Morningstar (MORN) 10-K 26 Feb 21 2020 FY Annual report Financial data

Cover Page Cover

Cover Page Cover - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2020	Feb. 12, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Document Transition Report	false
Entity File Number	000-51280
Entity Registrant Name	MORNINGSTAR, INC.
Entity Incorporation, State or Country Code	IL
Entity Tax Identification Number	36-3297908
Entity Address, Address Line One	22 West Washington Street
Entity Address, City or Town	Chicago
Entity Address, State or Province	IL
Entity Address, Postal Zip Code	60602
City Area Code	312
Local Phone Number	696-6000
Title of 12(b) Security	Common stock, no par value
Trading Symbol	MORN
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
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 Public Float			$ 3.1
Entity Common Stock, Shares Outstanding		42,903,180
Entity Central Index Key	0001289419
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Documents Incorporated by Reference [Text Block]	Certain parts of the registrant's Definitive Proxy Statement for the 2020 Annual Meeting of Shareholders are incorporated into Part III of this Form 10-K.
ICFR Auditor Attestation Flag	true

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue	$ 1,389.5	$ 1,179	$ 1,019.9
Operating expense:
Cost of revenue	556.4	483.1	411.1
Sales and marketing	206.4	177.9	148.5
General and administrative	272	210.7	147.8
Depreciation and amortization	139.5	117.7	96.7
Total operating expense	1,174.3	989.4	804.1
Operating income	215.2	189.6	215.8
Non-operating income:
Interest expense, net	(9.5)	(8.7)	(1.8)
Realized gains on sale of investments, reclassified from other comprehensive income	2.1	1.2	1
Gain on sale of a product line	0	0	10.5
Gain on sale of equity method investments	30	19.5	5.6
Holding gain on previously held equity interest	50.9	0	0
Other income (expense), net	(5.7)	(3.1)	1.8
Non-operating income (expense), net	67.8	8.9	17.1
Income before income taxes and equity in net loss of unconsolidated entities	283	198.5	232.9
Equity in net loss of unconsolidated entities	0.3	(0.9)	(2.1)
Income tax expense	59.7	45.6	47.8
Consolidated net income	$ 223.6	$ 152	$ 183
Net income per share:
Basic net income per share (in dollars per share)	$ 5.22	$ 3.56	$ 4.30
Diluted net income per share (in dollars per share)	5.18	3.52	4.25
Dividends per common share:
Dividends declared per common share (in dollars per share)	1.22	1.14	1.03
Dividends paid per common share (in dollars per share)	$ 1.20	$ 1.12	$ 1
Weighted average shares outstanding:
Basic (in shares)	42.9	42.7	42.6
Diluted (in shares)	43.2	43.2	43

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Consolidated net income	$ 223.6	$ 152	$ 183
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustment	37.3	11.5	(26.6)
Unrealized gains (losses) on securities:
Unrealized holding gains (losses) arising during period	2.9	3.8	(1)
Reclassification of gains included in net income	(1.6)	(0.9)	(0.8)
Other comprehensive income (loss)	38.6	14.4	(28.4)
Comprehensive income	$ 262.2	$ 166.4	$ 154.6

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 422.5	$ 334.1
Investments	41.7	33.4
Accounts receivable, less allowance for credit losses of $4.2 million and $4.1 million, respectively	205.1	188.5
Income tax receivable	2.2	6.3
Deferred commissions	21.1	16.9
Other current assets	37.4	24
Total current assets	730	603.2
Property, equipment, and capitalized software, net	155.1	154.7
Investments in unconsolidated entities	32.6	59.6
Goodwill	1,205	1,039.1
Operating lease assets	147.7	144.8
Intangible assets, net	380.1	333.4
Deferred tax asset, net	12.6	10.7
Deferred commissions	18.5	13.5
Other assets	14.4	11.9
Total assets	2,696	2,370.9
Current liabilities:
Accounts payable and accrued liabilities	64.5	58.9
Accrued compensation	169.2	137.5
Deferred revenue	306.8	250.1
Current portion of long-term debt	0	11
Operating lease liabilities	39.9	35.8
Contingent consideration liability	35	0
Other current liabilities	11.1	2.5
Total current liabilities	626.5	495.8
Operating lease liabilities	137.7	138.7
Accrued compensation	35.1	12.1
Deferred tax liabilities, net	108.9	95
Long-term debt	449.1	502.1
Deferred revenue	33.5	32.2
Other long-term liabilities	33.8	11.4
Total liabilities	1,424.6	1,287.3
Morningstar, Inc. shareholders’ equity:
Common stock, no par value, 200,000,000 shares authorized, of which 42,898,158 and 42,848,359 shares were outstanding as of December 31, 2020 and December 31, 2019, respectively	0	0
Treasury stock at cost, 11,135,446 and 10,840,173 shares as of December 31, 2020 and December 31, 2019, respectively	(767.3)	(728.7)
Additional paid-in capital	671.3	655
Retained earnings	1,389.4	1,217.9
Accumulated other comprehensive loss:
Currency translation adjustment	(25.7)	(63)
Unrealized gain on available-for-sale investments	3.7	2.4
Total accumulated other comprehensive loss	(22)	(60.6)
Total equity	1,271.4	1,083.6
Total liabilities and equity	$ 2,696	$ 2,370.9

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 4.2	$ 4.1
Common stock, no par value	$ 0	$ 0
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares outstanding	42,898,158	42,848,359
Treasury stock, shares	11,135,446	10,840,173

Consolidated Statement of Equit

Consolidated Statement of Equity - USD ($) $ in Millions	Total	Cumulative effect of accounting change related to the adoption of ASU No. 2014-09	Common Stock	Treasury Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Balance at Dec. 31, 2017	$ 804.9		$ 0	$ (708.2)	$ 601	$ 958.7	$ (46.6)
Balance (in shares) at Dec. 31, 2017			42,547,707
Increase (Decrease) in Stockholders' Equity
Consolidated net income	183					183
Other Comprehensive Income (loss)
Unrealized gain on available-for-sale investments, net of income tax	(1)						(1)
Reclassification of adjustments for gains included in net income, net of income tax	(0.8)						(0.8)
Foreign currency translation adjustment, net	(26.6)						(26.6)
Other comprehensive income (loss)	(28.4)						(28.4)
Issuance of common stock related to stock-option exercises and vesting of restricted stock units, net	(13.2)		$ 0	2.3	(15.5)	0	0
Reclassification of awards previously liability-classified that were converted to equity	4.5		$ 0	0	4.5	0	0
Issuance of common stock related to stock-option exercises and vesting of restricted stock units, net (in shares)			278,656
APIC, Share-based Payment Arrangement, Increase for Cost Recognition [Abstract]
Stock-based compensation — restricted stock units	19.8		$ 0	0	19.8	0	0
Stock-based compensation — performance share awards	10.2		0	0	10.2	0	0
Stock-based compensation — performance share awards	1.7		0	0	1.7	0	0
Dividends declared ($1.22 per share)	(43.9)		0	0	0	(43.9)	0
Common share repurchased	(20.9)		$ 0	(20.9)	0	0	0
Common share repurchased (in shares)			(202,245)
Balance at Dec. 31, 2018	934.7			(726.8)	621.7	1,114.8	(75)
Balance (in shares) at Dec. 31, 2018			42,624,118
APIC, Share-based Payment Arrangement, Increase for Cost Recognition [Abstract]
Foreign currency translation adjustment	(26.6)
Retained earnings		$ 17
Consolidated net income	152					152	0
Unrealized gain on available-for-sale investments, net of income tax	3.8					0	3.8
Reclassification of adjustments for gains included in net income, net of income tax	(0.9)					0	(0.9)
Foreign currency translation adjustment, net	11.5					0	11.5
Other comprehensive income (loss)	14.4					0	14.4
Issuance of common stock related to stock-option exercises and vesting of restricted stock units, net	(15.2)			2.7	(17.9)
Reclassification of awards previously liability-classified that were converted to equity	6.8				6.8
Issuance of common stock related to stock-option exercises and vesting of restricted stock units, net (in shares)			266,176
Stock-based compensation — restricted stock units	20.4				20.4
Stock-based compensation — performance share awards	20.6				20.6
Stock-based compensation — market stock units	3.4				3.4
Dividends declared ($1.22 per share)	(48.9)					(48.9)
Common share repurchased	(4.6)			(4.6)
Common share repurchased (in shares)			(41,935)
Balance at Dec. 31, 2019	$ 1,083.6			(728.7)	655	1,217.9	(60.6)
Balance (in shares) at Dec. 31, 2019	42,848,359		42,848,359
APIC, Share-based Payment Arrangement, Increase for Cost Recognition [Abstract]
Foreign currency translation adjustment	$ 11.5
Retained earnings	1,217.9
Consolidated net income	223.6					223.6
Unrealized gain on available-for-sale investments, net of income tax	2.9						2.9
Reclassification of adjustments for gains included in net income, net of income tax	(1.6)						(1.6)
Foreign currency translation adjustment, net	37.3						37.3
Other comprehensive income (loss)	38.6						38.6
Issuance of common stock related to stock-option exercises and vesting of restricted stock units, net	(23.1)			3.3	(26.4)
Reclassification of awards previously liability-classified that were converted to equity	6.1				6.1
Issuance of common stock related to stock-option exercises and vesting of restricted stock units, net (in shares)			364,724
Stock-based compensation — restricted stock units	22.2				22.2
Stock-based compensation — performance share awards	10.2				10.2
Stock-based compensation — market stock units	4.2				4.2
Dividends declared ($1.22 per share)	(52.1)					(52.1)
Common share repurchased	(41.9)			(41.9)
Common share repurchased (in shares)			(314,925)
Balance at Dec. 31, 2020	$ 1,271.4			$ (767.3)	$ 671.3	$ 1,389.4	$ (22)
Balance (in shares) at Dec. 31, 2020	42,898,158		42,898,158
APIC, Share-based Payment Arrangement, Increase for Cost Recognition [Abstract]
Foreign currency translation adjustment	$ 37.3
Retained earnings	$ 1,389.4

Consolidated Statement of Equ_2

Consolidated Statement of Equity (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Stockholders' Equity [Abstract]
Unrealized gain (loss) on available-for-sale investments, tax	$ 1.3	$ (0.7)	$ 1.8
Reclassification of adjustments for gains included in net income, tax	$ 0.3	$ 0.3	$ 1.2

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating activities
Consolidated net income	$ 223.6	$ 152	$ 183
Adjustments to reconcile consolidated net income to net cash flows from operating activities:
Depreciation and amortization	139.5	117.7	96.7
Deferred income taxes	(6.7)	(6)	(1.1)
Stock-based compensation expense	36.6	44.4	31.7
Provision for bad debt	2.8	2.3	2.5
Equity in net (income) loss of unconsolidated entities	(0.3)	0.9	2.1
Gain on sale of a product line	0	0	(10.5)
Gain on sale of equity method investments	(30)	(19.5)	(5.6)
Holding gain on previously held equity interest	(50.9)	0	0
Acquisition earn-out	27.8	0	0
Other, net	3	1.1	(2.5)
Changes in operating assets and liabilities
Accounts receivable	(9.2)	11.3	(29.6)
Accounts payable and accrued liabilities	(9.5)	3.2	6
Accrued compensation and deferred commissions	18.2	17.1	15.6
Income taxes, current	8	(11.6)	(12.4)
Deferred revenue	29.5	28.1	28.6
Other assets and liabilities	1.9	(6.6)	10.3
Cash provided by operating activities	384.3	334.4	314.8
Investing activities
Purchases of investment securities	(56.4)	(36.2)	(35.7)
Proceeds from maturities and sales of investment securities	46.9	35.8	51.2
Capital expenditures	(76.7)	(80)	(76.1)
Acquisitions, net of cash acquired	(67.8)	(681.9)	(0.4)
Proceeds from sale of a product line	0	0	10.5
Proceeds from sale of equity method investments, net	35.2	17.6	7.9
Purchases of equity- and cost-method investments	(6.7)	(1.5)	(7.4)
Other, net	1.7	(0.1)	0.1
Cash used for investing activities	(123.8)	(746.3)	(49.9)
Financing activities
Common shares repurchased	(41.9)	(4.9)	(20.9)
Dividends paid	(51.4)	(47.8)	(42.6)
Proceeds from revolving credit facility	60	610	0
Repayment of revolving credit facility	(130)	(160)	(110)
Proceeds from 2030 Notes	350	0	0
Repayment of term facility	343.4	5.6	0
Proceeds from stock-option exercises	1.9	0.2	0.1
Employee taxes withheld for restricted stock units	(25.1)	(15.2)	(13.3)
Other, net	(2.3)	(3)	(2.1)
Cash provided by (used for) financing activities	182.2	373.7	(188.8)
Effect of exchange rate changes on cash and cash equivalents	10.1	3	(15)
Net increase (decrease) in cash and cash equivalents	88.4	(35.2)	61.1
Cash and cash equivalents—beginning of period	334.1	369.3	308.2
Cash and cash equivalents—end of period	422.5	334.1	369.3
Supplemental disclosure of cash flow information:
Cash paid for income taxes	58.2	63.3	67
Cash paid for interest	11.1	11	3.7
Supplemental information of non-cash investing and financing activities:
Unrealized gain (loss) on available-for-sale investments	$ 1.8	$ 3.9	$ (2.7)

Description of Business

Description of Business	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Description of Business Morningstar, Inc. and its subsidiaries (Morningstar, we, our, the company) provide independent investment research for investors around the world. We offer an extensive line of products and services for individual investors, financial advisors, asset managers, retirement plan providers and sponsors, and private market/venture capital investors. We have operations in 29 countries. COVID-19 Update We continue to closely monitor the impact of the COVID-19 pandemic on all aspects of our business and in the geographies in which we operate, including how it affects our team members, customers, suppliers, and global markets. Since the situation surrounding the COVID-19 pandemic remains fluid, we are actively managing our response and have assessed potential impacts to our financial position and operating results related to our consolidated financial statements for the year ended December 31, 2020.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies The acronyms that appear in these Notes to our Consolidated Financial Statements refer to the following: ASC Accounting Standards Codification ASU Accounting Standards Update EITF Emerging Issues Task Force FASB Financial Accounting Standards Board SEC Securities and Exchange Commission Principles of Consolidation. We conduct our business operations through wholly owned or majority-owned operating subsidiaries. The accompanying consolidated financial statements include the accounts of Morningstar, Inc. and our subsidiaries. We consolidate assets, liabilities, and results of operations of subsidiaries in which we have a controlling interest and eliminate all significant intercompany accounts and transactions. We account for investments in entities in which we exercise significant influence, but do not control, using the equity method. As part of our investment management operations, we manage certain funds outside of the U.S. that are considered variable interest entities. For the majority of these variable interest entities, we do not have a variable interest. In cases where we do have a variable interest, we are not the primary beneficiary. Accordingly, we do not consolidate any of these variable interest entities. Use of Estimates. The preparation of financial statements in conformity with accounting principles generally accepted in the U.S. (GAAP) requires us to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues, and expenses during the reporting period. Actual results may differ from these estimates. Cash and Cash Equivalents. Cash and cash equivalents consist of cash and investments with original maturities of three months or less. We state them at cost, which approximates fair value. We state the portion of our cash equivalents that are invested in money market funds at fair value, as these funds are actively traded and have quoted market prices. Investments. We account for our investments in accordance with FASB ASC 320, Investments—Debt and Equity Securities (FASB ASC 320) . We classify our investments into three categories: held-to-maturity, trading, and available-for-sale. • Held-to-maturity: We classify certain investments, primarily certificates of deposit, as held-to-maturity securities, based on our intent and ability to hold these securities to maturity. We record held-to-maturity investments at amortized cost in our Consolidated Balance Sheets. • Trading: We classify certain other investments, primarily equity securities, as trading securities. We include realized and unrealized gains and losses associated with these investments as a component of our operating income in our Consolidated Statements of Income. We record these securities at their fair values in our Consolidated Balance Sheets. • Available-for-sale: Investments not considered held-to-maturity or trading securities are classified as available-for-sale securities. Available-for-sale securities primarily consist of equity securities, exchange-traded funds, and mutual funds. We report unrealized gains and losses for available-for-sale securities as other comprehensive income (loss), net of related income taxes. We record these securities at their fair values in our Consolidated Balance Sheets. Fair Value Measurements. FASB ASC 820, Fair Value Measurements (FASB ASC 820) defines fair value, establishes a framework for measuring fair value, and expands disclosures about fair value measurements. Under FASB ASC 820, fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants as of the measurement date. The standard applies whenever other standards require (or permit) assets or liabilities to be measured at fair value. FASB ASC 820 uses a fair value hierarchy based on three broad levels of valuation inputs: • Level 1: Valuations based on quoted prices in active markets for identical assets or liabilities that we have the ability to access. • Level 2: Valuations based on quoted prices in markets that are not active or for which all significant inputs are observable, either directly or indirectly. • Level 3: Valuations based on inputs that are unobservable and significant to the overall fair value measurement. We provide additional information about our cash equivalents and investments that are subject to FASB ASC 820 in Note 7. Concentration of Credit Risk. For the years ended December 31, 2020, 2019, and 2018, no single customer represented 5% or more of our consolidated revenue. If receivables from our customers become delinquent, we begin a collections process. We maintain an allowance for credit losses based on our estimate of the probable losses of accounts receivable. Property, Equipment, and Depreciation. We state property and equipment at historical cost, net of accumulated depreciation. We depreciate property and equipment using the straight-line method based on the useful life of the asset, which ranges from three Computer Software and Internal Product Development Costs. We capitalize certain costs in accordance with FASB ASC 350-40, Internal-Use Software , FASB ASC 350-50, Website Development Costs, and FASB ASC 985, Software . Internal product development costs mainly consist of employee costs for developing new web-based products and certain major enhancements of existing products. We amortize these costs on a straight-line basis over the estimated economic life, which is generally three years. We include capitalized software development costs related to projects that have not been placed into service in our construction in progress balance. The table below summarizes our depreciation expense related to capitalized developed software for the past three years: (in millions) 2020 2019 2018 Capitalized developed software depreciation expense $ 53.9 $ 61.1 $ 42.8 The table below summarizes our capitalized software development costs for the past three years: (in millions) 2020 2019 2018 Capitalized software development costs $ 60.3 $ 64.8 $ 53.5 Business Combinations . When we acquire a business, we account for the business combination in accordance with FASB ASC 805, Business Combinations (FASB ASC 805). We recognize and measure the fair value of the acquired business and allocate the purchase price to the identifiable tangible and intangible assets acquired and liabilities assumed based upon their estimated fair values at the date of acquisition. The difference between the purchase price and the estimated fair value of the net assets acquired or the excess of the aggregate estimated fair values of assets acquired and liabilities assumed is recorded as goodwill. In determining the estimated fair values of assets acquired and liabilities assumed in a business combination, we use various recognized valuation methods, including discounted cash flow, Monte Carlo simulations, and relief from royalty. For a business combination achieved in stages, we remeasure our previously held equity interest immediately before the acquisition to the acquisition date fair value and recognize any gain in our Consolidated Statements of Income. We recognize the fair value of any contingent payments at the date of acquisition as part of the consideration transferred to acquire a business. The liability associated with contingent consideration is remeasured to fair value at each reporting period subsequent to the date of acquisition considering factors that may impact the timing and amount of contingent payments until the term of the agreement has expired or the contingency is resolved. Any changes in the fair value measurement will be recorded in our Consolidated Statements of Income. In evaluating the characterization of contingent and deferred payments, we analyze relevant factors, including the nature of the payment, continuing employment requirements, incremental payments to employees of the acquired business, and timing and rationale underlying the transaction, to determine whether the payments should be accounted for as additional purchase consideration or post-combination related services. We expense direct costs related to the business combination, such as accounting, legal, valuation, and other professional fees, as incurred. We recognize restructuring costs, including severance and relocation for employees of the acquired entity, as post-combination expenses unless the target entity meets the criteria of ASC 420, Exit or Disposal Cost Obligations , on the acquisition date. As part of the purchase price allocation, we follow the requirements of FASB ASC 740, Income Taxes (FASB ASC 740). This includes establishing deferred tax assets or liabilities reflecting the difference between the values assigned for financial statement purposes and income tax purposes. In certain acquisitions, the goodwill resulting from the purchase price allocation may not be deductible for income tax purposes. FASB ASC 740 prohibits recognition of a deferred tax asset or liability for temporary differences in goodwill if goodwill is not amortizable and deductible for tax purposes. Goodwill . Changes in the carrying amount of our recorded goodwill are mainly the result of business acquisitions, divestitures, and the effect of foreign currency translations. In accordance with FASB ASC 350, Intangibles—Goodwill and Other , we do not amortize goodwill; instead, goodwill is subject to an impairment test annually, or whenever indicators of impairment exist. An impairment would occur if the carrying amount of a reporting unit exceeded the fair value of that reporting unit. We performed annual impairment reviews in the fourth quarter of 2020 and 2019. We did not record any impairment losses in 2020, 2019, and 2018. Intangible Assets. We amortize intangible assets using the straight-line method over their estimated useful lives, which range from one twenty years . We have no intangible assets with indefinite useful lives. In accordance with FASB ASC 360-10-35, Subsequent Measurement—Impairment or Disposal of Long-Lived Assets , we review intangible assets for impairment whenever events or changes in circumstances indicate that the carrying value may not be recoverable. If the value of future undiscounted cash flows is less than the carrying amount of an asset group, we record an impairment loss based on the excess of the carrying amount over the fair value of the asset group. We did not record any impairment losses in 2020 , 2019, and 2018. Revenue Recognition. On January 1, 2018, we began recognizing revenue in accordance with ASC Topic 606, Revenue from Contracts with Customers (ASC Topic 606). The Company has retained similar recognition and measurement upon adoption of ASC Topic 606 as under accounting standards in effect in prior periods. Under ASC Topic 606, we recognize revenue by applying the following five-step model to each of our customer arrangements: 1. Identify the customer contract; 2. Identify the performance obligations in the contract; 3. Determine the transaction price; 4. Allocate the transaction price to the performance obligations; and 5. Recognize revenue when (or as) performance obligations are satisfied. Revenues are recognized when (or as) performance obligations are satisfied by transferring a promised product or service to the customer. Products or services are transferred when (or as) the customer obtains control of the product or service. The transaction price for a customer arrangement is the amount we expect to be entitled to in exchange for transferring the promised product or service. The transaction price may include fixed amounts, variable amounts, or both. When the right to payment exceeds revenue recognized the result is an increase to deferred revenue. When a customer’s license-based contract is signed, the customer’s service is activated immediately. License-based arrangements, our largest source of revenue from customers, generally is billed for the entire term, or billed annually (if the contract term is longer than one year). Customers are typically given payment terms of thirty to sixty days, although some customers pay immediately. Revenue from contracts with customers is derived from license-based arrangements, asset-based arrangements, and transaction-based arrangements. License-based revenue, which represents subscription services available to customers and not a license under the accounting guidance, is generated through subscription contracts entered into with our customers of Morningstar Data, Morningstar Direct, Morningstar Advisor Workstation, Morningstar Enterprise Components, PitchBook Data, Sustainalytics, and other similar products. Our performance obligations under these contracts are typically satisfied over time, as the customer has access to the service during the term of the subscription license and the level of service is consistent during the contract period. Each individual day within the contract period is viewed to be a service and the entirety of the service subscription term is determined to be a series combined into a single performance obligation and recognized over-time and on a straight-line basis, typically over terms of 1 to 3 years. Asset-based revenue is generated through consulting service contracts with our customers of Morningstar Investment Management, Workplace Solutions, and Morningstar Indexes. Our performance obligations under these contracts are a daily asset management performance obligation, which is determined to be a daily service and thus satisfied over time as the customer receives continuous access to a service for the contract term. We recognize revenue daily over the contract term based on the value of assets under management and a tiered fee agreed to with the customer (typically in a range of 30-55 basis points of the customer’s average daily portfolio balance). Asset-based arrangements typically have a term of 1 to 3 years. The fees from such arrangements represent variable consideration, and the customer does not make separate purchasing decisions that result in additional performance obligations. Significant changes in the underlying fund assets, or significant disruptions in the market, are evaluated to determine if revisions on estimates of earned asset-based fees for the current quarter are needed. An estimate of the average daily portfolio balance is included in determining revenue for a given period. Estimates are based on the most recently reported quarter, and, as a result, it is unlikely a significant reversal of revenue would occur. Transaction-based revenue is generated through contracts with our customers for DBRS Morningstar products and services, Internet advertising on Morningstar.com, and Morningstar-sponsored conferences. Our performance obligations for D BRS Morningstar includ e the issuance of the rating and may include surveillance services for a period of time as agreed with the customer. We allocate the transaction price to the deliverables based on their relative selling price, which is generally based on the price we charge when the same deliverable is sold separately. Our performance obligation for the issuance of the rating is satisfied when the rating is issued, which is when we recognize the related revenue. Our performance obligations for surveillance services is satisfied over time, as the customer has access to the service during the surveillance period and the level of service is consistent during the contract period. Therefore, we recognize revenue for this performance obligation on a straight-line basis. Our performance obligations for Internet advertising and Morningstar-sponsored conferences are satisfied as the service is delivered; therefore, we recognize revenue when the performance obligation is satisfied (as the customer’s advertisements are displayed and at the completion of the Morningstar-sponsored conference). Our contracts with customers may include multiple performance obligations. For most of these arrangements, we generally allocate revenue to each performance obligation based on its estimated standalone selling price. We generally determine standalone selling prices based on prices charged to customers when the same performance obligation is sold separately. Our contracts with customers may include third-party involvement in providing goods or services to the customer. The inclusion of third-party content does not result in separate performance obligations because is it not delivered separately from the other service offerings. In these arrangements, the customer has contracted to receive a single, integrated and bundled solution with third-party and Morningstar content delivered via Morningstar’s subscription services. Revenue and related costs of revenue from third-party content is presented on a gross basis within the consolidated financial statements. Deferred revenue represents the portion of licenses or subscriptions billed or collected in advance of the service being provided which we expect to recognize as revenue in future periods. Sales Commissions. Under prior accounting standards, the Company expensed sales incentive compensation costs, (sales commissions) as incurred. Upon adoption of ASC Topic 606 and ASC 340-40, Other Assets and Deferred Costs - Contracts with Customers , on January 1, 2018, we began capitalizing sales commissions, which are considered directly attributable to obtaining a customer contract. Such costs are capitalized using a portfolio approach that aggregates these costs by legal entity within their geographical regions. Capitalized sales commissions are amortized using the straight-line method over a period that is consistent with the transfer of the products or services to the customer to which the sales commission relates. The period of transfer for each portfolio is the shorter of the weighted-average customer life, or the economic life of the underlying technology that delivers the products or services. As of December 31, 2020, the period of transfer was determined to be approximately two to three years. Discretionary amounts which are added to sales commission payments are expensed as incurred, as they are not considered to be directly attributable to obtaining a customer contract. Stock-Based Compensation Expense. We account for our stock-based compensation expense in accordance with FASB ASC 718, Compensation—Stock Compensation (FASB ASC 718). Our stock-based compensation expense reflects grants of restricted stock units, performance share awards, market stock units, and stock options. We measure the fair value of our restricted stock units, restricted stock, and performance share awards on the grant date based on the closing market price of Morningstar's common stock on the day prior to the grant. For market stock units, we estimate the fair value of the awards using a Monte Carlo valuation model. For stock options, we estimate the fair value of our stock options on the date of grant using the Black-Scholes option-pricing model. We amortize the fair values to stock-based compensation expense, net of estimated forfeitures, ratably over the vesting period. We estimate expected forfeitures of all employee stock-based awards and recognize compensation cost only for those awards expected to vest. We determine forfeiture rates based on historical experience and adjust the estimated forfeitures to actual forfeiture experience, as needed. Income Taxes. We record deferred income taxes for the temporary differences between the carrying amount of assets and liabilities for financial statement purposes and tax purposes in accordance with ASC 740. ASC 740 prescribes the minimum recognition threshold a tax position is required to meet before being recognized in the financial statements. It also provides guidance on derecognition, measurement, classification, interest and penalties, accounting in interim periods, and disclosure for uncertain tax positions. We recognize interest and penalties related to unrecognized tax benefits as part of income tax expense in our Consolidated Statements of Income. We classify liabilities related to unrecognized tax benefits as either current or long-term liabilities in our Consolidated Balance Sheet, depending on when we expect to make payment. Leases. We account for our right-of-use assets and operating lease liabilities in accordance with FASB ASC 842, Leases (FASB ASC 842) . We determine if a contract is or contains a lease at the inception of the contract. For identified operating leases, we recognize a lease liability and right-of-use asset on the consolidated balance sheet. The right-of-use asset represents our right to use an underlying asset for the lease term, and the operating lease liability represents the Company's obligation to make lease payments. Our lease agreements consist primarily of real estate leases for office space and non-real estate leases for office equipment. In cases where an agreement contains both a lease and non-lease component, we do not allocate consideration to both components, but account for each as a single lease component by class of underlying asset. There are few instances of short-term agreements in our lease portfolio, which are typically arranged as needed and paid on a month-to-month basis. These leases are not recognized on the Consolidated Balance Sheet, but monthly lease expense is recognized on the Consolidated Statements of Income. Right-of-Use assets and operating lease liabilities are measured using the present value of future lease payments of the lease term at the commencement date. Right-of-use assets also include initial direct costs incurred by the Company, net of pre-payments and lease incentives. In the absence of an explicit rate in the lease agreement, the discount rate used to calculate present value is equal to the Company's incremental borrowing rate. Operating lease expense is recognized on a straight-line basis over the life of the lease and is included in general and administrative expenses on the Consolidated Statements of Income.

