Verisk Analytics (VRSK) 10-K 20 Feb 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Feb. 16, 2018	Jun. 30, 2017
Document Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Trading Symbol	VRSK
Entity Registrant Name	Verisk Analytics, Inc.
Entity Central Index Key	1,442,145
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding (in shares)		165,020,572
Entity Public Float			$ 13,053,902,417
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 142.3	$ 135.1
Available-for-sale securities	3.8	3.4
Accounts receivable, net	345.5	263.9
Prepaid expenses	38.1	28.9
Income taxes receivable	28.8	49.3
Other current assets	39.1	20.3
Total current assets	597.6	500.9
Noncurrent assets:
Fixed assets, net	478.3	380.3
Intangible assets, net	1,345.3	1,010.8
Goodwill	3,368.7	2,578.1
Deferred income tax assets	15.9	15.6
Other assets	214.5	145.5
Total assets	6,020.3	4,631.2
Current liabilities:
Accounts payable and accrued liabilities	225.4	184
Short-term debt and current portion of long-term debt	724.4	106.8
Deferred revenues	384.7	330.8
Income taxes payable	3.1	0
Total current liabilities	1,337.6	621.6
Noncurrent liabilities:
Long-term debt	2,284.4	2,280.2
Deferred income tax liabilities	337.8	322.2
Other liabilities	135.1	74.8
Total liabilities	4,094.9	3,298.8
Commitments and contingencies
Stockholders’ equity:
Verisk common stock, $.001 par value; 2,000,000,000 shares authorized; 544,003,038 shares issued and 164,878,930 and 166,915,772 shares outstanding, respectively	0.1	0.1
Additional paid-in capital	2,180.1	2,121.6
Treasury stock, at cost, 379,124,108 and 377,087,266 shares, respectively	(3,150.5)	(2,891.4)
Retained earnings	3,308	2,752.9
Accumulated other comprehensive losses	(412.3)	(650.8)
Total stockholders’ equity	1,925.4	1,332.4
Total liabilities and stockholders’ equity	$ 6,020.3	$ 4,631.2

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock authorized (in shares)	2,000,000,000	2,000,000,000
Common stock issued (in shares)	544,003,038	544,003,038
Common stock outstanding (in shares)	164,878,930	166,915,772
Treasury stock (in shares)	379,124,108	377,087,266

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Revenues	$ 2,145.2	$ 1,995.2	$ 1,760.7
Expenses:
Cost of revenues (exclusive of items shown separately below)	783.8	714.4	612
Selling, general and administrative	322.8	301.6	278.3
Depreciation and amortization of fixed assets	135.6	119.1	96.6
Amortization of intangible assets	101.8	92.5	70.4
Total expenses	1,344	1,227.6	1,057.3
Operating income	801.2	767.6	703.4
Other income (expense):
Investment income and others, net	9.2	6.1	16.9
Gain on derivative instruments	0	0	85.2
Interest expense	(119.4)	(120)	(121.4)
Total other expense, net	(110.2)	(113.9)	(19.3)
Income before income taxes	691	653.7	684.1
Provision for income taxes	(135.9)	(202.2)	(196.6)
Income from continuing operations	555.1	451.5	487.5
Income from discontinued operations (Note 9)	0	253	33.4
Provision for income taxes from discontinued operations	0	(113.3)	(13.3)
Income from discontinued operations	0	139.7	20.1
Net income	$ 555.1	$ 591.2	$ 507.6
Basic net income per share:
Income from continuing operations (in dollars per share)	$ 3.36	$ 2.68	$ 2.95
Income from discontinued operations (in dollars per share)	0	0.83	0.12
Basic net income per share (in dollars per share)	3.36	3.51	3.07
Diluted net income per share:
Income from continuing operations (in dollars per share)	3.29	2.64	2.89
Income from discontinued operations (in dollars per share)	0	0.81	0.12
Diluted net income per share (in dollars per share)	$ 3.29	$ 3.45	$ 3.01
Weighted average shares outstanding:
Basic (in shares)	165,168,224	168,248,304	165,090,380
Diluted (in shares)	168,688,868	171,171,572	168,451,343

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 555.1	$ 591.2	$ 507.6
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustment	227	(395.6)	(162.7)
Unrealized holding gain on available-for-sale securities	0.4	0.3	0.1
Pension and postretirement adjustment	11.1	(13.5)	1.1
Total other comprehensive income (loss)	238.5	(408.8)	(161.5)
Comprehensive income	$ 793.6	$ 182.4	$ 346.1

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Millions	Total	Common Stock [Member]	Unearned KSOP Contributions [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Losses [Member]
Balance (in shares) at Dec. 31, 2014	544,003,038
Balance at Dec. 31, 2014	$ 211	$ 0.1	$ (0.2)	$ 1,171.2	$ (2,533.7)	$ 1,654.1	$ (80.5)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	507.6					507.6
Other comprehensive income/loss	(161.5)						(161.5)
Treasury stock acquired	(20.5)			100	(120.5)
KSOP shares earned (XX shares reissued from treasury stock)	14.1		0.2	13.6	0.3
Shares issued from equity offering	720.9			651.3	69.6
Stock options exercised, including tax benefit	69.2			57.5	11.7
Restricted stock lapsed, including tax benefit	1.3			0.1	1.2
Employee stock purchase plan	1.8			1.6	0.2
Stock based compensation	30.1			30.1
Net share settlement from restricted stock awards	(2.4)			(2.4)
Other stock issuances	$ 0.4			0.4
Balance (in shares) at Dec. 31, 2015	544,003,038
Balance at Dec. 31, 2015	$ 1,372	0.1	0	2,023.4	(2,571.2)	2,161.7	(242)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	591.2					591.2
Other comprehensive income/loss	(408.8)						(408.8)
Treasury stock acquired	(333.3)				(333.3)
KSOP shares earned (XX shares reissued from treasury stock)	14.5			13.2	1.3
Stock options exercised, including tax benefit	66.4			56.2	10.2
Restricted stock lapsed, including tax benefit	1.2				1.2
Employee stock purchase plan	2.3			2.1	0.2
Stock based compensation	29.9			29.9
Net share settlement from restricted stock awards	(3.1)			(3.1)
Other stock issuances	$ 0.1			(0.1)	0.2
Balance (in shares) at Dec. 31, 2016	544,003,038
Balance at Dec. 31, 2016	$ 1,332.4	0.1	0	2,121.6	(2,891.4)	2,752.9	(650.8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	555.1					555.1
Other comprehensive income/loss	238.5						238.5
Treasury stock acquired	(269.8)				(269.8)
Stock options exercised, including tax benefit	37.9			28.7	9.2
Restricted stock lapsed, including tax benefit	0			(1.1)	1.1
Employee stock purchase plan	2.4			2.2	0.2
Stock based compensation	31.8			31.8
Net share settlement from restricted stock awards	(2.9)			(2.9)
Other stock issuances	$ 0			(0.2)	0.2
Balance (in shares) at Dec. 31, 2017	544,003,038
Balance at Dec. 31, 2017	$ 1,925.4	$ 0.1	$ 0	$ 2,180.1	$ (3,150.5)	$ 3,308	$ (412.3)

CONSOLIDATED STATEMENTS OF CHA7

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Treasury stock acquired (in shares)	3,356,360	4,325,548
Tax benefit of stock options exercised		$ 22.1	$ 28
Common stock issued (in shares)	1,125,004	1,409,803	1,739,847
Other stock issuances (in shares)	21,352	26,106	5,844
Number of stock issued during period shares stock options exercised net of taxes (in shares)	36,067	38,250	32,882
Stock Issued During Period, Shares, Other			10,604,000
Restricted Stock [Member]
Tax benefit of stock options exercised		$ 1.2	$ 1.2
Common stock issued (in shares)	143,557	169,365	177,252
Employee Stock Purchase Plan [Member]
Common stock issued (in shares)	29,605	29,867	25,599
Verisk Class A [Member]
Treasury stock acquired (in shares)	3,356,360	4,325,548	1,088,474
Ksop [Member]
Shares issued in period (in shares)			145,007
Treasury Stock [Member] | Ksop [Member]
Shares issued in period (in shares)		181,198	47,686

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income	$ 555.1	$ 591.2	$ 507.6
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of fixed assets	135.6	126.2	120.6
Amortization of intangible assets	101.8	98.4	94.8
Amortization of debt issuance costs and original issue discount	4.2	5	12.9
Provision for doubtful accounts	2	2.4	1.3
KSOP stock based compensation expense	0	14.5	14.1
Stock based compensation	31.8	30	30.5
Gain on derivative instruments	0	0	(85.2)
Gain on sale of subsidiary	0	(265.9)	0
Realized loss on securities, net	0	0.5	0.2
Gain on sale of non-controlling equity investments in non-public companies	0	(1.5)	0
Gain on exercise of common stock warrants	0	0	(15.6)
Deferred income taxes	(73.6)	14.8	(4.1)
Loss on disposal of fixed assets	0.1	1	0.4
Loss on extinguishment of convertible note	0	0	0.5
Changes in assets and liabilities, net of effects from acquisitions:
Accounts receivable	(45.5)	(5.7)	(14.6)
Prepaid expenses and other assets	(30.6)	(26.5)	(2.2)
Income taxes	22.7	8.7	51.6
Accounts payable and accrued liabilities	28.5	(2.6)	(8.8)
Deferred revenues	29.2	(8.2)	(43.5)
Other liabilities	(17.8)	(4.8)	3.3
Net cash provided by operating activities	743.5	577.5	663.8
Cash flows from investing activities:
Acquisitions, net of cash acquired of $29.9 million, $2.1 million and $41.4 million, respectively	(873.3)	(67.7)	(2,858.2)
Proceeds from sale of subsidiary	0	714.6	0
Proceeds from extinguishment of convertible note	0	0	0.4
Escrow funding associated with acquisitions	(41.6)	(6.4)	(83.4)
Proceeds from the settlement of derivative instruments	0	0	85.2
Capital expenditures	(183.5)	(156.5)	(166.1)
Purchases of available-for-sale securities	(0.3)	(0.3)	(0.2)
Proceeds from sales and maturities of available-for-sale securities	0.4	0.5	0.4
Cash received from the exercise of common stock warrants	0	0	15.6
Other investing activities, net	(7.2)	9	0
Net cash (used in) provided by investing activities	(1,105.5)	493.2	(3,006.3)
Cash flows from financing activities:
Proceeds from issuance of long-term debt, net of original issue discount	0	0	1,244
Repayments of current portion of long-term debt	0	0	(170)
Repayments of long-term debt	0	0	(50)
Proceeds from issuance of short-term debt with original maturities greater than three months	455	0	830
Repayment of short-term debt with original maturities greater than three months	0	0	(15)
Proceeds (repayments) from short-term debt, net	160	(770)	(105)
Payment of debt issuance costs	(0.5)	(0.5)	(23.9)
Repurchases of common stock	(276.3)	(326.8)	(20.4)
Net share settlement of taxes from restricted stock awards	(2.9)	(3.1)	(2.4)
Proceeds from stock options exercised	35	41.1	38.8
Proceeds from issuance of stock as part of a public offering	0	0	720.8
Other financing activities, net	(7.8)	(4.9)	(6)
Net cash provided by (used in) financing activities	362.5	(1,064.2)	2,440.9
Effect of exchange rate changes	6.7	(9.7)	0.6
Increase (decrease) in cash and cash equivalents	7.2	(3.2)	99
Cash and cash equivalents, beginning of period	135.1	138.3	39.3
Cash and cash equivalents, end of period	142.3	135.1	138.3
Supplemental disclosures:
Income taxes paid	186.3	289.2	158.5
Interest paid	113.9	116.6	106.1
Noncash investing and financing activities:
Deferred tax liability established on the date of acquisitions	74.4	4.7	213
Tenant improvement allowance	0	0.1	1.6
Capital lease obligations	10.9	11.7	1.7
Capital expenditures included in accounts payable and accrued liabilities	2.9	1.9	2.8
Promissory note [Member]
Noncash investing and financing activities:
Received for sale of discontinued operations	0	82.9	0
Equity Securities [Member]
Noncash investing and financing activities:
Received for sale of discontinued operations	0	8.4	0
Verisk Class A [Member]
Noncash investing and financing activities:
Repurchases of common stock included in accounts payable and accrued liabilities	$ 0	$ 6.5	$ 0

CONSOLIDATED STATEMENTS OF CAS9

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Cash Flows [Abstract]
Net of cash acquired from acquisitions	$ 29.9	$ 2.1	$ 41.4

Organization

Organization	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Organization: Verisk Analytics, Inc. and its consolidated subsidiaries (“Verisk” or the “Company”) is a data analytics provider serving customers in insurance, energy and specialized markets, and financial services. Using various technologies to collect and analyze billions of records, Verisk draws on numerous data assets and domain expertise to provide first-to-market innovations that are integrated into customer workflows. Verisk offers predictive analytics and decision support solutions to customers in rating, underwriting, claims, catastrophe and weather risk, global risk analytics, natural resources intelligence, economic forecasting, and many other fields. Around the world, Verisk helps customers protect people, property, and financial assets. Verisk was established to serve as the parent holding company of Insurance Services Office, Inc. (“ISO”) upon completion of the initial public offering (“IPO”), which occurred on October 9, 2009. ISO was formed in 1971 as an advisory and rating organization for the property and casualty ("P&C") insurance industry to provide statistical and actuarial services, to develop insurance programs and to assist insurance companies in meeting state regulatory requirements. For over the past decade, the Company broadened its data assets, entered new markets, placed a greater emphasis on analytics, and pursued strategic acquisitions. Verisk trades under the ticker symbol “VRSK” on the NASDAQ Global Select Market.

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	Basis of Presentation and Summary of Significant Accounting Policies: The accompanying consolidated financial statements have been prepared on the basis of accounting principles generally accepted in the United States of America (“U.S. GAAP”). The preparation of financial statements in conformity with these accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Significant estimates include acquisition purchase price allocations, the fair value of goodwill, the realization of deferred tax assets, acquisition related liabilities, fair value of stock based compensation for stock options granted, and assets and liabilities for pension and postretirement benefits. Actual results may ultimately differ from those estimates. Certain reclassifications have been made to assets and liabilities for pension and postretirement benefits and cash flows from investing activities within the consolidated financial statements and in the notes to conform to the respective 2017 presentation. As of March 31, 2016, the Company's healthcare business qualified as assets held-for-sale. The healthcare business was sold on June 1, 2016. The results of operations for the Company's healthcare business are reported as discontinued operations for the years ended December 31, 2016 and 2015 (See Note 9). As of December 31, 2017 , the Company simplified the presentation of its consolidated financial statements. Amounts, except for share and per share data, are presented in millions. Significant accounting policies include the following: (a) Intercompany Accounts and Transactions The consolidated financial statements include the accounts of Verisk. All intercompany accounts and transactions have been eliminated. (b) Revenue Recognition The following describes the Company’s primary types of revenues and the applicable revenue recognition policies. The Company’s revenues are primarily derived from the sales of services and revenue is recognized as services are performed and information is delivered to customers. Revenue is recognized when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, fees and/or price is fixed or determinable, and collectability is reasonably assured. Revenue is recognized net of applicable sales tax withholdings. Industry-Standard Insurance Programs Industry-standard insurance programs, statistical agent and data services and actuarial services are sold to participating insurance company customers under annual agreements covering a calendar year where the price is determined at the inception of the agreement. In accordance with Accounting Standards Codification (“ASC”) 605, Revenue Recognition, the Company recognizes revenue ratably over the term of these annual agreements, as services are performed and continuous access to information is provided over the entire term of the agreements. Property-Specific Rating and Underwriting Information The Company provides property-specific rating information through reports issued for specific commercial properties, for which revenue is recognized when the report is delivered to the customer, provided that all other revenue recognition criteria are met. In addition, the Company provides hosting or software solutions that provide continuous access to information about the properties being insured and underwriting information in the form of standard policy forms to be used by customers. As the customer has a contractual right to take possession of the software without significant penalty, revenues from these arrangements are recognized ratably over the contract period from the time when the customer had access to the solution in accordance with ASC 985-605, Software Revenue Recognition (“ASC 985-605”). The Company recognizes software license revenue when the arrangement does not require significant production, customization or modification of the software and the following criteria are met: persuasive evidence of an agreement exists, delivery has occurred, fees are fixed or determinable, and collections are probable. These software arrangements include post-contract customer support (“PCS”). The Company recognizes software license revenue ratably over the duration of the annual license term as vendor specific objective evidence (“VSOE”) of PCS, the only remaining undelivered element, cannot be established in accordance with ASC 985-605. The PCS associated with these arrangements is coterminous with the duration of the license term. Insurance Insurance services primarily consist of term-based software licenses. These software arrangements include PCS, which includes unspecified upgrades on a when-and-if available basis. The Company recognizes software license revenue ratably over the duration of the annual license term as VSOE of PCS, the only remaining undelivered element, cannot be established in accordance with ASC 985-605. The PCS associated with these arrangements is coterminous with the duration of the license term. In certain instances, the customers are billed for access on a monthly basis for the term-based software licenses and the Company recognizes revenue accordingly. There are also services within insurance, which are comprised of transaction-based fees recognized as information is delivered to customers, provided that all other revenue recognition criteria have been met. Financial Services Financial services include various types of services to customers. The Company primarily recognizes revenue ratably for these services over the term of the agreements, as services are performed and continuous service is provided over the entire term of the agreements. In addition, there are certain services which are comprised of transaction-based fees; in these instances, revenue is recognized as information is delivered to customers, provided that all other revenue recognition criteria have been met. Energy and Specialized Markets The Company provides hosting solutions that give continuous access to research information such as data analytics and commercial intelligence for the energy, chemicals, metals and mining verticals. For the hosting arrangements, whereby the customer does not have the right to take possession of the software, which include PCS throughout the hosting term, revenues from these multiple element arrangements are recognized in accordance with ASC 605-25, Revenue recognition — Multiple element arrangements ("ASC 605-25"). The Company recognizes revenue ratably over the duration of the license term, since the contractual elements do not have stand alone value. Specialized markets consist of term-based software licenses. These software arrangements include PCS, which includes unspecified upgrades on a when-and-if available basis. The Company recognizes software license revenue ratably over the duration of the annual license term as VSOE of PCS, the only remaining undelivered element, cannot be established in accordance with ASC 985-605. The PCS associated with these arrangements is coterminous with the duration of the license term. In certain instances, the customers are billed for access on a monthly basis for the term-based software licenses and the Company recognizes revenue accordingly. In addition, specialized markets are comprised of transaction-based fees recognized as information is delivered to customers, provided that all other revenue recognition criteria have been met. The Company services long-term contract arrangements with certain customers. For these arrangements, revenue is recognized in accordance with ASC 605-35, Revenue Recognition — Construction-Type and Production-Type Contracts (“ASC 605-35”), using the percentage-of-completion method, which requires the use of estimates. In such instances, management is required to estimate the input measures, based on hours incurred to date compared to total estimated hours of the project, with consideration also given to output measures, such as contract milestones, when applicable. Adjustments to estimates are made in the period in which the facts requiring such revisions become known. Accordingly, recognized revenues and profits are subject to revisions as the contract progresses to completion. The Company considers the contract substantially complete when there is compliance with all performance specifications and there are no remaining costs or potential risk. There are also services within energy and specialized markets, which are comprised of transaction-based fees recognized as information is delivered to customers, provided that all other revenue recognition criteria have been met. (c) Deferred Revenues The Company invoices its customers in annual, quarterly, monthly, or milestone installments. Amounts billed and collected in advance of earnings are recorded as “Deferred revenues” in the accompanying consolidated balance sheets and are recognized as the services are performed and the applicable revenue recognition criteria are met. (d) Fixed Assets and Finite-lived Intangible Assets Property and equipment, internal-use software and finite-lived intangibles are stated at cost less accumulated depreciation and amortization, which are computed on a straight-line basis over their estimated useful lives. Leasehold improvements are amortized over the shorter of the useful life of the asset or the lease term. The Company’s internal software development costs primarily relate to internal-use software. Such costs are capitalized in the application development stage in accordance with ASC 350-40, Internal-use Software . The Company also capitalizes software development costs upon the establishment of technological feasibility for a product in accordance with ASC 985-20, Software to be Sold, Leased, or Marketed (“ASC 985-20”). Software development costs are amortized on a straight-line basis over a three -year period, which management believes represents the useful life of these capitalized costs. In accordance with ASC 360, Property, Plant & Equipment , whenever events or changes in circumstances indicate that the carrying amount of long-lived assets and finite-lived intangible assets may not be recoverable, the Company reviews its long-lived assets and finite-lived intangible assets for impairment by first comparing the carrying value of the assets to the sum of the undiscounted cash flows expected to result from the use and eventual disposition of the assets. If the carrying value exceeds the sum of the assets’ undiscounted cash flows, the Company estimates and recognizes an impairment loss by taking the difference between the carrying value and fair value of the assets. (e) Capital and Operating Leases The Company leases various property, plant and equipment. Leased property is accounted for under ASC 840, Leases (“ASC 840”). Accordingly, leased property that meets certain criteria is capitalized and the present value of the related lease payments is recorded as a liability. Amortization of assets accounted for as capital leases is computed utilizing the straight-line method over the shorter of the remaining lease term or the estimated useful life (principally three to four years for computer equipment and automobiles). All other leases are accounted for as operating leases. Rent expense for operating leases, which may have rent escalation provisions or rent holidays, is recorded on a straight-line basis over the non-cancelable lease period in accordance with ASC 840. The initial lease term generally includes the build-out period, where no rent payments are typically due under the terms of the lease. The difference between rent expensed and rent paid is recorded as deferred rent. Construction allowances received from landlords are recorded as a deferred rent credit and amortized to rent expense over the term of the lease. (f) Fair Value of Financial and Non-financial Instruments The Company follows the provisions of ASC 820-10, Fair Value Measurements (“ASC 820-10”), which defines fair value, establishes a framework for measuring fair value under U.S. GAAP and expands fair value measurement disclosures. The Company follows the provisions of ASC 820-10 for its financial assets and liabilities recognized or disclosed at fair value on a recurring basis. The Company follows the provisions of ASC 820-10 for its non-financial assets and liabilities recognized or disclosed at fair value. (g) Accounts Receivable and Allowance for Doubtful Accounts Accounts receivable is generally recorded at the invoiced amount. The allowance for doubtful accounts is estimated based on an analysis of the aging of the accounts receivable, historical write-offs, customer payment patterns, individual customer creditworthiness, current economic trends, and/or establishment of specific reserves for customers in adverse financial condition. The Company assesses the adequacy of the allowance for doubtful accounts on a quarterly basis. (h) Foreign Currency The Company has determined local currencies are the functional currencies of the foreign operations. The assets and liabilities of foreign subsidiaries are translated at the period-end rate of exchange and statement of operations items are translated at the average rates prevailing during the year. The resulting translation adjustment is recorded as a component of “Accumulated other comprehensive losses” in the accompanying consolidated statements of changes in stockholders’ equity. (i) Stock Based Compensation The Company follows ASC 718, Stock Compensation (“ASC 718”). Under ASC 718, stock based compensation cost is measured at the grant date, based on the fair value of the awards granted, and is recognized as expense over the requisite service period. Other equity awards, including restricted stock, are valued at the closing price of the Company’s common stock on the grant date. Restricted stock generally has a service vesting period of four years and the Company recognizes the expense ratably over this service vesting period. The Company estimates expected forfeitures of equity awards at the date of grant and recognizes compensation expense only for those awards expected to vest. The forfeiture assumption is ultimately adjusted to the actual forfeiture rate. Changes in the forfeiture assumptions may impact the total amount of expense ultimately recognized, as well as the timing of expense recognized over the requisite service period. The payment of taxes related to the vesting is recorded as a reduction to additional paid-in-capital. This transaction is reflected within "Net share settlement of restricted stock awards" within cash flows from financing activities in the accompanying consolidated statements of cash flows. The Company adopted Accounting Standards Update (“ASU”) No. 2016-09, Improvements to Employee Share-Based Payment Accounting (“ASU No. 2016-09”) on January 1, 2017. Excess tax benefit from exercised stock options is recorded as an income tax benefit in the accompanying consolidated statements of operations. This tax benefit is calculated as the excess of the intrinsic value of options exercised over the compensation recognized for financial reporting purposes. The amount of the tax benefit that has been realized is presented as an operating cash inflow within the accompanying consolidated statements of cash flows. (j) Research and Development Costs Research and development costs, which are primarily related to personnel and related overhead costs incurred in developing new services for customers, are expensed as incurred. Such costs were $37.4 million , $27.4 million and $20.6 million for the years ended December 31, 2017 , 2016 and 2015 , respectively, and were included in the accompanying consolidated statements of operations. (k) Advertising Costs Advertising costs, which are primarily associated with promoting the Company’s brand, names and solutions provided, are expensed as incurred. Such costs were $6.9 million , $6.5 million and $5.9 million for the years ended December 31, 2017 , 2016 and 2015 , respectively. (l) Income Taxes The Company accounts for income taxes under the asset and liability method under ASC 740, Income Taxes (“ASC 740”), which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. Deferred tax assets are recorded to the extent these assets are more likely than not to be realized. In making such determination, the Company considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax planning strategies and recent financial operations. Valuation allowances are recognized to reduce deferred tax assets if it is determined to be more likely than not that all or some of the potential deferred tax assets will not be realized. The Company follows ASC 740-10, Income Taxes (“ASC 740-10”) , which clarifies the accounting for uncertainty in income taxes recognized in the financial statements. ASC 740-10 provides that a tax benefit from an uncertain tax position may be recognized based on the technical merits when it is more likely than not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes. Income tax positions must meet a more likely than not recognition threshold in accordance with ASC 740-10. This standard also provides guidance on measurement, derecognition, classification, interest and penalties, accounting in interim periods, disclosure, and transition. The Company recognizes interest and penalties related to unrecognized tax benefits within the income tax expense line in the accompanying consolidated statements of operations. Accrued interest and penalties are included within “Other liabilities” on the accompanying consolidated balance sheets. (m) Earnings Per Share Basic and diluted earnings per share (“EPS”) are determined in accordance with ASC 260, Earnings per Share , which specifies the computation, presentation and disclosure requirements for EPS. Basic EPS excludes all dilutive common stock equivalents. It is based upon the weighted average number of common shares outstanding during the period. Diluted EPS, as calculated using the treasury stock method, reflects the potential dilution that would occur if the Company’s dilutive outstanding stock options and stock awards were issued. (n) Pension and Postretirement Benefits The Company accounts for its pension and postretirement benefits under ASC 715, Compensation — Retirement Benefits (“ASC 715”). ASC 715 requires the recognition of the funded status of a benefit plan in the balance sheet, the recognition in other comprehensive income (loss) of gains or losses and prior service costs arising during the period, but which are not included as components of periodic benefit cost or credit, and the measurement of defined benefit plan assets and obligations as of the balance sheet date. The Company utilizes a valuation date of December 31. (o) Product Warranty Obligations The Company provides warranty coverage for certain of its solutions. The Company recognizes a product warranty obligation when claims are probable and can be reasonably estimated. As of December 31, 2017 and 2016 , product warranty obligations were not material. In the ordinary course of business, the Company enters into numerous agreements that contain standard indemnities whereby the Company indemnifies another party for breaches of confidentiality, infringement of intellectual property or gross negligence. Such indemnifications are primarily granted under licensing of computer software. Most agreements contain provisions to limit the maximum potential amount of future payments that the Company could be required to make under these indemnifications; however, the Company is not able to develop an estimate of the maximum potential amount of future payments to be made under these indemnifications as the triggering events are not subject to predictability. (p) Loss Contingencies The Company accrues for costs relating to litigation, claims and other contingent matters when such liabilities become probable and reasonably estimable. Such estimates are based on management’s judgment. Actual amounts paid may differ from amounts estimated, and such differences will be charged to operations in the period in which the final determination of the liability is made. (q) Goodwill Goodwill represents the excess of acquisition costs over the fair value of tangible net assets and identifiable intangible assets of the businesses acquired. Goodwill and intangible assets deemed to have indefinite lives are not amortized. Intangible assets determined to have finite lives are amortized over their useful lives. Goodwill and intangible assets with indefinite lives are subject to impairment testing annually as of June 30 or whenever events or changes in circumstances indicate that the carrying amount may not be fully recoverable. The Company completed the required annual impairment test as of June 30, 2017 , which resulted in no impairment of goodwill in 2017 . This test compares the carrying value of each reporting unit to its fair value. If the fair value of the reporting unit exceeds the carrying value of the net assets, including goodwill assigned to that reporting unit, goodwill is not impaired. If the carrying value of the reporting unit’s net assets, including goodwill, exceeds the fair value of the reporting unit, then the Company will determine the implied fair value of the reporting unit’s goodwill. If the carrying value of a reporting unit’s goodwill exceeds its implied fair value, then an impairment loss is recorded for the difference between the carrying amount and the implied fair value of the goodwill. (r) Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2014-09, Revenue from Contracts with Customers (“Topic 606”). Topic 606 replaces numerous requirements in U.S. GAAP, including industry-specific requirements, and provides companies with a single revenue recognition model for recognizing revenue from contracts with customers. The core principle of Topic 606 is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The two permitted transition methods under Topic 606 are the full retrospective method, in which case the standard would be applied to each prior reporting period presented and the cumulative effect of applying the standard would be recognized at the earliest period shown, or the modified retrospective method, in which case the cumulative effect of applying the standard would be recognized at the date of initial application. In July 2015, the FASB approved the deferral of Topic 606's effective date by one year. Topic 606 is effective for annual reporting periods beginning after December 15, 2017. The FASB permits companies to adopt Topic 606 early, but not before the original effective date of the annual reporting periods beginning after December 15, 2016. T he Company established a corporate implementation team, which engaged with cross-functional representatives from all of its business verticals. The Company utilized a bottom-up approach, with the assistance of third party specialists, to analyze the impact of the standard on the contract portfolio by reviewing previous accounting policies and practices to identify potential differences that would result from applying the requirements of Topic 606 to revenue contracts. In addition, the Company identified and is in the process of implementing appropriate changes to its business processes, systems, and controls to support recognition and disclosure under Topic 606. The Company adopted Topic 606 using the modified retrospective approach effective January 1, 2018. The Company’s revenue streams primarily consist of subscription services provided through a hosted environment or by delivering term based software as well as other services including consulting and transactional solutions. Based on the Company's assessment, the analysis of the contract portfolio under Topic 606 results in the revenue for the majority of the Company's customer contracts being recognized over time, as the Company offers most of its solutions through a series of services primarily in a hosted environment, which is consistent with the Company's previous revenue recognition model. For the majority of its contracts, there is continuous transfer of control to the customer and the number of performance obligations under Topic 606 is consistent with those identified under the existing standard. An identified impact of adopting Topic 606 related to the deferral of commissions on revenue contracts, which were previously expensed as incurred but under Topic 606, the majority of such commissions will be capitalized and amortized over a period of time of up to five years. The Company determined the impact of the adoption on both revenue recognition for customer contracts and related commissions to be immaterial on its consolidated financial statements and disclosures. In January 2016, the FASB issued ASU No. 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU No. 2016-01”). The amendments in this update require all equity investments to be measured at fair value with changes in the fair value recognized through net income (other than those accounted for under equity method of accounting or those that result in consolidation of the investee). The amendments allow equity investments that do not have readily determinable fair values to be remeasured at fair value either upon occurrence of an observable price change or upon identification of an impairment. The amendments in ASU No. 2016-01 are effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. For amendments applicable to the Company, early adoption is not permitted. The cumulative-effect adjustment to retained earnings in connection to the adoption of ASU No. 2016-01 was immaterial to the consolidated financial statements as of January 1, 2018. In February 2016, the FASB issued ASU No. 2016-02, Leases ("ASU No. 2016-02"). This ASU amends the existing accounting considerations and treatments for leases through the creation of Topic 842, Leases , to increase transparency and comparability among organizations by requiring the recognition of lease assets and lease liabilities on the balance sheet and the disclosure of key information about lease arrangements. Lessees and lessors are required to disclose qualitative and quantitative information about leasing arrangements to enable a user of the financial statements to assess the amount, timing and uncertainty of cash flows arising from such leases. The amendments in ASU No. 2016-02 are effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years, and allows for modified retrospective adoption with early adoption permitted. The Company has decided not to early adopt the amendments and is presently evaluating changes to its processes to support the implementation of ASU No. 2016-02. The Company is also assessing the impact associated with the adoption of ASU No. 2016-02 on the consolidated balance sheet, which is expected to be material based upon review of the future contractual obligations. In March 2016, the FASB issued ASU No. 2016-08, Principal Versus Agent Considerations (“ASU No. 2016-08”). The amendments to this update are intended to improve the operability and understandability of the implementation guidance on principal versus agent considerations. The amendments in ASU No. 2016-08 are effective for annual reporting periods beginning after December 15, 2017, including interim reporting periods within that reporting period. Earlier application is permitted only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting period. The adoption of ASU No. 2016-08 is not expected to have a material impact on the Company's consolidated financial statements. In March 2016, the FASB issued ASU No. 2016-09, Improvements to Employee Share-Based Payment Accounting (“ASU No. 2016-09”). The objective of this update is to simplify several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. The Company adopted the guidance prospectively for the income statement impact of income taxes and has retrospectively applied the guidance to the condensed consolidated statements of cash flows for the impact of excess tax benefits on January 1, 2017 in accordance with ASU No. 2016-09. The presentation requirements for cash flows related to employee taxes paid for withheld shares had no impact to any of the periods presented in the condensed consolidated statements of cash flows, since such cash flows have historically been presented in financing activities. The treatment of forfeitures has not changed as the Company is electing to continue the current process of estimating the number of forfeitures. Accordingly, excess tax benefits from exercised stock options in 2017 were recorded as income tax benefit in the consolidated statements of operations for the year ended December 31, 2017 and presented as an operating activity on the condensed consolidated statements of cash flows for the years ended December 31, 2017 , 2016 and 2015 . There was no cumulative-effect adjustment required to retained earnings under the prospective method as of the beginning of the year because all tax benefits had been previously recognized when the tax deductions related to stock compensation were utilized to reduce tax payable. The Company did not record any deferred tax assets or tax liabilities as the result of the adoption of ASU 2016-09. In April 2016, the FASB issued ASU No. 2016-10, Identifying Performance Obligations and Licensing (“ASU No. 2016-10”). The amendments in this update clarify the following two aspects of Topic 606: identifying performance obligations and the licensing implementation guidance, while retaining the related principles for those areas. The amendments in ASU No. 2016-10 are effective for annual reporting periods beginning after December 15, 2017, including interim reporting periods within that reporting period. Earlier application is permitted only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting period. The Company has not elected to early adopt. The Company has been evaluating Topic 606 and refer to discussions above. In May 2016, the FASB issued ASU No. 2016-12, Narrow-Scope Improvements and Practical Expedients ("ASU No. 2016-12"). ASU No. 2016-12 does not change the core principle of the guidance in Topic 606. Rather, this update affects only the narrow scope improvements to the guidance on collectability, noncash consideration, and completed contracts at transition. The effective date and transition requirements for ASU 2016-12 are the same as the effective date and transition requirements for Topic 606. The adoption of ASU No. 2016-12 is not expected to have a material impact on the Company’s consolidated financial statements. In August 2016, the FASB issued ASU No. 2016-15, Classification of Certain Cash Receipts and Cash Payments ("ASU No. 2016-15"). The amendments in this update provide guidance on various specific cash flow issues to reduce diversity in the practice of how certain transactions are classified in the statement of cash flows. ASU No. 2016-15 is effective for fiscal years beginning after December 15, 2017, and interim periods within those

Concentration of Credit Risk

Concentration of Credit Risk	12 Months Ended
	Dec. 31, 2017
Risks and Uncertainties [Abstract]
Concentration of Credit Risk	Concentration of Credit Risk: Financial instruments that potentially expose the Company to credit risk consist primarily of cash and cash equivalents, available for sale securities and accounts receivable, which are generally not collateralized. The Company maintains its cash and cash equivalents in higher credit quality financial institutions in order to limit the amount of credit exposure. The total domestic cash balances are insured by the Federal Deposit Insurance Corporation (“FDIC”) to a maximum amount of $250.0 thousand per bank at December 31, 2017 and 2016 . At December 31, 2017 and 2016 , the Company had cash balances on deposit that exceeded the balance insured by the FDIC limit by approximately $40.6 million and $61.0 million with seven and four banks, respectively. At December 31, 2017 and 2016 , the Company also had cash on deposit with foreign banks of approximately $99.8 million and $73.1 million , respectively. The Company considers the concentration of credit risk associated with its trade accounts receivable to be commercially reasonable and believes that such concentration does not result in the significant risk of near-term severe adverse impacts. The Company’s top fifty customers represent approximately 34.2% of revenues for 2017 , 29.9% for 2016 and 40.8% for 2015 with no individual customer accounting for more than 2.1% of revenues during the year ended December 31, 2017 , 2.0% for 2016 and 2.3% for 2015 . No individual customer comprised more than 2.3% and 3.3% of accounts receivable at December 31, 2017 and 2016 , respectively.

