Affiliated Managers (MGR) 10-Q4 May 182018 Q1 Quarterly reportFinancial data

Company Profile

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2018	May 02, 2018
Document and Entity Information
Entity Registrant Name	AFFILIATED MANAGERS GROUP, INC.
Entity Central Index Key	1,004,434
Document Type	10-Q
Document Period End Date	Mar. 31, 2018
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		54,315,146
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Consolidated revenue	$ 612.4	$ 544.3
Consolidated expenses:
Compensation and related expenses	266.7	242
Selling, general and administrative	106.4	88.7
Intangible amortization and impairments	23.2	21.9
Interest expense	21.6	22.5
Depreciation and other amortization	5.5	5.2
Other expenses (net)	12	11.4
Total consolidated expenses	435.4	391.7
Equity method income (net)	96.3	85.9
Investment and other income	14.2	14.8
Income before income taxes	287.5	253.3
Income tax expense	63.5	59.7
Net income	224	193.6
Net income (non-controlling interests)	(71)	(71.1)
Net income (controlling interest)	$ 153	$ 122.5
Average shares outstanding (basic) (in shares)	54.6	56.7
Average shares outstanding (diluted) (in shares)	57	59.2
Earnings per share (basic) (in dollars per share)	$ 2.80	$ 2.16
Earnings per share (diluted) (in dollars per share)	2.77	2.13
Dividends per share (in dollars per share)	$ 0.30	$ 0.20

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 224	$ 193.6
Other comprehensive income (loss):
Foreign currency translation gain	29.1	12.2
Change in net realized and unrealized gain (loss) on derivative securities, net of tax	0.3	(0.3)
Change in net unrealized gain on investment securities, net of tax	0	4.9
Other comprehensive income	29.4	16.8
Comprehensive income	253.4	210.4
Comprehensive income (non-controlling interests)	(79.5)	(73.7)
Comprehensive income (controlling interest)	$ 173.9	$ 136.7

CONSOLIDATED CONDENSED BALANCE

CONSOLIDATED CONDENSED BALANCE SHEETS - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Assets
Cash and cash equivalents	$ 334.2	$ 439.5
Receivables	532.2	433.8
Goodwill	2,667.3	2,662.5
Acquired client relationships (net)	1,443.1	1,449.7
Equity method investments in Affiliates (net)	3,177	3,304.7
Fixed assets (net)	111.3	111
Investments and other assets	319.1	300.9
Total assets	8,584.2	8,702.1
Liabilities and Equity
Payables and accrued liabilities	667.3	807.2
Senior debt	1,556.4	1,550.3
Convertible securities	305.1	304.4
Deferred income tax liability (net)	474.9	467.4
Other liabilities	216.3	182.4
Total liabilities	3,220	3,311.7
Commitments and contingencies (Note 5)
Redeemable non-controlling interests	941.6	811.9
Equity:
Common stock ($0.01 par value, 153.0 shares authorized; 58.5 shares outstanding in 2017 and 2018)	0.6	0.6
Additional paid-in capital	664.2	808.6
Accumulated other comprehensive loss	(0.9)	(21.8)
Retained earnings	3,834.9	3,698.5
Total stockholders' equity before treasury stock	4,498.8	4,485.9
Less: Treasury stock, at cost (3.4 shares in 2017 and 4.2 shares in 2018)	(821.8)	(663.7)
Total stockholders' equity	3,677	3,822.2
Non-controlling interests	745.6	756.3
Total equity	4,422.6	4,578.5
Total liabilities and equity	$ 8,584.2	$ 8,702.1

CONSOLIDATED CONDENSED BALANCE5

CONSOLIDATED CONDENSED BALANCE SHEETS - Parenthetical - $ / shares shares in Millions	Mar. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	153	153
Common stock, shares outstanding (in shares)	58.5	58.5
Treasury stock, at cost (in shares)	4.2	3.4

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Treasury Stock at Cost	Non-controlling Interests
Beginning Balance (in shares) at Dec. 31, 2016		58.5
Beginning Balance at Dec. 31, 2016	$ 4,426.5	$ 0.6	$ 1,073.5	$ (122.9)	$ 3,054.4	$ (386)	$ 806.9
Increase (Decrease) in Stockholders' Equity
Net income	193.6				122.5		71.1
Other comprehensive income	16.8			14.2			2.6
Share-based compensation	9.4		9.4
Common stock issued under share-based incentive plans	5.1		(63.3)			68.4
Share repurchases	(80)					(80)
Dividends ($0.20 per share and $0.30 per share)	(11.5)				(11.5)
Issuance costs and other	0.1		0.1
Affiliate equity activity:
Affiliate equity expense	16.6		4				12.6
Issuances	0.8		(1.2)				2
Repurchases	34.2		34.2				0
Changes in redemption value of Redeemable non-controlling interests	(131.5)		(131.5)
Transfers to Redeemable non-controlling interests	(25.7)						(25.7)
Capital contributions by Affiliate equity holders	6.6						6.6
Distributions to non-controlling interests	(92)						(92)
Ending Balance (in shares) at Mar. 31, 2017		58.5
Ending Balance at Mar. 31, 2017	$ 4,369	$ 0.6	925.2	(108.7)	3,165.4	(397.6)	784.1
Beginning Balance (in shares) at Dec. 31, 2017	58.5	58.5
Beginning Balance at Dec. 31, 2017	$ 4,578.5	$ 0.6	808.6	(21.8)	3,698.5	(663.7)	756.3
Increase (Decrease) in Stockholders' Equity
Net income	224				153		71
Other comprehensive income	29.4			20.9			8.5
Share-based compensation	10.7		10.7
Common stock issued under share-based incentive plans	(9.5)		(2.2)			(7.3)
Share repurchases	(150.8)					(150.8)
Dividends ($0.20 per share and $0.30 per share)	(16.6)				(16.6)
Affiliate equity activity:
Affiliate equity expense	19.4		2.6				16.8
Issuances	7		(1.4)				8.4
Repurchases	14.4		14.4
Changes in redemption value of Redeemable non-controlling interests	(168.5)		(168.5)
Transfers to Redeemable non-controlling interests	(4.9)						(4.9)
Capital contributions by Affiliate equity holders	1.9						1.9
Distributions to non-controlling interests	$ (112.4)						(112.4)
Ending Balance (in shares) at Mar. 31, 2018	58.5	58.5
Ending Balance at Mar. 31, 2018	$ 4,422.6	$ 0.6	$ 664.2	$ (0.9)	$ 3,834.9	$ (821.8)	$ 745.6