Credit Arrangements

Credit Arrangements	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Credit Arrangements	Credit Arrangements Debt The following table summarizes our total debt and long-term debt as of December 31, 2020 and December 31, 2019. (in millions) As of December 31, 2020 As of December 31, 2019 Term Facility, net of unamortized debt issuance costs of $0.1 million and $1.3 million $ 100.8 $ 443.1 Revolving Credit Facility — 70.0 2.32% Senior Notes due October 26, 2030, net of unamortized debt issuance costs of $1.7 million 348.3 — Total debt $ 449.1 $ 513.1 Less: Current portion of long-term debt, net of unamortized debt issuance costs of $0.3 million — 11.0 Long-term debt $ 449.1 $ 502.1 Credit Agreement In connection with the acquisition of Ratings Acquisition Corp (DBRS) on July 2, 2019, the Company entered into a senior credit agreement (the Credit Agreement). The Credit Agreement provides the Company with a five-year multi-currency credit facility with an initial borrowing capacity of up to $750.0 million, including a $300.0 million revolving credit facility (the Revolving Credit Facility) and a term loan facility of $450.0 million (the Term Facility). The Credit Agreement also provides for the issuance of up to $50.0 million of letters of credit and a $100.0 million sub-limit for a swingline facility under the Revolving Credit Facility. The Credit Agreement will expire on July 2, 2024. As of December 31, 2020, our total outstanding debt under the Credit Agreement was $100.8 million with borrowing availability of $300.0 million under the Revolving Credit Facility. The interest rate applicable to any loan under the Credit Agreement is, at our option, either: (i) the applicable London interbank offered rate (LIBOR) plus an applicable margin for such loans, which ranges between 1.00% and 1.50%, based on our consolidated leverage ratio or (ii) the lender's base rate plus the applicable margin for such loans, which ranges between 0.00% and 0.50%, based on our consolidated leverage ratio. The proceeds of the Term Facility and initial borrowings under the Revolving Credit Facility were used to finance the acquisition of DBRS. The proceeds of future borrowings under the Revolving Credit Facility may be used for working capital, capital expenditures or any other lawful corporate purpose. The portions of deferred debt issuance costs related to the Revolving Credit Facility are included in other current and other non-current assets, and the portion of deferred debt issuance costs related to the Term Facility is reported as a reduction to the carrying amount of the Term Facility. Amortization of debt issuance costs related to the Revolving Credit Facility are amortized on a straight-line basis to interest expense over the term of the Credit Agreement. Amortization of debt issuance costs related to the Term Facility are amortized to interest expense using the effective interest method over the term of the Credit Agreement. 364-Day Revolving Credit Facility On June 30, 2020, we entered into a 364-day revolving credit facility (364-Day Revolving Credit Facility) providing for borrowings in an aggregate principal amount of up to $50.0 million. The proceeds of such borrowings may be used for working capital, capital expenditures, and any other lawful corporate purpose. As of December 31, 2020, no borrowings were outstanding. Private Placement Debt Offering On October 26, 2020, we completed the issuance and sale of $350.0 million aggregate principal amount of 2.32% senior notes due October 26, 2030 (the 2030 Notes), in a private placement exempt from the registration requirements of the Securities Act of 1933, as amended. Proceeds were primarily used to pay off a portion of the Company's outstanding debt under the Credit Agreement. Interest on the 2030 Notes will be paid semi-annually on each October 30 and April 30 during the term of the 2030 Notes and at maturity, with the first interest payment date occurring on April 30, 2021. As of December 31, 2020, our total outstanding debt under the 2030 Notes was $348.3 million. Compliance with Covenants Each of the Credit Agreement, the 364-Day Revolving Credit Facility, and the 2030 Notes include customary representations, warranties, and covenants, including financial covenants, that require us to maintain specified ratios of consolidated earnings before interest, taxes, depreciation, and amortization (EBITDA) to consolidated interest charges and consolidated funded indebtedness to consolidated EBITDA, which are tested on a quarterly basis. We were in compliance with these financial covenants as of December 31, 2020.

Income Per Share

Income Per Share	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Income Per Share	Income Per Share The following table shows how we reconcile our net income and the number of shares used in computing basic and diluted net income per share: (in millions, except per share amounts) 2020 2019 2018 Basic net income per share: Consolidated net income $ 223.6 $ 152.0 183.0 Weighted average common shares outstanding 42.9 42.7 42.6 Basic net income per share $ 5.22 $ 3.56 $ 4.30 Diluted net income per share: Consolidated net income $ 223.6 $ 152.0 $ 183.0 Weighted average common shares outstanding 42.9 42.7 42.6 Net effect of dilutive stock options and restricted stock units 0.3 0.5 0.4 Weighted average common shares outstanding for computing diluted income per share 43.2 43.2 43.0 Diluted net income per share $ 5.18 $ 3.52 $ 4.25

Revenue

Revenue	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenue	Revenue Disaggregation of Revenue The following table presents our revenue disaggregated by revenue type. Sales and usage-based taxes are excluded from revenue. Year ended December 31 (in millions) 2020 2019 2018 License-based $ 934.9 $ 812.7 $ 751.6 Asset-based 223.8 211.6 200.4 Transaction-based 230.8 154.7 67.9 Consolidated revenue $ 1,389.5 $ 1,179.0 $ 1,019.9 License-based performance obligations are generally satisfied over time as the customer has access to the product or service during the term of the subscription license and the level of service is consistent during the contract period. License-based agreements typically have a term of 1 to 3 years and are accounted for as subscription services available to customers and not as a license under the accounting guidance. License-based revenue is generated from the sale of Morningstar Data, Morningstar Direct, Morningstar Advisor Workstation, PitchBook, Sustainalytics, and other similar products. Asset-based performance obligations are satisfied over time as the customer receives continuous access to a service for the term. Asset-based arrangements typically have a term of 1 to 3 years. Asset-based fees represent variable consideration and the customer does not make separate purchasing decisions that result in additional performance obligations. Significant changes in the underlying fund assets and significant disruptions in the market are evaluated to determine whether estimates of earned asset-based fees need to be revised for the current quarter. The timing of client asset reporting and the structure of certain contracts can result in a one-quarter lag between market movements and the impact on earned revenue. An estimate of variable consideration is included in the initial transaction price only to the extent it is probable that a significant reversal in the amount of the revenue recognized will not occur. Estimates of asset-based fees are based on the most recently completed quarter and, as a result, it is unlikely a significant reversal of revenue would occur. Asset-based revenue is generated by Investment Management, Workplace Solutions, and Morningstar Indexes. Transaction-based performance obligations are satisfied when the product or service is completed or delivered. Transaction-based revenue is generated by DBRS Morningstar, Internet advertising, and Morningstar-sponsored conferences. DBRS Morningstar revenue includes revenue from surveillance services, which is recognized over time, as the customer has access to the service during the surveillance period. Contract liabilities Our contract liabilities represent deferred revenue. We record contract liabilities when cash payments are received or due in advance of our performance, including amounts which may be refundable. The contract liabilities balance as of December 31, 2020 had a net increase of $58.0 million, primarily driven by cash payments received or payable in advance of satisfying our performance obligations. We rec ognized $229.8 million of revenue in 2020 that was included in the contract liabilities balance as of December 31, 2019. We expect to recognize revenue related to our contract liabilities for 2021 and subsequent years as follows: (in millions) As of December 31, 2020 2021 $ 571.8 2022 153.6 2023 51.8 2024 16.2 2025 6.3 Thereafter 33.1 Total $ 832.8 The aggregate amount of revenue we expect to recognize for 2021 and subsequent years is higher than our contract liability balance of $340.3 million as of December 31, 2020. The difference represents the value of future obligations for signed contracts where we have not yet begun to satisfy the performance obligations or have partially satisfied performance obligations. The table above does not include variable consideration for unsatisfied performance obligations related to certain of our licensed-based, asset-based, and transaction-based contracts as of December 31, 2020. We are applying the optional exemption available under ASC Topic 606, as the variable consideration relates to these unsatisfied performance obligations being fulfilled as a series. The performance obligations related to these contracts are expected to be satisfied over the next 1 to 3 years as services are provided to the client. For license-based contracts, the consideration received for services performed is based on the number of future users, which is not known until the services are performed. The variable consideration for this revenue can be affected by the number of user licenses, which cannot be reasonably estimated. For asset-based contracts, the consideration received for services performed is based on future asset values, which are not known until the services are performed. The variable consideration for this revenue can be affected by changes in the underlying value of fund assets due to client redemptions, additional investments, or movements in the market. For transaction-based contracts for Internet advertising, the consideration received for services performed is based on the number of impressions, which is not known until the impressions are created. The variable consideration for this revenue can be affected by the timing and quantity of impressions in any given period and cannot be reasonably estimated. As of December 31, 2020, the table above also does not include revenue for unsatisfied performance obligations related to certain of our license-based and transaction-based contracts with durations of one year or less since we are applying the optional exemption under ASC Topic 606. For certain license-based contracts, the remaining performance obligation is expected to be less than one year based on the corresponding subscription terms or the existence of cancellation terms that may be enacted causing the contract term to be less than one year from December 31, 2020. For transaction-based contracts, such as new credit rating issuances and Morningstar-sponsored conferences, the related performance obligations are expected to be satisfied within the next 12 months. Contract Assets Our contract assets represent accounts receivable, less allowance for credit losses and deferred commissions. The following table summarizes our contract assets balance: As of December 31 (in millions) 2020 2019 Accounts receivable, less allowance for credit losses $ 205.1 $ 188.5 Deferred commissions 39.6 30.4 Total contract assets $ 244.7 $ 218.9

Segment and Geographical Area I

Segment and Geographical Area Information	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Segment and Geographical Area Information	Segment and Geographical Area Information Segment Information We report our results in a single reportable segment, which reflects how our chief operating decision maker allocates resources and evaluates our financial results. Because we have a single reportable segment, all required financial segment information can be found directly in the Consolidated Financial Statements. The accounting policies for our reportable segment are the same as those described in Note 2. We evaluate the performance of our reporting segment based on revenue and operating income. Geographical Area Information The tables below summarize our revenue, long-lived assets, which includes property, equipment, and capitalized software, net, and operating lease assets, by geographical area: Revenue by geographical area Year ended December 31 (in millions) 2020 2019 2018 United States $ 970.8 $ 866.4 $ 764.2 Asia 33.6 27.9 24.5 Australia 45.6 39.5 40.9 Canada 101.5 56.9 30.7 Continental Europe 113.8 88.0 81.2 United Kingdom 117.5 93.9 72.4 Other 6.7 6.4 6.0 Total International 418.7 312.6 255.7 Consolidated revenue $ 1,389.5 $ 1,179.0 $ 1,019.9 Property, equipment, and capitalized software, net by geographical area As of December 31 (in millions) 2020 2019 United States $ 127.0 $ 131.2 Asia 7.5 6.6 Australia 3.7 4.2 Canada 2.9 2.9 Continental Europe 6.2 2.3 United Kingdom 7.3 6.9 Other 0.5 0.6 Total International 28.1 23.5 Consolidated property, equipment, and capitalized software, net $ 155.1 $ 154.7 Operating lease assets by geographical area As of December 31 (in millions) 2020 2019 United States $ 89.2 $ 86.4 Asia 12.6 20.2 Australia 5.2 5.8 Canada 7.4 7.5 Continental Europe 17.0 6.3 United Kingdom 15.6 17.9 Other 0.7 0.7 Total International 58.5 58.4 Consolidated operating lease assets $ 147.7 $ 144.8

Investments and Fair Value Meas

Investments and Fair Value Measurements	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Investments and Fair Value Measurements	Investments and Fair Value Measurements We classify our investments into three categories: available-for-sale, held-to-maturity, and trading. Our investment portfolio consists of stocks, bonds, options, mutual funds, money market funds, or exchange-traded products that replicate the model portfolios and strategies created by Morningstar. These investment accounts may also include exchange-traded products where Morningstar is an index provider. We classify our investment portfolio as shown below: As of December 31 (in millions) 2020 2019 Available-for-sale $ 40.5 $ 25.8 Held-to-maturity 1.2 2.3 Trading securities — 5.3 Total $ 41.7 $ 33.4 The following table shows the cost, unrealized gains, and fair values related to investments classified as available-for-sale and held-to-maturity: As of December 31, 2020 As of December 31, 2019 (in millions) Cost Unrealized Unrealized Fair Cost Unrealized Unrealized Fair Available-for-sale: Equity securities and exchange-traded funds $ 24.6 $ 4.2 $ — $ 28.8 $ 19.0 $ 2.9 $ — $ 21.9 Mutual funds 10.0 0.8 — 10.8 3.7 0.2 — 3.9 Marketable debt securities 0.9 — — 0.9 — — — — Total $ 35.5 $ 5.0 $ — $ 40.5 $ 22.7 $ 3.1 $ — $ 25.8 Held-to-maturity: Certificates of deposit $ 1.2 $ — $ — $ 1.2 $ 2.3 $ — $ — $ 2.3 Total $ 1.2 $ — $ — $ 1.2 $ 2.3 $ — $ — $ 2.3 As of December 31, 2020 and December 31, 2019, investments with unrealized losses for greater than a 12-month period were not material to the Consolidated Balance Sheets and were not deemed to have other than temporary declines in value. The table below shows the cost and fair value of investments classified as available-for-sale and held-to-maturity based on their contractual maturities as of December 31, 2020 and December 31, 2019. As of December 31, 2020 As of December 31, 2019 (in millions) Cost Fair Value Cost Fair Value Available-for-sale: Equity securities, exchange-traded funds, mutual funds, and marketable debt securities $ 35.5 $ 40.5 $ 22.7 $ 25.8 Total $ 35.5 $ 40.5 $ 22.7 $ 25.8 Held-to-maturity: Due in one year or less $ 1.2 $ 1.2 $ 2.3 $ 2.3 Due in one to three years — — — — Total $ 1.2 $ 1.2 $ 2.3 $ 2.3 The following table shows the realized gains and losses arising from sales of our investments classified as available-for-sale recorded in our Consolidated Statements of Income: (in millions) 2020 2019 2018 Realized gains $ 2.1 $ 1.2 $ 1.8 Realized losses — — (0.8) Realized gains, net $ 2.1 $ 1.2 $ 1.0 We determine realized gains and losses using the specific identification method. The following table shows the net unrealized (losses) gains on trading securities as recorded in our Consolidated Statements of Income: (in millions) 2020 2019 2018 Unrealized (losses) gains, net $ (0.4) $ 0.6 $ (0.2) The table below shows the fair value of our assets and liabilities subject to fair value measurements that are measured at fair value on a recurring basis using the fair value hierarchy: Level 1: Valuations based on quoted prices in active markets for identical assets or liabilities that we have the ability to access. Level 2: Valuations based on quoted prices in markets that are not active or for which all significant inputs are observable, either directly or indirectly. Level 3: Valuations based on inputs that are unobservable and significant to the overall fair value measurement. Fair Value Fair Value Measurements as of December 31, 2020 as of Using Fair Value Hierarchy (in millions) December 31, 2020 Level 1 Level 2 Level 3 Financial assets: Available-for-sale investments Equity securities and exchange-traded funds $ 28.8 $ 28.8 $ — $ — Mutual funds 10.8 10.8 — — Marketable debt securities 0.9 0.9 — — Cash equivalents 0.8 0.8 — — Financial liabilities: Contingent consideration 53.7 — — 53.7 Total $ 95.0 $ 41.3 $ — $ 53.7 Fair Value Fair Value Measurements as of December 31, 2019 as of Using Fair Value Hierarchy (in millions) December 31, 2019 Level 1 Level 2 Level 3 Financial assets: Available-for-sale investments Equity securities and exchange-traded funds $ 21.9 $ 21.9 $ — $ — Mutual funds 3.9 3.9 — — Trading securities 5.3 5.3 — — Cash equivalents 0.9 0.9 — — Total $ 32.0 $ 32.0 $ — $ — Based on our analysis of the nature and risks of our investments in equity securities, mutual funds, marketable debt instruments, and exchange-traded funds, we have determined that presenting each of these investment categories in the aggregate is appropriate. We measure the fair value of money market funds, mutual funds, equity securities, marketable debt securities, and exchange-traded funds based on quoted prices in active markets for identical assets or liabilities. We did not hold any securities categorized as Level 2 or Level 3 as of December 31, 2020 and December 31, 2019. Financial liabilities that are classified as Level 3 within the fair value hierarchy include contingent consideration liabilities of $53.7 million that reflect potential future payments that are contingent upon the achievement of certain revenue metrics related to our acquisition of Sustainalytics. This additional purchase consideration, which is contingent, is recognized at fair value at the date of acquisition using a Monte Carlo simulation, which requires the use of management assumptions and inputs, such as projected financial information related to revenue growth and expected margin percentage, among other valuation related items, and is remeasured each reporting period until the contingency is resolved with any changes in fair value recorded in current period earnings. At December, 31, 2020, the fair value of the contingent consideration liability was impacted by foreign currency translations and not by adjustments to key assumptions used in our fair value estimates compared to the assumptions used in the acquisition date fair value estimates.

