt Instrument [Line Items]
Line of credit facility, commitment fee percentage		0.125%
Maximum
Debt Instrument [Line Items]
Line of credit facility, commitment fee percentage		0.40%
Commercial Paper and Letter Of Credit
Debt Instrument [Line Items]
Credit facility, remaining residual borrowing capacity		$ 541,000,000

Debt Obligations (Other Credit

Debt Obligations (Other Credit Facilities) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Commercial Paper and Letter Of Credit | Clearinghouse Credit Facilities
Debt Instrument [Line Items]
Remaining amount available	$ 198	$ 234

Retirement Plans (Details)

Retirement Plans (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Retirement Benefits [Abstract]
Employer contribution match, percent match			100.00%
Employer contribution match, percentage of employee contribution			6.00%
Defined contributions plan expense	$ 4	$ 3	$ 10	$ 10
Cost or expenses included in compensation and benefit expense	$ 5	$ 5	$ 15	$ 17

Share-Based Compensation (Narra

Share-Based Compensation (Narrative) (Details) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Jan. 31, 2017$ / sharesshares	Sep. 30, 2019USD ($)$ / sharespeer_groupshares	Sep. 30, 2018USD ($)$ / sharesshares	Sep. 30, 2019USD ($)program$ / sharespeer_groupshares	Sep. 30, 2018USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock shares reserved for future issuance (in shares)		10,300,000		10,300,000
Stock options exercised in period (in shares)		9,216	11,953	62,624	99,953
Net cash proceeds from the exercise of stock options | $				$ 1	$ 2
Share price (in dollars per share) | $ / shares		$ 99.35		$ 99.35
Stock options, exercisable (in shares)		296,711	300,000	296,711	300,000
Options exercisable, weighted average exercise price (in dollars per share) | $ / shares		$ 49.76	$ 36.55	$ 49.76	$ 36.55
Total pre-tax intrinsic value of stock options exercised | $		$ 1	$ 1	$ 5	$ 6
Share-based compensation expense before income taxes | $		$ 21	$ 18	$ 57	$ 51
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Discount from market price (as a percent)		15.00%	15.00%	15.00%	15.00%
Common stock shares reserved for future issuance (in shares)		1,700,000		1,700,000
Maximum percentage of shares purchased from annual compensation				10.00%
Discount given to employees (as a percent)				15.00%
Share-based compensation expense before income taxes | $		$ 1	$ 1	$ 3	$ 3
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost | $		66		$ 66
Weighted-average period unrecognized compensation cost is expected to be recognized, in years				1 year 9 months 18 days
PSUs | One-Year Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost | $		14		$ 14
Weighted-average period unrecognized compensation cost is expected to be recognized, in years				1 year 6 months
Performance period				1 year
Percentage of target amount granted, minimum				0.00%
Percentage of target amount granted, maximum				150.00%
Vesting period				3 years
Additional units granted above target (in shares)				51,914
PSUs | Three-Year Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost | $		$ 37		$ 37
Weighted-average period unrecognized compensation cost is expected to be recognized, in years				1 year 6 months
Performance period				3 years
Additional units granted above target (in shares)				99,622
Number of peer groups | peer_group		2		2
Performance-based long-term incentive program weighted percentage				50.00%
Minimum payout (as a percent)				0.00%
Maximum payout (as a percent)				200.00%
Share price (in dollars per share) | $ / shares		$ 89	$ 86.24	$ 89	$ 86.24
PSUs | Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of performance-based programs | program				2
PSUs, Negative TSR | Three-Year Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum payout (as a percent)				100.00%
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option awards granted (in shares)				0
Weighted-average grant date fair value (in dollars per share) | $ / shares	$ 66.68
Expected life (in years)	6 years
Employee Stock Option | CEO
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Stock option awards granted (in shares)	268,817
Second Anniversary | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage				25.00%
Second Anniversary | Employee Stock Option | CEO
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	33.33%
Third Anniversary | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage				25.00%
Fourth Anniversary | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage				50.00%