Cash and Cash Equivalents

Cash and Cash Equivalents	12 Months Ended
	Dec. 31, 2017
Cash and Cash Equivalents [Abstract]
Cash and Cash Equivalents	Cash and Cash Equivalents: Cash and cash equivalents consist of cash in banks, commercial paper, money-market funds, and other liquid instruments with original maturities of 90 days or less at the time of purchase.

Accounts Receivable

Accounts Receivable	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Accounts Receivable	Accounts Receivable: Accounts receivable consisted of the following at December 31: 2017 2016 Billed receivables $ 291.4 $ 216.4 Unbilled receivables 58.7 50.9 Total receivables 350.1 267.3 Less allowance for doubtful accounts (4.6 ) (3.4 ) Accounts receivable, net $ 345.5 $ 263.9

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements: Certain assets and liabilities of the Company are reported at fair value in the accompanying consolidated balance sheets. Such assets and liabilities include amounts for both financial and non-financial instruments. To increase consistency and comparability of assets and liabilities recorded at fair value, ASC 820-10 establishes a three-level fair value hierarchy to prioritize the inputs to valuation techniques used to measure fair value. ASC 820-10 requires disclosures detailing the extent to which companies’ measure assets and liabilities at fair value, the methods and assumptions used to measure fair value and the effect of fair value measurements on earnings. In accordance with ASC 820-10, the Company applied the following fair value hierarchy: Level 1 — Assets or liabilities for which the identical item is traded on an active exchange, such as publicly-traded instruments. Level 2 — Assets and liabilities valued based on observable market data for similar instruments. Level 3 — Assets or liabilities for which significant valuation assumptions are not readily observable in the market; instruments valued based on the best available data, some of which is internally-developed, and considers risk premiums that a market participant would require. The following table provides information for such assets and liabilities as of December 31, 2017 and 2016 . The fair values of cash and cash equivalents, accounts receivable, securities accounted for under ASC 323-10-25, accounts payable and accrued liabilities, and short-term debt approximate their carrying amounts because of the short-term nature of these instruments. The following table summarizes fair value measurements by level for cash equivalents and registered investment companies that were measured at fair value on a recurring basis: Quoted Prices December 31, 2017 Registered investment companies (1) $ 3.8 December 31, 2016 Registered investment companies (1) $ 3.4 (1) Registered investment companies are classified as available-for-sale securities and are valued using quoted prices in active markets multiplied by the number of shares owned. The Company has elected to carry its subordinated promissory note receivable and long-term debt at carrying value. The carrying value of the subordinated promissory note receivable represents amortized cost and has been included in "Other assets" in the accompanying consolidated balance sheets. The carrying value of the long-term debt represents amortized cost less unamortized discount and debt issuance costs. The Company assesses the fair value of these financial instruments based on an estimate of interest rates available to the Company for financial instruments with similar features, the Company’s current credit rating and spreads applicable to the Company. The following table summarizes the carrying value and estimated fair value of the long-term debt as of December 31, 2017 and 2016 respectively: Fair Value Hierarchy 2017 2016 Carrying Estimated Carrying Estimated Financial instrument not carried at fair value: Subordinated promissory note receivable Level 2 $ 95.3 $ 83.3 $ 84.1 $ 76.8 Long-term debt excluding capitalized leases Level 2 $ 2,280.6 $ 2,439.8 $ 2,277.3 $ 2,402.6

Fixed Assets

Fixed Assets	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Fixed Assets	Fixed Assets The following is a summary of fixed assets: Useful Life Cost Accumulated Net December 31, 2017 Furniture and office equipment 3-10 years $ 276.2 $ (183.5 ) $ 92.7 Leasehold improvements Lease term 83.1 (40.7 ) 42.4 Purchased software 3 years 123.0 (97.6 ) 25.4 Software development costs 3-7 years 525.3 (230.9 ) 294.4 Leased equipment 3-4 years 35.0 (29.7 ) 5.3 Aircraft equipment 2-10 years 20.4 (2.3 ) 18.1 Total fixed assets $ 1,063.0 $ (584.7 ) $ 478.3 December 31, 2016 Furniture and office equipment 3-10 years $ 238.8 $ (162.5 ) $ 76.3 Leasehold improvements Lease term 66.5 (32.3 ) 34.2 Purchased software 3 years 122.8 (90.9 ) 31.9 Software development costs 3-7 years 404.7 (169.8 ) 234.9 Leased equipment 3-4 years 32.8 (29.8 ) 3.0 Total fixed assets $ 865.6 $ (485.3 ) $ 380.3 Depreciation and amortization of fixed assets for the years ended December 31, 2017 , 2016 and 2015 were $135.6 million , $119.1 million and $96.6 million , of which $58.0 million , $43.6 million and $22.3 million related to amortization of internal-use software development costs, respectively. Amortization expense related to development of software for sale in accordance with ASC 985-20 was $9.5 million , $9.2 million and $9.2 million for the years ended December 31, 2017 , 2016 and 2015 , respectively. The Company had unamortized software development costs that had been capitalized in accordance with ASC 985-20 of $19.4 million , $25.6 million and $12.7 million as of December 31, 2017 , 2016 and 2015 , respectively. Leased equipment includes amounts held under capital leases for automobiles, computer software and computer equipment.

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Acquisitions	Acquisitions 2017 Acquisitions On December 29, 2017, the Company acquired 100 percent of the stock of PowerAdvocate, Inc. ("PowerAdvocate"), a provider of market, cost intelligence, and supply chain solutions serving the energy sector, for a net cash purchase price of $200.4 million , of which $10.0 million represents indemnity escrows. Within the Decision Analytics segment, PowerAdvocate expands the Company's offerings to the energy sector by adding proprietary spend data and cost models and providing insight into customers' cost savings opportunities. The preliminary purchase price allocation of the acquisition is presented in the table below. On December 22, 2017, the Company acquired 100 percent of the asset of Service Software, LLC. ("Service Software"), a provider of business management software for the construction industry, for a net cash purchase price of $6.8 million , of which $0.5 million represents indemnity escrows. Within the Decision Analytics segment, Service Software expands the Company's offerings to the insurance sector by integrating with the existing loss quantification solutions, which makes it possible for restoration professionals to save time by sharing job information, reducing duplicate data entry, and increasing productivity. The preliminary purchase price allocation of the acquisition is presented as part of "Others" in the table below. On November 9, 2017, the Company acquired 100 percent of the stock of Rebmark Legal Solutions Ltd. ("Rebmark"), a provider of injury claims solutions, for a net cash purchase price of $2.5 million , of which $0.2 million represents indemnity escrows. Rebmark has become part of the insurance vertical within the Decision Analytics segment. Rebmark’s solutions aid claimant and defendant lawyers, barristers, and claims handlers with the preparation of schedules of loss, which is useful in complex, high-value injury claims where calculations can be time-consuming and there is greater potential for error. The preliminary purchase price allocation of the acquisition is presented as part of "Others" in the table below. On August 31, 2017, the Company acquired 100 percent of the stock of Lundquist Consulting, Inc. ("LCI"), a provider of risk insight, prediction, and management solutions for banks and creditors, for a net cash purchase price of $150.6 million , of which $12.8 million represents indemnity escrows. LCI has become part of the financial services vertical within the Decision Analytics segment. This acquisition brings together the Company's proprietary data assets and LCI's proprietary time-series data, including consumer and commercial bankruptcies, consumer behavior, and legal and technical terms associated with debtor settlements. The preliminary purchase price allocation of the acquisition is presented in the table below. On August 23, 2017, the Company acquired 100 percent of the stock of Sequel Business Solutions Ltd. ("Sequel"), a provider of commercial and specialty insurance and reinsurance software based in the U.K., for a net cash purchase price of $320.3 million . Sequel has become part of the insurance vertical within the Decision Analytics segment. The acquisition of Sequel further enhances the Company's comprehensive offerings to the global complex commercial and specialty insurance industry, enabling integrated global data analytics through a specialized end-to-end workflow solution. The preliminary purchase price allocation of the acquisition is presented in the table below. On August 3, 2017, the Company acquired 100 percent of the stock of G2 Web Services, LLC ("G2"), a provider of merchant risk intelligence solutions for acquirers, commercial banks, and other payment system providers, for a net cash purchase price of $112.0 million , of which $5.6 million represents indemnity escrows. G2 has become part of the financial services vertical within the Decision Analytics segment. The acquisition of G2 positions the Company to further enhance its offerings to clients and partners, by providing solutions that help fight fraud, transaction laundering, and reputational risk within the global payments and e-commerce ecosystem. The preliminary purchase price allocation of the acquisition is presented in the table below. During the three months ended June 30, 2017, the Company acquired the net assets of Blue Skies Consulting, LLC, ControlCam, LLC, Krawietz Aerial Photography, LLC, Richard Crouse & Associates, Inc., Rocky Mountain Aerial Surveys, Inc., Skyview Aerial Photo, Inc., and Valley Air Photos, LLC (collectively referred to as "Aerial Imagery acquisitions"), a group of similar but unrelated companies, which gives the Company broad geographic coverage of the United States for aerial image capture purposes. The Aerial Imagery acquisitions provide multi-spectral aerial photographic services with expertise in offering digital photogrammetric and remote sensing data for mapping and surveying applications. The purchase consideration consists of an aggregate net cash purchase price of $28.1 million and a holdback of $3.1 million . Within the Company's Decision Analytics segment, the Aerial Imagery acquisitions enable the Company to enhance and maintain its database of images with the required frequency, resolution, and coverage across the United States ("U.S.") to support the Company's objective as the leading provider of loss quantification data, analytics, and decision-support solutions to the insurance industry, and the photogrammetry, surveying, mapping and other related markets. The preliminary purchase price allocation of the acquisition is presented as part of "Others" in the table below. On May 19, 2017, the Comp any acquired 100 percent of the stock o f MAKE Consulting A/S ("MAKE"), a research and advisory business specializing in wind power, for a net cash purchase price of $16.9 million , of which $2.7 million represents indemnity escrows. MAKE has become part of the energy and specialized markets vertical within the Decision Analytics segment. MAKE enhances the Company's offering to existing customers and forms a market analysis and advisory consortium on renewables and the transformation of the global electricity industry. With detailed coverage of power market fundamentals, solar, wind, energy storage, and grid edge technologies, the energy and specialized markets vertical is positioned to bring customers market analysis and insight on the evolution of the energy landscape and provide a comprehensive platform for the future. The preliminary purchase price allocation of the acquisition is presented in the table below. On March 31, 2017, the Company acquired 100 percent of the stock of Fintellix Solutions Private Limited ("Fintellix"), a Bangalore-based data solutions company specializing in the development of data management platforms and regulatory reporting solutions for financial institutions, for a net cash purchase price of $16.9 million , of which $1.8 million represents indemnity escrows. Fintellix has become part of the financial services vertical within the Decision Analytics segment. The acquisition of Fintellix positions the Company to expand the data hosting and regulatory platforms and better address the increasingly complex needs of its customers. The preliminary purchase price allocation of the acquisition is presented in the table below. On February 24, 2017, the Company acquired 100 percent of the stock of Emergent Network Intelligence Limited (“ENI”), a developer in insurance claims efficiency and fraud detection solutions based in the United Kingdom ("U.K."), for a net cash purchase price of $6.1 million , of which $0.5 million represents indemnity escrows. With the acquisition of ENI within the Decision Analytics segment, the Company's customers in the U.K. can take advantage of technologically advanced tools that allow them to improve motor vehicle claims workflow and reduce their costs and exposure to fraud. The preliminary purchase price allocation of the acquisition is presented as part of "Others" in the table below. On February 16, 2017, the Company acquired 100 percent of the stock of Healix International Holdings Limited (“Healix”), a software analytics provider in automated medical risk assessment for the travel insurance industry, for a net cash purchase price of $52.4 million , of which $7.5 million represents indemnity escrows. Healix is within the Company's Risk Assessment segment. The acquisition further expands the Company's offerings for the global insurance industry, providing solutions that are embedded with customer workflows and can help underwrite medical coverage for travelers with greater speed, accuracy, and efficiency. The preliminary purchase price allocation of the acquisition is presented in the table below. On January 21, 2017, the Company acquired 100 percent of the stock of Arium Limited ("Arium") for a net cash purchase price of $1.9 million . Arium specializes in liability risk modeling and decision support. Arium has become part of the insurance vertical within the Decision Analytics segment, and enables the Company to provide its customers with additional modeling solutions and analytics for the casualty market. The preliminary purchase price allocation of the acquisition is presented as part of "Others" in the table below. The preliminary purchase price allocations of the 2017 acquisitions resulted in the following: Healix Fintellix MAKE G2 Sequel LCI Power Others Total Cash and cash equivalents $ 0.9 $ 1.1 $ 1.5 $ 1.0 $ 16.0 $ 1.1 $ 7.7 $ 0.6 $ 29.9 Accounts receivable 0.9 2.1 0.9 3.7 9.5 3.1 8.3 1.9 30.4 Current assets — 0.3 2.7 3.4 1.4 — 0.5 0.8 9.1 Fixed assets — 0.1 — 6.4 7.5 5.7 0.2 12.0 31.9 Intangible assets 24.1 6.6 6.9 45.3 102.4 59.0 99.1 9.7 353.1 Goodwill 32.7 11.7 12.7 71.4 230.0 99.1 162.8 26.1 646.5 Other assets 7.5 2.0 0.1 2.8 — 12.8 10.0 1.2 36.4 Total assets acquired 66.1 23.9 24.8 134.0 366.8 180.8 288.6 52.3 1,137.3 Current liabilities 1.1 1.5 3.3 3.2 9.8 1.1 3.4 0.8 24.2 Deferred revenues 0.1 0.8 1.5 0.4 2.4 0.3 11.0 0.6 17.1 Deferred income taxes, net 4.1 1.8 1.6 14.6 18.3 14.9 18.4 0.7 74.4 Other liabilities 7.5 1.8 — 2.8 — 12.8 47.7 4.2 76.8 Total liabilities assumed 12.8 5.9 6.4 21.0 30.5 29.1 80.5 6.3 192.5 Net assets acquired 53.3 18.0 18.4 113.0 336.3 151.7 208.1 46.0 944.8 Cash acquired (0.9 ) (1.1 ) (1.5 ) (1.0 ) (16.0 ) (1.1 ) (7.7 ) (0.6 ) (29.9 ) Net cash purchase price $ 52.4 $ 16.9 $ 16.9 $ 112.0 $ 320.3 $ 150.6 $ 200.4 $ 45.4 $ 914.9 The preliminary amounts assigned to intangible assets by type for the 2017 acquisitions are summarized in the table below: Weighted Average Useful Life Total Technology-related 10 years $ 99.2 Marketing-related 5 years 20.4 Customer-related 12 years 190.5 Database-related 12 years 43.0 Total intangible assets $ 353.1 The preliminary allocations of the purchase price of these acquisitions are subject to revisions as additional information is obtained about the facts and circumstances that existed as of each acquisition date. The revisions may have an impact on the consolidated financial statements. The allocations of the purchase price will be finalized once all information is obtained, but not to exceed one year from the acquisition date. The primary areas of the purchase price allocation that are not yet finalized relate to fixed assets and operating leases, income and non-income taxes, deferred revenues, the valuation of intangible assets acquired, and residual goodwill. The preliminary amounts assigned to intangible assets by type for these acquisitions were based upon the Company's valuation model and historical experiences with entities with similar business characteristics. The goodwill of $628.2 million associated with the stock purchases of PowerAdvocate, Rebmark, LCI, Sequel, G2, MAKE, Fintellix, ENI, Healix and Arium is not deductible for tax purposes, with the exception of $20.2 million of goodwill attributable to G2. The goodwill of $18.3 million associated with the asset purchases of Service Software and Aerial Imagery acquisitions is deductible for tax purposes. For the year ended December 31, 2017 , the Company incurred transaction costs related to these acquisitions of $6.8 million , which are included within "Selling, general and administrative" expenses in the accompanying consolidated statements of operations. Refer to Note 10. Goodwill and Intangible Assets for further discussion. The 2017 acquisitions were immaterial, both individually and in the aggregate, to the Company's consolidated financial statements for the years ended December 31, 2017 and 2016 and therefore, supplemental information disclosure on an unaudited pro forma basis is not presented. 2016 Acquisitions On November 23, 2016, the Company acquired the net assets of IntelliStance, LLC ("MarketStance"), a provider of market intelligence data and analytics to the property/casualty insurance market, for a net cash purchase price of $8.6 million , of which $0.7 million represents indemnity escrows. MarketStance is within the Company's Risk Assessment segment. MarketStance has built a proprietary analytics model to provide actionable insights on customer's profitability and that enhances the Company's offerings. The final purchase price allocation of the acquisition is combined in the table below. On November 11, 2016, the Company acquired 100 percent of the stock of The GeoInformation Group Limited ("GeoInformation"), a provider of geographic data solutions, for a net cash purchase price of $6.3 million , of which $0.3 million represents indemnity escrows. GeoInformation offers mapping services and geospatial data and analytic solutions to companies and public sector organizations. GeoInformation's resources complement the Company's risk management and predictive analytics capabilities internationally within the Risk Assessment segment. The final purchase price allocation of the acquisition is combined in the table below. On October 20, 2016, the Company acquired 100 percent of the stock of Analyze Re, Inc. ("Analyze Re"), a software analytics provider for the reinsurance and insurance industries, for a net cash purchase price of $9.5 million , of which $1.0 million represents indemnity escrows. Analyze Re has become part of of the Company's Decision Analytics segment and enables the Company to provide its customers with additional real-time pricing, exposure management, and enterprise portfolio roll-up capabilities. The final purchase price allocation of the acquisition is combined in the table below. On August 19, 2016, the Company acquired the data and subscriptions business of Quest Offshore Resources, Inc. ("Quest Offshore"), which supplies market intelligence to the offshore oil and gas sector, for a net cash purchase price of $7.2 million , including a holdback of $0.8 million . The data and subscriptions business has become part of Wood Mackenzie Limited ("Wood Mackenzie") within the Decision Analytics segment and complements its existing upstream analysis expertise. The final purchase price allocation of the acquisition is combined in the table below. On July 26, 2016, the Company acquired 100 percent of the stock of Greentech Media, Inc. (“Greentech Media”), an information services provider for the electricity and renewables sector, for a net cash purchase price of $36.1 million , of which $4.4 million represents indemnity escrows. Greentech Media has become part of Wood Mackenzie within the Decision Analytics segment and enables Wood Mackenzie to provide its customers with market intelligence across several categories, including solar generation, energy storage, and smart grids that react to changes in supply and demand. The final purchase price allocation of the acquisition is combined in the table below. On April 14, 2016, the Company acquired 100 percent of the stock of Risk Intelligence Ireland Limited ("RII"), a provider of fraud detection, compliance, risk control, and process automation services to the Irish insurance industry, for a net cash purchase price of $6.2 million . RII enhances the ability of the Company's Risk Assessment segment to serve the international insurance market. The final purchase price allocation of the acquisition is combined in the table below. The combined final purchase price allocations of the 2016 acquisitions resulted in the following: Total Cash and cash equivalents $ 2.1 Accounts receivable 2.3 Current assets 0.3 Fixed assets 0.2 Intangible assets 30.5 Goodwill 55.4 Other assets 5.7 Total assets acquired 96.5 Current liabilities 2.2 Deferred revenues 7.7 Deferred income taxes, net 3.1 Other liabilities 7.5 Total liabilities assumed 20.5 Net assets acquired 76.0 Less: Cash acquired 2.1 Net cash purchase price $ 73.9 The impacts of finalization of the purchase accounting for MarketStance, GeoInformation, Analyze Re, Quest Offshore, Greentech Media, and RII during the measurement periods in accordance with ASC 805 were not material to the accompanying consolidated statements of operations for the years ended December 31, 2017 and 2016 . The goodwill of $42.9 million associated with the stock purchases of GeoInformation, Analyze Re, Greentech Media and RII is not deductible for tax purposes. The goodwill of $12.5 million associated with MarketStance and Quest Offshore asset acquisitions is deductible for tax purposes. For the year ended December 31, 2016 , the Company incurred transaction costs related to these acquisitions of $1.6 million , which are included within "Selling, general and administrative" expenses in the accompanying consolidated statements of operations. Refer to Note 10. Goodwill and Intangible Assets for further discussion. 2015 Acquisitions On November 20, 2015, the Company acquired 100 percent of the stock of The PCI Group ("PCI"). PCI is a consortium of five specialist companies that offer integrated data and subscriptions research in the chemicals, fibers, films, and plastics sectors. PCI has become part of Wood Mackenzie and continues to provide services to enhance Wood Mackenzie's chemicals capabilities in the Decision Analytics segment. The Company paid a net cash purchase price of $36.8 million after a working capital adjustment of $0.6 million . The final purchase price allocation of the acquisition is presented as “Others” in the table below. On November 6, 2015, the Company acquired 100 percent of the stock of Infield Systems Limited ("Infield"). Infield is a provider of business intelligence, analysis, and research to the oil, gas, and associated marine industries. Infield has become part of Wood Mackenzie and continues to provide services to enhance Wood Mackenzie's upstream and supply chain capabilities in the Decision Analytics segment. The Company paid a net cash purchase price of $14.1 million after a working capital adjustment of $0.3 million . The final purchase price allocation of the acquisition is presented as “Others” in the table below. On May 19, 2015, the Company acquired 100 percent of the stock of Wood Mackenzie for a net cash purchase price of $2,889.6 million , including $78.7 million of an indemnity escrow, which the Company financed through a combination of debt and equity offerings, borrowings under the Company's Credit Facility, and cash on hand. Due to the fact that a portion of the purchase price was funded in pounds sterling and the remainder in U.S. dollars, the Company entered into a foreign currency hedging instrument to purchase pounds sterling. The Company recorded a gain on the hedge of $85.2 million within "Gain on derivative instruments" in the accompanying consolidated statements of operations. The proceeds from the gain were utilized to partially fund the acquisition of Wood Mackenzie. Wood Mackenzie is a global provider of data analytics and commercial intelligence for the energy, chemicals, metals and mining verticals. This acquisition advances the Company’s strategy to expand internationally and positions the Company in the global energy market. Wood Mackenzie is included in the energy and specialized markets vertical, formerly named the specialized markets vertical, of the Decision Analytics segment. The final purchase price allocations of the acquisitions resulted in the following: Wood Mackenzie Others Total Cash and cash equivalents $ 35.4 $ 6.0 $ 41.4 Accounts receivable 80.3 2.0 82.3 Current assets 97.4 0.2 97.6 Fixed assets 71.9 0.3 72.2 Intangible assets 1,112.0 17.2 1,129.2 Goodwill 2,002.4 40.7 2,043.1 Other assets 2.0 5.0 7.0 Total assets acquired 3,401.4 71.4 3,472.8 Current liabilities 122.0 4.1 126.1 Deferred revenues 142.5 2.8 145.3 Deferred income taxes, net 204.3 2.9 207.2 Other liabilities 7.6 4.7 12.3 Total liabilities assumed 476.4 14.5 490.9 Net assets acquired 2,925.0 56.9 2,981.9 Less: Cash acquired 35.4 6.0 41.4 Net cash purchase price $ 2,889.6 $ 50.9 $ 2,940.5 The Company determined the fair values of the assets and liabilities of Wood Mackenzie, Infield and PCI with the assistance of valuations performed by third party specialists, discounted cash flow analysis and estimates made by management. The final amounts assigned to intangible assets by type for the acquisitions are summarized in the table below: Weighted Average Useful Life Total Technology-based 7 years $ 112.0 Marketing-related 20 years 234.1 Customer-related 14 years 284.4 Database-related 20 years 498.6 Total intangible assets $ 1,129.1 The impacts of finalization of the purchase accounting for Wood Mackenzie, Infield and PCI during the measurement periods in accordance with ASC 805 were not material to the accompanying consolidated statements of operations for the years ended December 31, 2016 and 2015 . The goodwill of $2,043.1 million associated with the stock purchases of PCI, Infield and Wood Mackenzie is not deductible for tax purposes. For the year ended December 31, 2015 , the Company incurred transaction costs related to these acquisitions of $27.6 million included within "Selling, general and administrative" expenses and $13.3 million included within "Interest expense" in the accompanying consolidated statements of operations. Refer to Note 10. Goodwill and Intangible Assets for further discussion. Acquisition Escrows Pursuant to the related acquisition agreements, the Company has funded various escrow accounts to satisfy pre-acquisition indemnity and tax claims arising subsequent to the acquisition dates, as well as a portion of the contingent payments. During the year ended December 31, 2017 , the Company released $3.8 million of indemnity escrows, of which $3.2 million related to the acquisition of PCI. During the year ended December 31, 2016 , the Company released $38.0 million of indemnity escrows, of which $37.0 million related to the Wood Mackenzie acquisition. At December 31, 2017 and 2016 , the current portion of the escrows amounted to $22.9 million and $4.1 million , and the noncurrent portion of the escrows amounted to $26.3 million and $6.3 million , respectively. The current and noncurrent portions of the escrows have been included in “Other current assets” and "Other assets" in the accompanying consolidated balance sheets, respectively.