Acquisitions, Goodwill, and Oth

Acquisitions, Goodwill, and Other Intangible Assets	Jul. 02, 2019
Acquisitions, Goodwill, and Other Intangible Assets [Abstract]
Goodwill and Intangible Assets Disclosure	Acquisitions, Goodwill, and Other Intangible Assets 2020 Acquisitions On January 31, 2020, we acquired Hueler Analytics' Stable Value Fund Comparative Universe Data and Stable Value Index (Hueler Analytics). We began consolidating the financial results of Hueler Analytics in our consolidated financial statements on January 31, 2020. On April 3, 2020, we acquired PlanPlus Global, a financial-planning, risk-profiling, and portfolio tracking software firm. The acquisition expands our financial-planning capabilities for advisors. We began consolidating the financial results of PlanPlus Global in our consolidated financial statements on April 3, 2020. Increased Ownership Interest in Sustainalytics Holding B.V. (Sustainalytics) On July 2, 2020, we completed the acquisition of the remaining 60% interest in Sustainalytics, a globally recognized leader in environmental, social, and governance (ESG) ratings and research, for an initial cash payment of $61.2 million . The acquisition was accounted for as a business combination with July 2, 2020 as the date of acquisition, and the Company was determined to be the acquirer. Accordingly, we began consolidating the financial results of Sustainalytics in our consolidated financial statements on July 2, 2020. We previously held an approximately 40% ownership interest in Sustainalytics, which had an estimated fair value of $75.4 million at the date of the acquisition and a book value of $24.5 million immediately prior to the acquisition, and resulted in the recording of a holding gain of $50.9 million. The transaction has been accounted for as a business combination using the acquisition method of accounting, which requires that assets acquired and liabilities assumed be recognized at their fair values as of the acquisition date. The values assigned to the assets acquired and liabilities assumed are based on preliminary estimates of fair value available as of July 2, 2020, and may be adjusted during the measurement period of up to 12 months from the acquisition date as further information becomes available. Any changes in the fair values of the assets acquired and liabilities assumed during the measurement period may result in adjustments to goodwill. Subsequent measurement changes for certain contingent liabilities will generally be recognized in the Company’s future earnings. Consideration related to the acquisition consists of an initial cash payment of $61.2 million and contingent payments with an acquisition date fair value of $75.2 million, a portion of which is treated as additional purchase consideration and the remainder, which is sometimes referred to as an earn-out, is accounted for and described a s compensation expense for purpose of the following discussion and disclosure. The acquisition date fair values of the additional purchase consideration and compensation were $47.4 million and $27.8 million, respectively. The contingent payments are due on the first and second anniversaries of the acquisition date, and each payment is determined based on a multiple of Sustainalytics' revenues for the years ended December 31, 2020 and 2021, respectively, which are also the measurement periods for determining the final payments. We used a Monte Carlo simulation to arrive at the estimated fair values of the contingent payments at the acquisition date. At subsequent balance sheet dates, the additional purchase consideration, including contingent payments, will continue to be measured at fair value and is classified as "Contingent consideration liability" and "Other long-term liabilities" on our Consolidated Balance Sheet as of December 31, 2020. The compensation will be measured based on probability weighted future benefits expected to be paid, and is reflected in "Current liabilities - Accrued compensation" and "Accrued Compensation" on our Consolidated Balance Sheet as of December 31, 2020. At December 31, 2020, the fair value of the contingent consideration liability was impacted by foreign currency translations and not by adjustments to key assumptions used in our fair value estimates compared to the assumptions used in the acquisition date fair value estimates. The book value of our 40% ownership interest immediately prior to the acquisition date was $24.5 million, and we recorded a $50.9 mil lion non-cash holding gain for the difference between the fair value and the book value of our previously held equity interest. The acquisition of the additional 60% interest was conside red an acquisition achieved in stages and resulted in the remeasurement of the previously held equity interest to fair value. The Company determined the fair value of the previously held equity interest using a discounted cash flow analysis (an income approach) based on projected cash flows for Sustainalytics combined with other valuation approaches and considerations to estimate total purchase consideration, which was divided by fully diluted outstanding shares to determine the fair value per share. The fair value per share was then applied to the shares of Sustainalytics held by the Company to derive the acquisition date fair value of the previously held equity interest. The gain is classified as "Holding gain on previously held equity interest" in our Consolidated Statement of Income for the year ended December 31, 2020. As of September 30, 2020, we completed our initial determination of the fair values of the acquired, identifiable assets and liabilities based on the information available. At December 31, 2020, there are various areas that are not yet finalized due to information that may become available subsequently, which may result in changes in the values assigned to various assets and liabilities, including, but not limited to, assumed current and deferred tax assets and liabilities. If additional information, including a final third-party valuation report, related to the acquisition date fair value determinations becomes available within 12 months of the acquisition date, there may be adjustments to these initial fair value measurements. We did not record any significant adjustments compared with our preliminary estimates at the date of acquisition during the fourth quarter of 2020. The following table summarizes our allocation of the estimated fair values of the assets acquired and liabilities assumed at the acquisition date: (in millions) Fair value of consideration transferred $ 108.6 Fair value of the previously held equity interest 75.4 Cash and cash equivalents $ 9.8 Accounts receivable 6.2 Intangible assets, net 79.5 Operating lease assets 5.2 Other current and non-current assets 7.4 Deferred revenue (21.2) Operating lease liability (5.2) Deferred tax liability, net (16.9) Other current and non-current liabilities (15.5) Total fair value of net assets acquired $ 49.3 Goodwill $ 134.7 At July 2, 2020, accounts receivable acquired were recorded at gross contractual amounts receivable, which approximates fair value. At December 31, 2020, substantially all amounts were collected. The preliminary allocation of the estimated fair values of the assets acquired and liabilities assumed includes $79.5 million of acquired intangible assets, as follows: (in millions) Weighted average useful life (years) Customer-related assets $ 22.9 20 Technology-based assets 46.7 10 Intellectual property 9.9 10 Total intangible assets $ 79.5 Goodwill of $134.7 million represents the excess over the fair value of the net tangible and intangible assets acquired. Goodwill is not deductible for income tax purposes. We recognized a preliminary net deferred tax liability of $16.9 million primarily because the amortization expense related to certain intangible assets is not deductible for income tax purposes. 2019 Acquisitions AdviserLogic On December 1, 2019, we acquired AdviserLogic, a cloud-based financial planning software platform for financial advisors in Australia. We began consolidating the financial results of AdviserLogic in our Consolidated Financial Statements on December 1, 2019. DBRS On July 2, 2019, we acquired 100% of the voting equity interests of DBRS for total cash consideration of $682.1 million. DBRS delivers comprehensive credit rating services and ongoing surveillance to customers in various market sectors across Canada, the U.S., and Europe. The combination of DBRS with Morningstar Credit Ratings' business (collectively, DBRS Morningstar) expands global asset class coverage and provides investors with fixed-income analysis and research through the combined platform. We began consolidating the financial results of this acquisition in our Consolidated Financial Statements on July 2, 2019. DBRS Morningstar contributed $127.6 million of revenue and $123.5 million of operating expense during the year ended December 31, 2019. We incurred transaction-related costs of $6.5 million during the year ended December 31, 2019. We accounted for this transaction using the acquisition method of accounting, which requires that assets acquired and liabilities assumed be recognized at their fair values as of the acquisition date. Morningstar was the accounting acquirer for purposes of accounting for the business combination. We finalized the purchase price allocation related to our acquisition of DBRS during 2020 and did not record any significant adjustments compared with our preliminary estimates at the date of acquisition. The following table summarizes our allocation of the estimated fair values of the assets acquired and liabilities assumed at the date of acquisition: (in millions) Cash consideration transferred $ 682.1 Cash and cash equivalents $ 8.5 Accounts receivable 28.8 Property, equipment, and capitalized software, net 12.8 Intangible assets, net 284.1 Goodwill 473.3 Operating lease assets 33.3 Other current and non-current assets 5.7 Deferred revenue (43.2) Deferred tax liability, net (66.6) Operating lease liabilities (35.0) Other current and non-current liabilities (19.6) Total fair value of DBRS $ 682.1 Accounts receivable acquired were recorded at gross contractual amounts receivable, which approximates fair value. The allocation of the estimated fair values of the assets acquired and liabilities assumed includes $284.1 million of acquired intangible assets, as follows: (in millions) Weighted Average Useful Life (years) Customer-related assets $ 219.1 10 Technology-based assets 29.4 5 Intellectual property (trademarks and trade names) 35.6 7 Total intangible assets $ 284.1 We recognized a net deferred tax liability of $66.6 million mainly because the amortization expense related to certain intangible assets is not deductible for income tax purposes. Goodwill of $473.3 million represents the excess over the fair value of the net tangible and intangible assets acquired. Goodwill is not deductible for income tax purposes. The following unaudited pro forma information presents a summary of our Consolidated Statements of Income for the year ended December 31, 2019 and 2018, as if we had completed the acquisition as of January 1, 2018. This unaudited pro forma information is presented for illustrative purposes and is not intended to represent or be indicative of the actual results of operations or expected synergies of DBRS Morningstar that would have been achieved had the acquisition occurred at the beginning of the earliest period presented, nor is it intended to represent or be indicative of future results of operations. In calculating the pro forma information below, we included an estimate of amortization expense related to the intangible assets acquired, depreciation expense due to changes in estimated remaining useful lives of long-lived assets, reduction in revenue as a result of the fair value adjustments to deferred revenue, and interest expense incurred on the long-term debt. Unaudited Pro Forma Financial Information (in millions) 2019 2018 Revenue $ 1,259.2 $ 1,184.5 Operating income 190.3 223.6 Net income 148.2 179.7 Basic net income per share $ 3.47 $ 4.22 Diluted net income per share $ 3.43 $ 4.18 Other acquisition activity during 2019 was not material. Goodwill The following table shows the changes in our goodwill balances from January 1, 2019 to December 31, 2020: (in millions) Balance as of January 1, 2019 $ 556.7 Acquisition of DBRS 473.3 Other, primarily foreign currency translation 9.1 Balance as of December 31, 2019 $ 1,039.1 Acquisition of Sustainalytics 134.7 Other, primarily foreign currency translation 31.2 Balance as of December 31, 2020 $ 1,205.0 We did not record any impairment losses in 2020, 2019, or 2018 as the estimated fair value of our reporting unit exceeded its carrying value and we did not note any indicators of impairment. We perform our annual impairment testing during the fourth quarter of each year. Intangible Assets The following table summarizes our intangible assets: As of December 31, 2020 As of December 31, 2019 (in millions) Gross Accumulated Net Weighted Gross Accumulated Net Weighted Customer-related assets $ 415.6 $ (163.7) $ 251.9 11 $ 377.9 $ (130.3) $ 247.6 11 Technology-based assets 223.2 (135.2) 88.0 7 163.7 (112.0) 51.7 7 Intellectual property & other 83.6 (43.4) 40.2 8 69.3 (35.2) 34.1 8 Total intangible assets $ 722.4 $ (342.3) $ 380.1 10 $ 610.9 $ (277.5) $ 333.4 10 The following table summarizes our amortization expense related to intangible assets: (in millions) 2020 2019 2018 Amortization expense $ 58.8 $ 36.5 $ 20.7 We did not record any impairment losses involving intangible assets in 2020, 2019, or 2018. We amortize intangible assets using the straight-line method over their expected economic useful lives. Based on acquisitions and divestitures completed through December 31, 2020, we expect intangible amortization expense for 2021 and subsequent years to be as follows: (in millions) 2021 $ 61.1 2022 53.1 2023 49.3 2024 43.2 2025 36.6 Thereafter 136.8 Total $ 380.1 Our estimates of future amortization expense for intangible assets may be affected by additional acquisitions, divestitures, changes in the estimated average useful lives, impairments, and foreign currency translation.

Divestitures

Divestitures	12 Months Ended
	Dec. 31, 2020
Discontinued Operations and Disposal Groups [Abstract]
Divestitures	Divestitures 2020 and 2019 Divestitures We did not complete any divestitures in 2020 or 2019. 2018 Divestitures

Investments in Unconsolidated E

Investments in Unconsolidated Entities	12 Months Ended
	Dec. 31, 2020
Investments in Unconsolidated Entities [Abstract]
Investments in Unconsolidated Entities	Investments in Unconsolidated Entities Our investments in unconsolidated entities consist primarily of the following: As of December 31 (in millions) 2020 2019 Investment in MJKK $ 18.9 $ 24.0 Investment in Sustainalytics — 25.3 Other-equity method investments 7.4 6.6 Cost method investments 6.3 3.7 Total investments in unconsolidated entities $ 32.6 $ 59.6 Morningstar Japan K.K. Morningstar Japan K.K. (MJKK) develops and markets financial information products and services customized for the Japanese market. MJKK’s shares are traded on the Tokyo Stock Exchange under the ticker 47650. We account for our investment in MJKK using the equity method. The following table summarizes our ownership percentage in MJKK and the market value of this investment based on MJKK’s publicly quoted share price: As of December 31 2020 2019 Morningstar’s approximate ownership of MJKK 22.4 % 30.4 % Approximate market value of Morningstar’s ownership in MJKK: Japanese yen (¥ in millions) ¥ 9,221.9 ¥ 10,319.0 Equivalent U.S. dollars ($ in millions) $ 89.4 $ 95.0 On October 19, 2020, we sold 3,850,000 shares of MJKK in an underwritten offering at a price per share of ¥437.9, resulting in net proceeds, after underwriting discounts and commissions, of $16.0 million, which resulted in a pre-tax gain of $12.2 million. In connection with this sale, we also granted an underwriter an overallotment option on 1,289,000 MJKK shares. On November 6, 2020, the option was exercised for 1,227,100 shares of MJKK common stock and we received $5.1 million for these shares, which resulted in a pre-tax gain of $3.8 million. Sustainalytics Holding B.V. (Sustainalytics). As of December 31, 2019, our investments in unconsolidated entities included a minority investment in Sustainalytics. On July 2, 2020, we purchased the remaining ownership interest in Sustainalytics. See Note 8 for additional information on our acquisition of Sustainalytics. Other investments in unconsolidated entities. On October 8, 2020, we sold the entire interest in one of our other unconsolidated entities for cash proceeds of $14.3 million, including accrued but unpaid dividends on preferred shares, which resulted in a pre-tax gain of $14.0 million .

Property, Equipment, and Capita

Property, Equipment, and Capitalized Software	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Property, Equipment, and Capitalized Software	Property, Equipment, and Capitalized Software, net The following table shows our property, equipment, and capitalized software, net summarized by major category: As of December 31 (in millions) 2020 2019 Capitalized software $ 390.2 $ 328.3 Capitalized equipment 74.6 70.1 Furniture and fixtures 35.6 33.7 Leasehold improvements 96.0 92.1 Telephone equipment 2.4 2.3 Construction in progress 8.6 5.5 Property, equipment, and capitalized software, at cost 607.4 532.0 Less accumulated depreciation (452.3) (377.3) Property, equipment, and capitalized software, net $ 155.1 $ 154.7 The following table summarizes our depreciation expense: (in millions) 2020 2019 2018 Depreciation expense $ 80.1 $ 81.2 $ 76.0

Leases

Leases	12 Months Ended
	Dec. 31, 2020
Leases, Operating [Abstract]
Operating Leases	Leases We lease office space and certain equipment under various operating and finance leases, with most of our lease portfolio consisting of operating leases for office space. We determine whether an arrangement is, or includes, an embedded lease at contract inception. Operating lease assets and lease liabilities are recognized at the commencement date and initially measured using the present value of lease payments over the defined lease term. Lease expense is recognized on a straight-line basis over the lease term. For finance leases, we also recognize a finance lease asset and finance lease liability at inception, with lease expense recognized as interest expense and amortization. A contract is or contains an embedded lease if the contract meets all of the below criteria: • there is an identified asset • we obtain substantially all of the economic benefits of the asset • we have the right to direct the use of the asset For initial measurement of the present value of lease payments and for subsequent measurement of lease modifications, we are required to use the rate implicit in the lease, if available. However, as most of our leases do not provide an implicit rate, we use our incremental borrowing rate, which is a collateralized rate. To apply the incremental borrowing rate, we used a portfolio approach and grouped leases based on similar lease terms in a manner whereby we reasonably expect that the application does not differ materially from a lease-by-lease approach. Our leases have remaining lease terms of approximately 1 year to 13 years, which may include the option to extend the lease when it is reasonably certain we will exercise that option. We do not have lease agreements with residual value guarantees, sale leaseback terms, or material restrictive covenants. Leases with an initial term of 12 months or less are not recognized on the balance sheet. We recognize lease expense for these leases on a straight-line basis over the lease term. The following table summarizes our operating lease assets and lease liabilities: Leases (in millions) Balance Sheet Classification As of December 31, 2020 As of December 31, 2019 Assets Operating Operating lease assets $ 147.7 $ 144.8 Liabilities Operating Operating lease liabilities, current $ 39.9 $ 35.8 Operating Operating lease liabilities, non-current 137.7 138.7 Total lease liabilities $ 177.6 $ 174.5 Our operating lease expense for the years ended December 31, 2020, 2019, and 2018 was $42.4 million, $33.9 million, and $32.5 million, respectively. Charges related to our operating leases that are variable and, therefore, not included in the measurement of the lease liabilities were $14.9 million and $12.7 million for the years ended December 31, 2020 and 2019, respectively. We made operating lease payments of $45.3 million and $33.1 million during the years ended December 31, 2020 and 2019, respectively. The following table shows our minimum future rental commitments due in each of the next five years and thereafter for operating leases: Minimum Future Lease Commitments (in millions) 2021 $ 47.3 2022 32.0 2023 27.8 2024 21.9 2025 19.8 Thereafter 56.3 Total minimum lease commitments 205.1 Adjustment for discount to present value 27.5 Total $ 177.6 The following table summarizes our weighted-average lease terms and weighted-average discount rates for our operating leases: As of December 31, 2020 Weighted-average remaining lease term (in years) 6.6 Weighted-average discount rate 4.3 %

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation Stock-Based Compensation Plans Our shareholders approved the Morningstar 2011 Stock Incentive Plan (the 2011 Plan) on May 17, 2011. As of that date, we stopped granting awards under the Morningstar 2004 Stock Incentive Plan (the 2004 Plan). The 2004 Plan amended and restated the Morningstar 1993 Stock Option Plan, the Morningstar 2000 Stock Option Plan, and the Morningstar 2001 Stock Option Plan. The 2011 Plan provides for a variety of stock-based awards, including, among other things, restricted stock units, restricted stock, performance share awards, market stock units, and stock options. We granted restricted stock units, restricted stock, and stock options under the 2004 Plan. All of our employees and our non-employee directors are eligible for awards under the 2011 Plan. Grants awarded under the 2011 Plan or the 2004 Plan that are forfeited, canceled, settled, or otherwise terminated without a distribution of shares, or shares withheld by us in connection with the exercise of options, will be available for awards under the 2011 Plan. For any shares subject to awards that are withheld by us in connection with the payment of any required income tax withholding, the 2011 Plan provides for the ability to have these shares become available for new awards, but this feature of the 2011 plan has not been implemented. The following table summarizes the number of shares available for future grants under our 2011 Plan: As of December 31 (in millions) 2020 Shares available for future grants 2.5 Accounting for Stock-Based Compensation Awards The following table summarizes our stock-based compensation expense and the related income tax benefit we recorded in the past three years: Year ended December 31 (in millions) 2020 2019 2018 Restricted stock units $ 22.2 $ 20.4 $ 19.8 Performance share awards 10.2 20.6 10.2 Market stock units 4.2 3.4 1.7 Total stock-based compensation expense $ 36.6 $ 44.4 $ 31.7 Income tax benefit related to the stock-based compensation expense $ 6.7 $ 10.0 $ 7.0 The following table summarizes the stock-based compensation expense included in each of our operating expense categories for the past three years: Year ended December 31 (in millions) 2020 2019 2018 Cost of revenue $ 13.5 $ 12.9 $ 11.7 Sales and marketing 4.6 5.6 3.5 General and administrative 18.5 25.9 16.5 Total stock-based compensation expense $ 36.6 $ 44.4 $ 31.7 The following table summarizes the amount of unrecognized stock-based compensation expense as of December 31, 2020 and the expected number of months over which the expense will be recognized: Unrecognized stock-based compensation expense (in millions) Weighted average expected amortization period (months) Restricted stock units $ 45.5 34 Market stock units 8.0 26 Total unrecognized stock-based compensation expense $ 53.5 33 In accordance with FASB ASC 718, we estimate forfeitures of employee stock-based awards and recognize compensation cost only for those awards expected to vest. Restricted Stock Units Restricted stock units (RSUs) represent the right to receive a share of Morningstar common stock when that unit vests. RSUs granted to employees vest ratably over a four-year period. RSUs granted to non-employee directors vest ratably over a three-year period. We measure the fair value of our RSUs on the grant date based on the closing market price of the underlying common stock on the day prior to grant. We amortize that value to stock-based compensation expense, net of estimated forfeitures, ratably over the vesting period. The following table summarizes restricted stock unit activity during the past three years: Restricted Stock Units (RSUs) Unvested Vested but Total Weighted RSUs Outstanding - December 31, 2017 604,879 3,279 608,158 $ 77.52 Granted 243,614 — 243,614 108.60 Dividend equivalents — 16 16 73.28 Vested (279,774) — (279,774) 80.68 Issued — (3,295) (3,295) 73.28 Forfeited (41,254) — (41,254) 86.47 RSUs Outstanding - December 31, 2018 527,465 — 527,465 $ 89.53 Granted 233,618 — 233,618 135.67 Vested (269,917) — (269,917) 95.67 Forfeited (31,721) — (31,721) 100.71 RSUs Outstanding - December 31, 2019 459,445 — 459,445 $ 108.61 Granted 245,078 — 245,078 153.01 Vested (240,297) — (240,297) 108.94 Forfeited (27,459) — (27,459) 119.22 RSUs Outstanding - December 31, 2020 436,767 — 436,767 $ 132.68 Market Stock Units Beginning in May 2017 , executive officers, other than Joe Mansueto, and certain other employees, were granted market stock units (MSUs). These MSUs represent the right to receive a target number of shares that will vest at the end of a three-year performance period depending on the Company’s total shareholder return over that three-year period. The MSUs that were granted in 2019 and 2020 to the executive officers and certain other employees also have a revenue kicker that will provide an increased number of shares that can be earned if certain 2022 and 2023, respectively, revenue goals are exceeded. We measure the fair value of our MSUs on the grant date using a Monte Carlo valuation model. We amortize that value to stock-based compensation expense ratably over the vesting period. We used the following assumptions to estimate the fair value of our MSUs: Assumptions for Monte Carlo Valuation Model Grant Date Expected volatility Dividend yield Risk-free interest rate May 15, 2017 17.4 % 1.20 % 1.49 % November 15, 2017 17.7 % 1.04 % 1.79 % May 15, 2018 17.4 % 0.89 % 2.70 % November 15, 2018 19.6 % 0.83 % 2.92 % May 15, 2019 20.3 % 0.84 % 2.17 % November 15, 2019 21.0 % 0.72 % 1.59 % May 15, 2020 25.4 % 0.83 % 0.20 % November 15, 2020 26.9 % 0.58 % 0.23 % The table below shows MSUs granted and market stock units outstanding as of December 31, 2020: As of December 31, 2020 MSUs granted during 2020 62,474 Weighted average fair value per award $ 110.78 Number of MSUs outstanding 115,377 Unamortized expense, based on current performance levels (in millions) $ 8.0 PitchBook Bonus Plan In connection with our acquisition of PitchBook, we adopted a management bonus sub-plan under the 2011 Plan for certain employees of PitchBook (the PitchBook Plan). We renewed the PitchBook Plan for the 2020-2022 period. Pursuant to the terms of this renewal, awards having an aggregate target value equal to $30.0 million will be available for issuance with annual grants of $7.5 million for 2020, $7.5 million in 2021, and $15.0 million in 2022 . Each grant will consist of performance-based share unit awards, which will vest over a one-year period and will be measured primarily based on the achievement of certain annual revenue targets specifically related to PitchBook’s business. Upon achievement of these targets, earned performance units will be settled in shares of our common stock on a one-for-one basis. If PitchBook exceeds certain performance conditions, the PitchBook Plan participants will receive payment for performance units in excess of the aggregate target values described above. If PitchBook fails to meet threshold performance conditions, the PitchBook Plan participants will not be entitled to receive payment for any performance units. The table below shows target performance share awards granted and shares that will be issued based on final performance levels for performance share awards granted as of December 31, 2020: As of December 31, 2020 Target performance share awards granted 49,280 Weighted average fair value per award $ 152.17 Number of shares that will be issued based on final 2020 performance levels 67,757 Unamortized expense, based on current performance levels (in millions) $ — Stock Options Stock options granted to employees vest ratably over a four-year period. Grants to our non-employee directors vest ratably over a three-year period. All grants expire 10 years after the date of grant. In May 2011, we granted 86,106 stock options under the 2004 Plan. We estimated the fair value of the options on the grant date using the Black-Scholes option-pricing model. The weighted average fair value of options granted during 2011 was $23.81 per share based on the following assumptions: Assumptions for Black-Scholes Option Pricing Model Expected life (years) 7.4 Volatility factor 35.1% Dividend yield 0.35% Interest rate 2.87% The following table summarizes stock option activity in the past three years for our various stock option grants: 2020 2019 2018 Option Grants Underlying Weighted Underlying Weighted Underlying Weighted Options outstanding—beginning of year 37,269 $ 57.28 40,685 $ 57.28 41,685 $ 57.28 Granted — — — — — — Canceled — — — — — — Exercised (33,669) 57.28 (3,416) 57.28 (1,000) 57.28 Options outstanding—end of year 3,600 $ 57.28 37,269 $ 57.28 40,685 $ 57.28 Options exercisable—end of year 3,600 $ 57.28 37,269 $ 57.28 40,685 $ 57.28 The following table summarizes the total intrinsic value (difference between the market value of our stock on the date of exercise and the exercise price of the option) of options exercised: (in millions) 2020 2019 2018 Intrinsic value of options exercised $ 3.9 $ 0.4 $ 0.1 The table below shows additional information for options outstanding and exercisable as of December 31, 2020: Options Outstanding Options Exercisable Range of Exercise Prices Number of Options Weighted Weighted Aggregate Exercisable Shares Weighted Average Remaining Contractual Life (years) Weighted Average Exercise Price Aggregate $57.28 3,600 0.37 $ 57.28 $ 0.6 3,600 0.37 $ 57.28 $ 0.6 Vested or Expected to Vest $57.28 3,600 0.37 $ 57.28 $ 0.6 The aggregate intrinsic value in the table above represents the total pretax intrinsic value all option holders would have received if they had exercised all outstanding options on December 31, 2020. The intrinsic value is based on our closing stock price of $231.57 on December 31, 2020.