Share-Based Compensation (Summa

Share-Based Compensation (Summary of Share-Based Compensation Expense) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Payment Arrangement [Abstract]
Share-based compensation expense before income taxes	$ 21	$ 18	$ 57	$ 51
Income tax benefit	(6)	(5)	(16)	(14)
Share-based compensation expense after income taxes	$ 15	$ 13	$ 41	$ 37

Share-Based Compensation (Sum_2

Share-Based Compensation (Summary of Restricted Stock Activity) (Details) - Restricted Stock	9 Months Ended
	Sep. 30, 2019$ / sharesshares
Number of Awards
Unvested balances at beginning of period (in shares) | shares	1,583,375
Granted (in shares) | shares	587,987
Vested (in shares) | shares	(492,535)
Forfeited (in shares) | shares	(127,501)
Unvested balances at end of period (in shares) | shares	1,551,326
Weighted-Average Grant Date Fair Value
Unvested balances at beginning of period (in dollars per share) | $ / shares	$ 68.62
Granted (in dollars per share) | $ / shares	84.73
Vested (in dollars per share) | $ / shares	59.46
Forfeited (in dollars per share) | $ / shares	73.36
Unvested balances at end of period (in dollars per share) | $ / shares	$ 77.23

Share-Based Compensation (Sched

Share-Based Compensation (Schedule of Weighted- Average Assumptions Used to Determine Weighted-Average Fair Values) (Details) - $ / shares	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant date share price (in dollars per share)	$ 99.35
PSUs | Three-Year Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average risk free interest rate	2.26%	2.36%
Expected volatility (as a percent)	16.50%	18.70%
Weighted-average grant date share price (in dollars per share)	$ 89	$ 86.24
Weighted-average fair value at grant date (in dollars per share)	$ 97.65	$ 116.86

Share-Based Compensation (Sum_3

Share-Based Compensation (Summary of PSU Activity) (Details) - PSUs	9 Months Ended
	Sep. 30, 2019$ / sharesshares
One-Year Program
Number of Awards
Unvested balances at beginning of period (in shares) | shares	314,231
Granted (in shares) | shares	179,599
Vested (in shares) | shares	(12,733)
Forfeited (in shares) | shares	(22,943)
Unvested balances at end of period (in shares) | shares	458,154
Weighted-Average Grant Date Fair Value
Unvested balances at beginning of period (in dollars per share) | $ / shares	$ 74.01
Granted (in dollars per share) | $ / shares	83.56
Vested (in dollars per share) | $ / shares	67.51
Forfeited (in dollars per share) | $ / shares	75.03
Unvested balances at end of period (in dollars per share) | $ / shares	$ 77.88
Three-Year Program
Number of Awards
Unvested balances at beginning of period (in shares) | shares	837,750
Granted (in shares) | shares	397,553
Vested (in shares) | shares	(431,751)
Forfeited (in shares) | shares	(6,101)
Unvested balances at end of period (in shares) | shares	797,451
Weighted-Average Grant Date Fair Value
Unvested balances at beginning of period (in dollars per share) | $ / shares	$ 96.57
Granted (in dollars per share) | $ / shares	96.55
Vested (in dollars per share) | $ / shares	93.25
Forfeited (in dollars per share) | $ / shares	103.29
Unvested balances at end of period (in dollars per share) | $ / shares	$ 98.31

Share-Based Compensation (Sum_4

Share-Based Compensation (Summary of Stock Options Valuation Assumptions) (Details) - Employee Stock Option	1 Months Ended
	Jan. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life (in years)	6 years
Weighted-average risk free interest rate	2.10%
Expected volatility	25.60%
Dividend yield	1.92%