CONSOLIDATED STATEMENTS OF CHA7

CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - Parenthetical - $ / shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Stockholders' Equity [Abstract]
Dividends per share (in dollars per share)	$ 0.30	$ 0.20

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flow from (used in) operating activities:
Net income	$ 224	$ 193.6
Adjustments to reconcile Net income to net cash flow from operating activities:
Intangible amortization and impairments	23.2	21.9
Depreciation and other amortization	5.5	5.2
Deferred income tax provision	13.4	35.3
Equity method income (net)	(96.3)	(85.9)
Distributions of earnings received from equity method investments	225.7	189.9
Share-based compensation and Affiliate equity expense	30.1	26
Other non-cash items	1.2	(5.7)
Changes in assets and liabilities:
Purchases of securities by Affiliate sponsored consolidated products	(9.9)	(9.1)
Sales of securities by Affiliate sponsored consolidated products	12.5	7.1
Increase in receivables	(92.4)	(75.1)
Increase in other assets	(4)	(0.7)
Decrease in payables, accrued liabilities and other liabilities	(128)	(180.4)
Cash flow from operating activities	205	122.1
Cash flow from (used in) investing activities:
Investments in Affiliates	0	(4.7)
Purchase of fixed assets	(5.5)	(4.1)
Purchase of investment securities	(5)	(6.2)
Sale of investment securities	6.6	31.3
Cash flow from (used in) investing activities	(3.9)	16.3
Cash flow from (used in) financing activities:
Borrowings of senior debt	440	75
Repayments of senior debt	(435)	(160)
Repurchase of common stock	(173.1)	(80)
Issuance of common stock	3	20.3
Dividends paid on common stock	(16.4)	(11.3)
Distributions to non-controlling interests	(112.4)	(92)
Affiliate equity issuances and repurchases	(8.3)	(17.6)
Other financing items	(10.9)	(11.8)
Cash flow used in financing activities	(313.1)	(277.4)
Effect of foreign exchange rate changes on cash and cash equivalents	6.7	1.8
Net decrease in cash and cash equivalents	(105.3)	(137.2)
Cash and cash equivalents at beginning of period	439.5	430.8
Cash and cash equivalents at end of period	$ 334.2	$ 293.6

Basis of Presentation and Use o

Basis of Presentation and Use of Estimates	3 Months Ended
Basis of Presentation and Use of Estimates	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Use of Estimates	Basis of Presentation and Use of Estimates The Consolidated Financial Statements of Affiliated Managers Group, Inc. (the “Company”) have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for full year financial statements. In the opinion of management, all normal and recurring adjustments considered necessary for a fair presentation of the Company’s financial position and results of operations have been included and all intercompany balances and transactions have been eliminated. During the quarter, the Company changed its Consolidated Financial Statement presentation to present non-classified Consolidated Statements of Income and Consolidated Condensed Balance Sheets. These changes, along with other reclassifications, have been made to the prior period’s financial statements to conform to the current period’s presentation. Operating results for interim periods are not necessarily indicative of the results that may be expected for any other period or for the full year. The Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2017 includes additional information about its operations, financial position and accounting policies, and should be read in conjunction with this Quarterly Report on Form 10-Q. The preparation of financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the reported amounts and disclosures in the financial statements. Actual results could differ from those estimates. All amounts in these notes, except per share data in the text and tables herein, are stated in millions unless otherwise indicated.