Discontinued Operations

Discontinued Operations	12 Months Ended
	Dec. 31, 2017
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	Discontinued Operations: 2016 Discontinued Operation On June 1, 2016, the Company sold 100 percent of the stock of its healthcare business, Verisk Health ("Verisk Health"), in exchange for a purchase price that consisted of $714.6 million of cash consideration after a working capital adjustment of $5.4 million , a subordinated promissory note with a face value of $100.0 million and an eight year maturity (the "Note"), and other contingent consideration (collectively, the "Sale"). Results of operations for the healthcare business are reported as a discontinued operation for the year ended December 31, 2016 and for all prior periods presented. The Note has a stated interest rate of 9.0% per annum, increasing to 11.0% per annum at the earlier of specified refinancings or acquisitions, or the fourth anniversary of the closing of the Sale. Interest shall accrue from the closing date and on each anniversary of the Sale until the Note is paid in full on the unpaid principal amount of the Note outstanding at the interest rate in effect (computed on the basis of a 360-day year of twelve 30-day months). On each anniversary of the Sale, accrued interest shall be paid in kind by adding the amount of such accrued interest to the outstanding principal amount of the Note. The issuer of the Note may, at its option at any time prior to the maturity date, prepay any, or all, of the principal amount of the Note, plus accrued but unpaid interest as of the elected prepayment date, without any premium or penalty. There is a mandatory prepayment of the Note as a result of (i) the proceeds of a specified dividend recapitalization received by the issuer, (ii) the consummation of a change of control of the issuer, or (iii) the sale, transfer or other disposition by the parent of the issuer of more than 10.0% of the capital stock of the issuer. As of December 31, 2017 , the Company had a receivable of $95.3 million outstanding under the Note. The carrying value of the Note represents amortized cost. The fair value of the Note is based on management estimates with the assistance of valuations performed by third party specialists, discounted cash flow analysis based on current market conditions and assumptions that the Note would be paid in full at maturity, including accrued interest, with no prepayment election. Refer to Note 6. Fair Value Measurements for further discussion. The Company also received a 10.0% non-participating interest in the issuer's stock, the exercise value of which will be contingent on the parent of the issuer realizing a specified rate of return on its investment. As of December 31, 2017 , the Company had an equity investment of $8.4 million related to such interest accounted for in accordance with ASC 323-10-25, The Equity Method of Accounting for Investments in Common Stock ("ASC 323-10-25"). The value of the equity investment has been included in "Other assets" in the accompanying consolidated balance sheets. The healthcare business met the criteria for being reported as discontinued operations and have been segregated from continuing operations. The following table summarizes the results from discontinued operations for the years ended December 31: 2016 2015 Revenues from discontinued operations $ 112.3 $ 307.3 Expenses: Cost of revenues (exclusive of items shown separately below) 75.9 191.3 Selling, general and administrative 36.5 34.3 Depreciation and amortization of fixed assets 7.1 24.0 Amortization of intangibles assets 5.9 24.4 Total expenses 125.4 274.0 Operating income (13.1 ) 33.3 Other income (expense): Gain on sale 265.9 — Investment income and others, net 0.2 0.1 Total other income 266.1 0.1 Income from discontinued operations before income taxes 253.0 33.4 Provision for income taxes (including tax on the gain of $111.8 million for 2016) (113.3 ) (13.3 ) Income from discontinued operations, net of tax $ 139.7 $ 20.1 Net cash provided by operating activities and net cash used in investing activities from the healthcare business for the years ended December 31: 2016 2015 Net cash provided by operating activities $ 21.4 $ 73.2 Net cash used in investing activities $ (10.6 ) $ (27.4 )

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Goodwill and Intangible Assets: The Company completed the required annual impairment test as of June 30, 2017 , 2016 and 2015 , which resulted in no impairment of goodwill. Based on the results of the impairment assessment as of June 30, 2017 , the Company determined that the fair value of its reporting units exceeded their respective carrying value. There were no goodwill impairment indicators after the date of the last annual impairment test. The following is a summary of the change in goodwill from December 31, 2015 through December 31, 2017 , both in total and as allocated to the Company’s operating segments: Risk Decision Total Goodwill at December 31, 2015 (1) $ 55.5 $ 2,697.5 $ 2,753.0 Acquisitions 16.2 43.8 60.0 Purchase accounting reclassifications — 12.8 12.8 Foreign currency translation adjustment (0.4 ) (247.3 ) (247.7 ) Goodwill at December 31, 2016 (1) 71.3 2,506.8 2,578.1 Current year acquisitions 32.7 613.8 646.5 Purchase accounting reclassifications (2.8 ) (1.6 ) (4.4 ) Foreign currency translation adjustment 3.3 145.2 148.5 Goodwill at December 31, 2017 (1) $ 104.5 $ 3,264.2 $ 3,368.7 (1) These balances are net of accumulated impairment charges of $3.2 million that occurred prior to December 31, 2015 . The Company’s intangible assets and related accumulated amortization consisted of the following: Weighted Cost Accumulated Net December 31, 2017 Technology-based 8 years $ 421.0 $ (222.9 ) $ 198.1 Marketing-related 17 years 263.9 (62.9 ) 201.0 Contract-based 6 years 5.0 (5.0 ) — Customer-related 14 years 704.2 (174.0 ) 530.2 Database-based 19 years 474.7 (58.7 ) 416.0 Total intangible assets $ 1,868.8 $ (523.5 ) $ 1,345.3 December 31, 2016 Technology-based 7 years $ 310.9 $ (196.6 ) $ 114.3 Marketing-related 17 years 227.5 (47.5 ) 180.0 Contract-based 6 years 5.0 (5.0 ) — Customer-related 14 years 483.1 (128.5 ) 354.6 Database-based 20 years 393.9 (32.0 ) 361.9 Total intangible assets $ 1,420.4 $ (409.6 ) $ 1,010.8 Amortization expense related to intangible assets for the years ended December 31, 2017 , 2016 and 2015 , was $101.8 million , $92.5 million , and $70.4 million , respectively. Estimated amortization expense in future periods through 2023 and thereafter for intangible assets subject to amortization is as follows: Year Amount 2018 $ 129.1 2019 128.2 2020 126.0 2021 115.5 2022 104.2 2023 and thereafter 742.3 Total $ 1,345.3

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes: Domestic and foreign income from continuing operations before income taxes was as follows: 2017 2016 2015 U.S. $ 669.9 $ 626.6 $ 573.3 Foreign 21.1 27.1 110.8 Total income from continuing operations $ 691.0 $ 653.7 $ 684.1 The components of the provision for income taxes from continuing operations for the years ended December 31 were as follows: 2017 2016 2015 Current: Federal $ 176.6 $ 171.7 $ 168.8 State and local 23.4 24.0 23.9 Foreign 9.5 3.6 3.3 Total current provision for income taxes 209.5 199.3 196.0 Deferred: Federal (66.3 ) 29.4 23.4 State and local 5.7 4.9 1.4 Foreign (13.0 ) (31.4 ) (24.2 ) Total deferred provision for income taxes (73.6 ) 2.9 0.6 Provision for income taxes $ 135.9 $ 202.2 $ 196.6 On December 22, 2017, President Trump signed comprehensive tax legislation commonly referred to as the Tax Cuts and Job Act ("Tax Act"). The Tax Act makes complex changes to the tax law which will impact the 2017 year, including but not limited to 1) a re-measurement of deferred tax assets and liabilities as a result of the corporate tax rate change from 35.0% to 21.0% , 2) 100% bonus depreciation on qualifying property placed in service after September 27, 2017, and 3) requiring a one-time repatriation tax on foreign earnings. Based on the initial analysis of the Tax Act, the Company has made reasonable estimates of its 2017 impact and has recorded provisional adjustments as follows: 1) Due to the federal corporate rate reduction, a re-measurement of deferred tax assets and liabilities resulted in the recording of a benefit of approximately $89.1 million . 2) 100% bonus depreciation on qualifying assets resulted in an estimated decrease to the current income tax payable of approximately $8.0 million . 3) The Company is not expected to be impacted by the one-time repatriation tax on foreign earnings. The Tax Act will also affect 2018 and forward, including but not limited to 1) a reduction in the federal corporate rate from 35.0% to 21.0% , 2) elimination of the corporate alternative minimum tax, 3) creation of a new minimum tax - the base erosion anti-abuse tax ("BEAT"), 4) a general elimination of U.S. federal income taxes on dividends from foreign subsidiaries, 5) a new provision designed to tax global intangible low-taxed income ("GILTI"), 6) a new limitation on deductible interest expense, 7) the repeal of Section 199 domestic production activity deduction, 8) a new limitation on the deductibility of certain executive compensation, 9) limitations on net operating losses ("NOL’s") generated after December 31, 2017, 10) a special deduction for Foreign Derived Intangible Income ("FDII") and various other items. The Company has evaluated the above provisions and other than the reduction in corporate tax rate, it does not believe that the new provisions will have a material impact on the provision for income taxes. The reconciliation between the Company’s effective tax rate on income from continuing operations and the statutory tax rate is as follows for the years ended December 31: 2017 2016 2015 Federal statutory rate 35.0 % 35.0 % 35.0 % State and local taxes, net of federal tax benefit 2.6 % 2.7 % 2.6 % Foreign tax differentials (2.1 )% (4.7 )% (6.8 )% Federal Tax Reform-deferred rate change (12.9 )% — % — % U.K. legislative change — % (1.0 )% (2.1 )% Stock-based compensation (2.5 )% — % — % Other (0.4 )% (1.1 )% — % Effective tax rate for continuing operations 19.7 % 30.9 % 28.7 % The decrease in the effective tax rate in 2017 compared to 2016 was primarily due to lowered federal income tax rates as a result of U.S. Tax Reform and the adoption of ASU No. 2016-09, partially offset by legislation enacted in the U.K. The tax effects of significant items comprising the Company’s deferred tax assets as of December 31 are as follows: 2017 2016 Deferred income tax asset: Employee wages, pension and other benefits $ 15.5 $ 30.1 Deferred rent 3.8 6.3 Net operating loss carryover 36.4 24.3 Capital and other unrealized losses 2.1 3.5 Interest expense 9.1 — Other 8.2 12.3 Total 75.1 76.5 Less valuation allowance (17.6 ) (8.1 ) Deferred income tax asset 57.5 68.4 Deferred income tax liability: Fixed assets and intangible assets (366.2 ) (355.2 ) Other (13.2 ) (19.8 ) Deferred income tax liability (379.4 ) (375.0 ) Deferred income tax liability, net $ (321.9 ) $ (306.6 ) The net deferred income liability of $321.9 million consists primarily of timing differences involving depreciation and amortization. The ultimate realization of the deferred tax assets depends on the Company’s ability to generate sufficient taxable income in the future. The Company has provided a valuation allowance against the deferred tax assets associated with the interest expense deduction limitation in the U.K. The Company has also provided for a valuation allowance against the deferred tax assets associated with the net operating losses of certain subsidiaries. The Company’s net operating loss carryforwards expire as follows: Years Amount 2018-2025 $ 1.9 2026-2030 3.8 2031-2037 205.8 Total $ 211.5 A valuation allowance has been established based on the Company’s evaluation of the likelihood of utilizing these benefits before they expire. The Company has determined that the generation of future taxable income from certain subsidiaries to fully realize the deferred tax assets is uncertain. Other than these items, the Company has determined, based on the Company’s historical operating performance, that taxable income of the Company will more likely than not be sufficient to fully realize the deferred tax assets. As of December 31, 2017, the Company has not made a provision for U.S. or additional foreign withholdings taxes for any additional outside basis difference inherent in its foreign subsidiaries, as these amounts continue to be indefinitely reinvested in foreign operations. Determining the amount of unrecognized deferred tax liability related to any additional outside basis difference in these entities is not practicable. The Company does not rely on these unremitted earnings as a source of funds for its domestic business as it expects to have sufficient cash flow in the U.S. to fund its U.S. operational and strategic needs. The Company follows ASC No. 740-10, which prescribes a comprehensive model for the financial statement recognition, measurement, presentation and disclosure of uncertain tax positions taken or expected to be taken in income tax returns. For each tax position, the Company must determine whether it is more likely than not that the position will be sustained upon examination based on the technical merits of the position, including resolution of any related appeals or litigation. A tax position that meets the more likely than not recognition threshold is then measured to determine the amount of benefit to recognize within the financial statements. No benefits may be recognized for tax positions that do not meet the more likely than not threshold. A reconciliation of the beginning and ending amount of unrecognized tax benefit is as follows: 2017 2016 2015 Unrecognized tax benefit as of January 1 $ 16.8 $ 14.5 $ 10.6 Gross increase in tax positions in prior period 1.7 2.5 7.1 Gross decrease in tax positions in prior period (1.2 ) (0.4 ) (2.6 ) Gross increase in tax positions in current period — 6.4 — Settlements — (5.3 ) (0.3 ) Lapse of statute of limitations (1.0 ) (0.9 ) (0.3 ) Unrecognized tax benefit as of December 31 $ 16.3 $ 16.8 $ 14.5 Of the total unrecognized tax benefits as of December 31, 2017 , 2016 and 2015 , $13.2 million , $13.8 million and $11.4 million , respectively, represent the amounts that, if recognized, would have a favorable effect on the Company’s effective tax rate in any future periods. The total gross amount of accrued interest and penalties for the years ended December 31, 2017 , 2016 and 2015 was $4.5 million , $3.4 million and $2.8 million , respectively. The Company’s practice is to recognize interest and penalties associated with income taxes as a component of “Provision for income taxes” in the accompanying consolidated statements of operations. The Company does not expect a significant increase in unrecognized benefits related to federal, foreign, or state tax exposures within the coming year. In addition, the Company believes that it is reasonably possible that approximately $0.5 million of its currently remaining unrecognized tax positions, each of which is individually insignificant, may be recognized by the end of 2018 as a result of a combination of audit settlements and lapses of statute of limitations, net of additional uncertain tax positions. The Company is subject to tax in the U.S. and in various state and foreign jurisdictions. The Company joined by its domestic subsidiaries, files a consolidated income tax return for the Federal income tax purposes. With few exceptions, none of which are material to the Company’s consolidated financial statements as of December 31, 2017 , the Company is no longer subject to U.S. federal, state, and local or non-US income tax examinations by tax authorities for tax years before 2013. The Internal Revenue Service is conducting an audit of Wood Mackenzie, Inc. for the period January 1, 2014 through May 19, 2015, as well as Verisk Analytics, Inc. & Subsidiaries for tax year ended December 31, 2014. In New Jersey, the Company is being audited for the years ended December 31, 2011 through 2014 with a statute extension until March 31, 2018. The Company is also under audit in Illinois for the year ended December 31, 2014. The Company does not expect that the results of these examinations will have a material effect on its financial position, results of operations or cash flow.

Composition of Certain Financia

Composition of Certain Financial Statement Captions	12 Months Ended
	Dec. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Composition of Certain Financial Statement Captions	Composition of Certain Financial Statement Captions: The following table presents the components of “Other current assets”, “Accounts payable and accrued liabilities” and “Other liabilities” as of December 31: 2017 2016 Other current assets: Acquisition related escrows $ 22.9 $ 4.1 Other current assets 16.2 16.2 Total other current assets $ 39.1 $ 20.3 Accounts payable and accrued liabilities: Accrued salaries, benefits and other related costs $ 115.3 $ 88.6 Escrow liabilities 22.9 4.1 Accrued interest 18.3 17.0 Trade accounts payable and other accrued expenses 68.9 74.3 Total accounts payable and accrued liabilities $ 225.4 $ 184.0

Debt

Debt	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Debt	Debt: The following table presents short-term and long-term debt by issuance as of December 31: Issuance Date Maturity Date 2017 2016 Short-term debt and current portion of long-term debt: Syndicated revolving credit facility Various Various $ 715.0 $ 100.0 Capital lease obligations Various Various 9.4 6.8 Short-term debt and current portion of long-term debt 724.4 106.8 Long-term debt: Senior notes: 4.000% senior notes, less unamortized discount and debt issuance costs of $9.1 million and $10.4 million, respectively 5/15/2015 6/15/2025 890.9 889.6 5.500% senior notes, less unamortized discount and debt issuance costs of $4.9 million and $5.0 million, respectively 5/15/2015 6/15/2045 345.1 345.0 4.125% senior notes, less unamortized discount and debt issuance costs of $2.9 million and $3.5 million, respectively 9/12/2012 9/12/2022 347.1 346.5 4.875% senior notes, less unamortized discount and debt issuance costs of $0.7 million and $1.4 million, respectively 12/8/2011 1/15/2019 249.3 248.6 5.80% senior notes, less unamortized discount and debt issuance costs of $1.8 million and $2.4 million, respectively 4/6/2011 5/1/2021 448.2 447.6 Capital lease obligations Various Various 7.6 7.1 Syndicated revolving credit facility debt issuance costs (3.8 ) (4.2 ) Long-term debt 2,284.4 2,280.2 Total debt $ 3,008.8 $ 2,387.0 Accrued interest associated with the Company’s outstanding debt obligations was $18.3 million and $17.0 million as of December 31, 2017 and 2016 , respectively, and included in “Accounts payable and accrued liabilities” within the accompanying consolidated balance sheets. Interest expense associated with the Company’s outstanding debt obligations was $119.4 million , $120.0 million and $121.4 million for the years ended December 31, 2017 , 2016 and 2015 , respectively. Senior Notes As of December 31, 2017 and 2016 , the Company had senior notes with an aggregate principal amount of $2,300.0 million outstanding. Interest on senior notes is payable semiannually. The discount and debt issuance costs were recorded in "Long-term debt" in the accompanying consolidated balance sheets and these costs will be amortized to "Interest expense" in the accompanying consolidated statements of operations over the life of the respective senior note. The indenture governing senior notes restricts the Company's ability to, among other things, create certain liens, enter into sale/leaseback transactions and consolidate with, sell, lease, convey or otherwise transfer all or substantially all of the Company's assets, or merge with or into, any other person or entity. As of December 31, 2017 and 2016 , the Company was in compliance with the financial debt covenants governing the senior notes. Syndicated Revolving Credit Facility The Company has a committed senior unsecured Syndicated Revolving Credit Facility (the "Credit Facility") with Bank of America N.A., JP Morgan Chase, N.A., Sun Trust Bank, Wells Fargo Bank N.A., Citizens Bank, N.A., Morgan Stanley, N.A., HSBC Bank USA, N.A., Royal Bank of Canada, BNP Paribas, TD Bank, N.A., The Northern Trust Company, and Capital One N.A. On May 18, 2017, the Company entered into the third amendment to the Credit Facility, which, among other things, extended the maturity date one year to May 15, 2022. The Credit Facility may be used for general corporate purposes, including working capital needs and capital expenditures, acquisitions and the share repurchase program (the "Repurchase Program"). The Credit Facility contains certain financial and other covenants that, among other things, impose certain restrictions on indebtedness, liens, investments, and capital expenditures. These covenants also place restrictions on mergers, asset sales, sale/leaseback transactions, payments between the Company and its subsidiaries, and certain transactions with affiliates. The financial covenants require that, at the end of any fiscal quarter, the Company has a consolidated interest coverage ratio of at least 3.0 to 1.0 and that it maintains, during any period of four fiscal quarters, a consolidated funded debt leverage ratio of less than 3.5 to 1.0. The Company was in compliance with all financial covenants under the Credit Facility as of December 31, 2017 . Interest on borrowings under the Credit Facility is payable at an interest rate of LIBOR plus 1.125% to 1.625% , depending upon the consolidated funded debt leverage ratio. A commitment fee on any unused balance is payable periodically and may range from 12.50 to 25.00 basis points based upon the consolidated funded debt leverage ratio. As of December 31, 2017 and 2016 , the Company had outstanding borrowings under the Credit Facility of $715.0 million and $100.0 million , respectively. Private Placements As of December 31, 2015, the Company had no outstanding private placement debt. The Company prepaid this debt and the contractual costs for the prepayment was $4.8 million , which was recorded to "Interest expense" in the accompanying consolidated statements of operations for the year ended December 31, 2015. Bridge Financing On March 10, 2015, in connection with the Company's acquisition of Wood Mackenzie, the Company entered into a commitment letter for a $2,300.0 million 364 -day bridge financing arrangement with Bank of America N.A. and Morgan Stanley Bank N.A. acting as joint lead arrangers. This financing arrangement was terminated upon the closing of the acquisition. The Company paid fees associated with this financing arrangement of $9.1 million . Due to the completion of the debt and equity offerings, this arrangement was terminated and the full $9.1 million of fees were recorded to "Interest expense" in the accompanying consolidated statements of operations for the year ended December 31, 2015. The Company was in compliance with all financial covenants at December 31, 2017 and 2016 . Debt Maturities The following table reflects the Company’s debt maturities: Year Amount 2018 $ 724.4 2019 253.9 2020 2.3 2021 451.4 2022 350.0 2023 and thereafter 1,250.0 Total $ 3,032.0

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity: The Company has 2,000,000,000 shares of authorized common stock as of December 31, 2017 and 2016 . The common shares have rights to any dividend declared by the board of directors, subject to any preferential or other rights of any outstanding preferred stock, and voting rights to elect all thirteen members of the board of directors. The Company has 80,000,000 shares of authorized preferred stock, par value $0.001 per share. The preferred shares have preferential rights over the common shares with respect to dividends and net distribution upon liquidation. The Company did not issue any preferred shares as of December 31, 2017 . Share Repurchase Program Since May 2010, the Company has authorized repurchases of up to $2,800.0 million of its common stock through its Repurchase Program. Since the introduction of share repurchase as a feature of the Company's capital management strategies in 2010, the Company has repurchased shares with an aggregate value of $2,433.8 million . As of December 31, 2017 , the Company had $366.2 million available to repurchase shares. The Company has no obligation to repurchase stock under this program and intends to use this authorization as a means of offsetting dilution from the issuance of shares under the ISO 401(k) Savings and Employee Stock Ownership Plan ("KSOP"), the Verisk 2013 Equity Incentive Plan (the "2013 Incentive Plan"), the Verisk 2009 Equity Incentive Plan (the “2009 Incentive Plan”), and the ISO 1996 Incentive Plan (the “1996 Incentive Plan”), while providing flexibility to repurchase additional shares if warranted. This authorization has no expiration date and may be increased, reduced, suspended, or terminated at any time. Shares that are repurchased under the Repurchase Program will be recorded as treasury stock and will be available for future issuance. During the years ended December 31, 2017 and 2016 , the Company repurchased 3,356,360 and 4,325,548 shares of common stock as part of the Repurchase Program at a weighted average price of $80.39 and $77.06 per share, respectively. The Company utilized cash from operations and borrowings from its Credit Facility to fund these repurchases. Treasury Stock As of December 31, 2017 , the Company’s treasury stock consisted of 379,124,108 shares of common stock. During the years ended December 31, 2017 and 2016 , the Company reissued 1,319,518 and 1,816,339 shares of common stock, under the 2013 Incentive Plan, 2009 Incentive Plan and the 1996 Incentive Plan, from the treasury shares at a weighted average price of $8.13 and $7.23 per share, respectively. Earnings Per Share The following is a reconciliation of the numerators and denominators of the basic and diluted EPS computations for the years ended December 31: 2017 2016 2015 (In millions, except for share and per share data) Numerator used in basic and diluted EPS: Income from continuing operations $ 555.1 $ 451.5 $ 487.5 Income from discontinued operations — 139.7 20.1 Net income $ 555.1 $ 591.2 $ 507.6 Denominator: Weighted average number of common shares used in basic EPS 165,168,224 168,248,304 165,090,380 Effect of dilutive shares: Potential common stock issuable from stock options and stock awards 3,520,644 2,923,268 3,360,963 Weighted average number of common shares and dilutive potential common shares used in diluted EPS 168,688,868 171,171,572 168,451,343 The potential shares of common stock that were excluded from diluted EPS were 1,967,409 , 1,724,338 and 1,221,301 at December 31, 2017 , 2016 and 2015 , respectively, because the effect of including those potential shares was anti-dilutive. Accumulated Other Comprehensive Losses The following is a summary of accumulated other comprehensive losses as of December 31: 2017 2016 Foreign currency translation adjustment $ (334.4 ) $ (561.4 ) Unrealized gains on available-for-sale securities, net of tax 0.7 0.3 Pension and postretirement adjustment, net of tax (78.6 ) (89.7 ) Accumulated other comprehensive losses $ (412.3 ) $ (650.8 ) The before tax and after tax amounts of other comprehensive loss for the years ended December 31, 2017 , 2016 and 2015 are summarized below: Before Tax Tax Benefit After Tax December 31, 2017 Foreign currency translation adjustment $ 227.0 $ — $ 227.0 Unrealized holding gain on available-for-sale securities before reclassifications 0.5 (0.1 ) 0.4 Unrealized holding gain on available-for-sale securities 0.5 (0.1 ) 0.4 Pension and postretirement adjustment before reclassifications 19.7 (4.9 ) 14.8 Amortization of net actuarial loss and prior service benefit reclassified from accumulated other comprehensive losses (2) (4.9 ) 1.2 (3.7 ) Pension and postretirement adjustment 14.8 (3.7 ) 11.1 Total other comprehensive income $ 242.3 $ (3.8 ) $ 238.5 December 31, 2016 Foreign currency translation adjustment $ (395.6 ) $ — $ (395.6 ) Unrealized holding gain on available-for-sale securities before reclassifications 0.5 (0.2 ) 0.3 Unrealized holding gain on available-for-sale securities 0.5 (0.2 ) 0.3 Pension and postretirement adjustment before reclassifications (18.1 ) 6.8 (11.3 ) Amortization of net actuarial loss and prior service benefit reclassified from accumulated other comprehensive losses (2) (3.6 ) 1.4 (2.2 ) Pension and postretirement adjustment (21.7 ) 8.2 (13.5 ) Total other comprehensive loss $ (416.8 ) $ 8.0 $ (408.8 ) December 31, 2015 Foreign currency translation adjustment $ (162.7 ) $ — $ (162.7 ) Unrealized holding gain on available-for-sale securities before reclassifications 0.4 (0.2 ) 0.2 Amount reclassified from accumulated other comprehensive losses (1) (0.2 ) 0.1 (0.1 ) Unrealized holding gain on available-for-sale securities 0.2 (0.1 ) 0.1 Pension and postretirement adjustment before reclassifications 5.3 (2.2 ) 3.1 Amortization of net actuarial loss and prior service benefit reclassified from accumulated other comprehensive losses (2) (3.3 ) 1.3 (2.0 ) Pension and postretirement adjustment 2.0 (0.9 ) 1.1 Total other comprehensive loss $ (160.5 ) $ (1.0 ) $ (161.5 ) (1) This accumulated other comprehensive losses component, before tax, is included under “Investment income and others, net” in the accompanying consolidated statements of operations. (2) This accumulated other comprehensive losses component, before tax, is included under “Cost of revenues” and “Selling, general and administrative” in the accompanying consolidated statements of operations. This component is also included in the computation of net periodic benefit (credit) cost (see Note 16 Pension and Postretirement Benefits for additional details).

Compensation Plans

Compensation Plans	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Compensation Plans	Compensation Plans: KSOP The Company has established the KSOP for the benefit of eligible employees in the U.S. and Puerto Rico. The KSOP includes both an employee savings component and an employee stock ownership component. The purpose of the combined plan is to enable the Company’s employees to participate in a tax-deferred savings arrangement under Internal Revenue Service Code Sections 401(a) and 401(k) (the “Code”), and to provide employee equity participation in the Company through the employee stock ownership plan (“ESOP”) accounts. Under the KSOP, eligible employees may make pre-tax and after-tax cash contributions as a percentage of their compensation, subject to certain limitations under the applicable provisions of the Code. The maximum pre-tax contribution that can be made to the 401(k) account as determined under the provisions of Code Section 401(g) is eighteen thousand dollars for 2017 , 2016 and 2015 . Certain eligible participants (age 50 and older) may contribute an additional six thousand dollars on a pre-tax basis for 2017 , 2016 and 2015 . After-tax contributions are limited to 10.0% of a participant’s compensation. The quarterly matching contributions are primarily equal to 75.0% of the first 6.0% of the participant’s contribution. The Company established the ESOP component as a funding vehicle for the KSOP. The common shares acquired by the KSOP were pledged as collateral under an intercompany loan agreement ("ESOP loan") between the KSOP and Company. The Company accounted for its ESOP in accordance with ASC 718-40, Employee Stock Ownership Plans (“ASC 718-40”) and ASC 480-10, Distinguishing Liabilities from Equity (“ASC 480-10”). As of December 31, 2015, the KSOP no longer had any outstanding ESOP loan balance with the Company. For the year ended December 31, 2015 , the Company instructed the KSOP to release 145,007 shares of common stock at a weighted average per price of $72.06 to fund the quarterly matching contributions. Upon maturity of the ESOP loan, the Company issued common stock under the KSOP from the Company's treasury shares to fund the 401(k) matching contributions. For the year ended December 31, 2016 , the Company issued 181,198 shares of common stock at a weighted average per price of $79.97 to fund the quarterly matching contributions. The Company also contributed a total of $18.8 million of cash to the KSOP for the year ended December 31, 2016 . For the year ended December 31, 2017 , the Company opted to fund the 401(k) matching contributions in cash in lieu of issuance of common stock from treasury shares and made cash contributions of $15.6 million . KSOP compensation expense including the discontinued operations funded by the Company's common stock for 2016 and 2015 was $14.5 million and $14.1 million , respectively. At December 31, 2017 , 2016 and 2015 , the fair value of Verisk common stock was $96.00 , $81.17 , and $76.88 per share, respectively. In 2005, the Company established the ISO Profit Sharing Plan (the “Profit Sharing Plan”), a defined contribution plan, to replace the qualified pension plan for all eligible employees hired on or after March 1, 2005. The Profit Sharing Plan is a component of the KSOP. Eligible employees participated in the Profit Sharing Plan if they completed 1,000 hours of service each plan year and were employed on December 31 of that year. The Company can make a discretionary contribution to the Profit Sharing Plan based on the annual performance of the Company. Participants vest once they have completed four years and 1,000 hours of service. For the years ended December 31, 2017 , 2016 and 2015 , there were no profit sharing contributions. Equity Compensation Plans All of the Company’s outstanding stock options and restricted stock are covered under the 2013 Incentive Plan, 2009 Incentive Plan or the 1996 Incentive Plan. Awards under the 2013 Incentive Plan may include one or more of the following types: (i) stock options (both nonqualified and incentive stock options), (ii) stock appreciation rights, (iii) restricted stock, (iv) restricted stock units, (v) performance awards, (vi) other share-based awards, and (vii) cash. Employees, directors and consultants are eligible for awards under the 2013 Incentive Plan. The Company issued common stock under these plans from the Company's treasury shares. The number of shares of common stock available for issuance under the 2013 Incentive Plan is 15,700,000 and such amount shall be reduced on a 1 -for-1 basis for every share issued that is subject to an option or stock appreciation right and on a 2.5 -for-1 basis for every share issued that is subject to an award other than an option or stock appreciation right. Shares that were subject to an award under the 2013 Incentive Plan that become forfeited, expired or otherwise terminated shall again be available for issuance under the 2013 Incentive Plan on a 1 -for-1 basis if the shares were subject to options or stock appreciation rights, and on an 2.5 -for-1 basis if the shares were subject to awards other than options or stock appreciation rights. As of December 31, 2017 , there were 6,761,346 shares of common stock reserved and available for future issuance. Cash received from stock option exercises including the discontinued operations for the years ended December 31, 2017 , 2016 and 2015 was $35.0 million , $41.1 million and $38.8 million , respectively. The Company has granted equity awards to key employees and directors. The nonqualified stock options have an exercise price equal to the closing price of the Company’s common stock on the grant date, with a ten -year contractual term. The fair value of the restricted stock is determined using the closing price of the Company's common stock on the grant date. The restricted stock is not assignable or transferable until it becomes vested. The Company recognizes the expense of the equity awards over the vesting period. A summary of the equity awards granted for the year ended December 31, 2017 is presented below. Grant Date Service Vesting Period Stock Options Restricted Stock Common Stock January 1 to December 31, 2017 Four-year graded vesting 1,318,107 273,966 — April 1, 2017 Two-year graded vesting 47,030 11,272 — July 1, 2017 One-year graded vesting 75,133 10,308 — April 1 to September 30, 2017 Not applicable — 1,304 3,573 1,440,270 296,850 3,573 The fair value of the stock options granted was estimated on the date of grant using a Black-Scholes option valuation model that uses the weighted-average assumptions noted in the following table during the years ended December 31: 2017 2016 2015 Option pricing model Black-Scholes Black-Scholes Black-Scholes Expected volatility 18.72 % 20.26 % 19.51 % Risk-free interest rate 1.82 % 1.14 % 1.29 % Expected term in years 4.5 4.5 4.5 Dividend yield — % — % — % Weighted average grant date fair value per stock option $ 15.71 $ 15.33 $ 13.58 The expected term for the stock options granted for a majority of the awards granted was estimated based on studies of historical experience and projected exercise behavior. However, for certain awards granted, for which no historical exercise pattern exists, the expected term was estimated using the simplified method. The risk-free interest rate is based on the yield of U.S. Treasury zero coupon securities with a maturity equal to the expected term of the equity award. The volatility factor is calculated using historical daily closing prices over the most recent period that is commensurate with the expected term of the stock option awards. The expected dividend yield was based on the Company’s expected annual dividend rate on the date of grant. A summary of options outstanding under the Incentive Plan and the Option Plan and changes during the three years then ended is presented below: Number Weighted Aggregate (In millions, except for share and per share data) Outstanding at January 1, 2015 9,205,690 $ 31.11 $ 303.3 Granted 1,884,262 $ 72.20 Exercised (1,739,847 ) $ 23.71 $ 87.0 Cancelled or expired (232,372 ) $ 64.05 Outstanding at December 31, 2015 9,117,733 $ 40.17 $ 334.7 Granted 1,364,916 $ 80.23 Exercised (1,409,803 ) $ 31.47 $ 69.3 Cancelled or expired (301,929 ) $ 73.01 Outstanding at December 31, 2016 8,770,917 $ 46.67 $ 302.6 Granted 1,440,270 $ 81.33 Exercised (1,125,004 ) $ 33.66 $ 57.2 Cancelled or expired (179,074 ) $ 76.70 Outstanding at December 31, 2017 8,907,109 $ 53.31 $ 380.2 Options exercisable at December 31, 2017 5,995,339 $ 41.50 $ 326.8 Options exercisable at December 31, 2016 6,148,349 $ 35.35 $ 281.7 A summary of the status of the Company’s nonvested options and changes is presented below: Number Weighted Nonvested balance at January 1, 2015 2,045,795 $ 12.55 Granted 1,884,262 $ 13.58 Vested (1,121,181 ) $ 13.24 Cancelled or expired (232,372 ) $ 13.05 Nonvested balance at December 31, 2015 2,576,504 $ 12.95 Granted 1,364,916 $ 15.33 Vested (1,016,923 ) $ 12.78 Cancelled or expired (301,929 ) $ 14.18 Nonvested balance at December 31, 2016 2,622,568 $ 14.12 Granted 1,440,270 $ 15.71 Vested (971,994 ) $ 14.19 Cancelled or expired (179,074 ) $ 14.53 Nonvested balance at December 31, 2017 2,911,770 $ 14.86 Intrinsic value for stock options is calculated based on the exercise price of the underlying awards and the quoted price of Verisk’s common stock as of the reporting date. The Company adopted ASU No. 2016-09 prospectively on January 1, 2017 and excess tax benefits from exercised stock options were recorded as income tax benefit in the accompanying consolidated statements of operations. This tax benefit is calculated as the excess of the intrinsic value of options exercised and restricted stock lapsed in excess of compensation recognized for financial reporting purposes. For the year ended December 31, 2017 , the Company recorded excess tax benefit from exercised stock options of $19.0 million as income tax benefit in the accompanying consolidated statements of operations. Prior to the adoption of ASU No. 2016-09, for the years ended December 31, 2016 and 2015 , the Company recorded excess tax benefit from exercised stock options of $23.3 million and $29.2 million , respectively, in "Additional paid-in capital" in the accompanying consolidated balance sheets. The Company realized $28.4 million , $31.4 million and $40.1 million of tax benefit within the Company’s tax payments through December 31, 2017 , 2016 and 2015 , respectively. The Company estimates expected forfeitures of equity awards at the date of grant and recognizes compensation expense only for those awards that the Company expects to vest. Estimated forfeiture is ultimately adjusted to actual forfeiture. Changes in the forfeiture assumptions may impact the total amount of expense ultimately recognized over the requisite service period and may impact the timing of expense recognized over the requisite service period. Stock based compensation expense, including the discontinued operations, for 2017 , 2016 and 2015 was $31.8 million , $30.0 million and $30.5 million , respectively. A summary of the status of the restricted stock awarded under the 2013 Incentive Plan and changes is presented below: Number Weighted Outstanding at January 1, 2015 442,310 $ 56.84 Granted 350,004 $ 72.24 Vested (211,265 ) $ 58.64 Forfeited (47,281 ) $ 63.10 Outstanding at December 31, 2015 533,768 $ 66.25 Granted 292,941 $ 80.27 Vested (230,683 ) $ 64.44 Forfeited (58,359 ) $ 72.86 Outstanding at December 31, 2016 537,667 $ 73.34 Granted 296,850 $ 82.02 Vested (197,403 ) $ 70.72 Forfeited (32,650 ) $ 77.13 Outstanding at December 31, 2017 604,464 $ 78.28 For the year ended December 31, 2017 and 2016 , certain employees had restricted stock vesting and covered the aggregate statutory minimum tax withholding of $2.9 million and $3.1 million through a net settlement of 36,067 shares and 38,250 shares, respectively. As of December 31, 2017 , there was $68.9 million of total unrecognized compensation cost related to nonvested share-based compensation arrangements granted under the 2013 Incentive Plan and the 2009 Incentive Plan. That cost is expected to be recognized over a weighted-average period of 2.53 years. As of December 31, 2017 , there were 2,911,770 and 604,331 nonvested stock options and restricted stock, respectively, of which 2,450,191 and 509,701 are expected to vest. The total grant date fair value of options vested during the years ended December 31, 2017 , 2016 and 2015 was $16.6 million , $14.2 million and $16.8 million , respectively. The total grant date fair value of restricted stock vested during the year ended December 31, 2017 , 2016 and 2015 was $17.6 million , $14.4 million and $16.3 million , respectively. The Company also offers eligible employees the opportunity to participate in an employee stock purchase plan ("ESPP"). Under the ESPP, participating employees may authorize payroll deductions of up to 20.0% of their regular base salary and up to 50.0% of their short-term incentive compensation, both of which in total may not exceed twenty-five thousand dollars in any calendar year, to purchase shares of the Company’s common stock at a 5.0% discount of its fair market value at the time of purchase. In accordance with ASC 718, the ESPP is noncompensatory as the purchase discount is 5.0% or less from the fair market value, substantially all employees that meet limited employment qualifications may participate, and it incorporates no option features. During the years ended December 31, 2017 , 2016 and 2015 , the Company issued 29,605 , 29,867 and 25,599 shares of common stock at a weighted average discounted price of $81.38 , $76.75 and $70.27 , respectively.