Defined Contribution Plan

Defined Contribution Plan	12 Months Ended
	Dec. 31, 2020
Defined Contribution Plan [Abstract]
Defined Contribution Plan	Defined-Contribution Plan We sponsor a defined-contribution 401(k) plan, which allows our U.S.-based employees to voluntarily contribute pretax dollars up to a maximum amount allowable by the U.S. Internal Revenue Service. In 2020, 2019, and 2018, we made matching contributions to our 401(k) plan in an amount equal to 75 cents for every dollar of an employee's contribution, up to a maximum of 7% of the employee's compensation in the pay period. The following table summarizes our matching contributions: (in millions) 2020 2019 2018 401(k) matching contributions $ 14.5 $ 12.0 $ 11.0

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Income Tax Expense and Effective Tax Rate The following table shows our income tax expense and our effective tax rate for the years ended December 31, 2020, 2019, and 2018: (in millions) 2020 2019 2018 Income before income taxes and equity in net income (loss) of unconsolidated entities $ 283.0 $ 198.5 $ 232.9 Equity in net income (loss) of unconsolidated entities 0.3 (0.9) (2.1) Total $ 283.3 $ 197.6 $ 230.8 Income tax expense $ 59.7 $ 45.6 $ 47.8 Effective tax rate 21.1 % 23.1 % 20.7 % Our effective tax rate in 2020 was 21.1%, a decrease of 2.0 percentage points, compared with 23.1% in 2019. The decrease is primarily attributable to the non-taxable holding gain on the previously held equity interest in Sustainalytics offset by the M&A-related earn-outs that is not deductible for tax purposes. Our effective tax rate in 2019 was 23.1%, an increase of 2.4 percentage points, compared with 20.7% in 2018, primarily due to minimum taxes and non-deductible expenses in 2019. The amount of accumulated undistributed earnings of our foreign subsidiaries was approximately $243.5 million as of December 31, 2020. In February 2019, we repatriated approximately $45.8 million of these foreign earnings to the U.S. Otherwise, we generally consider our U.S. directly-owned foreign subsidiary earnings to be permanently reinvested. We have not recorded deferred income taxes on the $243.5 million primarily because most of these earnings were previously subject to the one-time deemed mandatory repatriation tax under the Tax Cuts and Jobs Act of 2017 (Tax Reform Act). We maintain a deferred tax liability for foreign withholding taxes on certain foreign affiliate parent companies that are not indefinitely reinvested. The following table reconciles our income tax expense at the U.S. federal income tax rate to income tax expense as recorded: 2020 2019 2018 (in millions, except percentages) Amount % Amount % Amount % Income tax expense at U.S. federal rate $ 59.5 21.0 % $ 41.5 21.0 % $ 48.5 21.0 % State income taxes, net of federal income tax benefit 9.5 3.4 7.5 3.8 7.4 3.2 Impacts of Tax Reform Act (1) — — — — (2.3) (1.0) Stock-based compensation activity (4.9) (1.7) (2.2) (1.1) (2.6) (1.1) Equity in net income of unconsolidated subsidiaries (including holding gains upon acquisition) (13.8) (4.9) 0.3 0.2 1.0 0.4 Acquisition earn-out 7.6 2.7 — — — — Net change in valuation allowance related to non-U.S. deferred tax assets, primarily net operating losses 2.7 1.0 (2.1) (1.1) (0.2) (0.1) Difference between U.S. federal statutory and foreign tax rates (0.1) — 1.1 0.6 0.2 0.1 Change in unrecognized tax benefits 1.2 0.4 (0.9) (0.5) 1.0 0.4 Credits and incentives (2.2) (0.8) (2.2) (1.1) (3.6) (1.6) Foreign tax provisions (GILTI, FDII, and BEAT) (2) (2.7) (1.0) (1.4) (0.7) (3.7) (1.6) Non-deductible expenses and other, net 2.9 1.0 4.0 2.0 2.1 0.9 Total income tax expense $ 59.7 21.1 % $ 45.6 23.1 % $ 47.8 20.7 % (1) Impacts of the Tax Reform Act (change in U.S. tax rate, deemed mandatory repatriation, and deferred taxes). (2) The Tax Reform Act established the Global Intangible Low-Tax Income (GILTI) provision, which taxes U.S. allocated expenses and certain income from foreign operations; the Foreign-Derived Intangible Income (FDII) provision, which allows a deduction against certain types of U.S. taxable income resulting in a lower effective U.S. tax rate on such income; and the Base Erosion Anti-abuse Tax (BEAT), which is a new minimum tax based on cross-border service payments by U.S. entities. Income tax expense consists of the following: Year ended December 31 (in millions) 2020 2019 2018 Current tax expense: U.S. Federal $ 31.5 $ 28.3 $ 31.0 State 11.7 9.4 11.1 Non-U.S. 23.0 14.0 12.3 Current tax expense 66.2 51.7 54.4 Deferred tax expense (benefit): U.S. Federal 1.2 0.2 (3.0) State 0.4 — (1.7) Non-U.S. (8.1) (6.3) (1.9) Deferred tax expense, net (6.5) (6.1) (6.6) Income tax expense $ 59.7 $ 45.6 $ 47.8 The following table provides our income before income taxes and equity in net income (loss) of unconsolidated entities, generated by our U.S. and non-U.S. operations: Year ended December 31 (in millions) 2020 2019 2018 U.S. $ 197.4 $ 159.7 $ 188.2 Non-U.S. 85.6 38.8 44.7 Income before income taxes and equity in net income (loss) of unconsolidated entities $ 283.0 $ 198.5 $ 232.9 Deferred Tax Assets and Liabilities We recognize deferred income taxes for the temporary differences between the carrying amount of assets and liabilities for financial statement purposes and their tax basis. The tax effects of the temporary differences that give rise to the deferred income tax assets and liabilities are as follows: As of December 31 (in millions) 2020 2019 Deferred tax assets: Stock-based compensation expense $ 2.9 $ 7.6 Accrued liabilities 20.6 18.0 Deferred revenue 6.7 5.5 Net operating loss carryforwards - U.S. 0.1 0.2 Net operating loss carryforwards - Non-U.S. 7.9 4.5 Deferred royalty revenue 0.2 0.2 Allowance for doubtful accounts 1.4 1.4 Lease liabilities 32.8 — Deferred rent — 8.0 Other 0.7 0.6 Total deferred tax assets 73.3 46.0 Deferred tax liabilities: Acquired intangible assets (93.9) (82.7) Property, equipment, and capitalized software (25.1) (25.8) Lease right-of-use assets (25.9) — Unrealized exchange gains, net (1.3) (1.1) Prepaid expenses (12.1) (9.1) Investments in unconsolidated entities (6.0) (6.3) Withholding tax - foreign dividends (3.0) (3.0) Total deferred tax liabilities (167.3) (128.0) Net deferred tax liability before valuation allowance (94.0) (82.0) Valuation allowance (2.3) (2.3) Deferred tax liability, net $ (96.3) $ (84.3) The deferred tax assets and liabilities are presented in our Consolidated Balance Sheets as follows: As of December 31 (in millions) 2020 2019 Deferred tax asset, net $ 12.6 $ 10.7 Deferred tax liability, net (108.9) (95.0) Deferred tax liability, net $ (96.3) $ (84.3) The following table summarizes our U.S. net operating loss (NOL) carryforwards: As of December 31 (in millions) 2020 2019 Expiration Dates Expiration Dates U.S. federal NOLs subject to expiration dates $ 0.6 2023 $ 0.8 2023 The net decrease in the U.S. federal NOL carryforwards as of December 31, 2020 compared with 2019 primarily reflects the utilization of U.S. federal NOLs. We have not recorded a valuation allowance against the U.S. federal NOLs of $0.6 million because we expect the benefit of the U.S. federal NOLs to be fully utilized before expiration. The following table summarizes our NOL carryforwards for our non-U.S. operations: As of December 31 (in millions) 2020 2019 Non-U.S. NOLs subject to expiration dates from 2021 through 2040 $ 21.7 $ 6.8 Non-U.S. NOLs with no expiration date 11.6 14.6 Total $ 33.3 $ 21.4 Non-U.S. NOLs not subject to valuation allowances $ 24.5 $ 11.7 The change in non-U.S. NOL carryforwards as of December 31, 2020 compared with 2019 primarily reflects NOLs acquired in the Sustainalytics acquisition. In assessing the realizability of our deferred tax assets, we consider whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. We recorded a valuation allowance against approximately $8.8 million of the non-U.S. NOLs, reflecting the likelihood that the benefit of these NOLs will not be realized. Unrecognized Tax Benefits We conduct business globally and as a result, we file income tax returns in U.S. federal, state, local, and foreign jurisdictions. In the normal course of business, we are subject to examination by tax authorities throughout the world. The open tax years for our U.S. Federal tax returns and most state tax returns include the years 2015 to the present. We are currently under audit by federal, state, and local tax authorities in the U.S. as well as tax authorities in certain non-U.S. jurisdictions. It is likely that the examination phase of some of these federal, state, local, and non-U.S. audits will conclude in 2021. It is not possible to estimate the effect of current audits on previously recorded unrecognized tax benefits. As of December 31, 2020, our Consolidated Balance Sheet included a current liability of $7.6 million and a non-current liability of $5.1 million for unrecognized tax benefits. As of December 31, 2019, our Consolidated Balance Sheet included a current liability of $10.8 million and a non-current liability of $3.0 million for unrecognized tax benefits. These amounts include interest and penalties, less any associated tax benefits. The table below reconciles the beginning and ending amount of the gross unrecognized tax benefits as follows: (in millions) 2020 2019 Gross unrecognized tax benefits - beginning of the year $ 12.6 $ 13.1 Increases as a result of tax positions taken during a prior-year period 0.5 3.0 Decreases as a result of tax positions taken during a prior-year period (2.5) (0.2) Increases as a result of tax positions taken during the current period 1.3 1.2 Decreases relating to settlements with tax authorities — (3.8) Reductions as a result of lapse of the applicable statute of limitations (0.1) (0.7) Gross unrecognized tax benefits - end of the year $ 11.8 $ 12.6 In 2020, we recorded a net decrease of $0.8 million of gross unrecognized tax benefits before settlements and lapses of statutes of limitations, of which $1.2 million increased our income tax expense by $1.2 million. In addition, we reduced our unrecognized tax benefits by $0.1 million for settlements and lapses of statutes of limitations, of which $0.1 million decreased our income tax expense by $0.1 million. As of December 31, 2020, we had $11.8 million of gross unrecognized tax benefits, of which $11.8 million, if recognized, would reduce our effective income tax rate and decrease our income tax expense by $11.6 million. We record interest and penalties related to uncertain tax positions as part of our income tax expense. The following table summarizes our gross liability for interest and penalties: As of December 31 (in millions) 2020 2019 Liabilities for interest and penalties $ 1.4 $ 1.6 We recorded the decrease in the liabilities for penalties and interest, net of any tax benefits, to income tax expense in our Consolidated Statements of Income in 2020.

Contingencies

Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies We record accrued liabilities for litigation, regulatory, and other business matters when those matters represent loss contingencies that are both probable and estimable. In these cases, there may be an exposure to loss in excess of any amounts accrued. When a loss contingency is not both probable and estimable, we do not establish an accrued liability. As litigation, regulatory, or other business matters develop, we evaluate on an ongoing basis whether such matters present a loss contingency that is probable and estimable. Data Audits and Reviews In our global data business, we include in our products, or directly redistribute to our customers, data, and information licensed from third-party vendors. Our compliance with the terms of these licenses is reviewed internally and is also subject to audit by the third-party vendors. At a given time, we may be undergoing several such internal reviews and third-party vendor audits and the results and findings of which may indicate that we may be required to make a payment for prior data usage. Due to a lack of available information and data, as well as potential variations of any audit or internal review findings, we generally are not able to reasonably estimate a possible loss, or range of losses for these matters. While we cannot predict the outcome of these processes, we do not anticipate they will have a material adverse effect on our business, operating results, or financial position. Credit Ratings Matter On February 16, 2021, the SEC filed a civil action in the United States District Court for the Southern District of New York against Morningstar Credit Ratings, LLC (MCR). MCR was formerly registered with the SEC as a Nationally Recognized Statistical Ratings Organization, but effective in December 2019, it withdrew its NRSRO registration. MCR no longer operates as a credit rating agency. The SEC’s complaint relates to MCR’s former commercial mortgage-backed securities ratings methodology during the period from 2015 to March 2017, and it alleges violations of certain filing and internal control requirements that applied to MCR when it was an NRSRO. The SEC seeks injunctive relief, disgorgement, and civil money penalties. At this time, we do not believe any outcome in this litigation will have a material adverse effect on our business, operating results, or financial position. Other Matters We are involved from time to time in regulatory investigations and legal proceedings that arise in the normal course of our business. While it is difficult to predict the outcome of any particular investigation or proceeding, we do not believe the result of any of these matters will have a material adverse effect on our business, operating results, or financial position.

Share Repurchase Program

Share Repurchase Program	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Share Repurchase Program	Share Repurchase Program In December 2017, the board of directors approved a share repurchase program that authorizes the Company to repurchase up to $500.0 million in shares of the Company's outstanding common stock effective January 1, 2018 and expiring on December 31, 2020. As of December 31, 2020, we had repurchased a total of 559,105 shares for $67.5 million. On December 4, 2020, the board of directors approved a new share repurchase program that authorizes the Company to repurchase up to $400.0 million in shares of the Company's outstanding common stock, effective January 1, 2021. The new authorization expires on December 31, 2023. Under this authorization, we may repurchase shares from time to time at prevailing market prices on the open market or in private transactions in amounts that we deem appropriate.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements Recently adopted accounting pronouncements Leases: On February 25, 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), which requires lessees to recognize almost all leases on their balance sheet as a right-of-use asset and a lease liability. Expenses are recognized in the Consolidated Statements of Income in a manner similar to previous accounting guidance. Topic 842 originally required the use of a modified retrospective approach upon adoption. In July 2018, the FASB issued ASU No. 2018-11, Leases (Topic 842) - Targeted Improvements, which allows an additional transition method to adopt the new lease standard at the adoption date instead of the beginning of the earliest period presented. We elected this transition method at the adoption date of January 1, 2019. We also chose to elect the following practical expedients upon adoption: not to reassess whether any expired or existing contracts are or contain leases, not to reassess the lease classification for any expired or existing leases, not to reassess initial direct costs for any existing leases, and not to separately identify lease and nonlease components (i.e. maintenance costs) except for real estate leases. Additionally, we elected the short-term lease exemption, and are only applying the requirements of Topic 842 to long-term leases (leases greater than 1 year). The adoption of Topic 842 resulted in the presentation of $118.8 million of operating lease assets and $145.8 million of operating lease liabilities on the consolidated balance sheet as of March 31, 2019. At implementation, we also reclassified $29.7 million in deferred rent liabilities related to these leases, which decreased recognized operating lease assets. The new standard did not have a material impact on the statement of income. See Note 12 for additional information. Current Expected Credit Losses : On June 16, 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326) : Measurement of Credit Losses on Financial Instruments (ASU No. 2016-13) , which requires that expected credit losses relating to financial assets measured on an amortized cost basis and available-for-sale debt securities be recorded through an allowance for credit losses. ASU No. 2016-13 limits the amount of credit losses to be recognized for available-for-sale debt securities to the amount by which carrying value exceeds fair value and requires the reversal of previously recognized credit losses if fair value increases. On April 25, 2019, the FASB issued ASU No. 2019-04, Codification Improvements (ASU No. 2019-04), which clarifies certain aspects of accounting for credit losses. On May 15, 2019, the FASB issued ASU No. 2019-05, Financial Instruments-Credit Losses (Topic 326) : Targeted Transition Relief (ASU No. 2019-05), which allows entities to elect the fair value option on certain financial instruments. The new standard became effective for us on January 1, 2020 and was applied prospectively. As a result of the adoption of these standards, we made changes to our processes for the assessment of the adequacy of our allowance for credit losses on certain types of financial instruments, including accounts receivable. The adoption of ASU No. 2016-13, ASU No. 2019-04, and ASU No. 2019-05 did not have a material impact on the consolidated financial statements, related disclosures, or results of operations. Cloud Computing : On August 29, 2018, the FASB issued ASU No. 2018-15, Customer's Accounting for Fees Paid in a Cloud Computing Arrangement (ASU No. 2018-15), which helps entities evaluate the accounting for fees paid by a customer in a cloud computing arrangement (CCA) by providing guidance for determining when an arrangement includes a software license and when an arrangement is solely a hosted CCA service. The Company adopted this guidance prospectively beginning on January 1, 2020. Upon adoption, fees paid in a CCA will be evaluated for capitalization as a prepaid asset and expensed within the results of operations in the same financial statement line item as software license fees instead of depreciation and amortization expense. The adoption of ASU No. 2018-15 did not have a material impact on the consolidated financial statements, related disclosures, or results of operations. Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement: On August 28, 2018, the FASB issued ASU No. 2018-13 , Fair Value Measurement (Topic 820) : Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement (ASU No. 2018-13) , which eliminates, adds, and modifies certain disclosure requirements around items such as transfers between Level 1 and 2, policy of timing of transfers, and valuation process for Level 3. The new standard became effective for us on January 1, 202 0. Except for limited additions to related disclosures, the adoption of ASU No. 2018-13 did not have a material impact on our consolidated financial statements. Recently issued accounting pronouncements not yet adopted Income Taxes: On December 18, 2019, the FASB issued ASU No. 2019-12, Simplifying the Accounting for Income Taxes (ASU No. 2019-12), which is intended to simplify the accounting for income taxes by removing certain exceptions to the general principles of ASC 740, Income Taxes, and providing for simplification in several other areas. The new standard became effective for us on January 1, 2021. The adoption of ASU No. 2019-12 is not e xpected to have a material impact on our consolidated financial statements, related disclosures, and results of operations. Reference Rate Reform : On March 12, 2020, the FASB issued ASU No. 2020-04: Facilitation of the Effects of Reference Rate Reform on Financial Reporting (Topic 848) (ASU No. 2020-04), which provides temporary optional expedients and exceptions for applying generally accepted accounting principles to contract modifications resulting from reference rate reform initiatives. The intention of the standard is to ease the potential accounting and financial reporting burden associated with transitioning away from the expiring London Interbank Offered Rate (LIBOR) and other interbank offered rates to alternative benchmark rates. The amendments in this update are applicable to contract modifications that replace a reference LIBOR rate beginning on March 12, 2020 through December 31, 2022. The optional expedients apply to our Credit Agreement and allow the Company to account for modifications due to reference rate reform by prospectively adjusting the effective interest rate on the Credit Agreement. As of December 31, 2020, we have not modified the Credit Agreement related to reference rate reform. We plan to apply the optional practical expedients and exceptions to modifications of the Credit Agreement affected by reference rate reform and are evaluating the effect on our consolidated financial statements, related disclosures, and results of operations.