Accounting Standards and Polici

Accounting Standards and Policies	3 Months Ended
Accounting Standards and Policies	Mar. 31, 2018
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Accounting Standards and Policies	Accounting Standards and Policies Recently Adopted Accounting Standards During the quarter the Company adopted several new Accounting Standard Updates (“ASU”). While none of these ASUs had a significant impact on the Company’s Consolidated Financial Statements, the Company was required to update certain of its significant accounting policies. For a complete list of significant accounting policies, see the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2017. Revenue Recognition On January 1, 2018, the Company adopted ASU 2014-09, Revenue from Contracts with Customers (as amended), using a modified retrospective method and, as a result, updated its revenue recognition accounting policy as follows. Revenue primarily represents asset and performance based fees earned by the Company's Affiliates for managing the assets of clients. Substantially all of the Company’s Affiliate contracts contain a single performance obligation, which is investment management services. Investment management services are performed and consumed simultaneously and, therefore, the Company recognizes asset based fees ratably over time. Broker-dealer and administrative fees for services that are provided and consumed over time, and which are related to Affiliate sponsored investment products, are also included ratably in revenue. Revenue recognized by the Company is adjusted for any expense reimbursement arrangements. Performance based fees, including carried interests, are recognized only upon the satisfaction of performance obligations, resolution of any constraints and when it is improbable that there will be a significant reversal in the amount of revenue recognized. Performance based fees and carried interest may have a performance period that overlaps more than one reporting period. As such, any performance based fees or carried interest recognized in the current reporting period may relate to performance obligations satisfied in a previous reporting period. Revenue from investment management, broker-dealer and administrative services is typically based on the value of client assets over time, which are typically determined using observable market data. Services may be invoiced in advance or in arrears and are payable upon receipt. Any fees collected in advance are deferred and recognized as the services are performed and consumed. The Company and certain of its Affiliates have contractual arrangements with third parties to provide distribution-related services. Fees received and expenses incurred under these arrangements are primarily based on the value of client assets over time. Distribution-related fees are presented in revenue gross of any related expenses when the Company or its Affiliate is the principal in its role as primary obligor under its distribution-related services arrangements. Distribution-related expenses are presented within Selling, general and administrative expenses in the Consolidated Statements of Income. The Company and its Affiliates may enter into contracts for which the costs to obtain or fulfill the contract are based upon a percentage of the value of a client’s future assets under management. The Company and its Affiliates record these variable costs when incurred because they are subject to market volatility and are not estimable upon inception of a contract with a client. Any expenses paid in advance are capitalized and amortized on a systematic basis consistent with the transfer of services, which is the equivalent of recognizing the costs as incurred. Investments in Marketable Securities On January 1, 2018, the Company also adopted ASU 2016-01, Financial Instruments - Overall: Recognition and Measurement of Financial Assets and Financial Liabilities, using a modified retrospective method and, as a result, updated its Investments in marketable securities accounting policy as follows. Investments in marketable securities are carried at fair value and reported within Investments and other assets on the Consolidated Condensed Balance Sheets. Upon the adoption of ASU 2016-01, the Company no longer classifies these securities as either trading or available-for-sale securities. Realized and unrealized gains or losses on investments in marketable securities are reported within Investment and other income in the Consolidated Statements of Income. Realized gains and losses are recorded on the trade date on a specific identified basis. Recent Accounting Developments In February 2016, the Financial Accounting Standards Board (the “FASB”) issued ASU 2016-02, Leases, which requires lessees to record right-of-use assets and lease liabilities arising from most operating leases on the statement of financial position. The standard is effective for interim and annual periods beginning after December 15, 2018 for the Company and its consolidated Affiliates and for interim and annual periods beginning after December 15, 2019 for the Company’s equity method Affiliates. The standard must be adopted using a modified retrospective method. The Company is evaluating the impact of this standard on its Consolidated Financial Statements. In January 2017, the FASB issued ASU 2017-04, Intangibles - Goodwill and Other: Simplifying the Accounting for Goodwill Impairment. Under the new standard, a goodwill impairment will now be the amount by which a reporting unit’s carrying value exceeds its fair value. The standard is effective for interim and annual periods beginning after December 15, 2019. The Company will apply the standard prospectively upon adoption. The Company is evaluating the impact of this standard on its Consolidated Financial Statements.

Investments in Marketable Secur

Investments in Marketable Securities	3 Months Ended
Investments in Marketable Securities	Mar. 31, 2018
Marketable Securities [Abstract]
Investments in Marketable Securities	Investments in Marketable Securities As of December 31, 2017 and March 31, 2018 , the fair value of marketable securities was $77.8 million and $81.0 million , respectively, and marketable securities were principally investments in equity securities. Investments in marketable securities are reported within Investments and other assets. The following is a summary of the cost, gross unrealized gains and losses and fair value of investments in marketable securities: December 31, March 31, Cost $ 67.1 $ 74.2 Unrealized gains 13.0 9.0 Unrealized losses (2.3 ) (2.2 ) Fair value $ 77.8 $ 81.0 In the three months ended March 31, 2017 and 2018, the Company received proceeds of $37.3 million and $13.8 million , respectively, from the sale of investments in marketable securities and recorded net gains of $6.7 million and $ 2.8 million , respectively.