Pension and Postretirement Bene

Pension and Postretirement Benefits	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
Pension and Postretirement Benefits	Pension and Postretirement Benefits: The Company has a frozen qualified defined benefit pension plan for certain of its employees through membership in the Pension Plan for Insurance Organizations (the “Pension Plan”), a multiple-employer trust. Prior to the freeze, the Company applied a cash balance formula to determine future benefits. Under the cash balance formula, each participant has an account, which was credited annually based on salary rates determined by years of service, as well as the interest earned on the previous year-end cash balance. The Company also has a non-qualified frozen supplemental cash balance plan (“SERP”) for certain employees. The SERP is funded from the general assets of the Company. The Pension Plan’s funding policy is to contribute annually at an amount between the minimum funding requirements set forth in the Employee Retirement Income Security Act of 1974 and the maximum amount that can be deducted for federal income tax purposes. The minimum contribution requirement was and is expected to be $0 in 2017 and 2018 , respectively. The Company contributed $0.9 million and $1.0 million to the SERP in 2017 and 2016 , respectively, and expects to contribute $0.8 million in 2018 . The Company also provides certain healthcare and life insurance benefits for both active and retired employees. The Postretirement Health and Life Insurance Plan (the “Postretirement Plan”), which has been frozen, is contributory, requiring participants to pay a stated percentage of the premium for coverage. The Company does not expect to contribute to the Postretirement Plan in 2018 . The following table sets forth the changes in the benefit obligations and the plan assets, the (funded) unfunded status of the Pension Plan, SERP and Postretirement Plan, and the amounts recognized in the Company’s consolidated balance sheets at December 31: Pension Plan and SERP Postretirement Plan 2017 2016 2017 2016 Change in benefit obligation: Benefit obligation at January 1 $ 438.4 $ 419.6 $ 12.8 $ 15.8 Interest cost 17.1 19.3 0.4 0.4 Actuarial loss (gain) 25.4 28.5 0.7 (1.4 ) Plan participants’ contributions — — 1.6 1.9 Benefits paid (28.0 ) (29.0 ) (4.2 ) (4.4 ) Federal subsidy on benefits paid — — 0.5 0.5 Benefit obligation at December 31 $ 452.9 $ 438.4 $ 11.8 $ 12.8 Accumulated benefit obligation at December 31 $ 452.9 $ 438.4 Change in plan assets: Fair value of plan assets at January 1 $ 444.5 $ 438.6 $ 11.1 $ 13.0 Actual return on plan assets, net of expenses 67.3 33.9 0.1 0.1 Employer contributions, net 0.9 1.0 1.0 — Plan participants’ contributions — — 1.6 1.9 Benefits paid (28.0 ) (29.0 ) (4.2 ) (4.4 ) Federal subsidies received — — 0.5 0.5 Fair value of plan assets at December 31 $ 484.7 $ 444.5 $ 10.1 $ 11.1 (Funded) unfunded status at December 31 $ (31.8 ) $ (6.1 ) $ 1.7 $ 1.7 Amounts recognized in the consolidated balance sheets consist of: Pension assets, noncurrent $ (45.1 ) $ (19.6 ) $ — $ — Pension, SERP and postretirement benefits, current 0.8 0.9 — — Pension, SERP and postretirement benefits, noncurrent 12.5 12.6 1.7 1.7 Total Pension, SERP and Postretirement benefits $ (31.8 ) $ (6.1 ) $ 1.7 $ 1.7 The pre-tax components included within accumulated other comprehensive losses as of December 31 are summarized below: Pension Plan and SERP Postretirement Plan 2017 2016 2017 2016 Prior service benefit cost (credit) $ 3.5 $ 3.7 $ (0.5 ) $ (0.8 ) Actuarial losses 124.3 139.6 5.6 5.2 Accumulated other comprehensive losses, pretax $ 127.8 $ 143.3 $ 5.1 $ 4.4 The pre-tax components of net periodic benefit (credit) cost and the amounts recognized in other comprehensive loss are summarized below for the years ended December 31: Pension Plan and SERP Postretirement Plan 2017 2016 2015 2017 2016 2015 Interest cost $ 17.1 $ 19.3 $ 18.1 $ 0.4 $ 0.4 $ 0.5 Expected return on plan assets (31.1 ) (31.7 ) (34.4 ) (0.3 ) (0.5 ) (0.6 ) Amortization of prior service cost (credit) reclassified from accumulated other comprehensive losses 0.2 0.1 — (0.2 ) (0.1 ) (0.1 ) Amortization of net actuarial loss reclassified from accumulated other comprehensive losses 4.5 3.2 2.8 0.4 0.4 0.6 Net periodic benefit (credit) cost (9.3 ) (9.1 ) (13.5 ) 0.3 0.2 0.4 Amortization of prior service benefit cost (credit) reclassified from accumulated other comprehensive losses (0.2 ) (0.1 ) — 0.2 0.1 0.1 Amortization of actuarial loss reclassified from accumulated other comprehensive losses (0.1 ) — (0.2 ) — — — Net loss recognized reclassified from accumulated other comprehensive losses (4.4 ) (3.2 ) (2.6 ) (0.4 ) (0.4 ) — Plan amendments — — 3.8 — — — Actuarial gain (loss) (10.8 ) 26.4 (1.5 ) 0.9 (1.1 ) (1.6 ) Total recognized in other comprehensive loss (15.5 ) 23.1 (0.5 ) 0.7 (1.4 ) (1.5 ) Total recognized in net periodic benefit cost (credit) and other comprehensive loss $ (24.8 ) $ 14.0 $ (14.0 ) $ 1.0 $ (1.2 ) $ (1.1 ) The estimated amounts in accumulated other comprehensive losses that are expected to be recognized as components of net periodic benefit (credit) cost during 2018 are summarized below: Pension Plan Postretirement Total Amortization of prior service benefit cost (credit) $ 0.2 $ (0.2 ) $ — Amortization of net actuarial loss 3.4 0.5 3.9 Total $ 3.6 $ 0.3 $ 3.9 The weighted-average assumptions used to determine benefit obligations as of December 31, 2017 and 2016 and net periodic benefit (credit) cost for the years 2017 , 2016 and 2015 are provided below: Pension Plan and SERP Postretirement Plan Weighted-average assumptions used to determine benefit obligations: 2017 2016 2017 2016 Discount rate 3.50 % 3.99 % 3.00 % 3.25 % Expected return on plan assets 7.00 % 7.25 % 2.00 % 3.00 % Weighted-average assumptions used to determine net periodic benefit (credit) loss: 2017 2016 2015 2017 2016 2015 Discount rate 3.99 % 4.73 % 3.99 % 3.25 % 3.25 % 3.00 % Expected return on plan assets 7.25 % 7.50 % 7.50 % 3.00 % 4.00 % 4.00 % The following table presents the estimated future benefit payments for the respective plans. The future benefit payments for the Postretirement Plan are net of the federal Medicare subsidy. Pension Plan Postretirement Gross Benefit Gross Benefit Medicare Subsidy Net Benefit 2018 $ 30.5 $ 2.0 $ (0.3 ) $ 1.7 2019 $ 31.5 $ 1.8 $ (0.3 ) $ 1.5 2020 $ 30.1 $ 1.7 $ (0.3 ) $ 1.4 2021 $ 30.7 $ 1.5 $ (0.3 ) $ 1.2 2022 $ 29.9 $ 1.3 $ (0.3 ) $ 1.0 2023-2027 $ 141.7 $ 4.4 $ (0.2 ) $ 4.2 The healthcare cost trend rate for 2017 was 8.75% gradually decreasing to 4.50% in 2035. Assumed healthcare cost trend rates have a significant effect on the amounts reported for the healthcare plan. However, a 1.00% change in assumed healthcare cost trend rates would have an immaterial effect to our postretirement benefit obligation. The subsidy from the Medicare Prescription Drug, Improvement and Modernization Act of 2003 reduced the Company’s accumulated postretirement benefit obligation by approximately $1.6 million and $2.1 million as of December 31, 2017 and 2016 , and the net periodic benefit cost by approximately $2.0 thousand , $54.0 thousand and $7.0 thousand in fiscal 2017 , 2016 and 2015 , respectively. The expected return on the Pension Plan assets as of December 31, 2017 and 2016 was 7.00% and 7.25% , respectively, which was determined by taking into consideration the Company’s analysis of its actual historical investment returns to a broader long-term forecast after adjusting for the target investment allocation and reflecting the current economic environment. The Company’s investment guidelines target investment allocation of 60% equity securities and 40% debt securities. The Pension Plan assets consist primarily of investments in various fixed income and equity funds. Investment guidelines are established with each investment manager. These guidelines provide the parameters within which the investment managers agree to operate, including criteria that determine eligible and ineligible securities, diversification requirements and credit quality standards, where applicable. Investment managers are prohibited from entering into any speculative hedging transactions. The investment objective is to achieve a maximum total return with strong emphasis on preservation of capital in real terms. The domestic equity portion of the total portfolio should range between 40% and 60% . The international equity portion of the total portfolio should range between 10% and 20% . The fixed income portion of the total portfolio should range between 20% and 40% . The asset allocation at December 31, 2017 and 2016 , and target allocation for 2018 by asset category are as follows: Asset Category Target Allocation Percentage of Plan Assets 2017 2016 Equity securities 60.0 % 54.0 % 61.6 % Debt securities 40.0 % 37.9 % 37.8 % Other — % 8.1 % 0.6 % Total 100.0 % 100.0 % 100.0 % The Company has used the target investment allocation to derive the expected return as the Company believes this allocation will be retained on an ongoing basis that will be commensurate with the projected cash flows of the plan. The expected return for each investment category within the target investment allocation is developed using average historical rates of return for each targeted investment category, considering the projected cash flow of the Pension Plan. The difference between this expected return and the actual return on plan assets is generally deferred and recognized over subsequent periods through future net periodic benefit costs. The Company believes that the use of the average historical rates of returns is consistent with the timing and amounts of expected contributions to the plans and benefit payments to plan participants. These considerations provide the basis for reasonable assumptions with respect to the expected long-term rate of return on plan assets. The Company also maintains a voluntary employees beneficiary association plan (the “VEBA Plan”) under Section 501(c)(9) of the Internal Revenue Code to fund the Postretirement Plan. The asset allocation for the VEBA Plan at December 31, 2017 and target allocation for 2018 are 100% in debt securities. There were no transfers among Levels 1, 2 or 3 for the years ended December 31, 2017 and 2016 . Refer to Note 6. Fair Value Measurements for further discussion with respect to fair value hierarchy. The following table summarizes the fair value measurements by level of the Pension Plan and Postretirement Plan assets: Total Quoted Prices Significant Other Significant December 31, 2017 Equity Managed equity accounts (1) $ 201.4 $ 201.4 $ — $ — Equity — pooled separate account (2) 60.3 — 60.3 — Equity — partnerships (3) 0.2 — — 0.2 Debt Fixed income manager — pooled separate account (2) 183.6 — 183.6 — Fixed income manager — government securities (4) 10.1 10.1 — — Other Cash — pooled separate account (2) 0.5 — 0.5 — Global real estate account (5) 38.7 — 38.7 — Total $ 494.8 $ 211.5 $ 283.1 $ 0.2 December 31, 2016 Equity Managed equity accounts (1) $ 210.2 $ 210.2 $ — $ — Equity — pooled separate account (2) 63.2 — 63.2 — Equity — partnerships (3) 0.2 — — 0.2 Debt Fixed income manager — pooled separate account (2) 167.9 — 167.9 — Fixed income manager — government securities (4) 11.1 11.1 — — Other Cash — pooled separate account (2) 3.0 — 3.0 — Total $ 455.6 $ 221.3 $ 234.1 $ 0.2 (1) Valued at the closing price of shares for domestic stocks within the managed equity accounts, and valued at the net asset value (“NAV”) of shares for mutual funds at either the closing price reported in the active market or based on yields currently available on comparable securities of issuers with similar credit ratings for corporate bonds held by the Pension Plan in these managed accounts. (2) The pooled separate accounts invest in domestic and foreign stocks, bonds and mutual funds. The fair values of these stocks, bonds and mutual funds are publicly quoted and are used in determining the NAV of the pooled separate account, which is not publicly quoted. (3) Investments for which readily determinable prices do not exist are valued by the General Partner using either the market or income approach. In establishing the estimated fair value of investments, including those without readily determinable values, the General Partner assumes a reasonable period of time for liquidation of the investment, and takes into consideration the financial condition and operating results of the underlying portfolio company, nature of investment, restrictions on marketability, holding period, market conditions, foreign currency exposures, and other factors the General Partner deems appropriate. (4) The fund invested in the U.S. government, its agencies or instrumentalities or securities that are rated AAA by S&P, AAA by Fitch, or Aaa by Moody’s, including but not limited to mortgage securities such as agency and non-agency collateralized mortgage obligations, and other obligations that are secured by mortgages or mortgage backed securities, and valued at the closing price reported in the active market. (5) The funds invested in common stocks and other equity securities issued by domestic and foreign real estate companies, including real estate investment trusts ("REIT") and similar REIT-like entities. The fair values of these stocks, bonds and mutual funds are publicly quoted and are used in determining the NAV of the funds, which is not publicly quoted.

Segment Reporting

Segment Reporting	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Segment Reporting	Segment Reporting ASC 280-10, Disclosures About Segments of an Enterprise and Related Information (“ASC 280-10”), establishes standards for reporting information about operating segments. ASC 280-10 requires that a public business enterprise reports financial and descriptive information about its reportable operating segments. Operating segments are components of an enterprise for which separate financial information is available that is evaluated regularly by the chief operating decision maker (“CODM”) in deciding how to allocate resources and in assessing performance. The Company’s President and CEO is identified as the CODM as defined by ASC 280-10. To align with the internal management of the Company’s business operations based on service offerings, the Company is organized into the following two operating segments, which are also the Company’s reportable segments: Decision Analytics: The Company develops solutions that its customers use to analyze key processes in managing risk. The Company’s combination of algorithms and analytic methods incorporates its proprietary data to generate solutions. In most cases, the Company’s customers integrate the solutions into their models, formulas or underwriting criteria in order to predict potential loss events, ranging from hurricanes to earthquakes. The Company develops catastrophe and extreme event models and offers solutions covering natural and man-made risks, including acts of terrorism. The Company also develops solutions that allow customers to quantify costs after loss events occur. Fraud solutions include data on claim histories, analysis of claims to find emerging patterns of fraud, and identification of suspicious claims in the insurance sector. The Company further leverages predictive models and proprietary data to advise customers to make asset investment and portfolio allocation decisions in the global energy market. On June 1, 2016, the Company sold its healthcare business, Verisk Health. Results of operations for the healthcare business are reported as discontinued operations for the year ended December 31, 2016 and for all prior periods presented. Refer to Note 9 for more information. Risk Assessment: The Company is the leading provider of statistical, actuarial and underwriting data for the U.S. P&C insurance industry. The Company’s databases include cleansed and standardized records describing premiums and losses in insurance transactions, casualty and property risk attributes for commercial buildings and their occupants and fire suppression capabilities of municipalities. The Company uses this data to create policy language and proprietary risk classifications that are industry standards and to generate prospective loss cost estimates used to price insurance policies. The two aforementioned operating segments represent the segments for which separate discrete financial information is available and upon which operating results are regularly evaluated by the CODM in order to assess performance and allocate resources. The Company uses EBITDA as the profitability measure for making decisions regarding ongoing operations. EBITDA is net income before interest expense, provision for income taxes, depreciation and amortization of fixed and intangible assets. Operating expenses consist of direct and indirect costs principally related to personnel, facilities, software license fees, consulting, travel, and third-party information services. Indirect costs are generally allocated to the segments using fixed rates established by management based upon estimated expense contribution levels and other assumptions that management considers reasonable. The Company does not allocate interest expense and provision for income taxes, since these items are not considered in evaluating the segment’s overall operating performance. The CODM does not evaluate the financial performance of each segment based on assets or geographical locations. On a geographic basis, revenues from countries outside of the U.S. accounted for 21.7% , 22.6% and 18.2% of the Company's consolidated revenues for the years ended December 31, 2017 , 2016 and 2015 , respectively. No individual country outside of the U.S. accounted for 10.0% or more of the Company's consolidated revenues for the years ended December 31, 2017 , 2016 and 2015 . The following table provides the Company’s revenue and EBITDA by reportable segment for the years ended December 31, as well as a reconciliation to operating income for all periods presented in the accompanying consolidated statements of operations: 2017 2016 2015 Decision Analytics Risk Assessment Total Decision Analytics Risk Assessment Total Decision Analytics Risk Assessment Total Revenues $ 1,374.9 $ 770.3 $ 2,145.2 $ 1,270.9 $ 724.3 $ 1,995.2 $ 1,072.5 $ 688.2 $ 1,760.7 Expenses: Cost of revenues (exclusive of items shown separately below) (557.0 ) (226.8 ) (783.8 ) (490.7 ) (223.7 ) (714.4 ) (412.0 ) (200.0 ) (612.0 ) Selling, general and administrative (238.3 ) (84.5 ) (322.8 ) (214.9 ) (86.7 ) (301.6 ) (196.5 ) (81.8 ) (278.3 ) Investment income and others, net 9.5 (0.3 ) 9.2 4.5 1.6 6.1 16.8 0.1 16.9 EBITDA from discontinued operations — — — 266.0 — 266.0 81.7 — 81.7 Gain on derivative instruments — — — — — — 85.2 — 85.2 EBITDA 589.1 458.7 1,047.8 835.8 415.5 1,251.3 647.7 406.5 1,054.2 Depreciation and amortization of fixed assets (105.2 ) (30.4 ) (135.6 ) (91.4 ) (27.7 ) (119.1 ) (70.8 ) (25.8 ) (96.6 ) Amortization of intangible assets (97.8 ) (4.0 ) (101.8 ) (91.8 ) (0.7 ) (92.5 ) (70.0 ) (0.4 ) (70.4 ) Investment income and others, net (9.5 ) 0.3 (9.2 ) (4.5 ) (1.6 ) (6.1 ) (16.8 ) (0.1 ) (16.9 ) EBITDA from discontinued operations — — — (266.0 ) — (266.0 ) (81.7 ) — (81.7 ) Gain on derivative instruments — — — — — — (85.2 ) — (85.2 ) Operating income $ 376.6 $ 424.6 801.2 $ 382.1 $ 385.5 767.6 $ 323.2 $ 380.2 703.4 Investment income and others, net 9.2 6.1 16.9 Gain on derivative instruments — — 85.2 Interest expense (119.4 ) (120.0 ) (121.4 ) Income from continuing operations before income taxes $ 691.0 $ 653.7 $ 684.1 Operating segment revenue by type of service is provided below for the years ended December 31: 2017 2016 2015 Decision Analytics Insurance $ 784.7 $ 699.8 $ 647.2 Energy and specialized markets 444.7 442.8 308.8 Financial services 145.5 128.3 116.5 Total Decision Analytics 1,374.9 1,270.9 1,072.5 Risk Assessment Industry-standard insurance programs 593.6 554.1 524.6 Property-specific rating and underwriting information 176.7 170.2 163.6 Total Risk Assessment 770.3 724.3 688.2 Total consolidated revenues $ 2,145.2 $ 1,995.2 $ 1,760.7 Long-lived assets by country are provided below as of December 31: 2017 2016 Long-lived assets: U.S. $ 2,438.6 $ 1,754.0 U.K. 2,656.6 2,102.5 Other countries 327.5 273.8 Total long-lived assets $ 5,422.7 $ 4,130.3

Related Parties

Related Parties	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Related Parties	Related Parties: The Company considers its stockholders that own more than 5% of the outstanding stock within the class to be related parties as defined within ASC 850, Related Party Disclosures . The Company had no material transactions with related parties owning more than 5% of the entire class of stock as of December 31, 2017 and 2016 , except for transactions with the KSOP as disclosed in Note 15. Compensation Plans in the accompanying consolidated financial statements. In addition, the Company had no revenues from related parties for the years ended December 31, 2017 , 2016 and 2015 .

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies: The Company’s operations are conducted on leased premises. Approximate minimum rentals under long-term noncancelable leases for all leased premises, computer equipment and automobiles are as follows: Years Ending Operating Leases Capital Leases 2018 $ 40.6 $ 10.0 2019 41.8 4.2 2020 42.9 2.4 2021 34.6 1.4 2022 31.5 — 2023 and thereafter 173.9 — Net minimum lease payments $ 365.3 18.0 Less amount representing interest 1.0 Present value of net minimum lease capital payments $ 17.0 Most of the leases require payment of property taxes and utilities and, in certain cases, contain renewal options. Operating leases consist of office space. Capital leases consist of computer equipment, office equipment, and leased automobiles. Rent expense on operating leases approximated $39.0 million , $39.5 million and $37.3 million in 2017 , 2016 and 2015 , respectively. In addition, the Company is a party to legal proceedings with respect to a variety of matters in the ordinary course of business, including the matters described below. With respect to ongoing matters, the Company is unable, at the present time, to determine the ultimate resolution of or provide a reasonable estimate of the range of possible loss attributable to these matters or the impact they may have on the Company’s results of operations, financial position or cash flows. This is primarily because the matters are generally in early stages and discovery has either not commenced or been completed. Although the Company believes it has strong defenses and intends to vigorously defend these matters, the Company could in the future incur judgments or enter into settlements of claims that could have a material adverse effect on its results of operations, financial position or cash flows. Intellicorp Records, Inc. Litigation On September 9, 2015, the Company was served with a nationwide putative class action complaint filed in the Court of Common Pleas, Cuyahoga County in Ohio naming the Company’s subsidiary Intellicorp Records, Inc. (“Intellicorp”) titled Sherri Legrand v. Intellicorp Records, Inc. and The Cato Corporation et al. Defendants removed the case to the United States District Court for the Northern District of Ohio on October 8, 2015. Plaintiffs filed their First Amended Class Action Complaint on November 5, 2015 (“Amended Complaint”), which like the prior complaint claims violations of the Fair Credit Reporting Act ("FCRA") and alleges two putative class claims against Intellicorp, namely (i) a section 1681k(a) claim on behalf of all individuals who were the subjects of consumer reports furnished by Intellicorp, which contained public record information in the “Government Sanctions” section of the report on or after September 4, 2013 and continuing through the date the class list is prepared, and (ii) a section 1681e(b) claim on behalf of all individuals who were the subjects of consumer reports furnished by Intellicorp, which contained public record information in the “Government Sanctions” section of the report where the address or social security number of the subject of the report do not match the social security number or address contained in the government database on or after September 4, 2013 and continuing through the date the class list is prepared. Count I of the Amended Complaint alleges that defendant Cato violated the FCRA by procuring consumer reports on the plaintiff and other class members without making the stand-alone disclosure required by FCRA section 1681b(b)(2)(A)(i). Counts II and III allege that Intellicorp violated the FCRA section 1681e (b) by failing to follow reasonable procedures to assure maximum accuracy of the adverse information included in its consumer reports and FCRA section 1681k (a) by failing to maintain strict procedures to assure that the public record information reported, which was likely to have an adverse effect on the consumer was complete and up to date, respectively. The Amended Complaint alleges that defendants acted willfully and seeks statutory damages for the classes in an amount not less than one hundred dollars and not more than one thousand dollars per violation, punitive damages, equitable relief, costs and attorney’s fees. On April 24, 2017, the parties agreed to resolve the litigation in a Settlement Agreement and Release and plaintiffs filed their Motion for Preliminary Approval of the settlement on the same day. The settlement provides for a non-material cash payment by the Company, as well as certain non-monetary relief. The District Court granted the Motion for Preliminary Approval on April 25, 2017 and issued its Final Approval Order on October 31, 2017. Xactware Solutions, Inc. Patent Litigation On October 8, 2015, the Company was served with a summons and complaint in an action titled Eagle View Technologies, Inc. and Pictometry International Group, Inc. v. Xactware Solutions, Inc. and Verisk Analytics, Inc. filed in the United States District Court for the District of New Jersey. The complaint alleges that the Company’s Roof InSight, Property InSight and Aerial Sketch products infringe seven patents owned by Eagle View and Pictometry namely, Patent Nos. 436, 840, 152, 880, 770, 732 and 454. On November 30, 2015, plaintiffs filed a First Amended Complaint adding Patent Nos. 376 and 737 to the Patents in Suit. The First Amended Complaint seeks an entry of judgment by the Court that defendants have and continue to directly infringe and/or indirectly infringe, by way of inducement the Patents-in-Suit, permanent injunctive relief, damages, costs and attorney’s fees. On May 17, 2017, the District Court so ordered a Joint Stipulated Order of Partial Dismissal with Prejudice dismissing all claims or assertions pertaining to Pictometry Patents Nos. 880 and 732 and certain enumerated claims or assertions pertaining to Eagle View Patents Nos. 436, 840, 152, 770, 454, 376 and 737 (collectively the “Patents in Suit”). At this time, it is not reasonably possible to determine the ultimate resolution of, or estimate the liability related to this matter. Insurance Services Office, Inc. Litigation On August 1, 2014, the Company was served with an Amended Complaint filed in the United States District Court for the District of Colorado titled Snyder, et. al. v. ACORD Corp., et al. The action is brought by nineteen individual plaintiffs, on their own behalf and on behalf of a putative class, against more than 120 defendants, including the Company and ISO. Except for the Company, ISO and the defendant Acord Corporation, which provides standard forms to assist in insurance transactions, most of the other defendants are property and casualty insurance companies that plaintiffs claim conspired to underpay property damage claims. Plaintiffs claim that the Company and ISO, along with all the other defendants, violated state and federal antitrust and racketeering laws as well as state common law. On September 8, 2014, the Court entered an Order striking the Amended Complaint and granting leave to the plaintiffs to file a new complaint. On October 13, 2014, plaintiffs filed their Second Amended Complaint, which was re-filed by plaintiffs to correct errors as the Third Amended Complaint. The Third Amended Complaint similarly alleges that the defendants conspired to underpay property damage claims, but does not specifically allege what role the Company or ISO played in the alleged conspiracy. It claims that the Company and ISO, along with all the other defendants, violated state and federal antitrust and racketeering laws as well as state common law, and seeks all available relief including injunctive, statutory, actual and punitive damages as well as attorneys’ fees. On January 15, 2016, the Court granted defendants’ motions to dismiss all claims asserted in the Third Amended Complaint. Plaintiffs filed a motion for reconsideration of this dismissal on February 16, 2016. The Court granted defendants’ motion to strike the motion for reconsideration on March 2, 2016 and gave plaintiffs leave to file another motion for reconsideration in accordance with the rules which plaintiffs filed on March 11, 2016 and, which was denied by the Court on April 25, 2016. On April 1, 2016, plaintiffs also filed a Notice of Appeal of the Court’s January 15, 2016 Order, which dismissed all claims in the Third Amended Complaint. Plaintiffs also filed an appeal of the Court’s denial of the motion for reconsideration, which the Court of Appeals for the 10th Circuit consolidated with the appeal of the Court’s January 15, 2016 dismissal. Appellants filed their brief in support of the consolidated appeal on July 21, 2016 and Appellees filed their brief in response on September 21, 2016. On April 6, 2017, the Court of Appeals for the 10th Circuit affirmed the Court’s dismissal of the Third Amended Complaint. Appellants filed a motion for en banc reconsideration of the 10th Circuit’s affirmance of the dismissal of the Third Amended Complaint which was denied on May 26, 2017. Appellants filed their petition for a writ of certiorari in the Supreme Court on August 24, 2017 which was denied on October 30, 2017. Plaintiffs filed a Petition for Rehearing to the Supreme Court on November 27, 2017 which was denied on January 8, 2018. **************

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts and Reserves	12 Months Ended
	Dec. 31, 2017
Valuation and Qualifying Accounts [Abstract]
Schedule II - Valuation and Qualifying Accounts and Reserves	Schedule II Valuation and Qualifying Accounts and Reserves For the Years Ended December 31, 2017 , 2016 and 2015 (In millions) Description Balance at Charged to Deductions— Balance at Year ended December 31, 2017 Allowance for doubtful accounts $ 3.4 $ 2.0 (0.8 ) $ 4.6 Valuation allowance for income taxes $ 8.1 $ 10.0 (0.5 ) $ 17.6 Year ended December 31, 2016 Allowance for doubtful accounts $ 2.6 $ 2.2 (1.4 ) $ 3.4 Valuation allowance for income taxes $ 0.9 $ 7.2 $ — $ 8.1 Year Ended December 31, 2015 Allowance for doubtful accounts $ 3.2 $ 0.8 (1.4 ) $ 2.6 Valuation allowance for income taxes $ 0.7 $ 0.2 $ — $ 0.9 (1) Excludes discontinued operations (2) Primarily additional reserves for bad debts (3) Primarily accounts receivable balances written off, net of recoveries, and the expiration of loss carryforwards