Selected Quarterly Financial Da

Selected Quarterly Financial Data	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data	Selected Quarterly Financial Data (unaudited) 2020 2019 (in millions except per share amounts) Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Revenue $ 324.0 $ 327.9 $ 357.2 $ 380.4 $ 258.9 $ 273.9 $ 313.8 $ 332.4 Total operating expense 279.5 266.6 312.9 315.3 209.4 223.1 264.2 292.7 Operating income 44.5 61.3 44.3 65.1 49.5 50.8 49.6 39.7 Non-operating (expense) income, net (11.3) 2.6 48.2 (1) 28.3 (1) (3.3) 2.3 13.9 (1) (4.0) Income before income taxes and equity in net (loss) income of unconsolidated entities 33.2 63.9 92.5 93.4 46.2 53.1 63.5 35.7 Equity in net (loss) income of unconsolidated entities (0.8) (0.5) 0.6 1.0 (1.5) 0.7 (1.1) 1.0 Income tax expense 8.5 15.2 16.9 19.1 11.5 11.7 13.3 9.1 Consolidated net income $ 23.9 $ 48.2 $ 76.2 $ 75.3 $ 33.2 $ 42.1 $ 49.1 $ 27.6 Net income per share: Basic $ 0.56 $ 1.13 $ 1.78 $ 1.76 $ 0.78 $ 0.99 $ 1.15 $ 0.64 Diluted $ 0.55 $ 1.12 $ 1.76 $ 1.74 $ 0.77 $ 0.98 $ 1.14 $ 0.64 Dividends per common share: Dividends declared per common share $ 0.30 $ 0.30 $ — $ 0.62 $ 0.28 $ 0.28 $ — $ 0.58 Dividends paid per common share $ 0.30 $ 0.30 $ 0.30 $ 0.30 $ 0.28 $ 0.28 $ 0.28 $ 0.28 Weighted average shares outstanding: Basic 42.9 42.9 42.9 42.9 42.6 42.7 42.8 42.8 Diluted 43.3 43.2 43.2 43.2 43.0 43.1 43.2 43.3 (1) Non-operating income for the third quarter of 2020 includes a $50.9 million holding gain on the previously held equity interest related to our purchase of the remaining interest in Sustainalytics in July 202 0. Non-operating income for the fourth quarter of 2020 includes a $30.0 million gain related to the sale of two equity method investments. Non-operating income for the third quarter of 2019 includes a $19.5 million gain related to the sale of an equity method inve stment.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation. We conduct our business operations through wholly owned or majority-owned operating subsidiaries. The accompanying consolidated financial statements include the accounts of Morningstar, Inc. and our subsidiaries. We consolidate assets, liabilities, and results of operations of subsidiaries in which we have a controlling interest and eliminate all significant intercompany accounts and transactions. We account for investments in entities in which we exercise significant influence, but do not control, using the equity method. As part of our investment management operations, we manage certain funds outside of the U.S. that are considered variable interest entities. For the majority of these variable interest entities, we do not have a variable interest. In cases where we do have a variable interest, we are not the primary beneficiary. Accordingly, we do not consolidate any of these variable interest entities.
Use of Estimates	Use of Estimates. The preparation of financial statements in conformity with accounting principles generally accepted in the U.S. (GAAP) requires us to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues, and expenses during the reporting period. Actual results may differ from these estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents. Cash and cash equivalents consist of cash and investments with original maturities of three months or less. We state them at cost, which approximates fair value. We state the portion of our cash equivalents that are invested in money market funds at fair value, as these funds are actively traded and have quoted market prices.
Investments	Investments. We account for our investments in accordance with FASB ASC 320, Investments—Debt and Equity Securities (FASB ASC 320) . We classify our investments into three categories: held-to-maturity, trading, and available-for-sale. • Held-to-maturity: We classify certain investments, primarily certificates of deposit, as held-to-maturity securities, based on our intent and ability to hold these securities to maturity. We record held-to-maturity investments at amortized cost in our Consolidated Balance Sheets. • Trading: We classify certain other investments, primarily equity securities, as trading securities. We include realized and unrealized gains and losses associated with these investments as a component of our operating income in our Consolidated Statements of Income. We record these securities at their fair values in our Consolidated Balance Sheets. • Available-for-sale: Investments not considered held-to-maturity or trading securities are classified as available-for-sale securities. Available-for-sale securities primarily consist of equity securities, exchange-traded funds, and mutual funds. We report unrealized gains and losses for available-for-sale securities as other comprehensive income (loss), net of related income taxes. We record these securities at their fair values in our Consolidated Balance Sheets.
Fair Value Measurements	Fair Value Measurements. FASB ASC 820, Fair Value Measurements (FASB ASC 820) defines fair value, establishes a framework for measuring fair value, and expands disclosures about fair value measurements. Under FASB ASC 820, fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants as of the measurement date. The standard applies whenever other standards require (or permit) assets or liabilities to be measured at fair value. FASB ASC 820 uses a fair value hierarchy based on three broad levels of valuation inputs: • Level 1: Valuations based on quoted prices in active markets for identical assets or liabilities that we have the ability to access. • Level 2: Valuations based on quoted prices in markets that are not active or for which all significant inputs are observable, either directly or indirectly. • Level 3: Valuations based on inputs that are unobservable and significant to the overall fair value measurement. We provide additional information about our cash equivalents and investments that are subject to FASB ASC 820 in Note 7.
Concentration of Credit Risk	Concentration of Credit Risk. For the years ended December 31, 2020, 2019, and 2018, no single customer represented 5% or more of our consolidated revenue. If receivables from our customers become delinquent, we begin a collections process. We maintain an allowance for credit losses based on our estimate of the probable losses of accounts receivable.
Property, Equipment, and Depreciation	Property, Equipment, and Depreciation. We state property and equipment at historical cost, net of accumulated depreciation. We depreciate property and equipment using the straight-line method based on the useful life of the asset, which ranges from three
Computer Software and Internal Product Development Costs	Computer Software and Internal Product Development Costs. We capitalize certain costs in accordance with FASB ASC 350-40, Internal-Use Software , FASB ASC 350-50, Website Development Costs, and FASB ASC 985, Software . Internal product development costs mainly consist of employee costs for developing new web-based products and certain major enhancements of existing products. We amortize these costs on a straight-line basis over the estimated economic life, which is generally three years. We include capitalized software development costs related to projects that have not been placed into service in our construction in progress balance.
Business Combinations	Business Combinations . When we acquire a business, we account for the business combination in accordance with FASB ASC 805, Business Combinations (FASB ASC 805). We recognize and measure the fair value of the acquired business and allocate the purchase price to the identifiable tangible and intangible assets acquired and liabilities assumed based upon their estimated fair values at the date of acquisition. The difference between the purchase price and the estimated fair value of the net assets acquired or the excess of the aggregate estimated fair values of assets acquired and liabilities assumed is recorded as goodwill. In determining the estimated fair values of assets acquired and liabilities assumed in a business combination, we use various recognized valuation methods, including discounted cash flow, Monte Carlo simulations, and relief from royalty. For a business combination achieved in stages, we remeasure our previously held equity interest immediately before the acquisition to the acquisition date fair value and recognize any gain in our Consolidated Statements of Income. We recognize the fair value of any contingent payments at the date of acquisition as part of the consideration transferred to acquire a business. The liability associated with contingent consideration is remeasured to fair value at each reporting period subsequent to the date of acquisition considering factors that may impact the timing and amount of contingent payments until the term of the agreement has expired or the contingency is resolved. Any changes in the fair value measurement will be recorded in our Consolidated Statements of Income. In evaluating the characterization of contingent and deferred payments, we analyze relevant factors, including the nature of the payment, continuing employment requirements, incremental payments to employees of the acquired business, and timing and rationale underlying the transaction, to determine whether the payments should be accounted for as additional purchase consideration or post-combination related services. We expense direct costs related to the business combination, such as accounting, legal, valuation, and other professional fees, as incurred. We recognize restructuring costs, including severance and relocation for employees of the acquired entity, as post-combination expenses unless the target entity meets the criteria of ASC 420, Exit or Disposal Cost Obligations , on the acquisition date. As part of the purchase price allocation, we follow the requirements of FASB ASC 740, Income Taxes
Goodwill	Goodwill . Changes in the carrying amount of our recorded goodwill are mainly the result of business acquisitions, divestitures, and the effect of foreign currency translations. In accordance with FASB ASC 350, Intangibles—Goodwill and Other , we do not amortize goodwill; instead, goodwill is subject to an impairment test annually, or whenever indicators of impairment exist. An impairment would occur if the carrying amount of a reporting unit exceeded the fair value of that reporting unit. We performed annual impairment reviews in the fourth quarter of 2020
Intangible Assets	Intangible Assets. We amortize intangible assets using the straight-line method over their estimated useful lives, which range from one twenty years . We have no intangible assets with indefinite useful lives. In accordance with FASB ASC 360-10-35, Subsequent Measurement—Impairment or Disposal of Long-Lived Assets , we review intangible assets for impairment whenever events or changes in circumstances indicate that the carrying value may not be recoverable. If the value of future undiscounted cash flows is less than the carrying amount of an asset group, we record an impairment loss based on the excess of the carrying amount over the fair value of the asset group. We did not record any impairment losses in 2020 ,
Sales Commissions	Sales Commissions. Under prior accounting standards, the Company expensed sales incentive compensation costs, (sales commissions) as incurred. Upon adoption of ASC Topic 606 and ASC 340-40, Other Assets and Deferred Costs - Contracts with Customers
Stock-Based Compensation Expense	Stock-Based Compensation Expense. We account for our stock-based compensation expense in accordance with FASB ASC 718, Compensation—Stock Compensation (FASB ASC 718). Our stock-based compensation expense reflects grants of restricted stock units, performance share awards, market stock units, and stock options. We measure the fair value of our restricted stock units, restricted stock, and performance share awards on the grant date based on the closing market price of Morningstar's common stock on the day prior to the grant. For market stock units, we estimate the fair value of the awards using a Monte Carlo valuation model. For stock options, we estimate the fair value of our stock options on the date of grant using the Black-Scholes option-pricing model. We amortize the fair values to stock-based compensation expense, net of estimated forfeitures, ratably over the vesting period. We estimate expected forfeitures of all employee stock-based awards and recognize compensation cost only for those awards expected to vest. We determine forfeiture rates based on historical experience and adjust the estimated forfeitures to actual forfeiture experience, as needed.
Income Taxes	Income Taxes. We record deferred income taxes for the temporary differences between the carrying amount of assets and liabilities for financial statement purposes and tax purposes in accordance with ASC 740. ASC 740 prescribes the minimum recognition threshold a tax position is required to meet before being recognized in the financial statements. It also provides guidance on derecognition, measurement, classification, interest and penalties, accounting in interim periods, and disclosure for uncertain tax positions.
Segment Information	Segment Information We report our results in a single reportable segment, which reflects how our chief operating decision maker allocates resources and evaluates our financial results. Because we have a single reportable segment, all required financial segment information can be found directly in the Consolidated Financial Statements. The accounting policies for our reportable segment are the same as those described in Note 2. We evaluate the performance of our reporting segment based on revenue and operating income.
Lesses	Leases. We account for our right-of-use assets and operating lease liabilities in accordance with FASB ASC 842, Leases (FASB ASC 842) . We determine if a contract is or contains a lease at the inception of the contract. For identified operating leases, we recognize a lease liability and right-of-use asset on the consolidated balance sheet. The right-of-use asset represents our right to use an underlying asset for the lease term, and the operating lease liability represents the Company's obligation to make lease payments. Our lease agreements consist primarily of real estate leases for office space and non-real estate leases for office equipment. In cases where an agreement contains both a lease and non-lease component, we do not allocate consideration to both components, but account for each as a single lease component by class of underlying asset. There are few instances of short-term agreements in our lease portfolio, which are typically arranged as needed and paid on a month-to-month basis. These leases are not recognized on the Consolidated Balance Sheet, but monthly lease expense is recognized on the Consolidated Statements of Income. Right-of-Use assets and operating lease liabilities are measured using the present value of future lease payments of the lease term at the commencement date. Right-of-use assets also include initial direct costs incurred by the Company, net of pre-payments and lease incentives. In the absence of an explicit rate in the lease agreement, the discount rate used to calculate present value is equal to the Company's incremental borrowing rate. Operating lease expense is recognized on a straight-line basis over the life of the lease and is included in general and administrative expenses on the Consolidated Statements of Income.
Revenue from Contract with Customer	Revenue Recognition. On January 1, 2018, we began recognizing revenue in accordance with ASC Topic 606, Revenue from Contracts with Customers (ASC Topic 606). The Company has retained similar recognition and measurement upon adoption of ASC Topic 606 as under accounting standards in effect in prior periods. Under ASC Topic 606, we recognize revenue by applying the following five-step model to each of our customer arrangements: 1. Identify the customer contract; 2. Identify the performance obligations in the contract; 3. Determine the transaction price; 4. Allocate the transaction price to the performance obligations; and 5. Recognize revenue when (or as) performance obligations are satisfied. Revenues are recognized when (or as) performance obligations are satisfied by transferring a promised product or service to the customer. Products or services are transferred when (or as) the customer obtains control of the product or service. The transaction price for a customer arrangement is the amount we expect to be entitled to in exchange for transferring the promised product or service. The transaction price may include fixed amounts, variable amounts, or both. When the right to payment exceeds revenue recognized the result is an increase to deferred revenue. When a customer’s license-based contract is signed, the customer’s service is activated immediately. License-based arrangements, our largest source of revenue from customers, generally is billed for the entire term, or billed annually (if the contract term is longer than one year). Customers are typically given payment terms of thirty to sixty days, although some customers pay immediately. Revenue from contracts with customers is derived from license-based arrangements, asset-based arrangements, and transaction-based arrangements. License-based revenue, which represents subscription services available to customers and not a license under the accounting guidance, is generated through subscription contracts entered into with our customers of Morningstar Data, Morningstar Direct, Morningstar Advisor Workstation, Morningstar Enterprise Components, PitchBook Data, Sustainalytics, and other similar products. Our performance obligations under these contracts are typically satisfied over time, as the customer has access to the service during the term of the subscription license and the level of service is consistent during the contract period. Each individual day within the contract period is viewed to be a service and the entirety of the service subscription term is determined to be a series combined into a single performance obligation and recognized over-time and on a straight-line basis, typically over terms of 1 to 3 years. Asset-based revenue is generated through consulting service contracts with our customers of Morningstar Investment Management, Workplace Solutions, and Morningstar Indexes. Our performance obligations under these contracts are a daily asset management performance obligation, which is determined to be a daily service and thus satisfied over time as the customer receives continuous access to a service for the contract term. We recognize revenue daily over the contract term based on the value of assets under management and a tiered fee agreed to with the customer (typically in a range of 30-55 basis points of the customer’s average daily portfolio balance). Asset-based arrangements typically have a term of 1 to 3 years. The fees from such arrangements represent variable consideration, and the customer does not make separate purchasing decisions that result in additional performance obligations. Significant changes in the underlying fund assets, or significant disruptions in the market, are evaluated to determine if revisions on estimates of earned asset-based fees for the current quarter are needed. An estimate of the average daily portfolio balance is included in determining revenue for a given period. Estimates are based on the most recently reported quarter, and, as a result, it is unlikely a significant reversal of revenue would occur. Transaction-based revenue is generated through contracts with our customers for DBRS Morningstar products and services, Internet advertising on Morningstar.com, and Morningstar-sponsored conferences. Our performance obligations for D BRS Morningstar includ e the issuance of the rating and may include surveillance services for a period of time as agreed with the customer. We allocate the transaction price to the deliverables based on their relative selling price, which is generally based on the price we charge when the same deliverable is sold separately. Our performance obligation for the issuance of the rating is satisfied when the rating is issued, which is when we recognize the related revenue. Our performance obligations for surveillance services is satisfied over time, as the customer has access to the service during the surveillance period and the level of service is consistent during the contract period. Therefore, we recognize revenue for this performance obligation on a straight-line basis. Our performance obligations for Internet advertising and Morningstar-sponsored conferences are satisfied as the service is delivered; therefore, we recognize revenue when the performance obligation is satisfied (as the customer’s advertisements are displayed and at the completion of the Morningstar-sponsored conference). Our contracts with customers may include multiple performance obligations. For most of these arrangements, we generally allocate revenue to each performance obligation based on its estimated standalone selling price. We generally determine standalone selling prices based on prices charged to customers when the same performance obligation is sold separately. Our contracts with customers may include third-party involvement in providing goods or services to the customer. The inclusion of third-party content does not result in separate performance obligations because is it not delivered separately from the other service offerings. In these arrangements, the customer has contracted to receive a single, integrated and bundled solution with third-party and Morningstar content delivered via Morningstar’s subscription services. Revenue and related costs of revenue from third-party content is presented on a gross basis within the consolidated financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Acronyms Used	The acronyms that appear in these Notes to our Consolidated Financial Statements refer to the following: ASC Accounting Standards Codification ASU Accounting Standards Update EITF Emerging Issues Task Force FASB Financial Accounting Standards Board SEC Securities and Exchange Commission
Summary of Depreciation for Internally Developed Software	The table below summarizes our depreciation expense related to capitalized developed software for the past three years: (in millions) 2020 2019 2018 Capitalized developed software depreciation expense $ 53.9 $ 61.1 $ 42.8
Summary of Capitalized Software Development Costs	The table below summarizes our capitalized software development costs for the past three years: (in millions) 2020 2019 2018 Capitalized software development costs $ 60.3 $ 64.8 $ 53.5

Credit Arrangements (Tables)

Credit Arrangements (Tables)	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Summary of Total Debt and Long-term Debt	The following table summarizes our total debt and long-term debt as of December 31, 2020 and December 31, 2019. (in millions) As of December 31, 2020 As of December 31, 2019 Term Facility, net of unamortized debt issuance costs of $0.1 million and $1.3 million $ 100.8 $ 443.1 Revolving Credit Facility — 70.0 2.32% Senior Notes due October 26, 2030, net of unamortized debt issuance costs of $1.7 million 348.3 — Total debt $ 449.1 $ 513.1 Less: Current portion of long-term debt, net of unamortized debt issuance costs of $0.3 million — 11.0 Long-term debt $ 449.1 $ 502.1

Income Per Share (Tables)

Income Per Share (Tables)	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table shows how we reconcile our net income and the number of shares used in computing basic and diluted net income per share: (in millions, except per share amounts) 2020 2019 2018 Basic net income per share: Consolidated net income $ 223.6 $ 152.0 183.0 Weighted average common shares outstanding 42.9 42.7 42.6 Basic net income per share $ 5.22 $ 3.56 $ 4.30 Diluted net income per share: Consolidated net income $ 223.6 $ 152.0 $ 183.0 Weighted average common shares outstanding 42.9 42.7 42.6 Net effect of dilutive stock options and restricted stock units 0.3 0.5 0.4 Weighted average common shares outstanding for computing diluted income per share 43.2 43.2 43.0 Diluted net income per share $ 5.18 $ 3.52 $ 4.25

Revenue (Tables)

Revenue (Tables)	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table presents our revenue disaggregated by revenue type. Sales and usage-based taxes are excluded from revenue. Year ended December 31 (in millions) 2020 2019 2018 License-based $ 934.9 $ 812.7 $ 751.6 Asset-based 223.8 211.6 200.4 Transaction-based 230.8 154.7 67.9 Consolidated revenue $ 1,389.5 $ 1,179.0 $ 1,019.9
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction	We expect to recognize revenue related to our contract liabilities for 2021 and subsequent years as follows: (in millions) As of December 31, 2020 2021 $ 571.8 2022 153.6 2023 51.8 2024 16.2 2025 6.3 Thereafter 33.1 Total $ 832.8
Summary of Contract Assets and Change in Deferred Commissions	The following table summarizes our contract assets balance: As of December 31 (in millions) 2020 2019 Accounts receivable, less allowance for credit losses $ 205.1 $ 188.5 Deferred commissions 39.6 30.4 Total contract assets $ 244.7 $ 218.9

Segment and Geographical Area_2

Segment and Geographical Area Information (Tables)	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas	The tables below summarize our revenue, long-lived assets, which includes property, equipment, and capitalized software, net, and operating lease assets, by geographical area: Revenue by geographical area Year ended December 31 (in millions) 2020 2019 2018 United States $ 970.8 $ 866.4 $ 764.2 Asia 33.6 27.9 24.5 Australia 45.6 39.5 40.9 Canada 101.5 56.9 30.7 Continental Europe 113.8 88.0 81.2 United Kingdom 117.5 93.9 72.4 Other 6.7 6.4 6.0 Total International 418.7 312.6 255.7 Consolidated revenue $ 1,389.5 $ 1,179.0 $ 1,019.9 Property, equipment, and capitalized software, net by geographical area As of December 31 (in millions) 2020 2019 United States $ 127.0 $ 131.2 Asia 7.5 6.6 Australia 3.7 4.2 Canada 2.9 2.9 Continental Europe 6.2 2.3 United Kingdom 7.3 6.9 Other 0.5 0.6 Total International 28.1 23.5 Consolidated property, equipment, and capitalized software, net $ 155.1 $ 154.7 Operating lease assets by geographical area As of December 31 (in millions) 2020 2019 United States $ 89.2 $ 86.4 Asia 12.6 20.2 Australia 5.2 5.8 Canada 7.4 7.5 Continental Europe 17.0 6.3 United Kingdom 15.6 17.9 Other 0.7 0.7 Total International 58.5 58.4 Consolidated operating lease assets $ 147.7 $ 144.8

Investments and Fair Value Me_2

Investments and Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Schedule of Investments	We classify our investment portfolio as shown below: As of December 31 (in millions) 2020 2019 Available-for-sale $ 40.5 $ 25.8 Held-to-maturity 1.2 2.3 Trading securities — 5.3 Total $ 41.7 $ 33.4
Unrealized Gain (Loss) on Investments	The following table shows the cost, unrealized gains, and fair values related to investments classified as available-for-sale and held-to-maturity: As of December 31, 2020 As of December 31, 2019 (in millions) Cost Unrealized Unrealized Fair Cost Unrealized Unrealized Fair Available-for-sale: Equity securities and exchange-traded funds $ 24.6 $ 4.2 $ — $ 28.8 $ 19.0 $ 2.9 $ — $ 21.9 Mutual funds 10.0 0.8 — 10.8 3.7 0.2 — 3.9 Marketable debt securities 0.9 — — 0.9 — — — — Total $ 35.5 $ 5.0 $ — $ 40.5 $ 22.7 $ 3.1 $ — $ 25.8 Held-to-maturity: Certificates of deposit $ 1.2 $ — $ — $ 1.2 $ 2.3 $ — $ — $ 2.3 Total $ 1.2 $ — $ — $ 1.2 $ 2.3 $ — $ — $ 2.3
Investments Classified by Contractual Maturity Date	The table below shows the cost and fair value of investments classified as available-for-sale and held-to-maturity based on their contractual maturities as of December 31, 2020 and December 31, 2019. As of December 31, 2020 As of December 31, 2019 (in millions) Cost Fair Value Cost Fair Value Available-for-sale: Equity securities, exchange-traded funds, mutual funds, and marketable debt securities $ 35.5 $ 40.5 $ 22.7 $ 25.8 Total $ 35.5 $ 40.5 $ 22.7 $ 25.8 Held-to-maturity: Due in one year or less $ 1.2 $ 1.2 $ 2.3 $ 2.3 Due in one to three years — — — — Total $ 1.2 $ 1.2 $ 2.3 $ 2.3
Schedule of Realized Gain (Loss)	The following table shows the realized gains and losses arising from sales of our investments classified as available-for-sale recorded in our Consolidated Statements of Income: (in millions) 2020 2019 2018 Realized gains $ 2.1 $ 1.2 $ 1.8 Realized losses — — (0.8) Realized gains, net $ 2.1 $ 1.2 $ 1.0
Unrealized Gain Loss On Trading Securities	The following table shows the net unrealized (losses) gains on trading securities as recorded in our Consolidated Statements of Income: (in millions) 2020 2019 2018 Unrealized (losses) gains, net $ (0.4) $ 0.6 $ (0.2)
Fair Value, Assets Measured on Recurring Basis	The table below shows the fair value of our assets and liabilities subject to fair value measurements that are measured at fair value on a recurring basis using the fair value hierarchy: Level 1: Valuations based on quoted prices in active markets for identical assets or liabilities that we have the ability to access. Level 2: Valuations based on quoted prices in markets that are not active or for which all significant inputs are observable, either directly or indirectly. Level 3: Valuations based on inputs that are unobservable and significant to the overall fair value measurement. Fair Value Fair Value Measurements as of December 31, 2020 as of Using Fair Value Hierarchy (in millions) December 31, 2020 Level 1 Level 2 Level 3 Financial assets: Available-for-sale investments Equity securities and exchange-traded funds $ 28.8 $ 28.8 $ — $ — Mutual funds 10.8 10.8 — — Marketable debt securities 0.9 0.9 — — Cash equivalents 0.8 0.8 — — Financial liabilities: Contingent consideration 53.7 — — 53.7 Total $ 95.0 $ 41.3 $ — $ 53.7 Fair Value Fair Value Measurements as of December 31, 2019 as of Using Fair Value Hierarchy (in millions) December 31, 2019 Level 1 Level 2 Level 3 Financial assets: Available-for-sale investments Equity securities and exchange-traded funds $ 21.9 $ 21.9 $ — $ — Mutual funds 3.9 3.9 — — Trading securities 5.3 5.3 — — Cash equivalents 0.9 0.9 — — Total $ 32.0 $ 32.0 $ — $ —