Share-Based Compensation (Sum_5

Share-Based Compensation (Summary of Stock Option Activity) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Number of Stock Options
Outstanding at Beginning of period (in shares)			448,966
Exercised (in shares)	(9,216)	(11,953)	(62,624)	(99,953)
Forfeited (in shares)			(25)
Outstanding at End of period (in shares)	386,317		386,317		448,966
Stock options, exercisable (in shares)	296,711	300,000	296,711	300,000
Weighted-Average Exercise Price
Outstanding at Beginning of period (in dollars per share)			$ 49.25
Exercised (in dollars per share)			20.92
Forfeited (in dollars per share)			20.10
Outstanding at End of period (in dollars per share)	$ 53.68		53.68		$ 49.25
Options exercisable, weighted average exercise price (in dollars per share)	$ 49.76	$ 36.55	$ 49.76	$ 36.55
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Outstanding beginning balance, Weighted-Average Remaining Contractual Term (in years)			5 years 5 months 4 days		5 years 6 months 3 days
Outstanding ending balance, Weighted-Average Remaining Contractual Term (in years)			4 years 10 months 13 days
Outstanding beginning balance, Aggregate Intrinsic Value	$ 18		$ 18		$ 14
Outstanding ending balance, Aggregate Intrinsic Value	$ 15		$ 15

Nasdaq Stockholders' Equity (Na

Nasdaq Stockholders' Equity (Narrative) (Details)	Jul. 23, 2019USD ($)$ / shares	Apr. 23, 2019USD ($)$ / shares	Jan. 29, 2019USD ($)$ / shares	Oct. 31, 2019USD ($)$ / shares	Sep. 30, 2019USD ($)vote$ / sharesshares	Sep. 30, 2018$ / shares	Sep. 30, 2019USD ($)vote$ / sharesshares	Sep. 30, 2018$ / sharesshares	Oct. 22, 2019USD ($)	Dec. 31, 2018shares	Jan. 31, 2018USD ($)
Stockholders Equity [Line Items]
Common stock, shares authorized (in shares)					300,000,000		300,000,000			300,000,000
Common stock, shares issued (in shares)					169,802,172		169,802,172			170,709,425
Common stock, shares outstanding (in shares)					163,894,038		163,894,038			165,165,104
Common stock (in votes per share) | vote					1		1
Common stock holder voting rights, maximum percentage of the then-outstanding shares of Nasdaq common stock					5.00%		5.00%
Common stock in treasury (in shares)					5,908,134		5,908,134			5,544,321
Share repurchase program additional amount authorized | $											$ 500,000,000
Share repurchase program, authorized amount | $											$ 726,000,000
Remaining authorized share repurchase amounts under repurchase program | $					$ 132,000,000		$ 132,000,000
Number of shares of common stock repurchased (in shares)							2,053,855	4,508,426
Preferred stock, shares authorized (in shares)					30,000,000		30,000,000
Preferred stock par value (in dollars per share) | $ / shares					$ 0.01		$ 0.01
Preferred stock, series A preferred stock, shares issued (in shares)					0		0			0
Preferred stock, series A preferred stock, shares outstanding (in shares)					0		0
Payments of dividends | $							$ 228,000,000
Cash dividends declared per common share (in dollars per share) | $ / shares	$ 0.47	$ 0.47	$ 0.44		$ 0.47	$ 0.44	$ 1.38	$ 1.26
Dividends declared | $	$ 78,000,000	$ 77,000,000	$ 73,000,000				$ 228,000,000
Other Repurchases of Common Stock
Stockholders Equity [Line Items]
Number of shares of common stock repurchased (in shares)							363,813
Subsequent Event
Stockholders Equity [Line Items]
Share repurchase program additional amount authorized | $				$ 500,000,000
Remaining authorized share repurchase amounts under repurchase program | $									$ 632,000,000
Cash dividends declared per common share (in dollars per share) | $ / shares				$ 0.47
Dividends declared | $				$ 77,000,000

Nasdaq Stockholders' Equity (Co

Nasdaq Stockholders' Equity (Common Stock in Treasury) (Details) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Equity [Abstract]
Number of shares of common stock repurchased (in shares)	2,053,855	4,508,426
Average price paid per share (in dollars per share)	$ 97.37	$ 87.43
Total purchase price (in millions)	$ 200	$ 394

Nasdaq Stockholders' Equity (Sc

Nasdaq Stockholders' Equity (Schedule of Dividends Declared) (Details) - USD ($) $ / shares in Units, $ in Millions	Jul. 23, 2019	Apr. 23, 2019	Jan. 29, 2019	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Equity [Abstract]
Dividend Per Common Share	$ 0.47	$ 0.47	$ 0.44	$ 0.47	$ 0.44	$ 1.38	$ 1.26
Total Amount Paid	$ 78	$ 77	$ 73			$ 228