Basis of Presentation and Sum30

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Basis of Presentation	The accompanying consolidated financial statements have been prepared on the basis of accounting principles generally accepted in the United States of America (“U.S. GAAP”). The preparation of financial statements in conformity with these accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Significant estimates include acquisition purchase price allocations, the fair value of goodwill, the realization of deferred tax assets, acquisition related liabilities, fair value of stock based compensation for stock options granted, and assets and liabilities for pension and postretirement benefits. Actual results may ultimately differ from those estimates. Certain reclassifications have been made to assets and liabilities for pension and postretirement benefits and cash flows from investing activities within the consolidated financial statements and in the notes to conform to the respective 2017 presentation. As of March 31, 2016, the Company's healthcare business qualified as assets held-for-sale. The healthcare business was sold on June 1, 2016. The results of operations for the Company's healthcare business are reported as discontinued operations for the years ended December 31, 2016 and 2015 (See Note 9). As of December 31, 2017 , the Company simplified the presentation of its consolidated financial statements. Amounts, except for share and per share data, are presented in millions.
Intercompany Accounts and Transactions	The consolidated financial statements include the accounts of Verisk. All intercompany accounts and transactions have been eliminated.
Revenue Recognition	The following describes the Company’s primary types of revenues and the applicable revenue recognition policies. The Company’s revenues are primarily derived from the sales of services and revenue is recognized as services are performed and information is delivered to customers. Revenue is recognized when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, fees and/or price is fixed or determinable, and collectability is reasonably assured. Revenue is recognized net of applicable sales tax withholdings. Industry-Standard Insurance Programs Industry-standard insurance programs, statistical agent and data services and actuarial services are sold to participating insurance company customers under annual agreements covering a calendar year where the price is determined at the inception of the agreement. In accordance with Accounting Standards Codification (“ASC”) 605, Revenue Recognition, the Company recognizes revenue ratably over the term of these annual agreements, as services are performed and continuous access to information is provided over the entire term of the agreements. Property-Specific Rating and Underwriting Information The Company provides property-specific rating information through reports issued for specific commercial properties, for which revenue is recognized when the report is delivered to the customer, provided that all other revenue recognition criteria are met. In addition, the Company provides hosting or software solutions that provide continuous access to information about the properties being insured and underwriting information in the form of standard policy forms to be used by customers. As the customer has a contractual right to take possession of the software without significant penalty, revenues from these arrangements are recognized ratably over the contract period from the time when the customer had access to the solution in accordance with ASC 985-605, Software Revenue Recognition (“ASC 985-605”). The Company recognizes software license revenue when the arrangement does not require significant production, customization or modification of the software and the following criteria are met: persuasive evidence of an agreement exists, delivery has occurred, fees are fixed or determinable, and collections are probable. These software arrangements include post-contract customer support (“PCS”). The Company recognizes software license revenue ratably over the duration of the annual license term as vendor specific objective evidence (“VSOE”) of PCS, the only remaining undelivered element, cannot be established in accordance with ASC 985-605. The PCS associated with these arrangements is coterminous with the duration of the license term. Insurance Insurance services primarily consist of term-based software licenses. These software arrangements include PCS, which includes unspecified upgrades on a when-and-if available basis. The Company recognizes software license revenue ratably over the duration of the annual license term as VSOE of PCS, the only remaining undelivered element, cannot be established in accordance with ASC 985-605. The PCS associated with these arrangements is coterminous with the duration of the license term. In certain instances, the customers are billed for access on a monthly basis for the term-based software licenses and the Company recognizes revenue accordingly. There are also services within insurance, which are comprised of transaction-based fees recognized as information is delivered to customers, provided that all other revenue recognition criteria have been met. Financial Services Financial services include various types of services to customers. The Company primarily recognizes revenue ratably for these services over the term of the agreements, as services are performed and continuous service is provided over the entire term of the agreements. In addition, there are certain services which are comprised of transaction-based fees; in these instances, revenue is recognized as information is delivered to customers, provided that all other revenue recognition criteria have been met. Energy and Specialized Markets The Company provides hosting solutions that give continuous access to research information such as data analytics and commercial intelligence for the energy, chemicals, metals and mining verticals. For the hosting arrangements, whereby the customer does not have the right to take possession of the software, which include PCS throughout the hosting term, revenues from these multiple element arrangements are recognized in accordance with ASC 605-25, Revenue recognition — Multiple element arrangements ("ASC 605-25"). The Company recognizes revenue ratably over the duration of the license term, since the contractual elements do not have stand alone value. Specialized markets consist of term-based software licenses. These software arrangements include PCS, which includes unspecified upgrades on a when-and-if available basis. The Company recognizes software license revenue ratably over the duration of the annual license term as VSOE of PCS, the only remaining undelivered element, cannot be established in accordance with ASC 985-605. The PCS associated with these arrangements is coterminous with the duration of the license term. In certain instances, the customers are billed for access on a monthly basis for the term-based software licenses and the Company recognizes revenue accordingly. In addition, specialized markets are comprised of transaction-based fees recognized as information is delivered to customers, provided that all other revenue recognition criteria have been met. The Company services long-term contract arrangements with certain customers. For these arrangements, revenue is recognized in accordance with ASC 605-35, Revenue Recognition — Construction-Type and Production-Type Contracts (“ASC 605-35”), using the percentage-of-completion method, which requires the use of estimates. In such instances, management is required to estimate the input measures, based on hours incurred to date compared to total estimated hours of the project, with consideration also given to output measures, such as contract milestones, when applicable. Adjustments to estimates are made in the period in which the facts requiring such revisions become known. Accordingly, recognized revenues and profits are subject to revisions as the contract progresses to completion. The Company considers the contract substantially complete when there is compliance with all performance specifications and there are no remaining costs or potential risk. There are also services within energy and specialized markets, which are comprised of transaction-based fees recognized as information is delivered to customers, provided that all other revenue recognition criteria have been met.
Deferred Revenues	The Company invoices its customers in annual, quarterly, monthly, or milestone installments. Amounts billed and collected in advance of earnings are recorded as “Deferred revenues” in the accompanying consolidated balance sheets and are recognized as the services are performed and the applicable revenue recognition criteria are met.
Fixed Assets	Property and equipment, internal-use software and finite-lived intangibles are stated at cost less accumulated depreciation and amortization, which are computed on a straight-line basis over their estimated useful lives. Leasehold improvements are amortized over the shorter of the useful life of the asset or the lease term.
Finite-lived Intangible Assets	Property and equipment, internal-use software and finite-lived intangibles are stated at cost less accumulated depreciation and amortization, which are computed on a straight-line basis over their estimated useful lives. Leasehold improvements are amortized over the shorter of the useful life of the asset or the lease term.
Internal Use Software	The Company’s internal software development costs primarily relate to internal-use software. Such costs are capitalized in the application development stage in accordance with ASC 350-40, Internal-use Software . The Company also capitalizes software development costs upon the establishment of technological feasibility for a product in accordance with ASC 985-20, Software to be Sold, Leased, or Marketed (“ASC 985-20”). Software development costs are amortized on a straight-line basis over a three -year period, which management believes represents the useful life of these capitalized costs.
Fixed Assets and Finite-Lived Intangible Assets Impairment	In accordance with ASC 360, Property, Plant & Equipment , whenever events or changes in circumstances indicate that the carrying amount of long-lived assets and finite-lived intangible assets may not be recoverable, the Company reviews its long-lived assets and finite-lived intangible assets for impairment by first comparing the carrying value of the assets to the sum of the undiscounted cash flows expected to result from the use and eventual disposition of the assets. If the carrying value exceeds the sum of the assets’ undiscounted cash flows, the Company estimates and recognizes an impairment loss by taking the difference between the carrying value and fair value of the assets
Capital and Operating Leases	The Company leases various property, plant and equipment. Leased property is accounted for under ASC 840, Leases (“ASC 840”). Accordingly, leased property that meets certain criteria is capitalized and the present value of the related lease payments is recorded as a liability. Amortization of assets accounted for as capital leases is computed utilizing the straight-line method over the shorter of the remaining lease term or the estimated useful life (principally three to four years for computer equipment and automobiles). All other leases are accounted for as operating leases. Rent expense for operating leases, which may have rent escalation provisions or rent holidays, is recorded on a straight-line basis over the non-cancelable lease period in accordance with ASC 840. The initial lease term generally includes the build-out period, where no rent payments are typically due under the terms of the lease. The difference between rent expensed and rent paid is recorded as deferred rent. Construction allowances received from landlords are recorded as a deferred rent credit and amortized to rent expense over the term of the lease.
Fair Value Measurements	The Company follows the provisions of ASC 820-10, Fair Value Measurements (“ASC 820-10”), which defines fair value, establishes a framework for measuring fair value under U.S. GAAP and expands fair value measurement disclosures. The Company follows the provisions of ASC 820-10 for its financial assets and liabilities recognized or disclosed at fair value on a recurring basis. The Company follows the provisions of ASC 820-10 for its non-financial assets and liabilities recognized or disclosed at fair value. Certain assets and liabilities of the Company are reported at fair value in the accompanying consolidated balance sheets. Such assets and liabilities include amounts for both financial and non-financial instruments. To increase consistency and comparability of assets and liabilities recorded at fair value, ASC 820-10 establishes a three-level fair value hierarchy to prioritize the inputs to valuation techniques used to measure fair value. ASC 820-10 requires disclosures detailing the extent to which companies’ measure assets and liabilities at fair value, the methods and assumptions used to measure fair value and the effect of fair value measurements on earnings. In accordance with ASC 820-10, the Company applied the following fair value hierarchy: Level 1 — Assets or liabilities for which the identical item is traded on an active exchange, such as publicly-traded instruments. Level 2 — Assets and liabilities valued based on observable market data for similar instruments. Level 3 — Assets or liabilities for which significant valuation assumptions are not readily observable in the market; instruments valued based on the best available data, some of which is internally-developed, and considers risk premiums that a market participant would require.
Accounts Receivable and Allowance for Doubtful Accounts	Accounts receivable is generally recorded at the invoiced amount. The allowance for doubtful accounts is estimated based on an analysis of the aging of the accounts receivable, historical write-offs, customer payment patterns, individual customer creditworthiness, current economic trends, and/or establishment of specific reserves for customers in adverse financial condition. The Company assesses the adequacy of the allowance for doubtful accounts on a quarterly basis.
Foreign Currency	The Company has determined local currencies are the functional currencies of the foreign operations. The assets and liabilities of foreign subsidiaries are translated at the period-end rate of exchange and statement of operations items are translated at the average rates prevailing during the year. The resulting translation adjustment is recorded as a component of “Accumulated other comprehensive losses” in the accompanying consolidated statements of changes in stockholders’ equity.
Stock Based Compensation	The Company follows ASC 718, Stock Compensation (“ASC 718”). Under ASC 718, stock based compensation cost is measured at the grant date, based on the fair value of the awards granted, and is recognized as expense over the requisite service period. Other equity awards, including restricted stock, are valued at the closing price of the Company’s common stock on the grant date. Restricted stock generally has a service vesting period of four years and the Company recognizes the expense ratably over this service vesting period. The Company estimates expected forfeitures of equity awards at the date of grant and recognizes compensation expense only for those awards expected to vest. The forfeiture assumption is ultimately adjusted to the actual forfeiture rate. Changes in the forfeiture assumptions may impact the total amount of expense ultimately recognized, as well as the timing of expense recognized over the requisite service period. The payment of taxes related to the vesting is recorded as a reduction to additional paid-in-capital. This transaction is reflected within "Net share settlement of restricted stock awards" within cash flows from financing activities in the accompanying consolidated statements of cash flows. The Company adopted Accounting Standards Update (“ASU”) No. 2016-09, Improvements to Employee Share-Based Payment Accounting (“ASU No. 2016-09”) on January 1, 2017. Excess tax benefit from exercised stock options is recorded as an income tax benefit in the accompanying consolidated statements of operations. This tax benefit is calculated as the excess of the intrinsic value of options exercised over the compensation recognized for financial reporting purposes. The amount of the tax benefit that has been realized is presented as an operating cash inflow within the accompanying consolidated statements of cash flows.
Research and Development Costs	Research and development costs, which are primarily related to personnel and related overhead costs incurred in developing new services for customers, are expensed as incurred.
Advertising Costs	Advertising costs, which are primarily associated with promoting the Company’s brand, names and solutions provided, are expensed as incurred.
Income Taxes	The Company accounts for income taxes under the asset and liability method under ASC 740, Income Taxes (“ASC 740”), which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. Deferred tax assets are recorded to the extent these assets are more likely than not to be realized. In making such determination, the Company considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax planning strategies and recent financial operations. Valuation allowances are recognized to reduce deferred tax assets if it is determined to be more likely than not that all or some of the potential deferred tax assets will not be realized. The Company follows ASC 740-10, Income Taxes (“ASC 740-10”) , which clarifies the accounting for uncertainty in income taxes recognized in the financial statements. ASC 740-10 provides that a tax benefit from an uncertain tax position may be recognized based on the technical merits when it is more likely than not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes. Income tax positions must meet a more likely than not recognition threshold in accordance with ASC 740-10. This standard also provides guidance on measurement, derecognition, classification, interest and penalties, accounting in interim periods, disclosure, and transition. The Company recognizes interest and penalties related to unrecognized tax benefits within the income tax expense line in the accompanying consolidated statements of operations. Accrued interest and penalties are included within “Other liabilities” on the accompanying consolidated balance sheets.
Earnings Per Share	Basic and diluted earnings per share (“EPS”) are determined in accordance with ASC 260, Earnings per Share , which specifies the computation, presentation and disclosure requirements for EPS. Basic EPS excludes all dilutive common stock equivalents. It is based upon the weighted average number of common shares outstanding during the period. Diluted EPS, as calculated using the treasury stock method, reflects the potential dilution that would occur if the Company’s dilutive outstanding stock options and stock awards were issued.
Pension and Postretirement Benefits	The Company accounts for its pension and postretirement benefits under ASC 715, Compensation — Retirement Benefits (“ASC 715”). ASC 715 requires the recognition of the funded status of a benefit plan in the balance sheet, the recognition in other comprehensive income (loss) of gains or losses and prior service costs arising during the period, but which are not included as components of periodic benefit cost or credit, and the measurement of defined benefit plan assets and obligations as of the balance sheet date. The Company utilizes a valuation date of December 31.
Product Warranty Obligations	The Company provides warranty coverage for certain of its solutions. The Company recognizes a product warranty obligation when claims are probable and can be reasonably estimated. As of December 31, 2017 and 2016 , product warranty obligations were not material. In the ordinary course of business, the Company enters into numerous agreements that contain standard indemnities whereby the Company indemnifies another party for breaches of confidentiality, infringement of intellectual property or gross negligence. Such indemnifications are primarily granted under licensing of computer software. Most agreements contain provisions to limit the maximum potential amount of future payments that the Company could be required to make under these indemnifications; however, the Company is not able to develop an estimate of the maximum potential amount of future payments to be made under these indemnifications as the triggering events are not subject to predictability.
Loss Contingencies	The Company accrues for costs relating to litigation, claims and other contingent matters when such liabilities become probable and reasonably estimable. Such estimates are based on management’s judgment. Actual amounts paid may differ from amounts estimated, and such differences will be charged to operations in the period in which the final determination of the liability is made.
Goodwill	Goodwill represents the excess of acquisition costs over the fair value of tangible net assets and identifiable intangible assets of the businesses acquired. Goodwill and intangible assets deemed to have indefinite lives are not amortized. Intangible assets determined to have finite lives are amortized over their useful lives. Goodwill and intangible assets with indefinite lives are subject to impairment testing annually as of June 30 or whenever events or changes in circumstances indicate that the carrying amount may not be fully recoverable. The Company completed the required annual impairment test as of June 30, 2017 , which resulted in no impairment of goodwill in 2017 . This test compares the carrying value of each reporting unit to its fair value. If the fair value of the reporting unit exceeds the carrying value of the net assets, including goodwill assigned to that reporting unit, goodwill is not impaired. If the carrying value of the reporting unit’s net assets, including goodwill, exceeds the fair value of the reporting unit, then the Company will determine the implied fair value of the reporting unit’s goodwill. If the carrying value of a reporting unit’s goodwill exceeds its implied fair value, then an impairment loss is recorded for the difference between the carrying amount and the implied fair value of the goodwill.
Recent Accounting Pronouncements	In May 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2014-09, Revenue from Contracts with Customers (“Topic 606”). Topic 606 replaces numerous requirements in U.S. GAAP, including industry-specific requirements, and provides companies with a single revenue recognition model for recognizing revenue from contracts with customers. The core principle of Topic 606 is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The two permitted transition methods under Topic 606 are the full retrospective method, in which case the standard would be applied to each prior reporting period presented and the cumulative effect of applying the standard would be recognized at the earliest period shown, or the modified retrospective method, in which case the cumulative effect of applying the standard would be recognized at the date of initial application. In July 2015, the FASB approved the deferral of Topic 606's effective date by one year. Topic 606 is effective for annual reporting periods beginning after December 15, 2017. The FASB permits companies to adopt Topic 606 early, but not before the original effective date of the annual reporting periods beginning after December 15, 2016. T he Company established a corporate implementation team, which engaged with cross-functional representatives from all of its business verticals. The Company utilized a bottom-up approach, with the assistance of third party specialists, to analyze the impact of the standard on the contract portfolio by reviewing previous accounting policies and practices to identify potential differences that would result from applying the requirements of Topic 606 to revenue contracts. In addition, the Company identified and is in the process of implementing appropriate changes to its business processes, systems, and controls to support recognition and disclosure under Topic 606. The Company adopted Topic 606 using the modified retrospective approach effective January 1, 2018. The Company’s revenue streams primarily consist of subscription services provided through a hosted environment or by delivering term based software as well as other services including consulting and transactional solutions. Based on the Company's assessment, the analysis of the contract portfolio under Topic 606 results in the revenue for the majority of the Company's customer contracts being recognized over time, as the Company offers most of its solutions through a series of services primarily in a hosted environment, which is consistent with the Company's previous revenue recognition model. For the majority of its contracts, there is continuous transfer of control to the customer and the number of performance obligations under Topic 606 is consistent with those identified under the existing standard. An identified impact of adopting Topic 606 related to the deferral of commissions on revenue contracts, which were previously expensed as incurred but under Topic 606, the majority of such commissions will be capitalized and amortized over a period of time of up to five years. The Company determined the impact of the adoption on both revenue recognition for customer contracts and related commissions to be immaterial on its consolidated financial statements and disclosures. In January 2016, the FASB issued ASU No. 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU No. 2016-01”). The amendments in this update require all equity investments to be measured at fair value with changes in the fair value recognized through net income (other than those accounted for under equity method of accounting or those that result in consolidation of the investee). The amendments allow equity investments that do not have readily determinable fair values to be remeasured at fair value either upon occurrence of an observable price change or upon identification of an impairment. The amendments in ASU No. 2016-01 are effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. For amendments applicable to the Company, early adoption is not permitted. The cumulative-effect adjustment to retained earnings in connection to the adoption of ASU No. 2016-01 was immaterial to the consolidated financial statements as of January 1, 2018. In February 2016, the FASB issued ASU No. 2016-02, Leases ("ASU No. 2016-02"). This ASU amends the existing accounting considerations and treatments for leases through the creation of Topic 842, Leases , to increase transparency and comparability among organizations by requiring the recognition of lease assets and lease liabilities on the balance sheet and the disclosure of key information about lease arrangements. Lessees and lessors are required to disclose qualitative and quantitative information about leasing arrangements to enable a user of the financial statements to assess the amount, timing and uncertainty of cash flows arising from such leases. The amendments in ASU No. 2016-02 are effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years, and allows for modified retrospective adoption with early adoption permitted. The Company has decided not to early adopt the amendments and is presently evaluating changes to its processes to support the implementation of ASU No. 2016-02. The Company is also assessing the impact associated with the adoption of ASU No. 2016-02 on the consolidated balance sheet, which is expected to be material based upon review of the future contractual obligations. In March 2016, the FASB issued ASU No. 2016-08, Principal Versus Agent Considerations (“ASU No. 2016-08”). The amendments to this update are intended to improve the operability and understandability of the implementation guidance on principal versus agent considerations. The amendments in ASU No. 2016-08 are effective for annual reporting periods beginning after December 15, 2017, including interim reporting periods within that reporting period. Earlier application is permitted only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting period. The adoption of ASU No. 2016-08 is not expected to have a material impact on the Company's consolidated financial statements. In March 2016, the FASB issued ASU No. 2016-09, Improvements to Employee Share-Based Payment Accounting (“ASU No. 2016-09”). The objective of this update is to simplify several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. The Company adopted the guidance prospectively for the income statement impact of income taxes and has retrospectively applied the guidance to the condensed consolidated statements of cash flows for the impact of excess tax benefits on January 1, 2017 in accordance with ASU No. 2016-09. The presentation requirements for cash flows related to employee taxes paid for withheld shares had no impact to any of the periods presented in the condensed consolidated statements of cash flows, since such cash flows have historically been presented in financing activities. The treatment of forfeitures has not changed as the Company is electing to continue the current process of estimating the number of forfeitures. Accordingly, excess tax benefits from exercised stock options in 2017 were recorded as income tax benefit in the consolidated statements of operations for the year ended December 31, 2017 and presented as an operating activity on the condensed consolidated statements of cash flows for the years ended December 31, 2017 , 2016 and 2015 . There was no cumulative-effect adjustment required to retained earnings under the prospective method as of the beginning of the year because all tax benefits had been previously recognized when the tax deductions related to stock compensation were utilized to reduce tax payable. The Company did not record any deferred tax assets or tax liabilities as the result of the adoption of ASU 2016-09. In April 2016, the FASB issued ASU No. 2016-10, Identifying Performance Obligations and Licensing (“ASU No. 2016-10”). The amendments in this update clarify the following two aspects of Topic 606: identifying performance obligations and the licensing implementation guidance, while retaining the related principles for those areas. The amendments in ASU No. 2016-10 are effective for annual reporting periods beginning after December 15, 2017, including interim reporting periods within that reporting period. Earlier application is permitted only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting period. The Company has not elected to early adopt. The Company has been evaluating Topic 606 and refer to discussions above. In May 2016, the FASB issued ASU No. 2016-12, Narrow-Scope Improvements and Practical Expedients ("ASU No. 2016-12"). ASU No. 2016-12 does not change the core principle of the guidance in Topic 606. Rather, this update affects only the narrow scope improvements to the guidance on collectability, noncash consideration, and completed contracts at transition. The effective date and transition requirements for ASU 2016-12 are the same as the effective date and transition requirements for Topic 606. The adoption of ASU No. 2016-12 is not expected to have a material impact on the Company’s consolidated financial statements. In August 2016, the FASB issued ASU No. 2016-15, Classification of Certain Cash Receipts and Cash Payments ("ASU No. 2016-15"). The amendments in this update provide guidance on various specific cash flow issues to reduce diversity in the practice of how certain transactions are classified in the statement of cash flows. ASU No. 2016-15 is effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted. The Company has not elected to early adopt. The Company will evaluate the impact of ASU No. 2016-15 for future transactions subsequent to the effective date. In January 2017, the FASB issued ASU No. 2017-01, Clarifying the Definition of a Business ("ASU No. 2017-01"). Under the amendments in this update, an acquisition would have to include an input and a substantive process that together significantly contribute to the ability to create outputs to be considered a business. In acquisitions where outputs are not present, FASB has developed more stringent criteria for sets without outputs. ASU No. 2017-01 is effective for annual periods beginning after December 15, 2017, including interim periods within those periods. The amendments in this update should be applied prospectively on or after the effective date. No disclosures are required at transition. The Company will evaluate the impact of ASU No. 2017-01 for the future acquisitions subsequent to the effective date. In January 2017, the FASB issued ASU No. 2017-04, Simplifying the Test for Goodwill Impairment ("ASU No. 2017-04"). The guidance eliminates Step 2 of the goodwill impairment test, which requires a hypothetical purchase price allocation. A goodwill impairment will now be the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. The same one-step impairment test will be applied to goodwill at all reporting units, even those with zero or negative carrying amounts. Entities will be required to disclose the amount of goodwill at reporting units with zero or negative carrying amounts. ASU 2017-04 is effective for its annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company is currently evaluating ASU No. 2017-04 and has not yet determined the impact these amendments may have on its consolidated financial statements. In May 2017, the FASB issued ASU No. 2017-09, Scope of Modification Accounting ("ASU 2017-09"), that clarifies when changes to the terms or conditions of a share-based payment award must be accounted for as modifications. Under the guidance within this update, a company will not apply modification accounting to a share-based payment award if all of the following are the same immediately before and after the change: • The award’s fair value (or calculated value or intrinsic value, if those measurement methods are used) • The award’s vesting conditions • The award’s classification as an equity or liability instrument. ASU No. 2017-09 is effective for annual periods beginning after December 15, 2017, including interim periods within those periods. The amendments in this update should be applied prospectively to an award modified on or after the effective date. The Company will evaluate the impact of ASU No. 2017-09 for future award changes subsequent to the effective date.
Segment Reporting	ASC 280-10, Disclosures About Segments of an Enterprise and Related Information (“ASC 280-10”), establishes standards for reporting information about operating segments. ASC 280-10 requires that a public business enterprise reports financial and descriptive information about its reportable operating segments. Operating segments are components of an enterprise for which separate financial information is available that is evaluated regularly by the chief operating decision maker (“CODM”) in deciding how to allocate resources and in assessing performance. The Company’s President and CEO is identified as the CODM as defined by ASC 280-10. To align with the internal management of the Company’s business operations based on service offerings, the Company is organized into the following two operating segments, which are also the Company’s reportable segments: Decision Analytics: The Company develops solutions that its customers use to analyze key processes in managing risk. The Company’s combination of algorithms and analytic methods incorporates its proprietary data to generate solutions. In most cases, the Company’s customers integrate the solutions into their models, formulas or underwriting criteria in order to predict potential loss events, ranging from hurricanes to earthquakes. The Company develops catastrophe and extreme event models and offers solutions covering natural and man-made risks, including acts of terrorism. The Company also develops solutions that allow customers to quantify costs after loss events occur. Fraud solutions include data on claim histories, analysis of claims to find emerging patterns of fraud, and identification of suspicious claims in the insurance sector. The Company further leverages predictive models and proprietary data to advise customers to make asset investment and portfolio allocation decisions in the global energy market. On June 1, 2016, the Company sold its healthcare business, Verisk Health. Results of operations for the healthcare business are reported as discontinued operations for the year ended December 31, 2016 and for all prior periods presented. Refer to Note 9 for more information. Risk Assessment: The Company is the leading provider of statistical, actuarial and underwriting data for the U.S. P&C insurance industry. The Company’s databases include cleansed and standardized records describing premiums and losses in insurance transactions, casualty and property risk attributes for commercial buildings and their occupants and fire suppression capabilities of municipalities. The Company uses this data to create policy language and proprietary risk classifications that are industry standards and to generate prospective loss cost estimates used to price insurance policies.

Accounts Receivable (Tables)

Accounts Receivable (Tables)	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Summary of Accounts Receivable	Accounts receivable consisted of the following at December 31: 2017 2016 Billed receivables $ 291.4 $ 216.4 Unbilled receivables 58.7 50.9 Total receivables 350.1 267.3 Less allowance for doubtful accounts (4.6 ) (3.4 ) Accounts receivable, net $ 345.5 $ 263.9

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Schedule of Financial Assets and Liabilities Accounted at Fair Value	The following table summarizes fair value measurements by level for cash equivalents and registered investment companies that were measured at fair value on a recurring basis: Quoted Prices December 31, 2017 Registered investment companies (1) $ 3.8 December 31, 2016 Registered investment companies (1) $ 3.4 (1) Registered investment companies are classified as available-for-sale securities and are valued using quoted prices in active markets multiplied by the number of shares owned.
Schedule of Carrying Values and Estimated Fair Values of Long-Term Debt	The following table summarizes the carrying value and estimated fair value of the long-term debt as of December 31, 2017 and 2016 respectively: Fair Value Hierarchy 2017 2016 Carrying Estimated Carrying Estimated Financial instrument not carried at fair value: Subordinated promissory note receivable Level 2 $ 95.3 $ 83.3 $ 84.1 $ 76.8 Long-term debt excluding capitalized leases Level 2 $ 2,280.6 $ 2,439.8 $ 2,277.3 $ 2,402.6

Fixed Assets (Tables)

Fixed Assets (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Summary of Fixed Assets	The following is a summary of fixed assets: Useful Life Cost Accumulated Net December 31, 2017 Furniture and office equipment 3-10 years $ 276.2 $ (183.5 ) $ 92.7 Leasehold improvements Lease term 83.1 (40.7 ) 42.4 Purchased software 3 years 123.0 (97.6 ) 25.4 Software development costs 3-7 years 525.3 (230.9 ) 294.4 Leased equipment 3-4 years 35.0 (29.7 ) 5.3 Aircraft equipment 2-10 years 20.4 (2.3 ) 18.1 Total fixed assets $ 1,063.0 $ (584.7 ) $ 478.3 December 31, 2016 Furniture and office equipment 3-10 years $ 238.8 $ (162.5 ) $ 76.3 Leasehold improvements Lease term 66.5 (32.3 ) 34.2 Purchased software 3 years 122.8 (90.9 ) 31.9 Software development costs 3-7 years 404.7 (169.8 ) 234.9 Leased equipment 3-4 years 32.8 (29.8 ) 3.0 Total fixed assets $ 865.6 $ (485.3 ) $ 380.3

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Schedule of Preliminary Purchase Price Allocations of the Acquisitions	The preliminary purchase price allocations of the 2017 acquisitions resulted in the following: Healix Fintellix MAKE G2 Sequel LCI Power Others Total Cash and cash equivalents $ 0.9 $ 1.1 $ 1.5 $ 1.0 $ 16.0 $ 1.1 $ 7.7 $ 0.6 $ 29.9 Accounts receivable 0.9 2.1 0.9 3.7 9.5 3.1 8.3 1.9 30.4 Current assets — 0.3 2.7 3.4 1.4 — 0.5 0.8 9.1 Fixed assets — 0.1 — 6.4 7.5 5.7 0.2 12.0 31.9 Intangible assets 24.1 6.6 6.9 45.3 102.4 59.0 99.1 9.7 353.1 Goodwill 32.7 11.7 12.7 71.4 230.0 99.1 162.8 26.1 646.5 Other assets 7.5 2.0 0.1 2.8 — 12.8 10.0 1.2 36.4 Total assets acquired 66.1 23.9 24.8 134.0 366.8 180.8 288.6 52.3 1,137.3 Current liabilities 1.1 1.5 3.3 3.2 9.8 1.1 3.4 0.8 24.2 Deferred revenues 0.1 0.8 1.5 0.4 2.4 0.3 11.0 0.6 17.1 Deferred income taxes, net 4.1 1.8 1.6 14.6 18.3 14.9 18.4 0.7 74.4 Other liabilities 7.5 1.8 — 2.8 — 12.8 47.7 4.2 76.8 Total liabilities assumed 12.8 5.9 6.4 21.0 30.5 29.1 80.5 6.3 192.5 Net assets acquired 53.3 18.0 18.4 113.0 336.3 151.7 208.1 46.0 944.8 Cash acquired (0.9 ) (1.1 ) (1.5 ) (1.0 ) (16.0 ) (1.1 ) (7.7 ) (0.6 ) (29.9 ) Net cash purchase price $ 52.4 $ 16.9 $ 16.9 $ 112.0 $ 320.3 $ 150.6 $ 200.4 $ 45.4 $ 914.9 The final purchase price allocations of the acquisitions resulted in the following: Wood Mackenzie Others Total Cash and cash equivalents $ 35.4 $ 6.0 $ 41.4 Accounts receivable 80.3 2.0 82.3 Current assets 97.4 0.2 97.6 Fixed assets 71.9 0.3 72.2 Intangible assets 1,112.0 17.2 1,129.2 Goodwill 2,002.4 40.7 2,043.1 Other assets 2.0 5.0 7.0 Total assets acquired 3,401.4 71.4 3,472.8 Current liabilities 122.0 4.1 126.1 Deferred revenues 142.5 2.8 145.3 Deferred income taxes, net 204.3 2.9 207.2 Other liabilities 7.6 4.7 12.3 Total liabilities assumed 476.4 14.5 490.9 Net assets acquired 2,925.0 56.9 2,981.9 Less: Cash acquired 35.4 6.0 41.4 Net cash purchase price $ 2,889.6 $ 50.9 $ 2,940.5 The combined final purchase price allocations of the 2016 acquisitions resulted in the following: Total Cash and cash equivalents $ 2.1 Accounts receivable 2.3 Current assets 0.3 Fixed assets 0.2 Intangible assets 30.5 Goodwill 55.4 Other assets 5.7 Total assets acquired 96.5 Current liabilities 2.2 Deferred revenues 7.7 Deferred income taxes, net 3.1 Other liabilities 7.5 Total liabilities assumed 20.5 Net assets acquired 76.0 Less: Cash acquired 2.1 Net cash purchase price $ 73.9
Schedule of Amounts Assigned to Intangible Assets	The Company determined the fair values of the assets and liabilities of Wood Mackenzie, Infield and PCI with the assistance of valuations performed by third party specialists, discounted cash flow analysis and estimates made by management. The final amounts assigned to intangible assets by type for the acquisitions are summarized in the table below: Weighted Average Useful Life Total Technology-based 7 years $ 112.0 Marketing-related 20 years 234.1 Customer-related 14 years 284.4 Database-related 20 years 498.6 Total intangible assets $ 1,129.1 The preliminary amounts assigned to intangible assets by type for the 2017 acquisitions are summarized in the table below: Weighted Average Useful Life Total Technology-related 10 years $ 99.2 Marketing-related 5 years 20.4 Customer-related 12 years 190.5 Database-related 12 years 43.0 Total intangible assets $ 353.1