Acquisitions, Goodwill, and O_2

Acquisitions, Goodwill, and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Acquisitions, Goodwill, and Other Intangible Assets [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	The following table summarizes our allocation of the estimated fair values of the assets acquired and liabilities assumed at the acquisition date: (in millions) Fair value of consideration transferred $ 108.6 Fair value of the previously held equity interest 75.4 Cash and cash equivalents $ 9.8 Accounts receivable 6.2 Intangible assets, net 79.5 Operating lease assets 5.2 Other current and non-current assets 7.4 Deferred revenue (21.2) Operating lease liability (5.2) Deferred tax liability, net (16.9) Other current and non-current liabilities (15.5) Total fair value of net assets acquired $ 49.3 Goodwill $ 134.7 At July 2, 2020, accounts receivable acquired were recorded at gross contractual amounts receivable, which approximates fair value. At December 31, 2020, substantially all amounts were collected. The following table summarizes our allocation of the estimated fair values of the assets acquired and liabilities assumed at the date of acquisition: (in millions) Cash consideration transferred $ 682.1 Cash and cash equivalents $ 8.5 Accounts receivable 28.8 Property, equipment, and capitalized software, net 12.8 Intangible assets, net 284.1 Goodwill 473.3 Operating lease assets 33.3 Other current and non-current assets 5.7 Deferred revenue (43.2) Deferred tax liability, net (66.6) Operating lease liabilities (35.0) Other current and non-current liabilities (19.6) Total fair value of DBRS $ 682.1
Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination	(in millions) Weighted Average Useful Life (years) Customer-related assets $ 219.1 10 Technology-based assets 29.4 5 Intellectual property (trademarks and trade names) 35.6 7 Total intangible assets $ 284.1
Pro Forma Information		Unaudited Pro Forma Financial Information (in millions) 2019 2018 Revenue $ 1,259.2 $ 1,184.5 Operating income 190.3 223.6 Net income 148.2 179.7 Basic net income per share $ 3.47 $ 4.22 Diluted net income per share $ 3.43 $ 4.18
Schedule of Goodwill	The following table shows the changes in our goodwill balances from January 1, 2019 to December 31, 2020: (in millions) Balance as of January 1, 2019 $ 556.7 Acquisition of DBRS 473.3 Other, primarily foreign currency translation 9.1 Balance as of December 31, 2019 $ 1,039.1 Acquisition of Sustainalytics 134.7 Other, primarily foreign currency translation 31.2 Balance as of December 31, 2020 $ 1,205.0
Schedule of Intangible Assets	The following table summarizes our intangible assets: As of December 31, 2020 As of December 31, 2019 (in millions) Gross Accumulated Net Weighted Gross Accumulated Net Weighted Customer-related assets $ 415.6 $ (163.7) $ 251.9 11 $ 377.9 $ (130.3) $ 247.6 11 Technology-based assets 223.2 (135.2) 88.0 7 163.7 (112.0) 51.7 7 Intellectual property & other 83.6 (43.4) 40.2 8 69.3 (35.2) 34.1 8 Total intangible assets $ 722.4 $ (342.3) $ 380.1 10 $ 610.9 $ (277.5) $ 333.4 10
Schedule of Intangible Asset, Amortization Expense	The following table summarizes our amortization expense related to intangible assets: (in millions) 2020 2019 2018 Amortization expense $ 58.8 $ 36.5 $ 20.7
Schedule of Expected Amortization Expense	Based on acquisitions and divestitures completed through December 31, 2020, we expect intangible amortization expense for 2021 and subsequent years to be as follows: (in millions) 2021 $ 61.1 2022 53.1 2023 49.3 2024 43.2 2025 36.6 Thereafter 136.8 Total $ 380.1
Finite-Lived and Indefinite-Lived Intangible Assets Acquired as Part of Business Combination	The preliminary allocation of the estimated fair values of the assets acquired and liabilities assumed includes $79.5 million of acquired intangible assets, as follows: (in millions) Weighted average useful life (years) Customer-related assets $ 22.9 20 Technology-based assets 46.7 10 Intellectual property 9.9 10 Total intangible assets $ 79.5	The allocation of the estimated fair values of the assets acquired and liabilities assumed includes $284.1 million of acquired intangible assets, as follows: (in millions) Weighted Average Useful Life (years) Customer-related assets $ 219.1 10 Technology-based assets 29.4 5 Intellectual property (trademarks and trade names) 35.6 7 Total intangible assets $ 284.1

Investments in Unconsolidated_2

Investments in Unconsolidated Entities (Tables)	12 Months Ended
	Dec. 31, 2020
Investments in Unconsolidated Entities [Abstract]
Schedule of Equity Method And Cost Method Investments	Our investments in unconsolidated entities consist primarily of the following: As of December 31 (in millions) 2020 2019 Investment in MJKK $ 18.9 $ 24.0 Investment in Sustainalytics — 25.3 Other-equity method investments 7.4 6.6 Cost method investments 6.3 3.7 Total investments in unconsolidated entities $ 32.6 $ 59.6
Schedule of Equity Method Investments	We account for our investment in MJKK using the equity method. The following table summarizes our ownership percentage in MJKK and the market value of this investment based on MJKK’s publicly quoted share price: As of December 31 2020 2019 Morningstar’s approximate ownership of MJKK 22.4 % 30.4 % Approximate market value of Morningstar’s ownership in MJKK: Japanese yen (¥ in millions) ¥ 9,221.9 ¥ 10,319.0 Equivalent U.S. dollars ($ in millions) $ 89.4 $ 95.0

Property, Equipment, and Capi_2

Property, Equipment, and Capitalized Software (Tables)	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Schedule of Property, Equipment, and Capitalized Software by Major Category	The following table shows our property, equipment, and capitalized software, net summarized by major category: As of December 31 (in millions) 2020 2019 Capitalized software $ 390.2 $ 328.3 Capitalized equipment 74.6 70.1 Furniture and fixtures 35.6 33.7 Leasehold improvements 96.0 92.1 Telephone equipment 2.4 2.3 Construction in progress 8.6 5.5 Property, equipment, and capitalized software, at cost 607.4 532.0 Less accumulated depreciation (452.3) (377.3) Property, equipment, and capitalized software, net $ 155.1 $ 154.7
Summary of Depreciation Expense	The following table summarizes our depreciation expense: (in millions) 2020 2019 2018 Depreciation expense $ 80.1 $ 81.2 $ 76.0

Leases Leases (Tables)

Leases Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases, Operating [Abstract]
Summary of Operating Lease Assets and Lease Liabilities	The following table summarizes our operating lease assets and lease liabilities: Leases (in millions) Balance Sheet Classification As of December 31, 2020 As of December 31, 2019 Assets Operating Operating lease assets $ 147.7 $ 144.8 Liabilities Operating Operating lease liabilities, current $ 39.9 $ 35.8 Operating Operating lease liabilities, non-current 137.7 138.7 Total lease liabilities $ 177.6 $ 174.5
Schedule of Minimum Future Rental Commitments	The following table shows our minimum future rental commitments due in each of the next five years and thereafter for operating leases: Minimum Future Lease Commitments (in millions) 2021 $ 47.3 2022 32.0 2023 27.8 2024 21.9 2025 19.8 Thereafter 56.3 Total minimum lease commitments 205.1 Adjustment for discount to present value 27.5 Total $ 177.6
Schedule of Rent Expense	The following table summarizes our weighted-average lease terms and weighted-average discount rates for our operating leases:
Schedule of Deferred Rent	As of December 31, 2020 Weighted-average remaining lease term (in years) 6.6 Weighted-average discount rate 4.3 %

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Schedule of Shares Available for Future Grants	The following table summarizes the number of shares available for future grants under our 2011 Plan: As of December 31 (in millions) 2020 Shares available for future grants 2.5
Schedule of Stock-Based Compensation Expense	The following table summarizes our stock-based compensation expense and the related income tax benefit we recorded in the past three years: Year ended December 31 (in millions) 2020 2019 2018 Restricted stock units $ 22.2 $ 20.4 $ 19.8 Performance share awards 10.2 20.6 10.2 Market stock units 4.2 3.4 1.7 Total stock-based compensation expense $ 36.6 $ 44.4 $ 31.7 Income tax benefit related to the stock-based compensation expense $ 6.7 $ 10.0 $ 7.0
Allocation of Stock-based Compensation Expense	The following table summarizes the stock-based compensation expense included in each of our operating expense categories for the past three years: Year ended December 31 (in millions) 2020 2019 2018 Cost of revenue $ 13.5 $ 12.9 $ 11.7 Sales and marketing 4.6 5.6 3.5 General and administrative 18.5 25.9 16.5 Total stock-based compensation expense $ 36.6 $ 44.4 $ 31.7
Schedule of Uncategorized Stock-Based Compensation Expense	The following table summarizes the amount of unrecognized stock-based compensation expense as of December 31, 2020 and the expected number of months over which the expense will be recognized: Unrecognized stock-based compensation expense (in millions) Weighted average expected amortization period (months) Restricted stock units $ 45.5 34 Market stock units 8.0 26 Total unrecognized stock-based compensation expense $ 53.5 33
Schedule of Restricted Stock Units Award Activity	The following table summarizes restricted stock unit activity during the past three years: Restricted Stock Units (RSUs) Unvested Vested but Total Weighted RSUs Outstanding - December 31, 2017 604,879 3,279 608,158 $ 77.52 Granted 243,614 — 243,614 108.60 Dividend equivalents — 16 16 73.28 Vested (279,774) — (279,774) 80.68 Issued — (3,295) (3,295) 73.28 Forfeited (41,254) — (41,254) 86.47 RSUs Outstanding - December 31, 2018 527,465 — 527,465 $ 89.53 Granted 233,618 — 233,618 135.67 Vested (269,917) — (269,917) 95.67 Forfeited (31,721) — (31,721) 100.71 RSUs Outstanding - December 31, 2019 459,445 — 459,445 $ 108.61 Granted 245,078 — 245,078 153.01 Vested (240,297) — (240,297) 108.94 Forfeited (27,459) — (27,459) 119.22 RSUs Outstanding - December 31, 2020 436,767 — 436,767 $ 132.68
Schedule of Share-based Compensation Arrangement by Share-based Payment Award, Performance-Based Units, Vested and Expected to Vest [Table Text Block]	The table below shows target performance share awards granted and shares that will be issued based on final performance levels for performance share awards granted as of December 31, 2020: As of December 31, 2020 Target performance share awards granted 49,280 Weighted average fair value per award $ 152.17 Number of shares that will be issued based on final 2020 performance levels 67,757 Unamortized expense, based on current performance levels (in millions) $ —
Market Units, Valuation Assumptions	We used the following assumptions to estimate the fair value of our MSUs: Assumptions for Monte Carlo Valuation Model Grant Date Expected volatility Dividend yield Risk-free interest rate May 15, 2017 17.4 % 1.20 % 1.49 % November 15, 2017 17.7 % 1.04 % 1.79 % May 15, 2018 17.4 % 0.89 % 2.70 % November 15, 2018 19.6 % 0.83 % 2.92 % May 15, 2019 20.3 % 0.84 % 2.17 % November 15, 2019 21.0 % 0.72 % 1.59 % May 15, 2020 25.4 % 0.83 % 0.20 % November 15, 2020 26.9 % 0.58 % 0.23 %
Schedule of Market Stocks Units	The table below shows MSUs granted and market stock units outstanding as of December 31, 2020: As of December 31, 2020 MSUs granted during 2020 62,474 Weighted average fair value per award $ 110.78 Number of MSUs outstanding 115,377 Unamortized expense, based on current performance levels (in millions) $ 8.0
Schedule of Stock Options, Valuation Assumptions	The weighted average fair value of options granted during 2011 was $23.81 per share based on the following assumptions: Assumptions for Black-Scholes Option Pricing Model Expected life (years) 7.4 Volatility factor 35.1% Dividend yield 0.35% Interest rate 2.87%
Schedule of All Other Option Granted	The following table summarizes stock option activity in the past three years for our various stock option grants: 2020 2019 2018 Option Grants Underlying Weighted Underlying Weighted Underlying Weighted Options outstanding—beginning of year 37,269 $ 57.28 40,685 $ 57.28 41,685 $ 57.28 Granted — — — — — — Canceled — — — — — — Exercised (33,669) 57.28 (3,416) 57.28 (1,000) 57.28 Options outstanding—end of year 3,600 $ 57.28 37,269 $ 57.28 40,685 $ 57.28 Options exercisable—end of year 3,600 $ 57.28 37,269 $ 57.28 40,685 $ 57.28
Schedule of Intrinsic Value of Stock Options Exercised During Period	The following table summarizes the total intrinsic value (difference between the market value of our stock on the date of exercise and the exercise price of the option) of options exercised: (in millions) 2020 2019 2018 Intrinsic value of options exercised $ 3.9 $ 0.4 $ 0.1
Schedule of Options, Vested and Expected to Vest, Outstanding and Exercisable	The table below shows additional information for options outstanding and exercisable as of December 31, 2020: Options Outstanding Options Exercisable Range of Exercise Prices Number of Options Weighted Weighted Aggregate Exercisable Shares Weighted Average Remaining Contractual Life (years) Weighted Average Exercise Price Aggregate $57.28 3,600 0.37 $ 57.28 $ 0.6 3,600 0.37 $ 57.28 $ 0.6 Vested or Expected to Vest $57.28 3,600 0.37 $ 57.28 $ 0.6

Defined Contribution Plan (Tabl

Defined Contribution Plan (Tables)	12 Months Ended
	Dec. 31, 2020
Defined Contribution Plan [Abstract]
Schedule of Defined Contribution Plan, Employer Matching Contributions	The following table summarizes our matching contributions: (in millions) 2020 2019 2018 401(k) matching contributions $ 14.5 $ 12.0 $ 11.0

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Operating Loss Carryforwards [Line Items]
Schedule of Income Tax Expense and Effective Tax Rate	The following table shows our income tax expense and our effective tax rate for the years ended December 31, 2020, 2019, and 2018: (in millions) 2020 2019 2018 Income before income taxes and equity in net income (loss) of unconsolidated entities $ 283.0 $ 198.5 $ 232.9 Equity in net income (loss) of unconsolidated entities 0.3 (0.9) (2.1) Total $ 283.3 $ 197.6 $ 230.8 Income tax expense $ 59.7 $ 45.6 $ 47.8 Effective tax rate 21.1 % 23.1 % 20.7 %
Schedule of Effective Income Tax Rate Reconciliation	The following table reconciles our income tax expense at the U.S. federal income tax rate to income tax expense as recorded: 2020 2019 2018 (in millions, except percentages) Amount % Amount % Amount % Income tax expense at U.S. federal rate $ 59.5 21.0 % $ 41.5 21.0 % $ 48.5 21.0 % State income taxes, net of federal income tax benefit 9.5 3.4 7.5 3.8 7.4 3.2 Impacts of Tax Reform Act (1) — — — — (2.3) (1.0) Stock-based compensation activity (4.9) (1.7) (2.2) (1.1) (2.6) (1.1) Equity in net income of unconsolidated subsidiaries (including holding gains upon acquisition) (13.8) (4.9) 0.3 0.2 1.0 0.4 Acquisition earn-out 7.6 2.7 — — — — Net change in valuation allowance related to non-U.S. deferred tax assets, primarily net operating losses 2.7 1.0 (2.1) (1.1) (0.2) (0.1) Difference between U.S. federal statutory and foreign tax rates (0.1) — 1.1 0.6 0.2 0.1 Change in unrecognized tax benefits 1.2 0.4 (0.9) (0.5) 1.0 0.4 Credits and incentives (2.2) (0.8) (2.2) (1.1) (3.6) (1.6) Foreign tax provisions (GILTI, FDII, and BEAT) (2) (2.7) (1.0) (1.4) (0.7) (3.7) (1.6) Non-deductible expenses and other, net 2.9 1.0 4.0 2.0 2.1 0.9 Total income tax expense $ 59.7 21.1 % $ 45.6 23.1 % $ 47.8 20.7 % (1) Impacts of the Tax Reform Act (change in U.S. tax rate, deemed mandatory repatriation, and deferred taxes). (2) The Tax Reform Act established the Global Intangible Low-Tax Income (GILTI) provision, which taxes U.S. allocated expenses and certain income from foreign operations; the Foreign-Derived Intangible Income (FDII) provision, which allows a deduction against certain types of U.S. taxable income resulting in a lower effective U.S. tax rate on such income; and the Base Erosion Anti-abuse Tax (BEAT), which is a new minimum tax based on cross-border service payments by U.S. entities.
Schedule of Components of Income Tax Expense	Income tax expense consists of the following: Year ended December 31 (in millions) 2020 2019 2018 Current tax expense: U.S. Federal $ 31.5 $ 28.3 $ 31.0 State 11.7 9.4 11.1 Non-U.S. 23.0 14.0 12.3 Current tax expense 66.2 51.7 54.4 Deferred tax expense (benefit): U.S. Federal 1.2 0.2 (3.0) State 0.4 — (1.7) Non-U.S. (8.1) (6.3) (1.9) Deferred tax expense, net (6.5) (6.1) (6.6) Income tax expense $ 59.7 $ 45.6 $ 47.8
Schedule of Income before Income Tax	The following table provides our income before income taxes and equity in net income (loss) of unconsolidated entities, generated by our U.S. and non-U.S. operations: Year ended December 31 (in millions) 2020 2019 2018 U.S. $ 197.4 $ 159.7 $ 188.2 Non-U.S. 85.6 38.8 44.7 Income before income taxes and equity in net income (loss) of unconsolidated entities $ 283.0 $ 198.5 $ 232.9
Schedule of Deferred Tax Assets and Liabilities	The tax effects of the temporary differences that give rise to the deferred income tax assets and liabilities are as follows: As of December 31 (in millions) 2020 2019 Deferred tax assets: Stock-based compensation expense $ 2.9 $ 7.6 Accrued liabilities 20.6 18.0 Deferred revenue 6.7 5.5 Net operating loss carryforwards - U.S. 0.1 0.2 Net operating loss carryforwards - Non-U.S. 7.9 4.5 Deferred royalty revenue 0.2 0.2 Allowance for doubtful accounts 1.4 1.4 Lease liabilities 32.8 — Deferred rent — 8.0 Other 0.7 0.6 Total deferred tax assets 73.3 46.0 Deferred tax liabilities: Acquired intangible assets (93.9) (82.7) Property, equipment, and capitalized software (25.1) (25.8) Lease right-of-use assets (25.9) — Unrealized exchange gains, net (1.3) (1.1) Prepaid expenses (12.1) (9.1) Investments in unconsolidated entities (6.0) (6.3) Withholding tax - foreign dividends (3.0) (3.0) Total deferred tax liabilities (167.3) (128.0) Net deferred tax liability before valuation allowance (94.0) (82.0) Valuation allowance (2.3) (2.3) Deferred tax liability, net $ (96.3) $ (84.3)
Schedule of Deferred Tax Assets and Liabilities Included in Consolidated Balance Sheets	The deferred tax assets and liabilities are presented in our Consolidated Balance Sheets as follows: As of December 31 (in millions) 2020 2019 Deferred tax asset, net $ 12.6 $ 10.7 Deferred tax liability, net (108.9) (95.0) Deferred tax liability, net $ (96.3) $ (84.3)
Schedule of Gross Unrecognized Tax Benefits	The table below reconciles the beginning and ending amount of the gross unrecognized tax benefits as follows: (in millions) 2020 2019 Gross unrecognized tax benefits - beginning of the year $ 12.6 $ 13.1 Increases as a result of tax positions taken during a prior-year period 0.5 3.0 Decreases as a result of tax positions taken during a prior-year period (2.5) (0.2) Increases as a result of tax positions taken during the current period 1.3 1.2 Decreases relating to settlements with tax authorities — (3.8) Reductions as a result of lapse of the applicable statute of limitations (0.1) (0.7) Gross unrecognized tax benefits - end of the year $ 11.8 $ 12.6
Summary of Income Tax Examinations	The following table summarizes our gross liability for interest and penalties: As of December 31 (in millions) 2020 2019 Liabilities for interest and penalties $ 1.4 $ 1.6
U.S [Member]
Operating Loss Carryforwards [Line Items]
Summary of Operating Loss Carryforwards	The following table summarizes our U.S. net operating loss (NOL) carryforwards: As of December 31 (in millions) 2020 2019 Expiration Dates Expiration Dates U.S. federal NOLs subject to expiration dates $ 0.6 2023 $ 0.8 2023
Non-U.S. [Member]
Operating Loss Carryforwards [Line Items]
Summary of Operating Loss Carryforwards	The following table summarizes our NOL carryforwards for our non-U.S. operations: As of December 31 (in millions) 2020 2019 Non-U.S. NOLs subject to expiration dates from 2021 through 2040 $ 21.7 $ 6.8 Non-U.S. NOLs with no expiration date 11.6 14.6 Total $ 33.3 $ 21.4 Non-U.S. NOLs not subject to valuation allowances $ 24.5 $ 11.7 The change in non-U.S. NOL carryforwards as of December 31, 2020 compared with 2019 primarily reflects NOLs acquired in the Sustainalytics acquisition.

Selected Quarterly Financial _2

Selected Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Data	2020 2019 (in millions except per share amounts) Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Revenue $ 324.0 $ 327.9 $ 357.2 $ 380.4 $ 258.9 $ 273.9 $ 313.8 $ 332.4 Total operating expense 279.5 266.6 312.9 315.3 209.4 223.1 264.2 292.7 Operating income 44.5 61.3 44.3 65.1 49.5 50.8 49.6 39.7 Non-operating (expense) income, net (11.3) 2.6 48.2 (1) 28.3 (1) (3.3) 2.3 13.9 (1) (4.0) Income before income taxes and equity in net (loss) income of unconsolidated entities 33.2 63.9 92.5 93.4 46.2 53.1 63.5 35.7 Equity in net (loss) income of unconsolidated entities (0.8) (0.5) 0.6 1.0 (1.5) 0.7 (1.1) 1.0 Income tax expense 8.5 15.2 16.9 19.1 11.5 11.7 13.3 9.1 Consolidated net income $ 23.9 $ 48.2 $ 76.2 $ 75.3 $ 33.2 $ 42.1 $ 49.1 $ 27.6 Net income per share: Basic $ 0.56 $ 1.13 $ 1.78 $ 1.76 $ 0.78 $ 0.99 $ 1.15 $ 0.64 Diluted $ 0.55 $ 1.12 $ 1.76 $ 1.74 $ 0.77 $ 0.98 $ 1.14 $ 0.64 Dividends per common share: Dividends declared per common share $ 0.30 $ 0.30 $ — $ 0.62 $ 0.28 $ 0.28 $ — $ 0.58 Dividends paid per common share $ 0.30 $ 0.30 $ 0.30 $ 0.30 $ 0.28 $ 0.28 $ 0.28 $ 0.28 Weighted average shares outstanding: Basic 42.9 42.9 42.9 42.9 42.6 42.7 42.8 42.8 Diluted 43.3 43.2 43.2 43.2 43.0 43.1 43.2 43.3 (1) Non-operating income for the third quarter of 2020 includes a $50.9 million holding gain on the previously held equity interest related to our purchase of the remaining interest in Sustainalytics in July 202 0. Non-operating income for the fourth quarter of 2020 includes a $30.0 million gain related to the sale of two equity method investments. Non-operating income for the third quarter of 2019 includes a $19.5 million gain related to the sale of an equity method inve stment.