Investments in Affiliates and A

Investments in Affiliates and Affiliate Sponsored Investment Products	3 Months Ended
	Mar. 31, 2018
Variable Interest Entities
Investments in Affiliates and Affiliate Sponsored Investment Products	Investments in Affiliates and Affiliate Sponsored Investment Products In evaluating whether an investment must be consolidated, the Company evaluates the risk, rewards and significant terms of each of its Affiliates and other investments to determine if an investment is considered a voting rights entity (“VRE”) or a variable interest entity (“VIE”). An entity is a VRE when the total equity investment at risk is sufficient to enable the entity to finance its activities independently and when the equity holders have the obligation to absorb losses, the right to receive residual returns and the right to direct the activities of the entity that most significantly impact its economic performance. An entity is a VIE when it lacks one or more of the characteristics of a VRE, which for the Company are Affiliates structured as partnerships (or similar entities) where the limited partners lack substantive kick-out or substantive participation rights over the general partner. Assessing whether an entity is a VRE or VIE involves judgment. Upon the occurrence of certain events, management reviews and reconsiders its previous conclusion regarding the status of an entity as a VRE or a VIE. The Company consolidates VREs when it has control over significant operating, financial and investing decisions of the investment. When the Company lacks such control, but is deemed to have significant influence, the Company accounts for the investment under the equity method. Other investments in which the Company does not have rights to exercise significant influence are recorded at fair value, with changes in fair value reflected within Investment and other income. The Company consolidates VIEs when it is the primary beneficiary of the entity, which is defined as having the power to direct the activities that most significantly impact the VIE’s economic performance and the obligation to absorb losses of or the right to receive benefits from the entity that could potentially be significant to the VIE. The Company applies the equity method of accounting to VIEs where the Company is not the primary beneficiary, but has the ability to exercise significant influence over operating and financial matters of the VIE. Investments in Affiliates Substantially all of the Company’s Affiliates are considered VIEs and are either consolidated or accounted for under the equity method. A limited number of the Company’s Affiliates are considered VREs and most of these are accounted for under the equity method. When an Affiliate is consolidated, the portion of the Affiliate’s management equity owners’ earnings attributable to Owners’ Allocation is included in Net income (non-controlling interests) in the Consolidated Statements of Income. Undistributed Operating and Owners’ Allocation attributable to Affiliate management equity owners, along with their share of any tangible or intangible net assets, are presented within Non-controlling interests on the Consolidated Condensed Balance Sheets. Affiliate equity interests where the holder has certain rights to demand settlement are presented, at their current redemption values, as Redeemable non-controlling interests on the Consolidated Condensed Balance Sheets. The Company periodically issues, sells and repurchases the equity of its consolidated Affiliates. Because these transactions take place between entities that are under common control, any gains or losses attributable to these transactions are required to be included within Additional paid-in capital, net of any related income tax effects in the period the transactions occur. When an Affiliate is accounted for under the equity method, the Company’s share of an Affiliate’s earnings or losses, net of amortization and impairments, is included in Equity method income (net) in the Consolidated Statements of Income and the Company’s interest in the Affiliate is reported in Equity method investments in Affiliates (net) in the Consolidated Condensed Balance Sheets. The Company’s share of income taxes incurred directly by Affiliates accounted for under the equity method is recorded within Income tax expense in the Consolidated Statements of Income. The Company periodically evaluates its equity method investments for impairment. In such impairment evaluations, the Company assesses whether or not the fair value of the investment has declined below its carrying value for a period considered to be other-than-temporary. If the Company determines that a decline in fair value below the carrying value of the investment is other-than-temporary, then the carrying value of the investment is reduced to its fair value and the reduction is recorded in Equity method income (net). The unconsolidated assets, net of liabilities and non-controlling interests of equity method Affiliates considered VIEs, and the Company’s maximum risk of loss, were as follows: December 31, 2017 March 31, 2018 Unconsolidated Carrying Value and Unconsolidated Carrying Value and Affiliates accounted for under the equity method $ 1,594.4 $ 2,765.7 $ 1,285.7 $ 2,640.3 Affiliate Sponsored Investment Products The Company’s Affiliates sponsor various investment products where they also act as the investment advisor. These investment products are typically owned primarily by third-party investors; however, certain products are funded with general partner and seed capital investments from the Company and its consolidated Affiliates. Investors in Affiliate sponsored investment products are generally entitled to substantially all of the economics of these products, except for the management and performance fees earned by consolidated Affiliates or any gains or losses attributable to the Company or its consolidated Affiliates’ investments in these products. As a result, the Company does not generally consolidate these products unless the Company and/or the Affiliate’s interest in the product is considered substantial. When the Affiliate’s interest is considered substantial and the products are consolidated, the Company retains the specialized investment company accounting principles of the underlying products, and all of the underlying investments are carried at fair value in Investments and other assets in the Consolidated Condensed Balance Sheets, with corresponding changes in the investments’ fair values reflected in Investment and other income in the Consolidated Statements of Income. Purchases and sales of securities are presented within purchases and sales by Affiliate sponsored consolidated products in the Consolidated Statements of Cash Flows. When Affiliates no longer control these products, due to a reduction in ownership or other reasons, the products are deconsolidated. The net assets of unconsolidated VIEs attributable to Affiliate sponsored investment products, and the Company’s maximum risk of loss, were as follows: December 31, 2017 March 31, 2018 Unconsolidated VIE Net Assets Carrying Value and Maximum Exposure to Loss Unconsolidated VIE Net Assets Carrying Value and Maximum Exposure to Loss Affiliate sponsored investment products $ 2,154.6 $ 10.2 $ 2,291.5 $ 10.4

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
Commitments and Contingencies	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies From time to time, the Company and its Affiliates may be subject to claims, legal proceedings and other contingencies in the ordinary course of their business activities. Any such matters are subject to various uncertainties, and it is possible that some of these matters may be resolved in a manner unfavorable to the Company or its Affiliates. The Company and its Affiliates establish accruals, as necessary, for matters for which the outcome is probable and the amount of the liability can be reasonably estimated. The Company has committed to co-invest in certain Affiliate sponsored investment products. As of March 31, 2018 , these unfunded commitments were $120.4 million and may be called in future periods. As of March 31, 2018 , the Company was contingently liable, upon the achievement by certain Affiliates of specified financial targets, to make payments through 2020 related to the Company’s investments in these Affiliates. For its consolidated Affiliates, the Company was contingently liable for up to $18.2 million , and expected to make total payments of $10.2 million ( $8.2 million in 2018). The present value of the total expected payments was $9.8 million . For its equity method Affiliates, the Company was contingently liable to make payments up to $170.0 million and expected to make no payments. Affiliate equity interests provide holders with a conditional right to put their interests to the Company over time. See Note 13. In addition, in connection with an investment in an Affiliate accounted for under the equity method, the Company entered into an arrangement with a minority owner of the Affiliate that gives such owner the right to sell a portion of its ownership interest in the Affiliate to the Company annually beginning in the fourth quarter of 2018. The purchase price of these conditional purchases will be at fair market value on the date of the transaction. The Company and certain Affiliates operate under regulatory authorities that require the maintenance of minimum financial or capital requirements. Management is not aware of any significant violations of such requirements.