Discontinued Operations (Tables

Discontinued Operations (Tables)	12 Months Ended
	Dec. 31, 2017
Discontinued Operations and Disposal Groups [Abstract]
Schedule Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures	The following table summarizes the results from discontinued operations for the years ended December 31: 2016 2015 Revenues from discontinued operations $ 112.3 $ 307.3 Expenses: Cost of revenues (exclusive of items shown separately below) 75.9 191.3 Selling, general and administrative 36.5 34.3 Depreciation and amortization of fixed assets 7.1 24.0 Amortization of intangibles assets 5.9 24.4 Total expenses 125.4 274.0 Operating income (13.1 ) 33.3 Other income (expense): Gain on sale 265.9 — Investment income and others, net 0.2 0.1 Total other income 266.1 0.1 Income from discontinued operations before income taxes 253.0 33.4 Provision for income taxes (including tax on the gain of $111.8 million for 2016) (113.3 ) (13.3 ) Income from discontinued operations, net of tax $ 139.7 $ 20.1 Net cash provided by operating activities and net cash used in investing activities from the healthcare business for the years ended December 31: 2016 2015 Net cash provided by operating activities $ 21.4 $ 73.2 Net cash used in investing activities $ (10.6 ) $ (27.4 )

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Changes in Goodwill	The following is a summary of the change in goodwill from December 31, 2015 through December 31, 2017 , both in total and as allocated to the Company’s operating segments: Risk Decision Total Goodwill at December 31, 2015 (1) $ 55.5 $ 2,697.5 $ 2,753.0 Acquisitions 16.2 43.8 60.0 Purchase accounting reclassifications — 12.8 12.8 Foreign currency translation adjustment (0.4 ) (247.3 ) (247.7 ) Goodwill at December 31, 2016 (1) 71.3 2,506.8 2,578.1 Current year acquisitions 32.7 613.8 646.5 Purchase accounting reclassifications (2.8 ) (1.6 ) (4.4 ) Foreign currency translation adjustment 3.3 145.2 148.5 Goodwill at December 31, 2017 (1) $ 104.5 $ 3,264.2 $ 3,368.7 (1) These balances are net of accumulated impairment charges of $3.2 million that occurred prior to December 31, 2015 .
Schedule of Intangible Assets and Related Accumulated Amortization	The Company’s intangible assets and related accumulated amortization consisted of the following: Weighted Cost Accumulated Net December 31, 2017 Technology-based 8 years $ 421.0 $ (222.9 ) $ 198.1 Marketing-related 17 years 263.9 (62.9 ) 201.0 Contract-based 6 years 5.0 (5.0 ) — Customer-related 14 years 704.2 (174.0 ) 530.2 Database-based 19 years 474.7 (58.7 ) 416.0 Total intangible assets $ 1,868.8 $ (523.5 ) $ 1,345.3 December 31, 2016 Technology-based 7 years $ 310.9 $ (196.6 ) $ 114.3 Marketing-related 17 years 227.5 (47.5 ) 180.0 Contract-based 6 years 5.0 (5.0 ) — Customer-related 14 years 483.1 (128.5 ) 354.6 Database-based 20 years 393.9 (32.0 ) 361.9 Total intangible assets $ 1,420.4 $ (409.6 ) $ 1,010.8
Schedule of Estimated Amortization Expense	Estimated amortization expense in future periods through 2023 and thereafter for intangible assets subject to amortization is as follows: Year Amount 2018 $ 129.1 2019 128.2 2020 126.0 2021 115.5 2022 104.2 2023 and thereafter 742.3 Total $ 1,345.3

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of Income before Income Tax, Domestic and Foreign	Domestic and foreign income from continuing operations before income taxes was as follows: 2017 2016 2015 U.S. $ 669.9 $ 626.6 $ 573.3 Foreign 21.1 27.1 110.8 Total income from continuing operations $ 691.0 $ 653.7 $ 684.1
Schedule of Provision for Income Taxes	The components of the provision for income taxes from continuing operations for the years ended December 31 were as follows: 2017 2016 2015 Current: Federal $ 176.6 $ 171.7 $ 168.8 State and local 23.4 24.0 23.9 Foreign 9.5 3.6 3.3 Total current provision for income taxes 209.5 199.3 196.0 Deferred: Federal (66.3 ) 29.4 23.4 State and local 5.7 4.9 1.4 Foreign (13.0 ) (31.4 ) (24.2 ) Total deferred provision for income taxes (73.6 ) 2.9 0.6 Provision for income taxes $ 135.9 $ 202.2 $ 196.6
Schedule of Effective Tax Rate on Income from Continuing Operations	The reconciliation between the Company’s effective tax rate on income from continuing operations and the statutory tax rate is as follows for the years ended December 31: 2017 2016 2015 Federal statutory rate 35.0 % 35.0 % 35.0 % State and local taxes, net of federal tax benefit 2.6 % 2.7 % 2.6 % Foreign tax differentials (2.1 )% (4.7 )% (6.8 )% Federal Tax Reform-deferred rate change (12.9 )% — % — % U.K. legislative change — % (1.0 )% (2.1 )% Stock-based compensation (2.5 )% — % — % Other (0.4 )% (1.1 )% — % Effective tax rate for continuing operations 19.7 % 30.9 % 28.7 %
Summary of Deferred Tax Assets	The tax effects of significant items comprising the Company’s deferred tax assets as of December 31 are as follows: 2017 2016 Deferred income tax asset: Employee wages, pension and other benefits $ 15.5 $ 30.1 Deferred rent 3.8 6.3 Net operating loss carryover 36.4 24.3 Capital and other unrealized losses 2.1 3.5 Interest expense 9.1 — Other 8.2 12.3 Total 75.1 76.5 Less valuation allowance (17.6 ) (8.1 ) Deferred income tax asset 57.5 68.4 Deferred income tax liability: Fixed assets and intangible assets (366.2 ) (355.2 ) Other (13.2 ) (19.8 ) Deferred income tax liability (379.4 ) (375.0 ) Deferred income tax liability, net $ (321.9 ) $ (306.6 )
Summary of Company's Net Operating Loss Carryforwards Expires	The Company’s net operating loss carryforwards expire as follows: Years Amount 2018-2025 $ 1.9 2026-2030 3.8 2031-2037 205.8 Total $ 211.5
Schedule of Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefit	A reconciliation of the beginning and ending amount of unrecognized tax benefit is as follows: 2017 2016 2015 Unrecognized tax benefit as of January 1 $ 16.8 $ 14.5 $ 10.6 Gross increase in tax positions in prior period 1.7 2.5 7.1 Gross decrease in tax positions in prior period (1.2 ) (0.4 ) (2.6 ) Gross increase in tax positions in current period — 6.4 — Settlements — (5.3 ) (0.3 ) Lapse of statute of limitations (1.0 ) (0.9 ) (0.3 ) Unrecognized tax benefit as of December 31 $ 16.3 $ 16.8 $ 14.5

Composition of Certain Financ38

Composition of Certain Financial Statement Captions (Tables)	12 Months Ended
	Dec. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Schedule of Other Current Assets, Accounts Payable, Accrued Liabilities and Other Liabilities	The following table presents the components of “Other current assets”, “Accounts payable and accrued liabilities” and “Other liabilities” as of December 31: 2017 2016 Other current assets: Acquisition related escrows $ 22.9 $ 4.1 Other current assets 16.2 16.2 Total other current assets $ 39.1 $ 20.3 Accounts payable and accrued liabilities: Accrued salaries, benefits and other related costs $ 115.3 $ 88.6 Escrow liabilities 22.9 4.1 Accrued interest 18.3 17.0 Trade accounts payable and other accrued expenses 68.9 74.3 Total accounts payable and accrued liabilities $ 225.4 $ 184.0

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Summary of Short-Term and Long-Term Debt	The following table presents short-term and long-term debt by issuance as of December 31: Issuance Date Maturity Date 2017 2016 Short-term debt and current portion of long-term debt: Syndicated revolving credit facility Various Various $ 715.0 $ 100.0 Capital lease obligations Various Various 9.4 6.8 Short-term debt and current portion of long-term debt 724.4 106.8 Long-term debt: Senior notes: 4.000% senior notes, less unamortized discount and debt issuance costs of $9.1 million and $10.4 million, respectively 5/15/2015 6/15/2025 890.9 889.6 5.500% senior notes, less unamortized discount and debt issuance costs of $4.9 million and $5.0 million, respectively 5/15/2015 6/15/2045 345.1 345.0 4.125% senior notes, less unamortized discount and debt issuance costs of $2.9 million and $3.5 million, respectively 9/12/2012 9/12/2022 347.1 346.5 4.875% senior notes, less unamortized discount and debt issuance costs of $0.7 million and $1.4 million, respectively 12/8/2011 1/15/2019 249.3 248.6 5.80% senior notes, less unamortized discount and debt issuance costs of $1.8 million and $2.4 million, respectively 4/6/2011 5/1/2021 448.2 447.6 Capital lease obligations Various Various 7.6 7.1 Syndicated revolving credit facility debt issuance costs (3.8 ) (4.2 ) Long-term debt 2,284.4 2,280.2 Total debt $ 3,008.8 $ 2,387.0
Summary of Long Term Debt Maturities	The following table reflects the Company’s debt maturities: Year Amount 2018 $ 724.4 2019 253.9 2020 2.3 2021 451.4 2022 350.0 2023 and thereafter 1,250.0 Total $ 3,032.0

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Computation of Basic and Diluted Earnings Per Share	The following is a reconciliation of the numerators and denominators of the basic and diluted EPS computations for the years ended December 31: 2017 2016 2015 (In millions, except for share and per share data) Numerator used in basic and diluted EPS: Income from continuing operations $ 555.1 $ 451.5 $ 487.5 Income from discontinued operations — 139.7 20.1 Net income $ 555.1 $ 591.2 $ 507.6 Denominator: Weighted average number of common shares used in basic EPS 165,168,224 168,248,304 165,090,380 Effect of dilutive shares: Potential common stock issuable from stock options and stock awards 3,520,644 2,923,268 3,360,963 Weighted average number of common shares and dilutive potential common shares used in diluted EPS 168,688,868 171,171,572 168,451,343
Summary of Accumulated Other Comprehensive Losses	The following is a summary of accumulated other comprehensive losses as of December 31: 2017 2016 Foreign currency translation adjustment $ (334.4 ) $ (561.4 ) Unrealized gains on available-for-sale securities, net of tax 0.7 0.3 Pension and postretirement adjustment, net of tax (78.6 ) (89.7 ) Accumulated other comprehensive losses $ (412.3 ) $ (650.8 ) The pre-tax components included within accumulated other comprehensive losses as of December 31 are summarized below: Pension Plan and SERP Postretirement Plan 2017 2016 2017 2016 Prior service benefit cost (credit) $ 3.5 $ 3.7 $ (0.5 ) $ (0.8 ) Actuarial losses 124.3 139.6 5.6 5.2 Accumulated other comprehensive losses, pretax $ 127.8 $ 143.3 $ 5.1 $ 4.4
Schedule of Amounts Recognized in Other Comprehensive Income	The before tax and after tax amounts of other comprehensive loss for the years ended December 31, 2017 , 2016 and 2015 are summarized below: Before Tax Tax Benefit After Tax December 31, 2017 Foreign currency translation adjustment $ 227.0 $ — $ 227.0 Unrealized holding gain on available-for-sale securities before reclassifications 0.5 (0.1 ) 0.4 Unrealized holding gain on available-for-sale securities 0.5 (0.1 ) 0.4 Pension and postretirement adjustment before reclassifications 19.7 (4.9 ) 14.8 Amortization of net actuarial loss and prior service benefit reclassified from accumulated other comprehensive losses (2) (4.9 ) 1.2 (3.7 ) Pension and postretirement adjustment 14.8 (3.7 ) 11.1 Total other comprehensive income $ 242.3 $ (3.8 ) $ 238.5 December 31, 2016 Foreign currency translation adjustment $ (395.6 ) $ — $ (395.6 ) Unrealized holding gain on available-for-sale securities before reclassifications 0.5 (0.2 ) 0.3 Unrealized holding gain on available-for-sale securities 0.5 (0.2 ) 0.3 Pension and postretirement adjustment before reclassifications (18.1 ) 6.8 (11.3 ) Amortization of net actuarial loss and prior service benefit reclassified from accumulated other comprehensive losses (2) (3.6 ) 1.4 (2.2 ) Pension and postretirement adjustment (21.7 ) 8.2 (13.5 ) Total other comprehensive loss $ (416.8 ) $ 8.0 $ (408.8 ) December 31, 2015 Foreign currency translation adjustment $ (162.7 ) $ — $ (162.7 ) Unrealized holding gain on available-for-sale securities before reclassifications 0.4 (0.2 ) 0.2 Amount reclassified from accumulated other comprehensive losses (1) (0.2 ) 0.1 (0.1 ) Unrealized holding gain on available-for-sale securities 0.2 (0.1 ) 0.1 Pension and postretirement adjustment before reclassifications 5.3 (2.2 ) 3.1 Amortization of net actuarial loss and prior service benefit reclassified from accumulated other comprehensive losses (2) (3.3 ) 1.3 (2.0 ) Pension and postretirement adjustment 2.0 (0.9 ) 1.1 Total other comprehensive loss $ (160.5 ) $ (1.0 ) $ (161.5 ) (1) This accumulated other comprehensive losses component, before tax, is included under “Investment income and others, net” in the accompanying consolidated statements of operations. (2) This accumulated other comprehensive losses component, before tax, is included under “Cost of revenues” and “Selling, general and administrative” in the accompanying consolidated statements of operations. This component is also included in the computation of net periodic benefit (credit) cost (see Note 16 Pension and Postretirement Benefits for additional details).

Compensation Plans (Tables)

Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Other Share-based Compensation, Activity	A summary of the equity awards granted for the year ended December 31, 2017 is presented below. Grant Date Service Vesting Period Stock Options Restricted Stock Common Stock January 1 to December 31, 2017 Four-year graded vesting 1,318,107 273,966 — April 1, 2017 Two-year graded vesting 47,030 11,272 — July 1, 2017 One-year graded vesting 75,133 10,308 — April 1 to September 30, 2017 Not applicable — 1,304 3,573 1,440,270 296,850 3,573
Fair Value of Stock Options Granted Using Black- Scholes Valuation Model	The fair value of the stock options granted was estimated on the date of grant using a Black-Scholes option valuation model that uses the weighted-average assumptions noted in the following table during the years ended December 31: 2017 2016 2015 Option pricing model Black-Scholes Black-Scholes Black-Scholes Expected volatility 18.72 % 20.26 % 19.51 % Risk-free interest rate 1.82 % 1.14 % 1.29 % Expected term in years 4.5 4.5 4.5 Dividend yield — % — % — % Weighted average grant date fair value per stock option $ 15.71 $ 15.33 $ 13.58
Options Outstanding Under Incentive Plan and Option Plan	A summary of options outstanding under the Incentive Plan and the Option Plan and changes during the three years then ended is presented below: Number Weighted Aggregate (In millions, except for share and per share data) Outstanding at January 1, 2015 9,205,690 $ 31.11 $ 303.3 Granted 1,884,262 $ 72.20 Exercised (1,739,847 ) $ 23.71 $ 87.0 Cancelled or expired (232,372 ) $ 64.05 Outstanding at December 31, 2015 9,117,733 $ 40.17 $ 334.7 Granted 1,364,916 $ 80.23 Exercised (1,409,803 ) $ 31.47 $ 69.3 Cancelled or expired (301,929 ) $ 73.01 Outstanding at December 31, 2016 8,770,917 $ 46.67 $ 302.6 Granted 1,440,270 $ 81.33 Exercised (1,125,004 ) $ 33.66 $ 57.2 Cancelled or expired (179,074 ) $ 76.70 Outstanding at December 31, 2017 8,907,109 $ 53.31 $ 380.2 Options exercisable at December 31, 2017 5,995,339 $ 41.50 $ 326.8 Options exercisable at December 31, 2016 6,148,349 $ 35.35 $ 281.7
Summary of Nonvested Options	A summary of the status of the Company’s nonvested options and changes is presented below: Number Weighted Nonvested balance at January 1, 2015 2,045,795 $ 12.55 Granted 1,884,262 $ 13.58 Vested (1,121,181 ) $ 13.24 Cancelled or expired (232,372 ) $ 13.05 Nonvested balance at December 31, 2015 2,576,504 $ 12.95 Granted 1,364,916 $ 15.33 Vested (1,016,923 ) $ 12.78 Cancelled or expired (301,929 ) $ 14.18 Nonvested balance at December 31, 2016 2,622,568 $ 14.12 Granted 1,440,270 $ 15.71 Vested (971,994 ) $ 14.19 Cancelled or expired (179,074 ) $ 14.53 Nonvested balance at December 31, 2017 2,911,770 $ 14.86
Summary of Restricted Stock Activity Under Incentive Plan	A summary of the status of the restricted stock awarded under the 2013 Incentive Plan and changes is presented below: Number Weighted Outstanding at January 1, 2015 442,310 $ 56.84 Granted 350,004 $ 72.24 Vested (211,265 ) $ 58.64 Forfeited (47,281 ) $ 63.10 Outstanding at December 31, 2015 533,768 $ 66.25 Granted 292,941 $ 80.27 Vested (230,683 ) $ 64.44 Forfeited (58,359 ) $ 72.86 Outstanding at December 31, 2016 537,667 $ 73.34 Granted 296,850 $ 82.02 Vested (197,403 ) $ 70.72 Forfeited (32,650 ) $ 77.13 Outstanding at December 31, 2017 604,464 $ 78.28

Pension and Postretirement Be42

Pension and Postretirement Benefits (Tables)	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
Summary of Changes in Benefit Obligations and Plan Assets Amount Recognized	The following table sets forth the changes in the benefit obligations and the plan assets, the (funded) unfunded status of the Pension Plan, SERP and Postretirement Plan, and the amounts recognized in the Company’s consolidated balance sheets at December 31: Pension Plan and SERP Postretirement Plan 2017 2016 2017 2016 Change in benefit obligation: Benefit obligation at January 1 $ 438.4 $ 419.6 $ 12.8 $ 15.8 Interest cost 17.1 19.3 0.4 0.4 Actuarial loss (gain) 25.4 28.5 0.7 (1.4 ) Plan participants’ contributions — — 1.6 1.9 Benefits paid (28.0 ) (29.0 ) (4.2 ) (4.4 ) Federal subsidy on benefits paid — — 0.5 0.5 Benefit obligation at December 31 $ 452.9 $ 438.4 $ 11.8 $ 12.8 Accumulated benefit obligation at December 31 $ 452.9 $ 438.4 Change in plan assets: Fair value of plan assets at January 1 $ 444.5 $ 438.6 $ 11.1 $ 13.0 Actual return on plan assets, net of expenses 67.3 33.9 0.1 0.1 Employer contributions, net 0.9 1.0 1.0 — Plan participants’ contributions — — 1.6 1.9 Benefits paid (28.0 ) (29.0 ) (4.2 ) (4.4 ) Federal subsidies received — — 0.5 0.5 Fair value of plan assets at December 31 $ 484.7 $ 444.5 $ 10.1 $ 11.1 (Funded) unfunded status at December 31 $ (31.8 ) $ (6.1 ) $ 1.7 $ 1.7 Amounts recognized in the consolidated balance sheets consist of: Pension assets, noncurrent $ (45.1 ) $ (19.6 ) $ — $ — Pension, SERP and postretirement benefits, current 0.8 0.9 — — Pension, SERP and postretirement benefits, noncurrent 12.5 12.6 1.7 1.7 Total Pension, SERP and Postretirement benefits $ (31.8 ) $ (6.1 ) $ 1.7 $ 1.7
Summary of Pre-Tax Components of Accumulated Other Comprehensive Losses	The following is a summary of accumulated other comprehensive losses as of December 31: 2017 2016 Foreign currency translation adjustment $ (334.4 ) $ (561.4 ) Unrealized gains on available-for-sale securities, net of tax 0.7 0.3 Pension and postretirement adjustment, net of tax (78.6 ) (89.7 ) Accumulated other comprehensive losses $ (412.3 ) $ (650.8 ) The pre-tax components included within accumulated other comprehensive losses as of December 31 are summarized below: Pension Plan and SERP Postretirement Plan 2017 2016 2017 2016 Prior service benefit cost (credit) $ 3.5 $ 3.7 $ (0.5 ) $ (0.8 ) Actuarial losses 124.3 139.6 5.6 5.2 Accumulated other comprehensive losses, pretax $ 127.8 $ 143.3 $ 5.1 $ 4.4
Components of Net Periodic Benefit Cost and Amounts Recognized in Other Comprehensive Income	The pre-tax components of net periodic benefit (credit) cost and the amounts recognized in other comprehensive loss are summarized below for the years ended December 31: Pension Plan and SERP Postretirement Plan 2017 2016 2015 2017 2016 2015 Interest cost $ 17.1 $ 19.3 $ 18.1 $ 0.4 $ 0.4 $ 0.5 Expected return on plan assets (31.1 ) (31.7 ) (34.4 ) (0.3 ) (0.5 ) (0.6 ) Amortization of prior service cost (credit) reclassified from accumulated other comprehensive losses 0.2 0.1 — (0.2 ) (0.1 ) (0.1 ) Amortization of net actuarial loss reclassified from accumulated other comprehensive losses 4.5 3.2 2.8 0.4 0.4 0.6 Net periodic benefit (credit) cost (9.3 ) (9.1 ) (13.5 ) 0.3 0.2 0.4 Amortization of prior service benefit cost (credit) reclassified from accumulated other comprehensive losses (0.2 ) (0.1 ) — 0.2 0.1 0.1 Amortization of actuarial loss reclassified from accumulated other comprehensive losses (0.1 ) — (0.2 ) — — — Net loss recognized reclassified from accumulated other comprehensive losses (4.4 ) (3.2 ) (2.6 ) (0.4 ) (0.4 ) — Plan amendments — — 3.8 — — — Actuarial gain (loss) (10.8 ) 26.4 (1.5 ) 0.9 (1.1 ) (1.6 ) Total recognized in other comprehensive loss (15.5 ) 23.1 (0.5 ) 0.7 (1.4 ) (1.5 ) Total recognized in net periodic benefit cost (credit) and other comprehensive loss $ (24.8 ) $ 14.0 $ (14.0 ) $ 1.0 $ (1.2 ) $ (1.1 )
Summary of Accumulated Other Comprehensive Losses Recognized in Net Periodic Benefit	The estimated amounts in accumulated other comprehensive losses that are expected to be recognized as components of net periodic benefit (credit) cost during 2018 are summarized below: Pension Plan Postretirement Total Amortization of prior service benefit cost (credit) $ 0.2 $ (0.2 ) $ — Amortization of net actuarial loss 3.4 0.5 3.9 Total $ 3.6 $ 0.3 $ 3.9
Summary of Weighted-Average Assumptions Used in Calculating Net Periodic Benefit (Credit) Cost	The weighted-average assumptions used to determine benefit obligations as of December 31, 2017 and 2016 and net periodic benefit (credit) cost for the years 2017 , 2016 and 2015 are provided below: Pension Plan and SERP Postretirement Plan Weighted-average assumptions used to determine benefit obligations: 2017 2016 2017 2016 Discount rate 3.50 % 3.99 % 3.00 % 3.25 % Expected return on plan assets 7.00 % 7.25 % 2.00 % 3.00 % Weighted-average assumptions used to determine net periodic benefit (credit) loss: 2017 2016 2015 2017 2016 2015 Discount rate 3.99 % 4.73 % 3.99 % 3.25 % 3.25 % 3.00 % Expected return on plan assets 7.25 % 7.50 % 7.50 % 3.00 % 4.00 % 4.00 %
Summary of Estimated Future Benefit Payments for Respective Plans	The following table presents the estimated future benefit payments for the respective plans. The future benefit payments for the Postretirement Plan are net of the federal Medicare subsidy. Pension Plan Postretirement Gross Benefit Gross Benefit Medicare Subsidy Net Benefit 2018 $ 30.5 $ 2.0 $ (0.3 ) $ 1.7 2019 $ 31.5 $ 1.8 $ (0.3 ) $ 1.5 2020 $ 30.1 $ 1.7 $ (0.3 ) $ 1.4 2021 $ 30.7 $ 1.5 $ (0.3 ) $ 1.2 2022 $ 29.9 $ 1.3 $ (0.3 ) $ 1.0 2023-2027 $ 141.7 $ 4.4 $ (0.2 ) $ 4.2
Summary of Asset Allocation and Target Allocation	The asset allocation at December 31, 2017 and 2016 , and target allocation for 2018 by asset category are as follows: Asset Category Target Allocation Percentage of Plan Assets 2017 2016 Equity securities 60.0 % 54.0 % 61.6 % Debt securities 40.0 % 37.9 % 37.8 % Other — % 8.1 % 0.6 % Total 100.0 % 100.0 % 100.0 % The following table summarizes the fair value measurements by level of the Pension Plan and Postretirement Plan assets: Total Quoted Prices Significant Other Significant December 31, 2017 Equity Managed equity accounts (1) $ 201.4 $ 201.4 $ — $ — Equity — pooled separate account (2) 60.3 — 60.3 — Equity — partnerships (3) 0.2 — — 0.2 Debt Fixed income manager — pooled separate account (2) 183.6 — 183.6 — Fixed income manager — government securities (4) 10.1 10.1 — — Other Cash — pooled separate account (2) 0.5 — 0.5 — Global real estate account (5) 38.7 — 38.7 — Total $ 494.8 $ 211.5 $ 283.1 $ 0.2 December 31, 2016 Equity Managed equity accounts (1) $ 210.2 $ 210.2 $ — $ — Equity — pooled separate account (2) 63.2 — 63.2 — Equity — partnerships (3) 0.2 — — 0.2 Debt Fixed income manager — pooled separate account (2) 167.9 — 167.9 — Fixed income manager — government securities (4) 11.1 11.1 — — Other Cash — pooled separate account (2) 3.0 — 3.0 — Total $ 455.6 $ 221.3 $ 234.1 $ 0.2 (1) Valued at the closing price of shares for domestic stocks within the managed equity accounts, and valued at the net asset value (“NAV”) of shares for mutual funds at either the closing price reported in the active market or based on yields currently available on comparable securities of issuers with similar credit ratings for corporate bonds held by the Pension Plan in these managed accounts. (2) The pooled separate accounts invest in domestic and foreign stocks, bonds and mutual funds. The fair values of these stocks, bonds and mutual funds are publicly quoted and are used in determining the NAV of the pooled separate account, which is not publicly quoted. (3) Investments for which readily determinable prices do not exist are valued by the General Partner using either the market or income approach. In establishing the estimated fair value of investments, including those without readily determinable values, the General Partner assumes a reasonable period of time for liquidation of the investment, and takes into consideration the financial condition and operating results of the underlying portfolio company, nature of investment, restrictions on marketability, holding period, market conditions, foreign currency exposures, and other factors the General Partner deems appropriate. (4) The fund invested in the U.S. government, its agencies or instrumentalities or securities that are rated AAA by S&P, AAA by Fitch, or Aaa by Moody’s, including but not limited to mortgage securities such as agency and non-agency collateralized mortgage obligations, and other obligations that are secured by mortgages or mortgage backed securities, and valued at the closing price reported in the active market. (5) The funds invested in common stocks and other equity securities issued by domestic and foreign real estate companies, including real estate investment trusts ("REIT") and similar REIT-like entities. The fair values of these stocks, bonds and mutual funds are publicly quoted and are used in determining the NAV of the funds, which is not publicly quoted.