Description of Business (Detail

Description of Business (Details)	Dec. 31, 2020Countries
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of countries in which entity operates	29

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Business Acquisition [Line Items]
Depreciation expense	$ 80.1	$ 81.2	$ 76
Capitalized software development costs	$ 60.3	$ 64.8	53.5
Intangible assets useful life	10 years	10 years
Property, Equipment, and Depreciation	Property, Equipment, and Depreciation. We state property and equipment at historical cost, net of accumulated depreciation. We depreciate property and equipment using the straight-line method based on the useful life of the asset, which ranges from three
Minimum [Member]
Business Acquisition [Line Items]
Asset useful life	3 years
Intangible assets useful life	1 year
Revenue timing of cash payments	30 days
Revenue performance period	1 year
Revenue, basis over customer's average daily portfolio balance	0.30
Sales commissions, period of transfer	2 years
Maximum [Member]
Business Acquisition [Line Items]
Asset useful life	7 years
Intangible assets useful life	20 years
Revenue timing of cash payments	60 days
Revenue performance period	3 years
Revenue, basis over customer's average daily portfolio balance	0.55
Sales commissions, period of transfer	3 years
Internally developed software expense [Member]
Business Acquisition [Line Items]
Depreciation expense	$ 53.9	$ 61.1	$ 42.8
Capitalized software [Member]
Business Acquisition [Line Items]
Asset useful life	3 years
License-based | Minimum [Member]
Business Acquisition [Line Items]
Revenue performance period	1 year
License-based | Maximum [Member]
Business Acquisition [Line Items]
Revenue performance period	3 years
Asset-based | Minimum [Member]
Business Acquisition [Line Items]
Revenue performance period	1 year
Asset-based | Maximum [Member]
Business Acquisition [Line Items]
Revenue performance period	3 years

Credit Arrangements (Details)

Credit Arrangements (Details) - USD ($)	Jul. 02, 2019	Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019
Line of Credit Facility [Line Items]
Long-term Debt			$ 449,100,000	$ 513,100,000
Long-term debt			449,100,000	502,100,000
Remaining borrowing capacity			300,000,000
Long-term Debt, Current Maturities			0	11,000,000
Long-term Debt, Excluding Current Maturities			449,100,000	502,100,000
London Interbank Offered Rate (LIBOR) [Member] | Credit agreement [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate debt		1.00%
Medium-term Notes [Member] | Term Loan Facility [Member]
Line of Credit Facility [Line Items]
Long-term Debt			100,800,000	443,100,000
Maximum borrowing capacity	$ 450,000,000
Line of Credit [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 750,000,000
Line of Credit [Member] | Credit Agreement [Member] | Maximum [Member] | London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate debt	1.50%
Line of Credit [Member] | Credit Agreement [Member] | Maximum [Member] | Lender's base rate [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate debt	0.50%
Line of Credit [Member] | Credit Agreement [Member] | Minimum [Member] | London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate debt	1.00%
Line of Credit [Member] | Credit Agreement [Member] | Minimum [Member] | Lender's base rate [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate debt	0.00%
Line of Credit [Member] | July 2019 Revolving Credit Facility [Member] | Credit agreement [Member]
Line of Credit Facility [Line Items]
Long-term Debt			0	70,000,000
Maximum borrowing capacity	$ 300,000,000
Line of Credit [Member] | July 2019 Revolving Credit Facility [Member] | Letters of credit [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	50,000,000
Notes Payable, Other Payables | Private Placement Financing
Line of Credit Facility [Line Items]
Long-term Debt			348,300,000	$ 0
Other Long-term Debt			350,000,000
Other Long-term Debt			$ 350,000,000
Line of Credit [Member] | July 2019 Revolving Credit Facility [Member] | Credit agreement [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 100,000,000

Income Per Share (Details)

Income Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Basic net income per share:
Consolidated net income										$ 152	$ 183
Weighted average common shares outstanding (in shares)	42.9	42.9	42.9	42.9	42.8	42.8	42.7	42.6	42.9	42.7	42.6
Basic net income per share (in dollars per share)									$ 5.22	$ 3.56	$ 4.30
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest									$ 223.6	$ 152	$ 183
Diluted net income per share:
Consolidated net income										$ 152	$ 183
Weighted average common shares outstanding (in shares)	42.9	42.9	42.9	42.9	42.8	42.8	42.7	42.6	42.9	42.7	42.6
Net effect of dilutive stock options and restricted stock units (in shares)									0.3	0.5	0.4
Weighted average common shares outstanding for computing diluted income per share (in shares)	43.2	43.2	43.2	43.3	43.3	43.2	43.1	43	43.2	43.2	43
Diluted net income per share (in dollars per share)									$ 5.18	$ 3.52	$ 4.25

Revenue (Disaggregation of Reve

Revenue (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Consolidated revenue	$ 1,389.5	$ 1,179	$ 1,019.9
License-based
Disaggregation of Revenue [Line Items]
Consolidated revenue	934.9	812.7	751.6
Asset-based
Disaggregation of Revenue [Line Items]
Consolidated revenue	223.8	211.6	200.4
Transaction-based
Disaggregation of Revenue [Line Items]
Consolidated revenue	$ 230.8	$ 154.7	$ 67.9

Revenue (Disaggregation of Re_2

Revenue (Disaggregation of Revenue, Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenues	$ 1,389.5	$ 1,179	$ 1,019.9
Minimum [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue performance period	1 year
Maximum [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue performance period	3 years
Licensed-based Revenue
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenues	$ 934.9	812.7	751.6
Licensed-based Revenue | Minimum [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue performance period	1 year
Licensed-based Revenue | Maximum [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue performance period	3 years
Asset-based Revenue
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenues	$ 223.8	$ 211.6	$ 200.4
Asset-based Revenue | Minimum [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue performance period	1 year
Asset-based Revenue | Maximum [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue performance period	3 years

Revenue (Contract Liabilities,

Revenue (Contract Liabilities, Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
Revenue from Contract with Customer [Abstract]
Increase in contract liabilities from cash payments received	$ 58
Contract liability	$ 340.3
Minimum [Member]
Disaggregation of Revenue [Line Items]
Revenue performance period	1 year
Maximum [Member]
Disaggregation of Revenue [Line Items]
Revenue performance period	3 years

Revenue (Contract Liabilities_2

Revenue (Contract Liabilities, Expected Recognition) (Details) $ in Millions	Dec. 31, 2020USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 832.8
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	$ 571.8
Revenue performance 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	$ 153.6
Revenue performance 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	$ 51.8
Revenue performance 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	$ 16.2
Revenue performance period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 6.3
Revenue performance period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 33.1
Revenue performance period

Revenue (Summary of Contract As

Revenue (Summary of Contract Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Accounts receivable, less allowance for credit losses	$ 205.1	$ 188.5
Deferred commissions	39.6	30.4
Total contract assets	$ 244.7	$ 218.9

Revenue Contract Liabilities (D

Revenue Contract Liabilities (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
Revenue from Contract with Customer [Abstract]
Contract with Customer, Liability, Change in Timeframe, Performance Obligation Satisfied, Revenue Recognized	$ 229.8

Segment and Geographical Area_3

Segment and Geographical Area Information (Operating Lease Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Operating lease assets	$ 147.7	$ 144.8
United States [Member]
Segment Reporting Information [Line Items]
Operating lease assets	89.2	86.4
UNITED KINGDOM
Segment Reporting Information [Line Items]
Operating lease assets	15.6	17.9
Europe excluding the United Kingdom [Member]
Segment Reporting Information [Line Items]
Operating lease assets	17	6.3
AUSTRALIA
Segment Reporting Information [Line Items]
Operating lease assets	5.2	5.8
CANADA
Segment Reporting Information [Line Items]
Operating lease assets	7.4	7.5
Asia [Member]
Segment Reporting Information [Line Items]
Operating lease assets	12.6	20.2
Segment, Geographical, Group of Other Countries [Member]
Segment Reporting Information [Line Items]
Operating lease assets	0.7	0.7
Non United States [Member]
Segment Reporting Information [Line Items]
Operating lease assets	$ 58.5	$ 58.4

Segment and Geographical Area_4

Segment and Geographical Area Information (External Revenue and Long-Lived Assets) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 380.4	$ 357.2	$ 327.9	$ 324	$ 332.4	$ 313.8	$ 273.9	$ 258.9	$ 1,389.5	$ 1,179	$ 1,019.9
Long-lived assets	155.1				154.7				155.1	154.7
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									970.8	866.4	764.2
Long-lived assets	127				131.2				127	131.2
UNITED KINGDOM
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									117.5	93.9	72.4
Long-lived assets	7.3				6.9				7.3	6.9
Europe excluding the United Kingdom [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									113.8	88	81.2
Long-lived assets	6.2				2.3				6.2	2.3
AUSTRALIA
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									45.6	39.5	40.9
Long-lived assets	3.7				4.2				3.7	4.2
CANADA
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									101.5	56.9	30.7
Long-lived assets	2.9				2.9				2.9	2.9
Asia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									33.6	27.9	24.5
Long-lived assets	7.5				6.6				7.5	6.6
Segment, Geographical, Group of Other Countries [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									6.7	6.4	6
Long-lived assets	0.5				0.6				0.5	0.6
Non United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									418.7	312.6	$ 255.7
Long-lived assets	$ 28.1				$ 23.5				$ 28.1	$ 23.5

Investments and Fair Value Me_3

Investments and Fair Value Measurements (Classification of Securities) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Available-for-sale	$ 40.5	$ 25.8
Held-to-maturity	1.2	2.3
Trading securities	0	5.3
Total	$ 41.7	$ 33.4

Investments and Fair Value Me_4

Investments and Fair Value Measurements (Gains (Losses) on Investments) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Available-for-sale:
Available-for-sale securities, amortized cost basis	$ 35.5	$ 22.7
Available-for-sale securities, unrealized gain	5	3.1
Available-for-sale securities, unrealized loss	0	0
Available-for-sale securities, current	40.5	25.8
Held-to-maturity:
Held-to-maturity securities, total amortized cost	1.2	2.3
Held-to-maturity securities, unrealized gain	0	0
Held-to-maturity securities, unrealized loss	0	0
Held-to-maturity securities, current	1.2	2.3
Debt Securities, Available-for-sale, Realized Gain (Loss) [Abstract]
Available-for-sale securities, realized gains	2.1	1.2	$ 1.8
Available-for-sale securities, realized losses	0	0	(0.8)
Available-for-sale securities, realized gains, net	2.1	1.2	$ 1
Equity securities and exchange-traded funds
Available-for-sale:
Available-for-sale securities, amortized cost basis	24.6	19
Available-for-sale securities, unrealized gain	4.2	2.9
Available-for-sale securities, unrealized loss	0	0
Available-for-sale	28.8	21.9
Mutual funds
Available-for-sale:
Available-for-sale securities, amortized cost basis	10	3.7
Available-for-sale securities, unrealized gain	0.8	0.2
Available-for-sale securities, unrealized loss	0	0
Available-for-sale	10.8	3.9
Exchange Traded Funds
Available-for-sale:
Available-for-sale securities, amortized cost basis	0.9	0
Available-for-sale securities, unrealized gain	0	0
Available-for-sale securities, unrealized loss	0	0
Available-for-sale	0.9	0
Certificates of deposit [Member]
Held-to-maturity:
Held-to-maturity securities, total amortized cost	1.2	2.3
Held-to-maturity securities, unrealized gain	0	0
Held-to-maturity securities, unrealized loss	0	0
Held-to-maturity securities, current	$ 1.2	$ 2.3

Investments and Fair Value Me_5

Investments and Fair Value Measurements (Cost and Fair Value of Securities) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Available-for-sale Securities, Debt Maturities [Abstract]
Available-for-sale securities, equity securities and mutual funds, amortized cost basis	$ 35.5	$ 22.7
Available-for-sale securities, equity securities and mutual funds, fair value	40.5	25.8
Available-for-sale securities, amortized cost basis	35.5	22.7
Available-for-sale securities, current	40.5	25.8
Debt Securities, Held-to-maturity, Maturity [Abstract]
Held-to-maturity securities, due within one year, net carrying amount	1.2	2.3
Held-to-maturity securities, due within one year, fair value	1.2	2.3
Held-to-maturity securities, due within one year, carrying amount	0	0
Held-to-maturity securities, due within one year, fair value	0	0
Held-to-maturity securities, total amortized cost	1.2	2.3
Held-to-maturity securities, current	$ 1.2	$ 2.3

Investments and Fair Value Me_6

Investments and Fair Value Measurements (Unrealized Gains on Trading Securities) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Unrealized gains (losses), net	$ (0.4)	$ 0.6	$ (0.2)

Investments and Fair Value Me_7

Investments and Fair Value Measurements (Fair Value of Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	$ 0	$ 5.3
Equity securities and exchange-traded funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale	28.8	21.9
Mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale	10.8	3.9
Exchange Traded Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale	0.9	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		5.3
Cash equivalents, fair value disclosure	0.8	0.9
Investments, fair value disclosure	41.3	32
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Equity securities and exchange-traded funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale	28.8	21.9
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale	10.8	3.9
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other Security Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Exchange Traded Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale	0.9
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		0
Cash equivalents, fair value disclosure	0	0
Investments, fair value disclosure	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Equity securities and exchange-traded funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other Security Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Exchange Traded Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		0
Cash equivalents, fair value disclosure	0	0
Investments, fair value disclosure	53.7	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Equity securities and exchange-traded funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other Security Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale	53.7
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Exchange Traded Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale	0
Estimate of Fair Value Measurement [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities		5.3
Cash equivalents, fair value disclosure	0.8	0.9
Investments, fair value disclosure	95	32
Estimate of Fair Value Measurement [Member] | Fair Value, Recurring [Member] | Equity securities and exchange-traded funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale	28.8	21.9
Estimate of Fair Value Measurement [Member] | Fair Value, Recurring [Member] | Mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale	10.8	$ 3.9
Estimate of Fair Value Measurement [Member] | Fair Value, Recurring [Member] | Other Security Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale	53.7
Estimate of Fair Value Measurement [Member] | Fair Value, Recurring [Member] | Exchange Traded Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale	$ 0.9

Acquisitions, Goodwill, and O_3

Acquisitions, Goodwill, and Other Intangible Assets (Narrative) (Details) - USD ($)	Jul. 02, 2020	Jul. 02, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Holding gain on previously held equity interest	$ 50,900,000		$ 50,900,000	$ 0	$ 0
Consideration	$ 75,200,000
Impairment of intangible assets			0	0	0
Goodwill			1,205,000,000	1,039,100,000	556,700,000
Goodwill impairment loss			$ 0	0	$ 0
DBRS [Member]
Business Acquisition [Line Items]
Percentage of voting interests acquired		100.00%
Consideration		$ 682,100,000
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual		127,600,000
Acquisition estimated fair value		682,100,000
Intangible assets		284,100,000
Goodwill		473,300,000
Operating expense		$ 123,500,000
Transaction-related costs				$ 6,500,000
Sustainalytics [Member]
Business Acquisition [Line Items]
Percentage of voting interests acquired	60.00%
Cash paid to acquire the entity	$ 61,200,000
Percentage of voting interest before subsequent acquisition (percent)	40.00%
Equity interest in acquiree, fair value	$ 75,400,000
Consideration	$ 108,600,000
Percentage of voting interest after subsequent acquisition (percent)	40.00%
Goodwill	$ 134,700,000
Business Combination, Contingent Consideration, Asset	27,800,000
Business Combination, Consideration Transferred, Other	24,500,000
Business Combination, Consideration Transferred, Other	24,500,000
Sustainalytics [Member] | Purchase Consideration
Business Acquisition [Line Items]
Business Combination, Contingent Consideration, Asset	$ 47,400,000

Acquisitions, Goodwill, and O_4

Acquisitions, Goodwill, and Other Intangible Assets (Purchase Price Allocation) (Details) (Details) - USD ($) $ in Thousands	Jul. 02, 2020	Jul. 02, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition, Purchase Price Allocation [Abstract]
Consideration	$ 75,200
Accounts receivable and other current assets	79,500
Goodwill			$ 1,205,000	$ 1,039,100	$ 556,700
DBRS [Member]
Business Acquisition, Purchase Price Allocation [Abstract]
Consideration		$ 682,100
Cash and cash equivalents		8,500
Accounts receivable and other current assets		28,800
Deferred revenue		(43,200)
Business Combination, Recognized Identifiable Asset Acquired and Liability Assumed, Other Assets		5,700
Business Combination, Recognized Identifiable Asset Acquired and Liability Assumed, Lease Obligation		(35,000)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities		(66,600)
Acquisition estimated fair value		682,100
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment		12,800
Business Combination, Recognized Identifiable Asset Acquired and Liability Assumed, Operating Lease Asset		33,300
Intangible assets		284,100
Business Combination, Recognized Identifiable Asset Acquired and Liability Assumed, Other Liabilities		(19,600)
Goodwill		$ 473,300
Sustainalytics [Member]
Business Acquisition, Purchase Price Allocation [Abstract]
Consideration	108,600
Equity interest in acquiree, fair value	75,400
Cash and cash equivalents	9,800
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	6,200
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other	5,200
Deferred revenue	(21,200)
Business Combination, Recognized Identifiable Asset Acquired and Liability Assumed, Lease Obligation	(5,200)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities	(16,900)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities	(15,500)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net	$ 49,300
Percentage of voting interest before subsequent acquisition (percent)	40.00%
Goodwill	$ 134,700
Sustainalytics [Member] | Other Assets
Business Acquisition, Purchase Price Allocation [Abstract]
Accounts receivable and other current assets	$ 7,400

Acquisitions, Goodwill, and O_5

Acquisitions, Goodwill, and Other Intangible Assets (Allocation of Acquired Intangible Assets) (Details) - USD ($) $ in Thousands	Jul. 02, 2020	Jul. 02, 2019
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired	$ 79,500
Customer Related Assets
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired	$ 22,900
Weighted Average Useful Life (years)	20 years
Technology-based assets [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired	$ 46,700
Weighted Average Useful Life (years)	10 years
Intell. Property
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired	$ 9,900
Weighted Average Useful Life (years)	10 years
DBRS [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities		$ 66,600
Finite-lived Intangible Assets Acquired		$ 284,100
DBRS [Member] | Customer-related intangible assets [Member]
Business Acquisition [Line Items]
Weighted Average Useful Life (years)		10 years
DBRS [Member] | Customer-related assets [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired		$ 219,100
DBRS [Member] | Technology-based assets [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired		$ 29,400
Weighted Average Useful Life (years)		5 years
DBRS [Member] | Trademarks [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired		$ 35,600
DBRS [Member] | Intellectual property (trademarks and trade names) [Member]
Business Acquisition [Line Items]
Weighted Average Useful Life (years)		7 years

Acquisitions, Goodwill, and O_6

Acquisitions, Goodwill, and Other Intangible Assets (Schedule of Goodwill) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Goodwill [Roll Forward]
Goodwill, Beginning Balance	$ 1,039.1	$ 556.7
Goodwill, Acquired During Period	134.7	473.3
Goodwill, Ending Balance	1,205	1,039.1
Goodwill, Acquired in Other Acquisitions and Foreign Currency Translation Gain (Loss)	$ (31.2)	$ (9.1)

Acquisitions, Goodwill, and O_7

Acquisitions, Goodwill, and Other Intangible Assets (Schedule of Intangible Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross	$ 722.4	$ 610.9
Accumulated Amortization	(342.3)	(277.5)
Net	$ 380.1	$ 333.4
Weighted Average Useful  Life (years)	10 years	10 years
Intellectual property [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	$ 83.6	$ 69.3
Accumulated Amortization	(43.4)	(35.2)
Net	$ 40.2	$ 34.1
Weighted Average Useful  Life (years)	8 years	8 years
Customer-related assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	$ 415.6	$ 377.9
Accumulated Amortization	(163.7)	(130.3)
Net	$ 251.9	$ 247.6
Weighted Average Useful  Life (years)	11 years	11 years
Technology-based assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	$ 223.2	$ 163.7
Accumulated Amortization	(135.2)	(112)
Net	$ 88	$ 51.7
Weighted Average Useful  Life (years)	7 years	7 years

Acquisitions, Goodwill, and O_8

Acquisitions, Goodwill, and Other Intangible Assets (Amortization Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Acquisitions, Goodwill, and Other Intangible Assets [Abstract]
Amortization expense	$ 58.8	$ 36.5	$ 20.7
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2017	61.1
2018	53.1
2019	49.3
2020	43.2
2021	36.6
Thereafter	$ 136.8

Acquisitions, Goodwill, and O_9

Acquisitions, Goodwill, and Other Intangible Assets Acquisition, Goodwill, and Other Intangible Assets - Pro Forma (Details) - DBRS [Member] - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Revenue	$ 1,259.2	$ 1,184.5
Operating income	190.3	223.6
Net income	$ 148.2	$ 179.7
Basic net income per share attributable to Morningstar, Inc. (in dollars per share)	$ 3.47	$ 4.22
Diluted net income per share attributable to Morningstar, Inc. (in dollars per share)	$ 3.43	$ 4.18

Divestitures (Narrative) (Detai

Divestitures (Narrative) (Details) - USD ($) $ in Millions	Jan. 01, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of a product line		$ 0	$ 0	$ 10.5
Gain on sale of a product line		$ 0	$ 0	$ 10.5
Board Consulting Services Product Line | 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 sale of a product line	$ 10.5
Gain on sale of a product line	$ 10.5

Divestitures (Amounts Included

Divestitures (Amounts Included in the Gain on Sale of Business (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	$ 0	$ 0	$ 10.5

Investments in Unconsolidated_3

Investments in Unconsolidated Entities (Details) ¥ / shares in Units, ¥ in Millions, $ in Millions	Nov. 06, 2020USD ($)shares	Oct. 19, 2020USD ($)shares	Oct. 08, 2020USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2020JPY (¥)	Oct. 19, 2020¥ / shares	Dec. 31, 2019JPY (¥)
Schedule of Equity Method Investments [Line Items]
Cost method investments				$ 6.3	$ 3.7
Total investments in unconsolidated entities				32.6	59.6
Cost-method investments, other than temporary impairment				0	0
Equity method investment, other than temporary impairment				0	0
Proceeds from sale of equity method investments, net				35.2	17.6	$ 7.9
Gain on sale of equity method investments				30	19.5	5.6
Proceeds from sale of equity method investments, net				35.2	17.6	7.9
Gain on sale of equity method investments				30	19.5	$ 5.6
Other Equity Method Investments [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investments				7.4	6.6
YCharts [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage						22.00%
Morningstar Japan KK [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investments				$ 18.9	$ 24
Equity method investment, ownership percentage				22.40%	30.40%		22.40%		30.40%
Equity method investment, approximate market value				$ 89.4	$ 95		¥ 9,221.9		¥ 10,319
Proceeds from sale of equity method investments, net	$ 5.1	$ 16
Gain on sale of equity method investments	$ 3.8	$ 12.2
Sale of Stock, Number of Shares Issued in Transaction | shares	1,227,100	3,850,000
Sale of Stock, Price Per Share | ¥ / shares								¥ 437.9
Overallotment Option, Number of Shares Issued in Transaction | shares		1,289,000
Proceeds from sale of equity method investments, net	$ 5.1	$ 16
Gain on sale of equity method investments	$ 3.8	$ 12.2
Sale of Stock, Number of Shares Issued in Transaction | shares	1,227,100	3,850,000
Sale of Stock, Price Per Share | ¥ / shares								¥ 437.9
Overallotment Option, Number of Shares Issued in Transaction | shares		1,289,000
Sustainalytics [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investments				$ 0	$ 25.3
Ellevest [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage						17.00%
Other
Schedule of Equity Method Investments [Line Items]
Proceeds from sale of equity method investments, net			$ 14.3
Gain on sale of equity method investments			14
Proceeds from sale of equity method investments, net			14.3
Gain on sale of equity method investments			$ 14