Senior Debt

Senior Debt	3 Months Ended
Senior Debt	Mar. 31, 2018
Debt Disclosure [Abstract]
Senior Debt	Senior Debt The Company has a senior unsecured multicurrency revolving $1.45 billion credit facility (the “revolver”) and a senior unsecured $385.0 million term loan facility (the “term loan” and, together with the revolver, the “credit facilities”). In March 2018, the Company refinanced the term loan with the same outstanding borrowings and commercial terms, other than interest rates and the maturity date. Subject to certain conditions, the Company may further increase the commitments under the revolver by up to $350.0 million and borrow up to an additional $65.0 million under the term loan. The revolver matures on September 30, 2020 and the term loan matures on May 31, 2021.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
Fair Value Measurements	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The following tables summarize the Company’s financial assets and liabilities that are measured at fair value on a recurring basis: Fair Value Measurements December 31, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial Assets Cash equivalents $ 40.4 $ 40.4 $ — $ — Investments in marketable securities (1) 77.8 77.8 — — Foreign currency forward contracts (1) 0.2 — 0.2 — Financial Liabilities (2) Contingent payment arrangements $ 9.4 $ — $ — $ 9.4 Affiliate equity obligations 49.2 — — 49.2 Foreign currency forward contracts 0.6 — 0.6 — Fair Value Measurements March 31, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial Assets Cash equivalents $ 33.3 $ 33.3 $ — $ — Investments in marketable securities (1) 81.0 81.0 — — Foreign currency forward contracts (1) 1.2 — 1.2 — Financial Liabilities (2) Contingent payment arrangements $ 9.8 $ — $ — $ 9.8 Affiliate equity obligations 79.4 — — 79.4 Foreign currency forward contracts 1.3 — 1.3 — __________________________ (1) Amounts are presented within Investments and other assets. (2) Amounts are presented within Other liabilities. The following are descriptions of the financial assets and liabilities measured at fair value and the fair value methodologies used: Cash equivalents consist primarily of highly liquid investments in daily redeeming money market funds, without enacted liquidity fees or redemption gates that are valued at net asset value (“NAV”). Investments in marketable securities consist primarily of investments in publicly traded securities and funds advised by Affiliates that are valued at NAV. Publicly traded securities valued using unadjusted quoted market prices for identical instruments in active markets are classified as level 1. Publicly traded securities valued using quoted prices for similar instruments in active markets or quoted prices for identical or similar instruments in markets that are not active are classified as level 2. Investments in funds advised by Affiliates that are valued at NAV are classified as level 1. Contingent payment arrangements represent the present value of the expected future settlement of contingent payment arrangements related to the Company’s investments in consolidated Affiliates. The significant unobservable inputs that are used in the fair value measurement of these obligations are growth and discount rates. Increases in the growth rate result in a higher obligation while increases in the discount rate result in a lower obligation. Affiliate equity obligations include agreements to repurchase Affiliate equity. The significant unobservable inputs that are used in the fair value measurement of the agreements to repurchase Affiliate equity are growth and discount rates. Increases in the growth rate result in a higher obligation while increases in the discount rate result in a lower obligation. Foreign currency forward contracts use model-derived valuations in which all significant inputs are observable in active markets to determine fair value. It is the Company’s policy to value financial assets or liabilities transferred as of the beginning of the period in which the transfer occurs. There were no significant transfers of financial assets or liabilities between level 1 and level 2 in the three months ended March 31, 2017 and 2018 . Level 3 Financial Assets and Liabilities The following table presents the changes in level 3 liabilities: For the Three Months Ended March 31, 2017 2018 Contingent Payment Arrangements Affiliate Equity Obligations Contingent Payment Arrangements Affiliate Equity Obligations Balance, beginning of period $ 8.6 $ 12.1 $ 9.4 $ 49.2 Net realized and unrealized losses (1) 0.3 — 0.4 — Purchases and issuances (2) — 99.6 — 45.6 Settlements and reductions — (20.2 ) — (15.4 ) Balance, end of period $ 8.9 $ 91.5 $ 9.8 $ 79.4 Net change in unrealized losses relating to instruments still held at the reporting date $ 0.3 $ — $ 0.4 $ — ___________________________ (1) Accretion and changes in the expected value of the Company’s contingent payment arrangements and Affiliate equity obligations are recorded in Other expenses (net). (2) Includes transfers from Redeemable non-controlling interests. The following table presents certain quantitative information about the significant unobservable inputs used in valuing the Company’s level 3 financial liabilities: Quantitative Information About Level 3 Fair Value Measurements Valuation Techniques Unobservable Input Fair Value at Range at Fair Value at March 31, 2018 Range at March 31, 2018 Contingent payment arrangements Discounted cash flow Growth rates $ 9.4 7% - 8% $ 9.8 7% - 8% Discount rates 15% - 16% 15% - 16% Affiliate equity obligations Discounted cash flow Growth rates 49.2 0% - 11% 79.4 0% - 11% Discount rates 12% - 16% 12% - 16% Investments Measured at NAV as a Practical Expedient The Company’s Affiliates sponsor investment products in which the Company and Affiliates may make general partner and seed capital investments. The Company uses the NAV of these investments as a practical expedient for their fair value and reports these products within Investments and other assets. The following table summarizes the nature of the Company’s investments, unfunded commitments and any related liquidity restrictions or other factors that may impact the ultimate value realized: December 31, 2017 March 31, 2018 Category of Investment Fair Value Unfunded Commitments Fair Value Unfunded Commitments Private equity funds (1) $ 156.1 $ 98.8 $ 171.7 $ 120.4 Other funds (2) 8.9 — 8.2 — Other investments (3) $ 165.0 $ 98.8 $ 179.9 $ 120.4 ___________________________ (1) The Company uses NAV as a practical expedient one quarter in arrears (adjusted for current period calls and distributions) to determine the fair value. These funds primarily invest in a broad range of private equity funds, as well as making direct investments. Distributions will be received as the underlying assets are liquidated over the life of the funds, which is generally up to 15 years . (2) These are multi-disciplinary funds that invest across various asset classes and strategies, including long/short equity, credit and real estate. Investments are generally redeemable on a daily, monthly or quarterly basis. (3) Fair value attributable to the controlling interest was $80.1 million and $99.0 million as of December 31, 2017 and March 31, 2018, respectively. Other Financial Assets and Liabilities Not Carried at Fair Value The carrying amount of Receivables and Payables and accrued liabilities approximates fair value because of the short-term nature of these instruments. The carrying value of notes receivable, which is reported in Investments and other assets, approximates fair value because interest rates and other terms are at market rates. The carrying value of the credit facilities, which is reported in Senior debt, approximates fair value because the credit facilities have variable interest based on selected short-term rates. The following table summarizes the Company’s other financial liabilities not carried at fair value: December 31, 2017 March 31, 2018 Carrying Value Fair Value Carrying Value Fair Value Fair Value Hierarchy Senior notes (1) $ 745.7 $ 765.2 $ 745.8 $ 753.4 Level 2 Convertible securities 309.9 549.8 310.5 534.2 Level 2 ___________________________ (1) The carrying value of the senior notes is reported in Senior debt.