Segment Reporting (Tables)

Segment Reporting (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Schedule of Reconciliation Income Before Income Taxes	The following table provides the Company’s revenue and EBITDA by reportable segment for the years ended December 31, as well as a reconciliation to operating income for all periods presented in the accompanying consolidated statements of operations: 2017 2016 2015 Decision Analytics Risk Assessment Total Decision Analytics Risk Assessment Total Decision Analytics Risk Assessment Total Revenues $ 1,374.9 $ 770.3 $ 2,145.2 $ 1,270.9 $ 724.3 $ 1,995.2 $ 1,072.5 $ 688.2 $ 1,760.7 Expenses: Cost of revenues (exclusive of items shown separately below) (557.0 ) (226.8 ) (783.8 ) (490.7 ) (223.7 ) (714.4 ) (412.0 ) (200.0 ) (612.0 ) Selling, general and administrative (238.3 ) (84.5 ) (322.8 ) (214.9 ) (86.7 ) (301.6 ) (196.5 ) (81.8 ) (278.3 ) Investment income and others, net 9.5 (0.3 ) 9.2 4.5 1.6 6.1 16.8 0.1 16.9 EBITDA from discontinued operations — — — 266.0 — 266.0 81.7 — 81.7 Gain on derivative instruments — — — — — — 85.2 — 85.2 EBITDA 589.1 458.7 1,047.8 835.8 415.5 1,251.3 647.7 406.5 1,054.2 Depreciation and amortization of fixed assets (105.2 ) (30.4 ) (135.6 ) (91.4 ) (27.7 ) (119.1 ) (70.8 ) (25.8 ) (96.6 ) Amortization of intangible assets (97.8 ) (4.0 ) (101.8 ) (91.8 ) (0.7 ) (92.5 ) (70.0 ) (0.4 ) (70.4 ) Investment income and others, net (9.5 ) 0.3 (9.2 ) (4.5 ) (1.6 ) (6.1 ) (16.8 ) (0.1 ) (16.9 ) EBITDA from discontinued operations — — — (266.0 ) — (266.0 ) (81.7 ) — (81.7 ) Gain on derivative instruments — — — — — — (85.2 ) — (85.2 ) Operating income $ 376.6 $ 424.6 801.2 $ 382.1 $ 385.5 767.6 $ 323.2 $ 380.2 703.4 Investment income and others, net 9.2 6.1 16.9 Gain on derivative instruments — — 85.2 Interest expense (119.4 ) (120.0 ) (121.4 ) Income from continuing operations before income taxes $ 691.0 $ 653.7 $ 684.1
Schedule of Operating Segment Revenue by Type of Service	Operating segment revenue by type of service is provided below for the years ended December 31: 2017 2016 2015 Decision Analytics Insurance $ 784.7 $ 699.8 $ 647.2 Energy and specialized markets 444.7 442.8 308.8 Financial services 145.5 128.3 116.5 Total Decision Analytics 1,374.9 1,270.9 1,072.5 Risk Assessment Industry-standard insurance programs 593.6 554.1 524.6 Property-specific rating and underwriting information 176.7 170.2 163.6 Total Risk Assessment 770.3 724.3 688.2 Total consolidated revenues $ 2,145.2 $ 1,995.2 $ 1,760.7
Schedule of Long-lived Assets by Geographic Areas	Long-lived assets by country are provided below as of December 31: 2017 2016 Long-lived assets: U.S. $ 2,438.6 $ 1,754.0 U.K. 2,656.6 2,102.5 Other countries 327.5 273.8 Total long-lived assets $ 5,422.7 $ 4,130.3

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Schedule of Minimum Rentals under Long Term Noncancelable Leases for All Leased Premises, Computer Equipment and Automobiles	Approximate minimum rentals under long-term noncancelable leases for all leased premises, computer equipment and automobiles are as follows: Years Ending Operating Leases Capital Leases 2018 $ 40.6 $ 10.0 2019 41.8 4.2 2020 42.9 2.4 2021 34.6 1.4 2022 31.5 — 2023 and thereafter 173.9 — Net minimum lease payments $ 365.3 18.0 Less amount representing interest 1.0 Present value of net minimum lease capital payments $ 17.0

Basis of Presentation and Sum45

Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Restricted stock service vesting period (in years)	4 years
Research and development costs	$ 37,400,000	$ 27,400,000	$ 20,600,000
Advertisement costs	6,900,000	6,500,000	$ 5,900,000
Impairment of goodwill	$ 0
Prepaid commission	5 years
Accounting Standards Update 2016-09 [Member] | Retained Earnings [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Cumulative effect of new accounting principle in period of adoption		$ 0
Restricted Stock [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Restricted stock service vesting period (in years)	4 years
Software Development Costs [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Estimated useful life (in years)	3 years
Lease Agreements [Member] | Minimum [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Estimated useful life (in years)	3 years
Lease Agreements [Member] | Maximum [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Estimated useful life (in years)	4 years

Concentration of Credit Risk -

Concentration of Credit Risk - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017USD ($)BankCustomer	Dec. 31, 2016USD ($)BankCustomer	Dec. 31, 2015Customer
Concentration Risk [Line Items]
Total cash balances insured by the Federal Deposit Insurance Corporation | $	$ 250,000	$ 250,000
Cash balances on deposit | $	$ 40,600,000	$ 61,000,000
Number of banks | Bank	7	4
Cash deposit with foreign banks | $	$ 99,800,000	$ 73,100,000
Sales Revenue, Net [Member] | Top Fifty Customers [Member]
Concentration Risk [Line Items]
Number of customers | Customer	50	50	50
Concentration risk percent	34.20%	29.90%	40.80%
Sales Revenue, Net [Member] | Individual Customer [Member]
Concentration Risk [Line Items]
Number of customers | Customer	0	0	0
Concentration risk percent	2.10%	2.00%	2.30%
Accounts Receivable [Member] | Individual Customer [Member]
Concentration Risk [Line Items]
Number of customers | Customer	0	0
Concentration risk percent	2.30%	3.30%

Cash and Cash Equivalents (Deta

Cash and Cash Equivalents (Details)	12 Months Ended
	Dec. 31, 2017
Cash and Cash Equivalents [Abstract]
Maturity of time deposits (in years)	90 days

Accounts Receivable - Summary o

Accounts Receivable - Summary of Accounts Receivable (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables	$ 350.1	$ 267.3
Less allowance for doubtful accounts	(4.6)	(3.4)
Accounts receivable, net	345.5	263.9
Billed receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables	291.4	216.4
Unbilled receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables	$ 58.7	$ 50.9

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets and Liabilities Accounted at Fair Value (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Registered investment companies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Registered investment companies	$ 3.8	$ 3.4

Fair Value Measurements - Long-

Fair Value Measurements - Long-Term Debt (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Accounts and notes receivable, net	$ 95.3	$ 84.1
Notes receivable, fair value	83.3	76.8
Carrying Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt excluding capitalized leases	2,280.6	2,277.3
Estimated Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt excluding capitalized leases	$ 2,439.8	$ 2,402.6

Fixed Assets - Summary of Fixed

Fixed Assets - Summary of Fixed Assets (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Cost	$ 1,063	$ 865.6
Accumulated Depreciation and Amortization	(584.7)	(485.3)
Net	478.3	380.3
Furniture and office equipment [Member]
Property, Plant and Equipment [Line Items]
Cost	276.2	238.8
Accumulated Depreciation and Amortization	(183.5)	(162.5)
Net	$ 92.7	$ 76.3
Furniture and office equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	3 years	3 years
Furniture and office equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	10 years	10 years
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Cost	$ 83.1	$ 66.5
Accumulated Depreciation and Amortization	(40.7)	(32.3)
Net	42.4	34.2
Purchased software [Member]
Property, Plant and Equipment [Line Items]
Cost	123	122.8
Accumulated Depreciation and Amortization	(97.6)	(90.9)
Net	$ 25.4	$ 31.9
Useful life (in years)	3 years	3 years
Software development costs [Member]
Property, Plant and Equipment [Line Items]
Cost	$ 525.3	$ 404.7
Accumulated Depreciation and Amortization	(230.9)	(169.8)
Net	$ 294.4	$ 234.9
Software development costs [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	3 years	3 years
Software development costs [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	7 years	7 years
Leased equipment [Member]
Property, Plant and Equipment [Line Items]
Cost	$ 35	$ 32.8
Accumulated Depreciation and Amortization	(29.7)	(29.8)
Net	$ 5.3	$ 3
Leased equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	3 years	3 years
Leased equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	4 years	4 years
Aircraft Equipment [Member]
Property, Plant and Equipment [Line Items]
Cost	$ 20.4
Accumulated Depreciation and Amortization	(2.3)
Net	$ 18.1
Aircraft Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	2 years
Aircraft Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	10 years

Fixed Assets - Additional Infor

Fixed Assets - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Depreciation and amortization of fixed assets	$ 135.6	$ 119.1	$ 96.6
Amortization expense related to software development	58	43.6	22.3
Software development costs [Member]
Property, Plant and Equipment [Line Items]
Depreciation and amortization of fixed assets	9.5	9.2	9.2
Unamortized software development costs	$ 19.4	$ 25.6	$ 12.7

Acquisitions - Additional Infor

Acquisitions - Additional Information (Detail) - USD ($) $ in Millions

Dec. 29, 2017

Dec. 22, 2017

Nov. 09, 2017

Aug. 31, 2017

Aug. 23, 2017

Aug. 03, 2017

May 19, 2017

Mar. 31, 2017

Feb. 24, 2017

Feb. 16, 2017

Jan. 21, 2017

Nov. 23, 2016

Nov. 11, 2016

Oct. 20, 2016

Aug. 19, 2016

Jul. 26, 2016

Apr. 14, 2016

Nov. 20, 2015

Nov. 06, 2015

May 19, 2015

Jun. 30, 2017

Dec. 31, 2017

Dec. 31, 2016

Dec. 31, 2015

Business Acquisition [Line Items]

Goodwill, non tax deductible amount

$ 628.2

$ 42.9

$ 2,043.1

Goodwill, tax deductible amount

12.5

Amount funded for escrows

41.6

6.4

83.4

Gain on derivative instruments

0

0

85.2

Escrow release

3.8

38

Current portion of escrow

22.9

4.1

Noncurrent portion of escrow

26.3

6.3

Selling, General and Administrative Expenses [Member]

Business Acquisition [Line Items]

Acquisition related costs

6.8

1.6

Business transaction costs

27.6

Interest Expense [Member]

Business Acquisition [Line Items]

Business transaction costs

$ 13.3

PowerAdvocate, Inc. [Member]

Business Acquisition [Line Items]

Percentage of acquisition

100.00%

Consideration transferred

$ 200.4

Indemnification assets as of acquisition date

$ 10

Service Software, Inc. [Member]

Business Acquisition [Line Items]

Percentage of acquisition

100.00%

Consideration transferred

$ 6.8

Indemnification assets as of acquisition date

$ 0.5

Rebmark Legal Solutions Ltd. [Member]

Business Acquisition [Line Items]

Percentage of acquisition

100.00%

Consideration transferred

$ 2.5

Indemnification assets as of acquisition date

$ 0.2

LCI [Member]

Business Acquisition [Line Items]

Percentage of acquisition

100.00%

Consideration transferred

$ 150.6

Indemnification assets as of acquisition date

$ 12.8

Sequel [Member]

Business Acquisition [Line Items]

Percentage of acquisition

100.00%

Consideration transferred

$ 320.3

G2 Web Services [Member]

Business Acquisition [Line Items]

Percentage of acquisition

100.00%

Consideration transferred

$ 112

Indemnification assets as of acquisition date

$ 5.6

Goodwill, tax deductible amount

20.2

Aerial Imagery [Member]

Business Acquisition [Line Items]

Consideration transferred

$ 28.1

Holdback amount

$ 3.1

Goodwill, tax deductible amount

18.3

MAKE Consulting A/S [Member]

Business Acquisition [Line Items]

Percentage of acquisition

100.00%

Consideration transferred

$ 16.9

Indemnification assets as of acquisition date

$ 2.7

Fintellix Solutions Private Limited [Member]

Business Acquisition [Line Items]

Percentage of acquisition

100.00%

Consideration transferred

$ 16.9

Indemnification assets as of acquisition date

$ 1.8

Emergent Network Intelligence Limited [Member]

Business Acquisition [Line Items]

Percentage of acquisition

100.00%

Consideration transferred

$ 6.1

Indemnification assets as of acquisition date

$ 0.5

Healix International Holdings Limited [Member]

Business Acquisition [Line Items]

Percentage of acquisition

100.00%

Consideration transferred

$ 52.4

Indemnification assets as of acquisition date

$ 7.5

Arium Limited [Member]

Business Acquisition [Line Items]

Percentage of acquisition

100.00%

Consideration transferred

$ 1.9

MarketStance [Member]

Business Acquisition [Line Items]

Net cash purchase price

$ 8.6

Acquisition related escrow funding

$ 0.7

The GeoInformation Group [Member]

Business Acquisition [Line Items]

Net cash purchase price

$ 6.3

Acquisition related escrow funding

$ 0.3

Ownership percentage acquired

100.00%

Analyze Re, Inc. [Member]

Business Acquisition [Line Items]

Net cash purchase price

$ 9.5

Acquisition related escrow funding

$ 1

Ownership percentage acquired

100.00%

Quest Offshore [Member]

Business Acquisition [Line Items]

Net cash purchase price

$ 7.2

Amount funded for escrows

$ 0.8

Greentech [Member]

Business Acquisition [Line Items]

Net cash purchase price

$ 36.1

Acquisition related escrow funding

$ 4.4

Ownership percentage acquired

100.00%

RII [Member]

Business Acquisition [Line Items]

Net cash purchase price

$ 6.2

Ownership percentage acquired

100.00%

PCI [Member]

Business Acquisition [Line Items]

Percentage of acquisition

100.00%

Net cash purchase price

$ 36.8

Working capital adjustment

$ 0.6

Escrow release

$ 3.2

Infield [Member]

Business Acquisition [Line Items]

Percentage of acquisition

100.00%

Net cash purchase price

$ 14.1

Working capital adjustment

$ 0.3

Wood Mackenzie [Member]

Business Acquisition [Line Items]

Net cash purchase price

$ 2,889.6

Acquisition related escrow funding

$ 78.7

Ownership percentage acquired

100.00%

Gain on derivative instruments

$ 85.2

Escrow release

$ 37

Acquisitions - Purchase Price A

Acquisitions - Purchase Price Allocations of Acquisitions (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition, Contingent Consideration [Line Items]
Goodwill	$ 3,368.7	$ 2,578.1	$ 2,753
Less: Cash acquired	(29.9)	(2.1)	(41.4)
Net cash purchase price	873.3	67.7	2,858.2
2017 Acquisitions [Member]
Business Acquisition, Contingent Consideration [Line Items]
Cash and cash equivalents	29.9
Accounts receivable	30.4
Current assets	9.1
Fixed assets	31.9
Intangible assets	353.1
Goodwill	646.5
Other assets	36.4
Total assets acquired	1,137.3
Current liabilities	24.2
Deferred revenues	17.1
Deferred income taxes, net	74.4
Other liabilities	76.8
Total liabilities assumed	192.5
Net assets acquired	944.8
Less: Cash acquired	(29.9)
Net cash purchase price	914.9
Healix International Holdings Limited [Member]
Business Acquisition, Contingent Consideration [Line Items]
Cash and cash equivalents	0.9
Accounts receivable	0.9
Current assets	0
Fixed assets	0
Intangible assets	24.1
Goodwill	32.7
Other assets	7.5
Total assets acquired	66.1
Current liabilities	1.1
Deferred revenues	0.1
Deferred income taxes, net	4.1
Other liabilities	7.5
Total liabilities assumed	12.8
Net assets acquired	53.3
Less: Cash acquired	(0.9)
Net cash purchase price	52.4
Fintellix Solutions Private Limited [Member]
Business Acquisition, Contingent Consideration [Line Items]
Cash and cash equivalents	1.1
Accounts receivable	2.1
Current assets	0.3
Fixed assets	0.1
Intangible assets	6.6
Goodwill	11.7
Other assets	2
Total assets acquired	23.9
Current liabilities	1.5
Deferred revenues	0.8
Deferred income taxes, net	1.8
Other liabilities	1.8
Total liabilities assumed	5.9
Net assets acquired	18
Less: Cash acquired	(1.1)
Net cash purchase price	16.9
MAKE Consulting A/S [Member]
Business Acquisition, Contingent Consideration [Line Items]
Cash and cash equivalents	1.5
Accounts receivable	0.9
Current assets	2.7
Fixed assets	0
Intangible assets	6.9
Goodwill	12.7
Other assets	0.1
Total assets acquired	24.8
Current liabilities	3.3
Deferred revenues	1.5
Deferred income taxes, net	1.6
Other liabilities	0
Total liabilities assumed	6.4
Net assets acquired	18.4
Less: Cash acquired	(1.5)
Net cash purchase price	16.9
G2 Web Services [Member]
Business Acquisition, Contingent Consideration [Line Items]
Cash and cash equivalents	1
Accounts receivable	3.7
Current assets	3.4
Fixed assets	6.4
Intangible assets	45.3
Goodwill	71.4
Other assets	2.8
Total assets acquired	134
Current liabilities	3.2
Deferred revenues	0.4
Deferred income taxes, net	14.6
Other liabilities	2.8
Total liabilities assumed	21
Net assets acquired	113
Less: Cash acquired	(1)
Net cash purchase price	112
Sequel [Member]
Business Acquisition, Contingent Consideration [Line Items]
Cash and cash equivalents	16
Accounts receivable	9.5
Current assets	1.4
Fixed assets	7.5
Intangible assets	102.4
Goodwill	230
Other assets	0
Total assets acquired	366.8
Current liabilities	9.8
Deferred revenues	2.4
Deferred income taxes, net	18.3
Other liabilities	0
Total liabilities assumed	30.5
Net assets acquired	336.3
Less: Cash acquired	(16)
Net cash purchase price	320.3
LCI [Member]
Business Acquisition, Contingent Consideration [Line Items]
Cash and cash equivalents	1.1
Accounts receivable	3.1
Current assets	0
Fixed assets	5.7
Intangible assets	59
Goodwill	99.1
Other assets	12.8
Total assets acquired	180.8
Current liabilities	1.1
Deferred revenues	0.3
Deferred income taxes, net	14.9
Other liabilities	12.8
Total liabilities assumed	29.1
Net assets acquired	151.7
Less: Cash acquired	(1.1)
Net cash purchase price	150.6
PowerAdvocate, Inc. [Member]
Business Acquisition, Contingent Consideration [Line Items]
Cash and cash equivalents	7.7
Accounts receivable	8.3
Current assets	0.5
Fixed assets	0.2
Intangible assets	99.1
Goodwill	162.8
Other assets	10
Total assets acquired	288.6
Current liabilities	3.4
Deferred revenues	11
Deferred income taxes, net	18.4
Other liabilities	47.7
Total liabilities assumed	80.5
Net assets acquired	208.1
Less: Cash acquired	(7.7)
Net cash purchase price	200.4
Others [Member]
Business Acquisition, Contingent Consideration [Line Items]
Cash and cash equivalents	0.6		6
Accounts receivable	1.9		2
Current assets	0.8		0.2
Fixed assets	12		0.3
Intangible assets	9.7		17.2
Goodwill	26.1		40.7
Other assets	1.2		5
Total assets acquired	52.3		71.4
Current liabilities	0.8		4.1
Deferred revenues	0.6		2.8
Deferred income taxes, net	0.7		2.9
Other liabilities	4.2		4.7
Total liabilities assumed	6.3		14.5
Net assets acquired	46		56.9
Less: Cash acquired	(0.6)		(6)
Net cash purchase price	$ 45.4		50.9
2016 Acquisitions [Member]
Business Acquisition, Contingent Consideration [Line Items]
Cash and cash equivalents		2.1
Accounts receivable		2.3
Current assets		0.3
Fixed assets		0.2
Intangible assets		30.5
Goodwill		55.4
Other assets		5.7
Total assets acquired		96.5
Current liabilities		2.2
Deferred revenues		7.7
Deferred income taxes, net		3.1
Other liabilities		7.5
Total liabilities assumed		20.5
Net assets acquired		76
Less: Cash acquired		(2.1)
Net cash purchase price		$ 73.9
Business Acquisitions 2015 [Member]
Business Acquisition, Contingent Consideration [Line Items]
Cash and cash equivalents			41.4
Accounts receivable			82.3
Current assets			97.6
Fixed assets			72.2
Intangible assets			1,129.2
Goodwill			2,043.1
Other assets			7
Total assets acquired			3,472.8
Current liabilities			126.1
Deferred revenues			145.3
Deferred income taxes, net			207.2
Other liabilities			12.3
Total liabilities assumed			490.9
Net assets acquired			2,981.9
Less: Cash acquired			(41.4)
Net cash purchase price			2,940.5
Wood Mackenzie [Member]
Business Acquisition, Contingent Consideration [Line Items]
Cash and cash equivalents			35.4
Accounts receivable			80.3
Current assets			97.4
Fixed assets			71.9
Intangible assets			1,112
Goodwill			2,002.4
Other assets			2
Total assets acquired			3,401.4
Current liabilities			122
Deferred revenues			142.5
Deferred income taxes, net			204.3
Other liabilities			7.6
Total liabilities assumed			476.4
Net assets acquired			2,925
Less: Cash acquired			(35.4)
Net cash purchase price			$ 2,889.6

Acquisitions - Amounts Assigned

Acquisitions - Amounts Assigned to Intangible Assets (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2015
2017 Acquisitions [Member]
Business Acquisition, Contingent Consideration [Line Items]
Total intangible assets	$ 353.1
2017 Acquisitions [Member] | Technology-based [Member]
Business Acquisition, Contingent Consideration [Line Items]
Weighted Average Useful Life (in years)	10 years
Total intangible assets	$ 99.2
2017 Acquisitions [Member] | Marketing-related [Member]
Business Acquisition, Contingent Consideration [Line Items]
Weighted Average Useful Life (in years)	5 years
Total intangible assets	$ 20.4
2017 Acquisitions [Member] | Customer-related [Member]
Business Acquisition, Contingent Consideration [Line Items]
Weighted Average Useful Life (in years)	12 years
Total intangible assets	$ 190.5
2017 Acquisitions [Member] | Database Related [Member]
Business Acquisition, Contingent Consideration [Line Items]
Weighted Average Useful Life (in years)	12 years
Total intangible assets	$ 43
Business Acquisitions 2015 [Member]
Business Acquisition, Contingent Consideration [Line Items]
Total intangible assets		$ 1,129.1
Business Acquisitions 2015 [Member] | Technology-based [Member]
Business Acquisition, Contingent Consideration [Line Items]
Weighted Average Useful Life (in years)		7 years
Total intangible assets		$ 112
Business Acquisitions 2015 [Member] | Marketing-related [Member]
Business Acquisition, Contingent Consideration [Line Items]
Weighted Average Useful Life (in years)		20 years
Total intangible assets		$ 234.1
Business Acquisitions 2015 [Member] | Customer-related [Member]
Business Acquisition, Contingent Consideration [Line Items]
Weighted Average Useful Life (in years)		14 years
Total intangible assets		$ 284.4
Business Acquisitions 2015 [Member] | Database Related [Member]
Business Acquisition, Contingent Consideration [Line Items]
Weighted Average Useful Life (in years)		20 years
Total intangible assets		$ 498.6

Discontinued Operations - Addit

Discontinued Operations - Additional Information (Details) - USD ($)	Jun. 01, 2016	Dec. 31, 2017	Dec. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Accounts and notes receivable, net		$ 95,300,000	$ 84,100,000
Verisk Health [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percentage of subsidiary stock for sale	100.00%
Sale price of disposal group	$ 714,600,000
Working capital adjustment	$ 5,400,000
Disposition percent to require prepayment	10.00%
Verisk Health [Member] | Carrying value [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration		$ 8,400,000
Verisk Health [Member] | Common Stock [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership percentage acquired	10.00%
Verisk Health [Member] | Interest Rate Floor [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Stated interest rate	9.00%
Verisk Health [Member] | Interest Rate Cap [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Stated interest rate	11.00%
Verisk Health [Member] | Par Value [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration	$ 100,000,000
Debt instrument, term (in years)	8 years

Discontinued Operations - Resul

Discontinued Operations - Results from Discontinued Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other income (expense):
Investment income and others, net	$ 9.2	$ 6.1	$ 16.9
Income from discontinued operations before income taxes	0	253	33.4
Provision for income taxes from discontinued operations	0	(113.3)	(13.3)
Tax effect of gain (loss)		111.8
Discontinued Operations, Disposed of by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues from discontinued operations		112.3	307.3
Expenses:
Cost of revenues (exclusive of items shown separately below)		75.9	191.3
Selling, general and administrative		36.5	34.3
Depreciation and amortization of fixed assets		7.1	24
Amortization of intangibles assets		5.9	24.4
Total expenses		125.4	274
Operating income		(13.1)	33.3
Other income (expense):
Gain on sale		265.9	0
Investment income and others, net		0.2	0.1
Total other income		266.1	0.1
Income from discontinued operations before income taxes		253	33.4
Provision for income taxes from discontinued operations		(113.3)	(13.3)
Income from discontinued operations, net of tax	$ 0	$ 139.7	$ 20.1

Discontinued Operations - Cash

Discontinued Operations - Cash Activities (Details) - Verisk Health [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net cash provided by operating activities	$ 21.4	$ 73.2
Net cash used in investing activities	$ (10.6)	$ (27.4)

Goodwill and Intangible Asset59

Goodwill and Intangible Assets - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill, impairment loss	$ 0	$ 0	$ 0
Amortization of intangible assets	$ 101,800,000	$ 92,500,000	$ 70,400,000

Goodwill and Intangible Asset60

Goodwill and Intangible Assets - Summary of Changes in Goodwill (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 2,578.1	$ 2,753
Current year acquisitions	646.5	60
Purchase accounting reclassifications	(4.4)	12.8
Foreign currency translation adjustment	148.5	(247.7)
Goodwill, ending balance	3,368.7	2,578.1
Accumulated impairment charges			$ 3.2
Risk Assessment [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	71.3	55.5
Current year acquisitions	32.7	16.2
Purchase accounting reclassifications	(2.8)	0
Foreign currency translation adjustment	3.3	(0.4)
Goodwill, ending balance	104.5	71.3
Decision Analytics [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	2,506.8	2,697.5
Current year acquisitions	613.8	43.8
Purchase accounting reclassifications	(1.6)	12.8
Foreign currency translation adjustment	145.2	(247.3)
Goodwill, ending balance	$ 3,264.2	$ 2,506.8

Goodwill and Intangible Asset61

Goodwill and Intangible Assets - Intangible Assets and Related Accumulated Amortization (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Cost	$ 1,868.8	$ 1,420.4
Accumulated Amortization	(523.5)	(409.6)
Total	$ 1,345.3	$ 1,010.8
Technology-based [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life (in years)	8 years	7 years
Cost	$ 421	$ 310.9
Accumulated Amortization	(222.9)	(196.6)
Total	$ 198.1	$ 114.3
Marketing-related [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life (in years)	17 years	17 years
Cost	$ 263.9	$ 227.5
Accumulated Amortization	(62.9)	(47.5)
Total	$ 201	$ 180
Contract-based [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life (in years)	6 years	6 years
Cost	$ 5	$ 5
Accumulated Amortization	(5)	(5)
Total	$ 0	$ 0
Customer-related [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life (in years)	14 years	14 years
Cost	$ 704.2	$ 483.1
Accumulated Amortization	(174)	(128.5)
Total	$ 530.2	$ 354.6
Database-based [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life (in years)	19 years	20 years
Cost	$ 474.7	$ 393.9
Accumulated Amortization	(58.7)	(32)
Total	$ 416	$ 361.9

Goodwill and Intangible Asset62

Goodwill and Intangible Assets - Estimated Amortization Expense (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
2,018	$ 129.1
2,019	128.2
2,020	126
2,021	115.5
2,022	104.2
2023 and thereafter	742.3
Total	$ 1,345.3	$ 1,010.8

Income Taxes - Domestic and For

Income Taxes - Domestic and Foreign Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
U.S.	$ 669.9	$ 626.6	$ 573.3
Foreign	21.1	27.1	110.8
Income before income taxes	$ 691	$ 653.7	$ 684.1

Income Taxes - Provision for In

Income Taxes - Provision for Income Taxes (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
Federal	$ 176.6	$ 171.7	$ 168.8
State and local	23.4	24	23.9
Foreign	9.5	3.6	3.3
Total current provision for income taxes	209.5	199.3	196
Deferred:
Federal	(66.3)	29.4	23.4
State and local	5.7	4.9	1.4
Foreign	(13)	(31.4)	(24.2)
Total deferred provision for income taxes	(73.6)	2.9	0.6
Provision for income taxes	$ 135.9	$ 202.2	$ 196.6

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Bonus Deprecation	100.00%
Tax cuts and jobs act, income tax expense (benefit)	$ (89.1)
Increase (decrease) in income taxes payable	8
Deferred tax liability	321.9	$ 306.6
Unrecognized tax benefits that would have a favorable effect on the Company's effective tax rate in any future periods	13.2	13.8	$ 11.4
The total gross amount of accrued interest and penalties	4.5	$ 3.4	$ 2.8
Significant change in unrecognized tax benefits is reasonably possible approximately	$ 0.5

Income Taxes - Effective Tax Ra

Income Taxes - Effective Tax Rate on Income from Continuing Operations (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Federal statutory rate	35.00%	35.00%	35.00%
State and local taxes, net of federal tax benefit	2.60%	2.70%	2.60%
Foreign tax differentials	(2.10%)	(4.70%)	(6.80%)
Federal Tax Reform-deferred rate change	(12.90%)	0.00%	0.00%
U.K. legislative change	0.00%	(1.00%)	(2.10%)
Stock-based compensation	(2.50%)	0.00%	0.00%
Other	(0.40%)	(1.10%)	0.00%
Effective tax rate for continuing operations	19.70%	30.90%	28.70%

Income Taxes - Summary of Defer

Income Taxes - Summary of Deferred Tax Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Deferred income tax asset:
Employee wages, pension and other benefits	$ 15.5	$ 30.1
Deferred rent	3.8	6.3
Net operating loss carryover	36.4	24.3
Capital and other unrealized losses	2.1	3.5
Interest expense	9.1	0
Other	8.2	12.3
Total	75.1	76.5
Less valuation allowance	(17.6)	(8.1)
Deferred income tax asset	57.5	68.4
Deferred income tax liability:
Fixed assets and intangible assets	(366.2)	(355.2)
Other	(13.2)	(19.8)
Deferred income tax liability	(379.4)	(375)
Deferred income tax liability, net	$ (321.9)	$ (306.6)

Income Taxes - Summary of Compa

Income Taxes - Summary of Company's Net Operating Loss Carryforwards Expires (Detail) $ in Millions	Dec. 31, 2017USD ($)
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 211.5
2018-2025 [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	1.9
2026-2030 [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	3.8
2031-2037 [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 205.8

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefit (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Unrecognized tax benefit as of January 1	$ 16.8	$ 14.5	$ 10.6
Gross increase in tax positions in prior period	1.7	2.5	7.1
Gross decrease in tax positions in prior period	(1.2)	(0.4)	(2.6)
Gross increase in tax positions in current period	0	6.4	0
Settlements	0	(5.3)	(0.3)
Lapse of statute of limitations	(1)	(0.9)	(0.3)
Unrecognized tax benefit as of December 31	$ 16.3	$ 16.8	$ 14.5

Composition of Certain Financ70

Composition of Certain Financial Statement Captions - Schedule of Other Current Assets, Accounts Payable, Accrued Liabilities and Other Liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Other current assets:
Acquisition related escrows	$ 22.9	$ 4.1
Other current assets	16.2	16.2
Total other current assets	39.1	20.3
Accounts payable and accrued liabilities:
Accrued salaries, benefits and other related costs	115.3	88.6
Escrow liabilities	22.9	4.1
Accrued interest	18.3	17
Trade accounts payable and other accrued expenses	68.9	74.3
Total accounts payable and accrued liabilities	$ 225.4	$ 184

Debt - Short-Term and Long-Term

Debt - Short-Term and Long-Term Debt (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Short-term debt and current portion of long-term debt	$ 724.4	$ 106.8
Capital lease obligations	7.6	7.1
Long-term debt	2,284.4	2,280.2
Total debt	$ 3,008.8	2,387
4.000% Senior Notes Due in 2025 [Member]
Debt Instrument [Line Items]
Debt instrument, issuance date	May 15, 2015
Debt instrument, maturity date	Jun. 15, 2025
Long-term debt	$ 890.9	889.6
Unamortized discount on senior notes	$ (9.1)	$ (10.4)
Interest rate, stated percentage		4.00%
5.500% Senior Notes Due in 2045 [Member]
Debt Instrument [Line Items]
Debt instrument, issuance date	May 15, 2015
Debt instrument, maturity date	Jun. 15, 2045
Long-term debt	$ 345.1	$ 345
Unamortized discount on senior notes	$ (4.9)	$ (5)
Interest rate, stated percentage		5.50%
4.125% Senior Notes Due in 2022 [Member]
Debt Instrument [Line Items]
Debt instrument, issuance date	Sep. 12, 2012
Debt instrument, maturity date	Sep. 12, 2022
Long-term debt	$ 347.1	$ 346.5
Unamortized discount on senior notes	$ (2.9)	$ (3.5)
Interest rate, stated percentage		4.125%
4.875% Senior Notes Due in 2019 [Member]
Debt Instrument [Line Items]
Debt instrument, issuance date	Dec. 8, 2011
Debt instrument, maturity date	Jan. 15, 2019
Long-term debt	$ 249.3	$ 248.6
Unamortized discount on senior notes	$ (0.7)	$ (1.4)
Interest rate, stated percentage		4.875%
5.80% Senior Notes Due in 2021 [Member]
Debt Instrument [Line Items]
Debt instrument, issuance date	Apr. 6, 2011
Debt instrument, maturity date	May 1, 2021
Long-term debt	$ 448.2	$ 447.6
Unamortized discount on senior notes	(1.8)	$ (2.4)
Interest rate, stated percentage		5.80%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt	715	$ 100
Capital lease obligations [Member]
Debt Instrument [Line Items]
Debt	9.4	6.8
Line of Credit [Member]
Debt Instrument [Line Items]
Unamortized discount on senior notes	$ (3.8)	$ (4.2)

Debt - Additional Information (

Debt - Additional Information (Detail)	Mar. 10, 2015USD ($)	Dec. 31, 2017USD ($)fiscal_quarter	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Debt Instrument [Line Items]
Accrued interest		$ 18,300,000	$ 17,000,000
Interest expense		119,400,000	120,000,000	$ 121,400,000
Long-term debt, gross		$ 2,300,000,000	2,300,000,000
Number of quarters | fiscal_quarter		4
Short-term debt and current portion of long-term debt		$ 724,400,000	106,800,000
Bridge loan	$ 2,300,000,000
Interest Expense [Member]
Debt Instrument [Line Items]
Repayments of debt				4,800,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Short-term debt		$ 715,000,000	$ 100,000,000
Private Placement [Member]
Debt Instrument [Line Items]
Short-term debt and current portion of long-term debt				0
Bridge Loan [Member]
Debt Instrument [Line Items]
Interest expense				$ 9,100,000
Debt instrument, term (in days)	364 days
Loan commitment fee [Member] | Minimum [Member]
Debt Instrument [Line Items]
Interest rate, stated percentage		12.50%
Loan commitment fee [Member] | Maximum [Member]
Debt Instrument [Line Items]
Interest rate, stated percentage		25.00%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Interest coverage ratio		3
Leverage ratio, first four fiscal quarters		3.5
Revolving Credit Facility [Member] | Minimum [Member]
Debt Instrument [Line Items]
Interest rate, stated percentage		1.125%
Revolving Credit Facility [Member] | Maximum [Member]
Debt Instrument [Line Items]
Interest rate, stated percentage		1.625%

Debt - Summary of Long Term Deb

Debt - Summary of Long Term Debt Maturities (Detail) $ in Millions	Dec. 31, 2017USD ($)
Debt Disclosure [Abstract]
2,018	$ 724.4
2,019	253.9
2,020	2.3
2,021	451.4
2,022	350
2023 and thereafter	1,250
Total	$ 3,032