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Numerator:
Net income attributable to common shareholders	$ 150	$ 163	$ 571	$ 502
Denominator:
Weighted-average common shares outstanding for basic earnings per share (in shares)	164,331,832	164,227,243	165,086,951	165,622,428
Weighted-average effect of dilutive securities:
Employee equity awards (in shares)	1,705,665	2,071,426	1,611,232	1,931,307
Contingent issuance of common stock (in shares)	992,247	992,247	330,749	330,749
Weighted-average common shares outstanding for diluted earnings per share (in shares)	167,029,744	167,290,916	167,028,932	167,884,484
Basic and diluted earnings per share:
Basic earnings per share (in dollars per share)	$ 0.91	$ 0.99	$ 3.46	$ 3.03
Diluted earnings per share (in dollars per share)	$ 0.90	$ 0.97	$ 3.42	$ 2.99

Fair Value of Financial Instr_3

Fair Value of Financial Instruments (Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Assets at Fair Value
Financial investments, at fair value	$ 201	$ 268
Fair Value, Measurements, Recurring
Assets at Fair Value
Financial investments, at fair value	201	268
Default fund and margin deposit investments	1,134	1,649
Total assets at fair value	1,335	1,917
Liabilities at Fair Value
Other financial instruments		112
Total liabilities at fair value		112
Fair Value, Measurements, Recurring | Level 1
Assets at Fair Value
Financial investments, at fair value	152	133
Default fund and margin deposit investments	134	327
Total assets at fair value	286	460
Liabilities at Fair Value
Other financial instruments		0
Total liabilities at fair value		0
Fair Value, Measurements, Recurring | Level 2
Assets at Fair Value
Financial investments, at fair value	49	135
Default fund and margin deposit investments	1,000	1,322
Total assets at fair value	1,049	1,457
Liabilities at Fair Value
Other financial instruments		112
Total liabilities at fair value		112
Fair Value, Measurements, Recurring | Level 3
Assets at Fair Value
Financial investments, at fair value	0	0
Default fund and margin deposit investments	0	0
Total assets at fair value	$ 0	0
Liabilities at Fair Value
Other financial instruments		0
Total liabilities at fair value		$ 0

Fair Value of Financial Instr_4

Fair Value of Financial Instruments (Narrative) (Details) - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	$ 201,000,000	$ 259,000,000
Liability due to market default	0
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other financial instruments		112,000,000
Liability due to market default		112,000,000
Fair value assets	1,335,000,000	1,917,000,000
Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other financial instruments		112,000,000
Fair value assets	1,049,000,000	1,457,000,000
Fair Value, Measurements, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value assets	0	0
Fair Value, Measurements, Nonrecurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of debt utilizing discounted cash flow analyses	3,700,000,000	3,900,000,000
Foreign Government Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	$ 166,000,000	$ 166,000,000

Clearing Operations (Narrative)

Clearing Operations (Narrative) (Details)	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)fundcontract	Sep. 30, 2018USD ($)contract	Dec. 31, 2018USD ($)
Clearing Operations [Line Items]
Number of member sponsored default funds | fund			4
Loss due to commodities market default		$ 133,000,000
Clearing default loss		8,000,000
Capital relief program expense	$ 23,000,000
Liability due to market default	0		$ 0
Default funds and margin deposits	2,422,000,000		2,422,000,000		$ 4,742,000,000
Default fund contributions	525,000,000		525,000,000
Committed capital	201,000,000		201,000,000		268,000,000
Liability Waterfall
Clearing Operations [Line Items]
Junior capital, cash deposits and pledged assets	32,000,000		32,000,000
Senior capital, cash deposits and pledged assets	20,000,000		20,000,000
Committed capital	88,000,000		88,000,000
Utilize as capital resources
Clearing Operations [Line Items]
Default fund contributions	422,000,000		422,000,000
Utilize as member posted surplus balance
Clearing Operations [Line Items]
Default fund contributions	103,000,000		$ 103,000,000
Minimum
Clearing Operations [Line Items]
Reverse purchase agreements, maturity range			2 days
Maximum
Clearing Operations [Line Items]
Reverse purchase agreements, maturity range			18 days
Nasdaq Clearing
Clearing Operations [Line Items]
Default fund cash contributions invested in highly rated government debt securities			$ 856,000,000
Maturity period of time deposits			90 days
Committed capital	140,000,000		$ 140,000,000
Power of assessment of the clearing member's contribution to the financial markets and commodities markets default funds (as a percent)			100.00%
Contract value of resale and repurchase agreements	2,100,000,000	$ 4,100,000,000	$ 2,100,000,000	$ 4,100,000,000
Total number of derivative contracts cleared | contract			5,580,836	6,835,634
Nasdaq Clearing | Reverse Repurchase Agreements
Clearing Operations [Line Items]
Default funds and margin deposits	278,000,000		$ 278,000,000
Fair Value, Measurements, Recurring
Clearing Operations [Line Items]
Liability due to market default					112,000,000
Collateral due to market default					112,000,000
Committed capital	$ 201,000,000		$ 201,000,000		$ 268,000,000