Goodwill and Acquired Client Re

Goodwill and Acquired Client Relationships	3 Months Ended
Goodwill and Acquired Client Relationships	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Acquired Client Relationships	Goodwill and Acquired Client Relationships The following tables present the changes in the Company’s consolidated Affiliates’ Goodwill and components of Acquired client relationships (net): Goodwill Total Balance, as of December 31, 2017 $ 2,662.5 Foreign currency translation 4.8 Balance, as of March 31, 2018 $ 2,667.3 Acquired Client Relationships (Net) Definite-lived Indefinite-lived Total Gross Book Value Accumulated Amortization Net Book Value Net Book Value Net Book Value Balance, as of December 31, 2017 $ 1,295.5 $ (874.5 ) $ 421.0 $ 1,028.7 $ 1,449.7 Intangible amortization and impairments — (23.2 ) (23.2 ) — (23.2 ) Foreign currency translation 2.2 — 2.2 14.4 16.6 Balance, as of March 31, 2018 $ 1,297.7 $ (897.7 ) $ 400.0 $ 1,043.1 $ 1,443.1 Definite-lived acquired client relationships are amortized over their expected period of economic benefit. The Company recorded amortization expense within Intangible amortization and impairments, for these relationships of $21.9 million and $23.2 million for the three months ended March 31, 2017 and 2018, respectively. Based on relationships existing as of March 31, 2018 , the Company estimates that its consolidated annual amortization expense will be approximately $90 million in each of 2018 and 2019, approximately $65 million in 2020 and approximately $40 million in each of 2021 and 2022.

Equity Method Investments in Af

Equity Method Investments in Affiliates	3 Months Ended
Equity Method Investments in Affiliates	Mar. 31, 2018
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments in Affiliates	Equity Method Investments in Affiliates The following table presents the change in Equity method investments in Affiliates (net): Total Balance, as of December 31, 2017 $ 3,304.7 Equity method earnings 126.3 Equity method intangible amortization (30.0 ) Distributions of earnings from equity method investments (225.7 ) Foreign currency translation 11.6 Other (9.9 ) Balance, as of March 31, 2018 $ 3,177.0 Definite-lived acquired relationships at the Company’s equity method Affiliates are amortized over their expected period of economic benefit. The Company recognized amortization expense for these relationships of $21.7 million and $30.0 million for the three months ended March 31, 2017 and 2018, respectively. Based on relationships existing as of March 31, 2018 , the Company estimates the annual amortization expense attributable to its equity method Affiliates will be approximately $100 million in 2018 and approximately $90 million in each of 2019, 2020, 2021 and 2022. The Company has determined that one of its equity method Affiliates is significant under Rule 10-01(b)(1) of Regulation S-X. For the three months ended March 31, 2017 and 2018, this equity method Affiliate recognized revenue of $ 265.6 million and $ 310.7 million, respectively, and net income of $ 148.6 million and $ 169.6 million, respectively.

Related Party Transactions

Related Party Transactions	3 Months Ended
Related Party Transactions	Mar. 31, 2018
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions A prior owner of one of the Company’s Affiliates retained interests in certain of the Affiliate’s private equity investment partnerships. The prior owner’s interests are presented in Other liabilities and were $61.2 million and $57.0 million at December 31, 2017 and March 31, 2018 , respectively. The Company and its Affiliates earn asset and performance based fees and incur distribution and other expenses for services provided to Affiliate sponsored investment products. In addition, Affiliate management owners and Company officers may serve as trustees or directors of certain investment vehicles from which an Affiliate earns fees. The Company had liabilities to related parties for contingent payment arrangements in connection with certain business combinations. The net present value of the total amounts payable were $9.4 million and $9.8 million as of December 31, 2017 and March 31, 2018 , respectively, and were included in Other liabilities. The Company has related party transactions in association with its Affiliate equity transactions, as more fully described in Notes 12 and 13.

Share-Based Compensation

Share-Based Compensation	3 Months Ended
Share-Based Compensation	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	Share-Based Compensation The following table presents share-based compensation expense: For the Three Months Ended March 31, 2017 2018 Share-based compensation $ 9.4 $ 10.7 Tax benefit 3.6 2.7 The Company had $63.5 million and $89.7 million of unrecognized share-based compensation expense as of December 31, 2017 and March 31, 2018 , respectively, which will be recognized over a weighted average period of approximately two years (assuming no forfeitures). Stock Options The following table summarizes transactions in the Company’s stock options: Stock Options Weighted Average Exercise Price Weighted Average Remaining Contractual Life (years) Unexercised options outstanding - December 31, 2017 0.6 $ 122.04 Options granted 0.0 203.22 Options exercised (0.0 ) 98.69 Options forfeited — — Unexercised options outstanding - March 31, 2018 0.6 124.49 3.8 Exercisable at March 31, 2018 0.2 120.03 2.0 For the three months ended March 31, 2017 and 2018, the Company granted stock options with fair values of $0.4 million and $0.5 million , respectively. Stock options generally vest over a period of three to four years and expire seven years after the grant date. All options have been granted with exercise prices equal to the closing price of the Company’s common stock on the grant date. In certain circumstances, option awards also require certain performance conditions to be satisfied in order for the options to be exercised. The fair value of options granted was estimated using the Black-Scholes option pricing model and were $46.49 and $53.81 , per option, for the three months ended March 31, 2017 and 2018, respectively. The weighted average grant date assumptions used to estimate the fair value of options granted were as follows: For the Three Months Ended March 31, 2017 2018 Dividend yield 0.5 % 0.7 % Expected volatility 30.1 % 24.6 % Risk-free interest rate 2.2 % 2.6 % Expected life of options (in years) 5.7 5.7 Forfeiture rate — % — % Restricted Stock The following table summarizes transactions in the Company’s restricted stock units: Restricted Stock Units Weighted Average Grant Date Value Unvested units - December 31, 2017 0.4 $ 162.32 Units granted 0.2 203.23 Units vested (0.0 ) 204.40 Units forfeited (0.0 ) 173.41 Unvested units - March 31, 2018 0.6 172.59 For the three months ended March 31, 2017 and 2018, the Company granted awards with fair values of $36.4 million and $36.7 million , respectively. These awards were valued based on the closing price of the Company’s common stock on the grant date and the number of awards expected to be delivered. Awards containing vesting conditions generally require service over a period of three to four years and may also require the satisfaction of certain performance conditions.