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017USD ($)boardmember$ / sharesshares	Dec. 31, 2016$ / sharesshares	Dec. 31, 2015shares
Class of Stock [Line Items]
Common stock authorized (in shares)	2,000,000,000	2,000,000,000
Board members | boardmember	13
Authorized preferred stock (in shares)	80,000,000
Preferred stock par value per share (in dollars per share) | $ / shares	$ 0.001
Share repurchase program, authorized capacity | $	$ 2,800,000,000
Treasury stock, cumulative value, acquired, cost method | $	2,433,800,000
Available shares for repurchase | $	$ 366,200,000
Treasury stock acquired (in shares)	3,356,360	4,325,548
Treasury stock (in shares)	379,124,108	377,087,266
Reissued of common stock (in shares)	1,319,518	1,816,339
Weighted average price per share (in dollars per share) | $ / shares	$ 8.13	$ 7.23
Common stock shares excluded from diluted EPS (in shares)	1,967,409	1,724,338	1,221,301
Verisk Class A [Member]
Class of Stock [Line Items]
Treasury stock acquired (in shares)	3,356,360	4,325,548	1,088,474
Weighted average repurchase price of shares (in dollars per share) | $ / shares	$ 80.39	$ 77.06
Treasury stock (in shares)	379,124,108

Stockholders' Equity - Computat

Stockholders' Equity - Computation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income from continuing operations	$ 555.1	$ 451.5	$ 487.5
Net income	$ 555.1	$ 591.2	$ 507.6
Denominator:
Weighted average number of common shares used in basic EPS (in shares)	165,168,224	168,248,304	165,090,380
Effect of dilutive shares:
Potential common stock issuable from stock options and stock awards (in shares)	3,520,644	2,923,268	3,360,963
Weighted average number of common shares and dilutive potential common shares used in diluted EPS (in shares)	168,688,868	171,171,572	168,451,343
Discontinued Operations, Disposed of by Sale [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income (loss) from discontinued operations, net	$ 0	$ 139.7	$ 20.1

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Accumulated Other Comprehensive Losses (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Equity [Abstract]
Foreign currency translation adjustment	$ (334.4)	$ (561.4)
Unrealized gains on available-for-sale securities, net of tax	0.7	0.3
Pension and postretirement adjustment, net of tax	(78.6)	(89.7)
Accumulated other comprehensive losses	$ (412.3)	$ (650.8)

Stockholders' Equity - Other Co

Stockholders' Equity - Other Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Before Tax
Other comprehensive income	$ 242.3	$ (416.8)	$ (160.5)
Tax Benefit (Expense)
Other comprehensive income	(3.8)	8	(1)
After Tax
Other comprehensive income	238.5	(408.8)	(161.5)
Foreign Currency Adjustment [Member]
Before Tax
Other comprehensive income	227	(395.6)	(162.7)
Tax Benefit (Expense)
Other comprehensive income	0	0	0
After Tax
Other comprehensive income	227	(395.6)	(162.7)
Available-for-Sale Securities Adjustment [Member]
Before Tax
Other comprehensive income (loss) before reclassifications	0.5	0.5	0.4
Reclassification from accumulated other comprehensive income			(0.2)
Other comprehensive income	0.5	0.5	0.2
Tax Benefit (Expense)
Other comprehensive income (loss) before reclassifications	(0.1)	(0.2)	(0.2)
Reclassification from accumulated other comprehensive income			0.1
Other comprehensive income	(0.1)	(0.2)	(0.1)
After Tax
Other comprehensive income (loss) before reclassifications	0.4	0.3	0.2
Reclassification from accumulated other comprehensive income			(0.1)
Other comprehensive income	0.4	0.3	0.1
Pension and Postretirement Adjustment [Member]
Before Tax
Other comprehensive income (loss) before reclassifications	19.7	(18.1)	5.3
Reclassification from accumulated other comprehensive income	(4.9)	(3.6)	(3.3)
Other comprehensive income	14.8	(21.7)	2
Tax Benefit (Expense)
Other comprehensive income (loss) before reclassifications	(4.9)	6.8	(2.2)
Reclassification from accumulated other comprehensive income	1.2	1.4	1.3
Other comprehensive income	(3.7)	8.2	(0.9)
After Tax
Other comprehensive income (loss) before reclassifications	14.8	(11.3)	3.1
Reclassification from accumulated other comprehensive income	(3.7)	(2.2)	(2)
Other comprehensive income	$ 11.1	$ (13.5)	$ 1.1

Compensation Plans - Additional

Compensation Plans - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017USD ($)Hours_of_Service$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares	Dec. 31, 2015USD ($)$ / sharesshares	May 15, 2013shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Debt structure, direct loan, amount			$ 0
Required contribution to new loan agreement		$ 18,800,000
KSOP compensation expense (in shares)	$ 0	14,500,000	14,100,000
KSOP compensation expense	$ 31,800,000	$ 30,000,000	$ 30,500,000
Common stock shares fair value (in dollars per share) | $ / shares	$ 96	$ 81.17	$ 76.88
Number of service hours (in hours) | Hours_of_Service	1,000
Restricted stock service vesting period (in years)	4 years
Profit sharing contributions	$ 0	$ 0	$ 0
Proceeds from stock options exercised	$ 35,000,000	41,100,000	38,800,000
Nonqualified stock option contractual term (in years)	10 years
Excess tax benefit from stock option exercised	$ 19,000,000	23,300,000	29,200,000
Realized tax benefit from stock option exercised	28,400,000	31,400,000	40,100,000
Net share settlement from restricted stock awards	$ 2,900,000	$ 3,100,000	$ 2,400,000
Number of stock issued during period shares stock options exercised net of taxes (in shares) | shares	36,067	38,250	32,882
Total unrecognized compensation cost related to nonvested share based compensation arrangements	$ 68,900,000
Unrecognized compensation cost weighted average period (in years)	2 years 6 months 12 days
Non vested stock option (in shares) | shares	2,911,770
Stock option expected to vest (in shares) | shares	2,450,191
Total fair value of options vested	$ 16,600,000	$ 14,200,000	$ 16,800,000
Grant date fair value restricted stock vested	$ 17,600,000	14,400,000	16,300,000
Authorized payroll deductions on base salary	20.00%
Maximum payroll deductions on short-term incentive compensation	50.00%
Maximum amount of payroll deductions	$ 25,000
Purchase discount	5.00%
Additional Paid-in Capital [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net share settlement from restricted stock awards	$ 2,900,000	$ 3,100,000	$ 2,400,000
Verisk Class A [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Class A common stock reserved (in shares) | shares				15,700,000
Basis to reduce shares authorized for shares issued subject to option or stock appreciation rights				1
Basis to reduce shares authorized for shares issued subject to awards other than option or stock appreciation rights				2.5
Common stock, shares issued (in shares) | shares	6,761,346
Verisk [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued in period (in shares) | shares		181,198
Shares of Verisk Class A common stock issued, discounted price per share (in dollars per share) | $ / shares		$ 79.97
KSOP compensation expense (in shares)	$ 15,600,000
Ksop [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued in period (in shares) | shares			145,007
Shares of Verisk Class A common stock issued, discounted price per share (in dollars per share) | $ / shares			$ 72.06
ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued in period (in shares) | shares	29,605	29,867	25,599
Shares of Verisk Class A common stock issued, discounted price per share (in dollars per share) | $ / shares	$ 81.38	$ 76.75	$ 70.27
Ksop [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax contribution of compensation	$ 18,000	$ 18,000	$ 18,000
Minimum participant age, additional employee contributions (in years)	50 years
Contributions of additional pre-tax basis	$ 6,000	6,000	6,000
After tax contribution are limited for compensation	10.00%
Matching contributions in Class A common stock	75.00%
Matching contributions initial in Class A common stock	6.00%
KSOP compensation expense		$ 14,500,000	$ 14,100,000
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock service vesting period (in years)	4 years
Non vested stock option (in shares) | shares	604,331
Stock option expected to vest (in shares) | shares	509,701

Compensation Plans Compensation

Compensation Plans Compensation Plans - Summary of Equity Awards (Details) - shares	Jul. 01, 2017	Apr. 01, 2017	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)				1,440,270	1,364,916	1,884,262
Common stock issued (in shares)				1,125,004	1,409,803	1,739,847
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)				1,440,270
Stock Options [Member] | Four-year Graded Vesting [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity award contractual term (in years)			4 years
Stock options granted (in shares)				1,318,107
Stock Options [Member] | Two-year Graded Vesting [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity award contractual term (in years)		2 years
Stock options granted (in shares)				47,030
Stock Options [Member] | One-year Graded Vesting [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity award contractual term (in years)	1 year
Stock options granted (in shares)				75,133
Stock Options [Member] | Not applicable [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)				0
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock granted (in shares)				296,850	292,941	350,004
Common stock issued (in shares)				143,557	169,365	177,252
Restricted Stock [Member] | Four-year Graded Vesting [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock granted (in shares)				273,966
Restricted Stock [Member] | Two-year Graded Vesting [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock granted (in shares)				11,272
Restricted Stock [Member] | One-year Graded Vesting [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock granted (in shares)				10,308
Restricted Stock [Member] | Not applicable [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock granted (in shares)				1,304
Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock issued (in shares)				3,573
Common Stock [Member] | Four-year Graded Vesting [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock issued (in shares)				0
Common Stock [Member] | Two-year Graded Vesting [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock issued (in shares)				0
Common Stock [Member] | One-year Graded Vesting [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock issued (in shares)				0
Common Stock [Member] | Not applicable [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock issued (in shares)				3,573

Compensation Plans - Fair Value

Compensation Plans - Fair Value of Stock Options Granted Using Black- Scholes Valuation Model (Detail) - Stock Options [Member] - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option pricing model	Black-Scholes	Black-Scholes	Black-Scholes
Expected volatility	18.72%	20.26%	19.51%
Risk-free interest rate	1.82%	1.14%	1.29%
Expected term (in years)	4 years 6 months	4 years 6 months	4 years 6 months
Dividend yield	0.00%	0.00%	0.00%
Weighted average grant date fair value per stock option (in dollars per share)	$ 15.71	$ 15.33	$ 13.58

Compensation Plans - Options Ou

Compensation Plans - Options Outstanding Under Incentive Plan and Option Plan (Detail) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Number of Options
Number of options outstanding, beginning balance (in shares)	8,770,917	9,117,733	9,205,690
Number of options granted (in shares)	1,440,270	1,364,916	1,884,262
Number of options, exercised (in shares)	(1,125,004)	(1,409,803)	(1,739,847)
Number of options, canceled or expired (in shares)	(179,074)	(301,929)	(232,372)
Number of options outstanding, ending balance (in shares)	8,907,109	8,770,917	9,117,733
Number of options exercisable (in shares)	5,995,339	6,148,349
Weighted Average Exercise Price Per Share
Weighted average exercise price per share, beginning balance (in dollars per share)	$ 46.67	$ 40.17	$ 31.11
Weighted average exercise price per share, granted (in dollars per share)	81.33	80.23	72.20
Weighted average exercise price per share , exercised (in dollars per share)	33.66	31.47	23.71
Weighted average exercise price per share, canceled or expired (in dollars per share)	76.70	73.01	64.05
Weighted average exercise price per share, ending balance (in dollars per share)	53.31	46.67	$ 40.17
Weighted average exercise price, options exercisable (in dollars per share)	$ 41.50	$ 35.35
Options, Additional Disclosures
Aggregate intrinsic value option outstanding, beginning balance	$ 302.6	$ 334.7	$ 303.3
Aggregate intrinsic value, exercised	57.2	69.3	87
Aggregate intrinsic value option outstanding, ending balance	380.2	302.6	$ 334.7
Aggregate intrinsic value of stock option exercisable	$ 326.8	$ 281.7

Compensation Plans - Summary of

Compensation Plans - Summary of Nonvested Options (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Number of Options
Number of options outstanding, beginning balance (in shares)	8,770,917	9,117,733	9,205,690
Number of options granted (in shares)	1,440,270	1,364,916	1,884,262
Number of options, canceled or expired (in shares)	(179,074)	(301,929)	(232,372)
Number of options outstanding, ending balance (in shares)	8,907,109	8,770,917	9,117,733
Non Vested Options [Member]
Number of Options
Number of options outstanding, beginning balance (in shares)	2,622,568	2,576,504	2,045,795
Number of options granted (in shares)	1,440,270	1,364,916	1,884,262
Number of options, vested (in shares)	(971,994)	(1,016,923)	(1,121,181)
Number of options, canceled or expired (in shares)	(179,074)	(301,929)	(232,372)
Number of options outstanding, ending balance (in shares)	2,911,770	2,622,568	2,576,504
Weighted Average Grant-Date Fair Value Per Share
Weighted average grant-date fair value per share, nonvested beginning balance (in dollars per share)	$ 14.12	$ 12.95	$ 12.55
Weighted average grant-date fair value per share, granted (in dollars per share)	15.71	15.33	13.58
Weighted average grant-date fair value per share, vested (in dollars per share)	14.19	12.78	13.24
Weighted average grant-date fair value per share, cancelled or expired (in dollars per share)	14.53	14.18	13.05
Weighted average grant-date fair value per share, nonvested ending balance (in dollars per share)	$ 14.86	$ 14.12	$ 12.95

Compensation Plans - Summary 83

Compensation Plans - Summary of Restricted Stock Activity Under Incentive Plan (Detail) - Restricted Stock [Member] - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Number of Shares
Number of shares, outstanding beginning balance (in shares)	537,667	533,768	442,310
Number of shares, granted (in shares)	296,850	292,941	350,004
Number of shares, vested (in shares)	(197,403)	(230,683)	(211,265)
Number of shares, forfeited (in shares)	(32,650)	(58,359)	(47,281)
Number of shares, outstanding ending balance (in shares)	604,464	537,667	533,768
Weighted Average Grant Date Fair Value Per Share
Weighted average grant-date fair value per share, outstanding, beginning balance (in dollars per share)	$ 73.34	$ 66.25	$ 56.84
Weighted average grant-date fair value per share, granted (in dollars per share)	82.02	80.27	72.24
Weighted average grant-date fair value per share, vested (in dollars per share)	70.72	64.44	58.64
Weighted average grant-date fair value per share, forfeited (in dollars per share)	77.13	72.86	63.10
Weighted average grant-date fair value per share, outstanding, ending balance (in dollars per share)	$ 78.28	$ 73.34	$ 66.25

Pension and Postretirement Be84

Pension and Postretirement Benefits - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Healthcare cost trend rate	8.75%
Decreased healthcare cost trend rate	4.50%
Change in assumed healthcare cost trend rates	1.00%
Reduction in accumulated postretirement benefit obligation for subsidy	$ 1,600,000	$ 2,100,000
Effect of subsidy on net periodic postretirement benefit cost	$ 2,000	$ 54,000	$ 7,000
Expected plan asset allocation	100.00%
Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Domestic equity portion of portfolio	40.00%
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Domestic equity portion of portfolio	60.00%
Equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target allocation	60.00%
Debt securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target allocation	40.00%
Foreign Pension Plans [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
International equity portion of portfolio	10.00%
Foreign Pension Plans [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
International equity portion of portfolio	20.00%
Fixed Income Funds [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Fixed income portion of portfolio	20.00%
Fixed Income Funds [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Fixed income portion of portfolio	40.00%
Veba [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation	100.00%
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Deferred compensation arrangement with individual, contributions by employer	$ 0
Estimated future employer contributions in next fiscal year	$ 0
Target allocation	100.00%
Actual plan asset allocation	100.00%	100.00%
Pension Plan And Supplemental Cash Balance Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Company contribution to defined benefit plan	$ 900,000	$ 1,000,000
Estimated future employer contributions in next fiscal year	800,000
Postretirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Company contribution to defined benefit plan	$ 1,000,000	$ 0
Expected return on plan assets, benefit obligations	2.00%	3.00%
Pension Plan and SERP Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Company contribution to defined benefit plan	$ 900,000	$ 1,000,000
Expected return on plan assets, benefit obligations	7.00%	7.25%

Pension and Postretirement Be85

Pension and Postretirement Benefits - Summary of Changes in Benefit Obligations and Plan Assets Amount Recognized (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Change in plan assets:
Fair value of plan assets at January 1	$ 455.6
Fair value of plan assets at December 31	494.8	$ 455.6
Pension Plan and SERP Plan [Member]
Change in benefit obligation:
Benefit obligation at January 1	438.4	419.6
Interest cost	17.1	19.3	$ 18.1
Actuarial loss (gain)	25.4	28.5
Plan participants’ contributions	0	0
Benefits paid	28	29
Federal subsidy on benefits paid	0	0
Benefit obligation at December 31	452.9	438.4	419.6
Accumulated benefit obligation at December 31	452.9	438.4
Change in plan assets:
Fair value of plan assets at January 1	444.5	438.6
Actual return on plan assets, net of expenses	67.3	33.9
Employer contributions, net	0.9	1
Plan participants’ contributions	0	0
Benefits paid	(28)	(29)
Federal subsidies received	0	0
Fair value of plan assets at December 31	484.7	444.5	438.6
(Funded) unfunded status at December 31	(31.8)	(6.1)
Pension assets, noncurrent	(45.1)	(19.6)
Pension, SERP and postretirement benefits, current	0.8	0.9
Pension, SERP and postretirement benefits, noncurrent	12.5	12.6
Total Pension, SERP and Postretirement benefits	(31.8)	(6.1)
Postretirement Plan [Member]
Change in benefit obligation:
Benefit obligation at January 1	12.8	15.8
Interest cost	0.4	0.4	0.5
Actuarial loss (gain)	0.7	(1.4)
Plan participants’ contributions	1.6	1.9
Benefits paid	4.2	4.4
Federal subsidy on benefits paid	0.5	0.5
Benefit obligation at December 31	11.8	12.8	15.8
Change in plan assets:
Fair value of plan assets at January 1	11.1	13
Actual return on plan assets, net of expenses	0.1	0.1
Employer contributions, net	1	0
Plan participants’ contributions	1.6	1.9
Benefits paid	(4.2)	(4.4)
Federal subsidies received	0.5	0.5
Fair value of plan assets at December 31	10.1	11.1	$ 13
(Funded) unfunded status at December 31	1.7	1.7
Pension assets, noncurrent	0	0
Pension, SERP and postretirement benefits, current	0	0
Pension, SERP and postretirement benefits, noncurrent	1.7	1.7
Total Pension, SERP and Postretirement benefits	$ 1.7	$ 1.7

Pension and Postretirement Be86

Pension and Postretirement Benefits - Summary of Pre-Tax Components of Accumulated Other Comprehensive Losses (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Pension Plan and SERP Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Prior service benefit cost (credit)	$ 3.5	$ 3.7
Actuarial losses	124.3	139.6
Accumulated other comprehensive losses, pretax	127.8	143.3
Postretirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Prior service benefit cost (credit)	(0.5)	(0.8)
Actuarial losses	5.6	5.2
Accumulated other comprehensive losses, pretax	$ 5.1	$ 4.4

Pension and Postretirement Be87

Pension and Postretirement Benefits - Components of Net Periodic Benefit Cost and Amounts Recognized in Other Comprehensive Income (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pension Plan and SERP Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 17.1	$ 19.3	$ 18.1
Expected return on plan assets	(31.1)	(31.7)	(34.4)
Amortization of prior service cost (credit) reclassified from accumulated other comprehensive losses	0.2	0.1	0
Amortization of net actuarial loss reclassified from accumulated other comprehensive losses	4.5	3.2	2.8
Net periodic benefit (credit) cost	(9.3)	(9.1)	(13.5)
Amortization of prior service benefit cost (credit) reclassified from accumulated other comprehensive losses	(0.2)	(0.1)	0
Amortization of actuarial loss reclassified from accumulated other comprehensive losses	(0.1)	0	(0.2)
Net loss recognized reclassified from accumulated other comprehensive losses	(4.4)	(3.2)	(2.6)
Plan amendments	0	0	3.8
Actuarial gain (loss)	(10.8)	26.4	(1.5)
Total recognized in other comprehensive loss	(15.5)	23.1	(0.5)
Total recognized in net periodic benefit cost (credit) and other comprehensive loss	(24.8)	14	(14)
Postretirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	0.4	0.4	0.5
Expected return on plan assets	(0.3)	(0.5)	(0.6)
Amortization of prior service cost (credit) reclassified from accumulated other comprehensive losses	(0.2)	(0.1)	(0.1)
Amortization of net actuarial loss reclassified from accumulated other comprehensive losses	0.4	0.4	0.6
Net periodic benefit (credit) cost	0.3	0.2	0.4
Amortization of prior service benefit cost (credit) reclassified from accumulated other comprehensive losses	0.2	0.1	0.1
Amortization of actuarial loss reclassified from accumulated other comprehensive losses	0	0	0
Net loss recognized reclassified from accumulated other comprehensive losses	(0.4)	(0.4)	0
Plan amendments	0	0	0
Actuarial gain (loss)	0.9	(1.1)	(1.6)
Total recognized in other comprehensive loss	0.7	(1.4)	(1.5)
Total recognized in net periodic benefit cost (credit) and other comprehensive loss	$ 1	$ (1.2)	$ (1.1)

Pension and Postretirement Be88

Pension and Postretirement Benefits - Summary of Accumulated Other Comprehensive Losses Recognized in Net Periodic Benefit (Detail) $ in Millions	Dec. 31, 2017USD ($)
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service benefit cost (credit)	$ 0
Amortization of net actuarial loss	3.9
Total	3.9
Pension Plan and SERP Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service benefit cost (credit)	0.2
Amortization of net actuarial loss	3.4
Total	3.6
Postretirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service benefit cost (credit)	(0.2)
Amortization of net actuarial loss	0.5
Total	$ 0.3

Pension and Postretirement Be89

Pension and Postretirement Benefits - Summary of Weighted-Average Assumptions Used in Calculating Net Periodic Benefit (Credit) Cost (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pension Plan and SERP Plan [Member]
Weighted-average assumptions used to determine benefit obligations:
Discount rate	3.50%	3.99%
Expected return on plan assets	7.00%	7.25%
Weighted-average assumptions used to determine net periodic benefit (credit) loss:
Discount rate	3.99%	4.73%	3.99%
Expected return on plan assets	7.25%	7.50%	7.50%
Postretirement Plan [Member]
Weighted-average assumptions used to determine benefit obligations:
Discount rate	3.00%	3.25%
Expected return on plan assets	2.00%	3.00%
Weighted-average assumptions used to determine net periodic benefit (credit) loss:
Discount rate	3.25%	3.25%	3.00%
Expected return on plan assets	3.00%	4.00%	4.00%

Pension and Postretirement Be90

Pension and Postretirement Benefits - Summary of Estimated Future Benefit Payments for Respective Plans (Detail) $ in Millions	Dec. 31, 2017USD ($)
Pension Plan and SERP Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Gross benefit amount, 2018	$ 30.5
Gross benefit amount, 2019	31.5
Gross benefit amount, 2020	30.1
Gross benefit amount, 2021	30.7
Gross benefit amount, 2022	29.9
Gross benefit amount, 2022-2026	141.7
Postretirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Gross benefit amount, 2018	2
Medicare subsidy payments, 2018	(0.3)
Net benefit amount, 2018	1.7
Gross benefit amount, 2019	1.8
Medicare subsidy payments, 2019	(0.3)
Net benefit amount, 2019	1.5
Gross benefit amount, 2020	1.7
Medicare subsidy payments, 2020	(0.3)
Net benefit amount, 2020	1.4
Gross benefit amount, 2021	1.5
Medicare subsidy payments, 2021	(0.3)
Net benefit amount, 2021	1.2
Gross benefit amount, 2022	1.3
Medicare subsidy payments, 2022	(0.3)
Net benefit amount, 2022	1
Gross benefit amount, 2022-2026	4.4
Medicare subsidy payments, 2022-2026	(0.2)
Net benefit amount, 2022-2026	$ 4.2

Pension and Postretirement Be91

Pension and Postretirement Benefits - Summary of Asset Allocation and Target Allocation (Detail) - Pension Plan [Member]	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	100.00%
Summary of asset allocation and target allocation
Percentage of Plan Assets	100.00%	100.00%
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	60.00%
Summary of asset allocation and target allocation
Percentage of Plan Assets	54.00%	61.60%
Debt securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	40.00%
Summary of asset allocation and target allocation
Percentage of Plan Assets	37.90%	37.80%
Other Asset Category [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	0.00%
Summary of asset allocation and target allocation
Percentage of Plan Assets	8.10%	0.60%

Pension and Postretirement Be92

Pension and Postretirement Benefits - Summary of Fair Value Measurements of Pension Plan Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 494.8	$ 455.6
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	211.5	221.3
Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	283.1	234.1
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.2	0.2
Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	201.4	210.2
Equity Funds [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	201.4	210.2
Equity Funds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	60.3	63.2
Equity Securities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Equity Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	60.3	63.2
Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Equity Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.2	0.2
Equity Partnerships [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Equity Partnerships [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Equity Partnerships [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.2	0.2
Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	183.6	167.9
Fixed Income Securities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fixed Income Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	183.6	167.9
Fixed Income Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
US Treasury and Government [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10.1	11.1
US Treasury and Government [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10.1	11.1
US Treasury and Government [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
US Treasury and Government [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.5	3
Cash and Cash Equivalents [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and Cash Equivalents [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.5	3
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	$ 0
Global Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	38.7
Global Real Estate [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Global Real Estate [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	38.7
Global Real Estate [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0

Segment Reporting - Additional

Segment Reporting - Additional Information (Detail) - segment	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting [Abstract]
Number of operating segments	2
Number of reportable segments	2
Revenue outside of US	21.70%	22.60%	18.20%
Percentage of revenue outside of US	10.00%	10.00%	10.00%

Segment Reporting - Reconciliat

Segment Reporting - Reconciliation Income Before Income Taxes (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Revenues	$ 2,145.2	$ 1,995.2	$ 1,760.7
Expenses:
Cost of revenues (exclusive of items shown separately below)	(783.8)	(714.4)	(612)
Selling, general and administrative	(322.8)	(301.6)	(278.3)
Investment income and others, net	9.2	6.1	16.9
EBITDA from discontinued operations	0	266	81.7
Gain on derivative instruments	0	0	85.2
EBITDA	1,047.8	1,251.3	1,054.2
Depreciation and amortization of fixed assets	(135.6)	(119.1)	(96.6)
Amortization of intangible assets	(101.8)	(92.5)	(70.4)
Investment income and others, net	(9.2)	(6.1)	(16.9)
EBITDA from discontinued operations	0	(266)	(81.7)
Gain on derivative instruments	0	0	85.2
Operating income	801.2	767.6	703.4
Interest expense	(119.4)	(120)	(121.4)
Income before income taxes	691	653.7	684.1
Decision Analytics [Member]
Segment Reporting Information [Line Items]
Revenues	1,374.9	1,270.9	1,072.5
Expenses:
Cost of revenues (exclusive of items shown separately below)	(557)	(490.7)	(412)
Selling, general and administrative	(238.3)	(214.9)	(196.5)
Investment income and others, net	9.5	4.5	16.8
EBITDA from discontinued operations	0	266	81.7
Gain on derivative instruments	0	0	85.2
EBITDA	589.1	835.8	647.7
Depreciation and amortization of fixed assets	(105.2)	(91.4)	(70.8)
Amortization of intangible assets	(97.8)	(91.8)	(70)
Investment income and others, net	(9.5)	(4.5)	(16.8)
EBITDA from discontinued operations	0	(266)	(81.7)
Gain on derivative instruments	0	0	85.2
Operating income	376.6	382.1	323.2
Risk Assessment [Member]
Segment Reporting Information [Line Items]
Revenues	770.3	724.3	688.2
Expenses:
Cost of revenues (exclusive of items shown separately below)	(226.8)	(223.7)	(200)
Selling, general and administrative	(84.5)	(86.7)	(81.8)
Investment income and others, net	(0.3)	1.6	0.1
EBITDA from discontinued operations	0	0	0
Gain on derivative instruments	0	0	0
EBITDA	458.7	415.5	406.5
Depreciation and amortization of fixed assets	(30.4)	(27.7)	(25.8)
Amortization of intangible assets	(4)	(0.7)	(0.4)
Investment income and others, net	0.3	(1.6)	(0.1)
EBITDA from discontinued operations	0	0	0
Gain on derivative instruments	0	0	0
Operating income	$ 424.6	$ 385.5	$ 380.2

Segment Reporting - Operating S

Segment Reporting - Operating Segment Revenue by Type of Service (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Revenues	$ 2,145.2	$ 1,995.2	$ 1,760.7
Decision Analytics [Member]
Segment Reporting Information [Line Items]
Revenues	1,374.9	1,270.9	1,072.5
Decision Analytics [Member] | Insurance [Member]
Segment Reporting Information [Line Items]
Revenues	784.7	699.8	647.2
Decision Analytics [Member] | Energy and Specialized Markets [Member]
Segment Reporting Information [Line Items]
Revenues	444.7	442.8	308.8
Decision Analytics [Member] | Financial services [Member]
Segment Reporting Information [Line Items]
Revenues	145.5	128.3	116.5
Risk Assessment [Member]
Segment Reporting Information [Line Items]
Revenues	770.3	724.3	688.2
Risk Assessment [Member] | Industry-standard insurance programs [Member]
Segment Reporting Information [Line Items]
Revenues	593.6	554.1	524.6
Risk Assessment [Member] | Property-specific rating and underwriting information [Member]
Segment Reporting Information [Line Items]
Revenues	$ 176.7	$ 170.2	$ 163.6

Segment Reporting - Long-lived

Segment Reporting - Long-lived Assets and Revenue by Geographic Region (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Long-lived assets	$ 5,422.7	$ 4,130.3
U.S. [Member]
Segment Reporting Information [Line Items]
Long-lived assets	2,438.6	1,754
U.K. [Member]
Segment Reporting Information [Line Items]
Long-lived assets	2,656.6	2,102.5
Other countries [Member]
Segment Reporting Information [Line Items]
Long-lived assets	$ 327.5	$ 273.8

Related Parties - Additional In

Related Parties - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Related Party Transactions [Abstract]
Percentage of ownership on outstanding common stock required to become related party (more than)	5.00%	5.00%
Revenues from related parties	$ 0	$ 0	$ 0

Commitments and Contingencies -

Commitments and Contingencies - Minimum Rentals under Long Term Noncancelable Leases for All Leased Premises, Computer Equipment and Automobiles (Detail) $ in Millions	Dec. 31, 2017USD ($)
Operating Leases
2,018	$ 40.6
2,019	41.8
2,020	42.9
2,021	34.6
2,022	31.5
2023 and thereafter	173.9
Net minimum lease payments	365.3
Capital Leases
2,018	10
2,019	4.2
2,020	2.4
2,021	1.4
2,022	0
2023 and thereafter	0
Net minimum lease payments	18
Less amount representing interest	1
Present value of net minimum lease capital payments	$ 17

Commitments and Contingencies99

Commitments and Contingencies - Additional Information (Detail)	Nov. 05, 2015claim	Oct. 08, 2015patent	Aug. 01, 2014plaintiffdefendant	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Loss Contingencies [Line Items]
Rent expense on operating leases				$ 39,000,000	$ 39,500,000	$ 37,300,000
Number of putative classes | claim	2
Xactware Solutions [Member]
Loss Contingencies [Line Items]
Patents allegedly infringed (in patents) | patent		7
Insurance Services Office [Member]
Loss Contingencies [Line Items]
Number of plaintiffs | plaintiff			19
Number of defendants (more than) | defendant			120
Minimum [Member] | Intellicorp Records, Inc. [Member]
Loss Contingencies [Line Items]
Damages sought				100
Maximum [Member] | Intellicorp Records, Inc. [Member]
Loss Contingencies [Line Items]
Damages sought				$ 1,000

Schedule II - Valuation and 100

Schedule II - Valuation and Qualifying Accounts and Reserves (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016		Dec. 31, 2015
Allowance for doubtful accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	[1]	$ 3.4	$ 2.6		$ 3.2
Charged to Expenses / Against Revenue	[2]	2	2.2		0.8
Deductions - Write-offs	[3]	(0.8)	(1.4)		(1.4)
Balance at End of Year		4.6	3.4	[1]	2.6	[1]
Valuation allowance for income taxes [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	[1]	8.1	0.9		0.7
Charged to Expenses / Against Revenue	[2]	10	7.2		0.2
Deductions - Write-offs	[3]	(0.5)	0		0
Balance at End of Year		$ 17.6	$ 8.1	[1]	$ 0.9	[1]
[1]	Excludes discontinued operations
[2]	Primarily additional reserves for bad debts
[3]	Primarily accounts receivable balances written off, net of recoveries, and the expiration of loss carryforwards