Clearing Operations (Schedule o

Clearing Operations (Schedule of Clearing Member Default Fund Contributions And Margin Deposits) (Details) $ in Millions	Sep. 30, 2019USD ($)
Clearing Operations [Line Items]
Default fund contributions	$ 525
Margin deposits	5,773
Total	6,298
Cash Contributions
Clearing Operations [Line Items]
Default fund contributions	406
Margin deposits	2,016
Total	2,422
Non-Cash Contributions
Clearing Operations [Line Items]
Default fund contributions	119
Margin deposits	3,757
Total	$ 3,876

Clearing Operations (Schedule_2

Clearing Operations (Schedule of Derivative Contracts) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2019USD ($)TWhcontract	Sep. 30, 2018TWhcontract
Clearing Operations [Line Items]
Market value of derivative contracts | $	$ 1,485
Total number of cleared contracts | contract	69,956,891	71,644,112
Total volume in cleared power, in Terawatt hours (TWh) | TWh	614	853
Commodity and seafood options, futures and forwards
Clearing Operations [Line Items]
Market value of derivative contracts | $	$ 359
Total number of cleared contracts | contract	393,153	1,506,560
Fixed-income options and futures
Clearing Operations [Line Items]
Market value of derivative contracts | $	$ 925
Total number of cleared contracts | contract	15,780,707	16,833,278
Stock options and futures
Clearing Operations [Line Items]
Market value of derivative contracts | $	$ 120
Total number of cleared contracts | contract	18,030,431	17,735,228
Index options and futures
Clearing Operations [Line Items]
Market value of derivative contracts | $	$ 81
Total number of cleared contracts | contract	35,752,600	35,569,046

Income Taxes (Components of Inc

Income Taxes (Components of Income Tax Provision) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income tax provision	$ 65	$ 46	$ 196	$ 234
Percent change in income tax provision	41.30%		(16.20%)
Effective tax rate	30.20%	22.00%	25.60%	31.80%

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - Accounting Standards Update 2018-02 $ in Millions	9 Months Ended
	Sep. 30, 2018USD ($)
Accumulated Other Comprehensive Loss
Income Tax Disclosure [Line Items]
Reclassification from AOCI, tax amount	$ 142
Employee Benefit Plan Adjustment Gains and Losses
Income Tax Disclosure [Line Items]
Reclassification from AOCI, tax amount	135
Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent
Income Tax Disclosure [Line Items]
Reclassification from AOCI, tax amount	$ 7

Commitments, Contingencies an_2

Commitments, Contingencies and Guarantees (Details)	Sep. 02, 2014exchange	Sep. 30, 2019USD ($)shares	Dec. 31, 2018USD ($)	Oct. 31, 2018USD ($)
Commitments and Contingencies Disclosure [Line Items]
Financial guarantees obtained		$ 11,000,000	$ 12,000,000
National exchanges named as defendants | exchange	7
Estimate of possible loss of revenue				$ 1,000,000
eSpeed
Commitments and Contingencies Disclosure [Line Items]
Contingent future issuance of common stock (in shares) | shares		992,247
Revenue required to trigger annual issuance of Nasdaq common stock		$ 25,000,000
Escrow Agreement
Commitments and Contingencies Disclosure [Line Items]
Contingency, accrual		12,000,000
ICBC
Commitments and Contingencies Disclosure [Line Items]
Margin deposits contributed to brokers		15,000,000
Clearinghouse Credit Facilities
Commitments and Contingencies Disclosure [Line Items]
Credit facility, available liquidity		$ 198,000,000	$ 234,000,000