Redeemable Non-Controlling Inte

Redeemable Non-Controlling Interests	3 Months Ended
Redeemable Non-Controlling Interests	Mar. 31, 2018
Noncontrolling Interest [Abstract]
Redeemable Non-Controlling Interests	Redeemable Non-Controlling Interests Affiliate equity interests provide holders with an equity interest in one of the Company’s Affiliates, consistent with the structured partnership interests in place at the respective Affiliate. Affiliate equity holders generally have a conditional right to put their interests to the Company at certain intervals (between five and 15 years from the date the equity interest is received or on an annual basis following an Affiliate equity holder’s departure). The current redemption value of the Company’s Affiliate equity interests is presented as Redeemable non-controlling interests. Changes in the current redemption value are recorded to Additional paid-in capital. When the Company has an unconditional obligation to repurchase Affiliate equity interests, they are reclassified to Other liabilities. The following table presents the changes in Redeemable non-controlling interests: Redeemable Non-controlling interests Balance, as of December 31, 2017 $ 811.9 Changes attributable to consolidated products 1.9 Transfers to Other liabilities (45.6 ) Transfers from Non-controlling interests 4.9 Changes in redemption value 168.5 Balance, as of March 31, 2018 $ 941.6

Affiliate Equity

Affiliate Equity	3 Months Ended
Affiliate Equity	Mar. 31, 2018
Affiliate Equity [Abstract]
Affiliate Equity	Affiliate Equity Affiliate equity interests are allocated income in a manner that is consistent with the structured partnership interests in place at the respective Affiliate. The Company’s Affiliates generally pay quarterly distributions to Affiliate equity holders. For the three months ended March 31, 2017 and 2018, distributions paid to Affiliate equity holders were $92.0 million and $112.4 million , respectively. The Company periodically repurchases Affiliate equity interests from and issues Affiliate equity interests to its Affiliate partners, its employees and its officers. For the three months ended March 31, 2017 and 2018, the amount of cash paid for repurchases was $23.6 million and $14.5 million , respectively. For the three months ended March 31, 2017 and 2018, the total amount of cash received for issuances was $6.0 million and $6.2 million , respectively. Sales and repurchases of Affiliate equity generally occur at fair value; however, the Company also grants Affiliate equity to its Affiliate partners, its employees and its officers as a form of compensation. If the equity is issued for consideration below the fair value of the equity or repurchased for consideration above the fair value of the equity, then such difference is recorded as compensation expense in Compensation and related expenses over the requisite service period. The following table presents Affiliate equity expense: For the Three Months Ended March 31, 2017 2018 Controlling interest $ 4.0 $ 2.6 Non-controlling interests 12.6 16.8 Total $ 16.6 $ 19.4 The following table presents unrecognized Affiliate equity expense: Controlling Interest Remaining Life Non-controlling Interests Remaining Life December 31, 2017 $ 33.3 5 years $ 95.9 6 years March 31, 2018 39.1 5 years 115.5 6 years The Company records amounts receivable from and payable to Affiliate equity holders in connection with the transfer of Affiliate equity interests that have not settled at the end of the period. The total receivable was $12.4 million and $17.2 million at December 31, 2017 and March 31, 2018 , respectively, and was included in Investments and other assets. The total payable was $49.2 million and $79.4 million as of December 31, 2017 and March 31, 2018 , respectively, and was included in Other liabilities. Effects of Changes in the Company’s Ownership in Affiliates The Company periodically acquires interests from, and transfers interests to, Affiliate equity holders. Because these transactions do not result in a change of control, any gain or loss related to these transactions is recorded to Additional paid-in capital, which increases or decreases the controlling interest’s equity. No gain or loss related to these transactions is recognized in the Consolidated Statements of Income or Comprehensive Income. While the Company presents the current redemption value of Affiliate equity within Redeemable non-controlling interests, with changes in the current redemption value increasing or decreasing the controlling interest’s equity over time, the following table presents the cumulative effect that ownership changes had on the controlling interest’s equity related only to Affiliate equity transactions that settled during the applicable periods: For the Three Months Ended March 31, 2017 2018 Net income (controlling interest) $ 122.5 $ 153.0 Decrease in controlling interest paid-in capital from Affiliate equity issuances (1.2 ) (1.0 ) Decrease in controlling interest paid-in capital from Affiliate equity repurchases (52.6 ) (33.1 ) Net income (controlling interest) including net impact of Affiliate equity transactions $ 68.7 $ 118.9