Property, Equipment, and Capi_3

Property, Equipment, and Capitalized Software (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment, Net [Abstract]
Property, equipment, and capitalized software, at cost	$ 607.4	$ 532
Less accumulated depreciation	(452.3)	(377.3)
Property, equipment, and capitalized software, net	155.1	154.7
Depreciation expense	80.1	81.2	$ 76
Computer equipment [Member]
Property, Plant and Equipment, Net [Abstract]
Property, equipment, and capitalized software, at cost	74.6	70.1
Capitalized software [Member]
Property, Plant and Equipment, Net [Abstract]
Property, equipment, and capitalized software, at cost	390.2	328.3
Furniture and fixtures [Member]
Property, Plant and Equipment, Net [Abstract]
Property, equipment, and capitalized software, at cost	35.6	33.7
Leasehold improvements [Member]
Property, Plant and Equipment, Net [Abstract]
Property, equipment, and capitalized software, at cost	96	92.1
Telephone equipment [Member]
Property, Plant and Equipment, Net [Abstract]
Property, equipment, and capitalized software, at cost	2.4	2.3
Construction in progress [Member]
Property, Plant and Equipment, Net [Abstract]
Property, equipment, and capitalized software, at cost	$ 8.6	$ 5.5

Leases (Schedule of Operating L

Leases (Schedule of Operating Lease Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Operating Leased Assets [Line Items]
Operating lease assets	$ 147.7	$ 144.8
Operating lease liabilities, current	39.9	35.8
Operating lease liabilities, non-current	137.7	138.7
Total lease liabilities	$ 177.6	$ 174.5
Minimum [Member]
Operating Leased Assets [Line Items]
Term of contract	1 year
Maximum [Member]
Operating Leased Assets [Line Items]
Term of contract	13 years

Leases (Operating Leases) (Deta

Leases (Operating Leases) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2020	$ 47.3
2021	32
2022	27.8
2023	21.9
2024	19.8
Thereafter	56.3
Total minimum lease commitments	205.1
Adjustment for discount to present value	$ 27.5
Weighted-average remaining lease term (in years)	6 years 7 months 6 days
Operating lease expense	$ 42.4	$ 33.9	$ 32.5
Variable operating lease charges	14.9	12.7
Payments on operating leases	$ 45.3	33.1
Operating Lease, Weighted Average Discount Rate, Percent	4.30%
Total lease liabilities	$ 177.6	$ 174.5

Stock-Based Compensation (Narra

Stock-Based Compensation (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	12 Months Ended
	May 31, 2011	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation expense		$ 53.5
Expected amortization period (months)		33 months
Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award expiration period		10 years
Restricted stock units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		4 years
Unrecognized stock-based compensation expense		$ 45.5
Expected amortization period (months)		34 months
2004 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option granted	86,106
Fair value per share (in dollars per share)		$ 23.81
Non-employee director [Member] | Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		3 years
Non-employee director [Member] | Restricted stock units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		3 years
Employee [Member] | Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		4 years
PitchBook Plan [Member] | Performance share awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		1 year

Stock-Based Compensation (Share

Stock-Based Compensation (Shares Available for Future Grants) (Details) shares in Millions	Dec. 31, 2020shares
Share-based Payment Arrangement [Abstract]
Shares available for future grants	2.5

Stock-Based Compensation (Alloc

Stock-Based Compensation (Allocation of Stock-Based Compensation Costs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 36.6	$ 44.4	$ 31.7
Income tax benefit related to the stock-based compensation expense	6.7	10	7
Restricted stock units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	22.2	20.4	19.8
Performance share awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	10.2	20.6	10.2
Market Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 4.2	$ 3.4	$ 1.7

Stock-Based Compensation (Unrec

Stock-Based Compensation (Unrecognized Stock-Based Compensation Expense) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Income tax benefit related to the stock-based compensation expense	$ 53.5
Expected amortization period (months)	33 months
Restricted stock units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Income tax benefit related to the stock-based compensation expense	$ 45.5
Expected amortization period (months)	34 months
Market Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Income tax benefit related to the stock-based compensation expense	$ 8
Expected amortization period (months)	26 months

Stock-Based Compensation (Restr

Stock-Based Compensation (Restricted Stock Units Activity) (Details) - Restricted stock units [Member] - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
RSUs Outstanding, Beginning Balance, Unvested	459,445	527,465	604,879
RSUs Outstanding, Beginning Balance, Vested but Deferred	0	0	3,279
RSUs Outstanding, Beginning Balance	459,445	527,465	608,158
RSUs Outstanding, Beginning Balance, Weighted Average Grant Date Value per RSU	$ 108.61	$ 89.53	$ 77.52
Target performance share awards granted	245,078	233,618	243,614
Granted, Vested but Deferred	0	0	0
Granted	245,078	233,618	243,614
Granted, Weighted Average Grant Date Value per RSU	$ 153.01	$ 135.67	$ 108.60
Dividend equivalents, Unvested			0
Dividends equivalents, Vested but Deferred			16
Dividends equivalents			16
Dividends equivalents, Weighted Average Grant Date Value per RSU			$ 73.28
Vested, Unvested	(240,297)	(269,917)	(279,774)
Vested, Vested but Deferred	0	0	0
Vested	(240,297)	(269,917)	(279,774)
Vested, Weighted Average Grant Date Value per RSU	$ 108.94	$ 95.67	$ 80.68
Issued, Unvested			0
Issued, Vested but Deferred			(3,295)
Issued			(3,295)
Issued, Weighted Average Grant Date Value per RSU			$ 73.28
Forfeited, Unvested	(27,459)	(31,721)	(41,254)
Forfeited, Vested but Deferred	0	0	0
Forfeited	(27,459)	(31,721)	(41,254)
Forfeited, Weighted Average Grant Date Value per RSU	$ 119.22	$ 100.71	$ 86.47
RSUs Outstanding, Ending Balance, Unvested	436,767	459,445	527,465
RSUs Outstanding, Ending Balance, Vested but Deferred	0	0	0
RSUs Outstanding, Ending Balance	436,767	459,445	527,465
RSUs Outstanding, Ending Balance, Weighted Average Grant Date Value per RSU	$ 132.68	$ 108.61	$ 89.53

Stock-Based Compensation (Assum

Stock-Based Compensation (Assumptions Used to Estimate Fair Value of Market Units (Details) - Market Stock Units [Member]	Nov. 15, 2020	May 15, 2020	Nov. 15, 2019	May 15, 2019	Nov. 15, 2018	May 15, 2018	Nov. 15, 2017	May 15, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	26.90%	25.40%	21.00%	20.30%	19.60%	17.40%	17.70%	17.40%
Dividend yield	0.58%	0.83%	0.72%	0.84%	0.83%	0.89%	1.04%	1.20%
Risk-free interest rate	0.23%	0.20%	1.59%	2.17%	2.92%	2.70%	1.79%	1.49%

Stock-Based Compensation (Marke

Stock-Based Compensation (Market Units) (Details) - Market Stock Units [Member]	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Market stock units granted (in shares)	62,474
Weighted average fair value per award (in dollars per share) | $ / shares	$ 110.78
Number of target market stock units outstanding (in shares)	115,377

Stock-Based Compensation (Ass_2

Stock-Based Compensation (Assumptions for Black-Scholes Option Pricing Model) (Details) - Stock options [Member]	12 Months Ended
	Dec. 31, 2020
Assumptions for Black-Scholes Option Pricing Model [Line Items]
Expected life (years):	7 years 4 months 24 days
Expected volatility	35.10%
Dividend yield	0.35%
Risk-free interest rate	2.87%

Stock-Based Compensation (Stock

Stock-Based Compensation (Stock Option Activity) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Option exercise price grouping [Member]
Intrinsic Value of Options Exercised [Abstract]
Intrinsic value of options exercised	$ 3.9	$ 0.4	$ 0.1
Option grants excluding options granted at discount [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning Balance, Options, Outstanding, Underlying Shares	37,269	40,685	41,685
Granted, Underlying Shares	0	0	0
Canceled, Underlying Shares	0	0	0
Exercised, Underlying Shares	(33,669)	(3,416)	(1,000)
Ending Balance, Options, Outstanding, Underlying Shares	3,600	37,269	40,685
Options, Weighted Average Exercise Price [Abstract]
Beginning Balance, Options, Outstanding, Weighted Average Exercise Price	$ 57.28	$ 57.28	$ 57.28
Granted, Weighted Average Exercise Price	0	0	0
Canceled, Weighted Average Exercise Price	0	0	0
Expected exercise price:	57.28	57.28	57.28
Ending Balance, Options, Outstanding, Weighted Average Exercise Price	$ 57.28	$ 57.28	$ 57.28
Options, Exercisable, Number of Shares and Weighted Average Exercise Price [Abstract]
Options exercisable - end of year, Underlying Shares	3,600	37,269	40,685
Options exercisable - end of year, Weighted Average Exercise Price	$ 57.28	$ 57.28	$ 57.28

Stock-Based Compensation (Addit

Stock-Based Compensation (Additional Information on Options) (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)$ / sharesshares
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Options Outstanding, Weighted Average Remaining Contractual Life (years)	4 months 13 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	4 months 13 days
Options Outstanding, Weighted Average Remaining Contractual Life (years), Vested or Expected to vest	4 months 13 days
Closing Stock Price Used to Calculate Intrinsic Value	$ 231.57
Range One [Member]
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Expected exercise price:	57.28
Exercise price range, lower range limit	57.28
Exercise price range, upper range limit	$ 59.35
Options Outstanding, Number of Options | shares	3,600
Options Outstanding, Weighted Average Exercise Price	$ 57.28
Options Outstanding, Aggregate Intrinsic Value | $	$ 0.6
Options Exercisable, Exercisable Shares | shares	3,600
Options Exercisable, Weighted Average Exercise Price	$ 57.28
Options Exercisable, Aggregate Intrinsic Value | $	$ 0.6
Option Outstanding, Number of Options, Vested or Expected to Vest | shares	3,600
Options Outstanding, Weighted Average Exercise Price, Vested or Expected to Vest	$ 57.28
Options Outstanding, Average Intrinsic Value, Vested or Expected to Vest | $	$ 0.6

Stock-Based Compensation (Total

Stock-Based Compensation (Total Stock-Based Compensation Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	$ 36.6	$ 44.4	$ 31.7
Cost of revenue [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	13.5	12.9	11.7
Selling and marketing expense [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	4.6	5.6	3.5
General and administrative expense [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	$ 18.5	$ 25.9	$ 16.5

Stock-based Compensation (Pitch

Stock-based Compensation (PitchBook Bonus Plan) (Details) - Performance share awards [Member] $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)$ / sharesshares
PitchBook Plan, Renewal For 2020 To 2022 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuance, aggregate target value	$ 30
Target value of shares expected to be granted in year one	7.5
Target value of shares expected to be granted in year two	7.5
Target value of shares expected to be granted in year three	$ 15
PitchBook Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	1 year
Shares of common stock to be issued for each equity instrument | shares	1
Target performance share awards granted | shares	49,280
Weighted average fair value per award | $ / shares	$ 152.17
Number of shares that will be issued based on final 2020 performance levels | shares	67,757
Unamortized expense, based on current performance levels (in millions)	$ 0

Defined Contribution Plan (Deta

Defined Contribution Plan (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Contribution Plan [Abstract]
401(k) matching contributions	$ 14,500,000	$ 12,000,000	$ 11,000,000
Matching contribution to 401(k) for every dollar	$ 0.75	$ 0.75	$ 0.75
Matching contribution percent to employee's contribution in pay period	7.00%	7.00%	7.00%

Income Taxes (Schedule of Incom

Income Taxes (Schedule of Income Tax Expense and Effective Tax Rate) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income before income taxes and equity in net income (loss) of unconsolidated entities	$ 93.4	$ 92.5	$ 63.9	$ 33.2	$ 35.7	$ 63.5	$ 53.1	$ 46.2	$ 283	$ 198.5	$ 232.9
Equity in net income (loss) of unconsolidated entities	1	0.6	(0.5)	(0.8)	1	(1.1)	0.7	(1.5)	0.3	(0.9)	(2.1)
Income loss from continuing operations before income taxes domestic and foreign									283.3	197.6	230.8
Income tax expense	$ 19.1	$ 16.9	$ 15.2	$ 8.5	$ 9.1	$ 13.3	$ 11.7	$ 11.5	$ 59.7	$ 45.6	$ 47.8
Effective income tax rate									21.10%	23.10%	20.70%

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Contingency [Line Items]
Effective income tax rate (percent)	21.10%	23.10%	20.70%
Effective income tax rate, increase (decrease) from prior year (percent)	2.00%	(2.40%)
Accumulated undistributed earnings from foreign subsidiaries	$ 243.5
Foreign earnings repatriated	45.8
Unrecognized tax benefits included in current liabilities	7.6	$ 10.8
Unrecognized tax benefits included in non-current liabilities	5.1	3
Unrecognized tax benefits, period increase (decrease)	0.8
Result of tax position taken during period	1.2
Increase in income tax expense	1.2
Reductions resulting from settlements and lapse of statute of limitations	0.1
Decrease of unrecognized tax benefits relating to settlements with tax authorities	0.1
Reductions resulting from settlements and lapse statute of limitations, tax effect	0.1
Decreases relating to settlements with tax authorities	0	3.8
Reductions as a result of lapse of the applicable statute of limitations	0.1	0.7
Gross unrecognized tax benefits	11.8	12.6	$ 13.1
Unrecognized tax benefits that would impact effective tax rate	11.8
Decrease in income tax expense upon recognition of gross unrecognized tax benefits	11.6
Foreign Tax Authority [Member]
Income Tax Contingency [Line Items]
Operating loss carryforwards	33.3	21.4
Operating loss carryforwards, not subject to valuation allowances	24.5	11.7
Subject to Expiration Date [Member] | Domestic Tax Authority [Member]
Income Tax Contingency [Line Items]
Operating loss carryforwards	0.6	0.8
Subject to Expiration Date [Member] | Foreign Tax Authority [Member]
Income Tax Contingency [Line Items]
Operating loss carryforwards	21.7	$ 6.8
Valuation Allowance | Foreign Tax Authority [Member]
Income Tax Contingency [Line Items]
Operating Loss Carryforwards, Valuation Allowance	$ 8.8

Income Taxes (Schedule of Effec

Income Taxes (Schedule of Effective Income Tax Rate Reconciliation) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Examination [Line Items]
Income tax expense at U.S. federal rate									$ 59.5	$ 41.5	$ 48.5
Income tax expense at U.S. federal rate, percent									21.00%	21.00%	21.00%
State income taxes, net of federal income tax benefit									$ 9.5	$ 7.5	$ 7.4
State income taxes, net of federal income tax benefit, percent									3.40%	3.80%	3.20%
Impacts of Tax Reform Act									$ 0	$ 0	$ (2.3)
Impacts of Tax Reform Act, percent									0	0	(0.010)
Stock-based compensation activity									$ (4.9)	$ (2.2)	$ (2.6)
Stock-based compensation activity, percent									(1.70%)	(1.10%)	(1.10%)
Equity in net income of unconsolidated subsidiaries (including holding gains upon acquisition)									$ (13.8)	$ 0.3	$ 1
Holding gain upon acquisition of additional ownership of equity method investments, percent									(4.90%)	0.20%	0.40%
Effective Income Tax Rate Reconciliation,Other Reconciling Items, Percent									2.70%	0.00%	0.00%
Effective Income Tax Rate Reconciliation, Other Reconciling Items, Amount									$ 7.6	$ 0	$ 0
Net change in valuation allowance related to non-U.S. deffered tax assets, primarily net operating losses									$ 2.7	$ (2.1)	$ (0.2)
Net change in valuation allowance related to non-U.S. deffered tax assets, primarily net operating losses, percent									1.00%	(1.10%)	(0.10%)
Difference between U.S. federal statutory and foreign tax rates									$ (0.1)	$ 1.1	$ 0.2
Difference between U.S. federal statutory and foreign tax rates, percent									0.00%	0.60%	0.10%
Foreign tax provisions (GILTI, FDII, and BEAT)									$ (2.7)	$ (1.4)	$ (3.7)
Foreign tax provisions (GILTI, FDII, and BEAT), percent									(1.00%)	(0.70%)	(1.60%)
Change in unrecognized tax benefits									$ 1.2	$ (0.9)	$ 1
Changes in unrecognized tax benefits, percent									0.40%	(0.50%)	0.40%
Other tax credits									$ (2.2)	$ (2.2)	$ (3.6)
Other tax credits, percent									(0.80%)	(1.10%)	(1.60%)
Other - net									$ 2.9	$ 4	$ 2.1
Other - net, percent									1.00%	2.00%	0.90%
Income tax expense	$ 19.1	$ 16.9	$ 15.2	$ 8.5	$ 9.1	$ 13.3	$ 11.7	$ 11.5	$ 59.7	$ 45.6	$ 47.8
Income tax expense, percent									21.10%	23.10%	20.70%

Income Taxes (Schedule of Compo

Income Taxes (Schedule of Components of Income Tax Expense) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Federal									$ 31.5	$ 28.3	$ 31
State									11.7	9.4	11.1
Non-U.S.									23	14	12.3
Current tax expense									66.2	51.7	54.4
Federal									1.2	0.2	(3)
State									0.4	0	(1.7)
Non-U.S.									(8.1)	(6.3)	(1.9)
Deferred tax expense (benefit)									(6.5)	(6.1)	(6.6)
Income tax expense	$ 19.1	$ 16.9	$ 15.2	$ 8.5	$ 9.1	$ 13.3	$ 11.7	$ 11.5	$ 59.7	$ 45.6	$ 47.8

Income Taxes (Schedule of Inc_2

Income Taxes (Schedule of Income before Income Taxes and Equity in Net Income of Unconsolidated Entities) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
U.S.									$ 197.4	$ 159.7	$ 188.2
Non-U.S.									85.6	38.8	44.7
Income before income taxes and equity in net loss of unconsolidated entities	$ 93.4	$ 92.5	$ 63.9	$ 33.2	$ 35.7	$ 63.5	$ 53.1	$ 46.2	$ 283	$ 198.5	$ 232.9

Income Taxes (Schedule of Defer

Income Taxes (Schedule of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Stock-based compensation expense	$ 2.9	$ 7.6
Accrued liabilities	20.6	18
Deferred revenue	6.7	5.5
Net operating loss carryforwards - U.S.	0.1	0.2
Net operating loss carryforwards - Non-U.S.	7.9	4.5
Deferred royalty revenue	0.2	0.2
Allowance for doubtful accounts	1.4	1.4
Lease liabilities	32.8	0
Deferred rent	0	8
Other	0.7	0.6
Total deferred tax assets	73.3	46
Deferred tax liabilities:
Acquired intangible assets	(93.9)	(82.7)
Property, equipment and capitalized software	(25.1)	(25.8)
Deferred Tax Liabilities, Leasing Arrangements	(25.9)	0
Unrealized exchange gains, net	(1.3)	(1.1)
Prepaid expenses	(12.1)	(9.1)
Investments in unconsolidated entities	(6)	(6.3)
Deferred Tax Liabilities, Foreign Dividends Withholding Tax	3	3
Total deferred tax liabilities	167.3	128
Net deferred tax liability before valuation allowance	94	82
Valuation allowance	(2.3)	(2.3)
Total deferred tax liabilities	$ (96.3)	$ (84.3)

Income Taxes (Schedule of Def_2

Income Taxes (Schedule of Deferred Tax Assets and Liabilities Included in Consolidated Balance Sheets) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Deferred tax asset, net	$ 12.6	$ 10.7
Deferred tax liability, net	108.9	95
Deferred tax liability, net	$ (96.3)	$ (84.3)

Income Taxes (Summary of Operat

Income Taxes (Summary of Operating Loss Carryforwards - U.S and Non-U.S) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Non-U.S. [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 33.3	$ 21.4
Operating loss carryforwards, not subject to valuation allowances	24.5	11.7
Non-U.S. [Member] | Subject to Expiration Date [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	21.7	6.8
Non-U.S. [Member] | No Expiration Date [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	11.6	14.6
U.S [Member] | Subject to Expiration Date [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 0.6	$ 0.8

Income Taxes (Accounting for Un

Income Taxes (Accounting for Uncertainty in Tax Positions) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Gross unrecognized tax benefits - beginning of the year	$ 12.6	$ 13.1
Increases as a resulting of tax positions taken during a prior-year period	0.5	3
Decreases as a result of tax positions taken during a prior-year period	(2.5)	(0.2)
Increases as a result of tax positions taken during the current period	1.3	1.2
Decreases relating to settlements with tax authorities	0	(3.8)
Reductions as a result of lapse of the applicable statute of limitations	(0.1)	(0.7)
Gross unrecognized tax benefits - end of the year	$ 11.8	$ 12.6

Income Taxes (Summary of Income

Income Taxes (Summary of Income Tax Examinations) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Liabilities for interest and penalties	$ 1.4	$ 1.6

Share Repurchase Program (Detai

Share Repurchase Program (Details)	Dec. 31, 2020USD ($)shares
Equity [Abstract]
Stock repurchase program, authorized amount	$ 500,000,000
Shares repurchased, program life to date, shares | shares	559,105
Shares repurchased, program life to date, value	$ 67,500,000

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements Recent Accounting Pronouncements (Recently Adopted Accounting Pronouncements) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease assets	$ 147.7	$ 144.8
Operating lease liabilities	$ 177.6	$ 174.5
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease assets			$ 118.8
Operating lease liabilities			145.8
Deferred rent			$ 29.7

Selected Quarterly Financial _3

Selected Quarterly Financial Data - Schedule of Quarterly Financial Data (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	Jan. 01, 2018	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue		$ 380.4	$ 357.2	$ 327.9	$ 324	$ 332.4	$ 313.8	$ 273.9	$ 258.9	$ 1,389.5	$ 1,179	$ 1,019.9
Total operating expense		315.3	312.9	266.6	279.5	292.7	264.2	223.1	209.4	1,174.3	989.4	804.1
Operating income		65.1	44.3	61.3	44.5	39.7	49.6	50.8	49.5	215.2	189.6	215.8
Non-operating income (expense), net		28.3	48.2	2.6	(11.3)	(4)	13.9	2.3	(3.3)	67.8	8.9	17.1
Income before income taxes and equity in net income (loss) of unconsolidated entities		93.4	92.5	63.9	33.2	35.7	63.5	53.1	46.2	283	198.5	232.9
Equity in net income (loss) of unconsolidated entities		1	0.6	(0.5)	(0.8)	1	(1.1)	0.7	(1.5)	0.3	(0.9)	(2.1)
Income tax expense		$ 19.1	$ 16.9	$ 15.2	$ 8.5	$ 9.1	$ 13.3	$ 11.7	$ 11.5	59.7	45.6	47.8
Consolidated net income										$ 223.6	$ 152	$ 183
Earnings Per Share, Basic and Diluted [Abstract]
Basic (in dollars per share)		$ 1.76	$ 1.78	$ 1.13	$ 0.56	$ 0.64	$ 1.15	$ 0.99	$ 0.78
Diluted (in dollars per share)		1.74	1.76	1.12	0.55	0.64	1.14	0.98	0.77
Dividends Per Common Share: [Abstract]
Common stock, dividends, per share, declared (in dollars per share)		0.62	0	0.30	0.30	0.58	0	0.28	0.28	$ 1.22	$ 1.14	$ 1.03
Dividends paid per common share (in dollars per share)		$ 0.30	$ 0.30	$ 0.30	$ 0.30	$ 0.28	$ 0.28	$ 0.28	$ 0.28	$ 1.20	$ 1.12	$ 1
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Weighted average common shares outstanding - basic (in shares)		42.9	42.9	42.9	42.9	42.8	42.8	42.7	42.6	42.9	42.7	42.6
Weighted average common shares outstanding - diluted (in shares)		43.2	43.2	43.2	43.3	43.3	43.2	43.1	43	43.2	43.2	43
Gain on sale of a product line										$ 0	$ 0	$ 10.5
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Board Consulting Services Product Line
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Gain on sale of a product line	$ 10.5