Business Segments (Narrative) (

Business Segments (Narrative) (Details) $ in Millions	1 Months Ended	9 Months Ended
	Sep. 30, 2018USD ($)	Sep. 30, 2019segment
Segment Reporting [Abstract]
Number of operating segments | segment		4
Loss due to commodities market default allocated to junior capital | $	$ 8

Business Segments (Schedule of

Business Segments (Schedule of Operating Segments) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Total revenues	$ 1,096	$ 964	$ 3,197	$ 3,141
Transaction-based expenses	(464)	(364)	(1,308)	(1,259)
Revenues less transaction-based expenses	632	600	1,889	1,882
Operating income	226	246	757	787
Operating Segments | Market Services
Segment Reporting Information [Line Items]
Total revenues	690	586	1,995	1,968
Transaction-based expenses	(464)	(364)	(1,308)	(1,259)
Revenues less transaction-based expenses	226	222	687	709
Operating income	129	121	392	402
Operating Segments | Corporate Services
Segment Reporting Information [Line Items]
Total revenues	124	121	368	364
Transaction-based expenses	0	0	0	0
Revenues less transaction-based expenses	124	121	368	364
Operating income	45	40	134	117
Operating Segments | Information Services
Segment Reporting Information [Line Items]
Total revenues	198	179	585	528
Transaction-based expenses	0	0	0	0
Revenues less transaction-based expenses	198	179	585	528
Operating income	126	117	372	342
Operating Segments | Market Technology
Segment Reporting Information [Line Items]
Total revenues	84	68	239	194
Transaction-based expenses	0	0	0	0
Revenues less transaction-based expenses	84	68	239	194
Operating income	15	9	29	20
Corporate Items
Segment Reporting Information [Line Items]
Total revenues	0	10	10	87
Transaction-based expenses	0	0	0	0
Revenues less transaction-based expenses	0	10	10	87
Operating income	$ (89)	$ (41)	$ (170)	$ (94)

Business Segments (Corporate It

Business Segments (Corporate Items) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Revenues - divested businesses		$ 1,096	$ 964	$ 3,197	$ 3,141
Expenses:
Amortization expense of acquired intangible assets		25	27	76	83
Merger and strategic initiatives expense		10	6	25	7
Restructuring charges		30	0	30	0
Clearing default loss	$ 8
Operating income		226	246	757	787
Corporate Items
Segment Reporting Information [Line Items]
Revenues - divested businesses		0	10	10	87
Expenses:
Amortization expense of acquired intangible assets		25	27	76	83
Merger and strategic initiatives expense		10	6	25	7
Restructuring charges		30	0	30	0
Provision for notes receivable		20	0	20	0
Clearing default loss		0	8	0	8
Extinguishment of debt		0	0	11	0
Expenses - divested businesses		0	8	8	75
Other		4	2	10	8
Total expenses		89	51	180	181
Operating income		$ (89)	$ (41)	$ (170)	$ (94)

Restructuring Charges (Narrativ

Restructuring Charges (Narrative) (Details) - Asset impairments	Sep. 30, 2019USD ($)
Minimum
Restructuring Cost and Reserve [Line Items]
Restructuring, expected cost	$ 65,000,000
Maximum
Restructuring Cost and Reserve [Line Items]
Restructuring, expected cost	$ 75,000,000

Restructuring Charges (Summary

Restructuring Charges (Summary of Restructuring Plan) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	$ 30	$ 0	$ 30	$ 0
Asset impairments
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	23		23
Accelerated depreciation
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	2		2
Severance and employee-related costs
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	3		3
Other
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	$ 2		$ 2