Income Taxes

Income Taxes	3 Months Ended
Income Taxes	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes On December 22, 2017, changes in U.S. tax laws were enacted which significantly revised U.S. corporate income tax by, among other things, lowering the corporate income tax rate, implementing a modified territorial tax system, and imposing a one-time transition tax on deemed repatriated foreign earnings and profits. In 2017, the Company recorded a provisional one-time net benefit of $194.1 million as a reasonable estimate of the impact of the changes in U.S. tax laws. During the three months ended March 31, 2018 , the Company did no t record any changes to its provisional amount. The impact of the changes in U.S. tax laws may be refined as further guidance, interpretations or information becomes available, upon completion by the Company of its evaluation of the impact of the changes in U.S. tax laws or upon the Company’s election of a policy with respect to the deferred tax effects of the Global Intangible Low Tax Income provisions of U.S. tax laws. The Company’s consolidated income tax provision includes taxes attributable to the controlling interest and, to a lesser extent, taxes attributable to the non-controlling interests. The following table presents the consolidated provision for income taxes: For the Three Months Ended March 31, 2017 2018 Controlling interest: Current tax $ 22.4 $ 47.3 Intangible-related deferred taxes 19.8 13.2 Other deferred taxes 15.6 0.3 Total controlling interest 57.8 60.8 Non-controlling interests: Current tax $ 2.0 $ 2.8 Deferred taxes (0.1 ) (0.1 ) Total non-controlling interests 1.9 2.7 Provision for income taxes $ 59.7 $ 63.5 Income before income taxes (controlling interest) $ 180.3 $ 213.8 Effective tax rate (controlling interest) (1) 32.1 % 28.4 % __________________________ (1) Taxes attributable to the controlling interest divided by Income before income taxes (controlling interest).

Earnings Per Share

Earnings Per Share	3 Months Ended
Earnings Per Share	Mar. 31, 2018
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share The calculation of basic earnings per share is based on the weighted average number of shares of the Company’s common stock outstanding during the period. Diluted earnings per share is similar to basic earnings per share, but adjusts for the dilutive effect of the potential issuance of incremental shares of the Company’s common stock. The following is a reconciliation of the numerator and denominator used in the calculation of basic and diluted earnings per share available to common stockholders: For the Three Months Ended March 31, 2017 2018 Numerator Net income (controlling interest) $ 122.5 $ 153.0 Interest expense on convertible securities, net of taxes 3.8 4.7 Net income (controlling interest), as adjusted $ 126.3 $ 157.7 Denominator Average shares outstanding (basic) 56.7 54.6 Effect of dilutive instruments: Stock options and restricted stock units 0.3 0.2 Convertible securities 2.2 2.2 Average shares outstanding (diluted) 59.2 57.0 Average shares outstanding (diluted) in the table above excludes share-based awards that have not satisfied performance conditions and the anti-dilutive effect of the following share-based awards: For the Three Months Ended March 31, 2017 2018 Stock options and restricted stock units 0.2 0.1 The Company may settle portions of its Affiliate equity purchases in shares of its common stock. Because it is the Company’s intent to settle these potential purchases in cash, the calculation of diluted earnings per share excludes any potential dilutive effect from possible share settlements of Affiliate equity purchases. In the three months ended March 31, 2018, the Company repurchased 0.8 million shares of its common stock at an average price per share of $ 192.70 .

Comprehensive Income

Comprehensive Income	3 Months Ended
Comprehensive Income	Mar. 31, 2018
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Comprehensive Income	Comprehensive Income The following table presents the tax effects allocated to each component of Other comprehensive income (loss): For the Three Months Ended March 31, 2017 2018 Pre-Tax Tax Benefit Net of Tax Pre-Tax Tax Benefit Net of Tax Foreign currency translation adjustment $ 12.2 $ — $ 12.2 $ 29.1 $ — $ 29.1 Change in net realized and unrealized gain (loss) on derivative securities (0.3 ) 0.0 (0.3 ) 0.3 — 0.3 Change in net unrealized gain (loss) on investment securities 7.3 (2.4 ) 4.9 — — — Other comprehensive income (loss) $ 19.2 $ (2.4 ) $ 16.8 $ 29.4 $ — $ 29.4 The components of accumulated other comprehensive income (loss), net of taxes, were as follows: Foreign Currency Translation Adjustment Realized and Unrealized Gains (Losses) on Derivative Securities Unrealized Gains (Losses) on Investment Securities (1) Total Balance, as of December 31, 2017 $ (85.9 ) $ (0.4 ) $ 2.1 $ (84.2 ) Other comprehensive income before reclassifications 29.1 0.0 — 29.1 Amounts reclassified — 0.3 (2.1 ) (1.8 ) Net other comprehensive income (loss) 29.1 0.3 (2.1 ) 27.3 Balance, as of March 31, 2018 $ (56.8 ) $ (0.1 ) $ — $ (56.9 ) __________________________ (1) In connection with the Company’s adoption of ASU 2016-01, the unrealized losses on investment securities, which related to the non-controlling interests, were reclassified to Non-controlling interests on the Consolidated Condensed Balance Sheets.

Subsequent Events

Subsequent Events	3 Months Ended
Subsequent Events	Mar. 31, 2018
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events As of May 3, 2018, the Company had repurchased 0.2 million shares of common stock, at an average share price of $162.32 .

Accounting Standards and Poli26

Accounting Standards and Policies (Policies)	3 Months Ended
Accounting Standards and Policies (Policies)	Mar. 31, 2018
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Basis of Presentation	The Consolidated Financial Statements of Affiliated Managers Group, Inc. (the “Company”) have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for full year financial statements. In the opinion of management, all normal and recurring adjustments considered necessary for a fair presentation of the Company’s financial position and results of operations have been included and all intercompany balances and transactions have been eliminated. During the quarter, the Company changed its Consolidated Financial Statement presentation to present non-classified Consolidated Statements of Income and Consolidated Condensed Balance Sheets. These changes, along with other reclassifications, have been made to the prior period’s financial statements to conform to the current period’s presentation. Operating results for interim periods are not necessarily indicative of the results that may be expected for any other period or for the full year. The Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2017 includes additional information about its operations, financial position and accounting policies, and should be read in conjunction with this Quarterly Report on Form 10-Q. All amounts in these notes, except per share data in the text and tables herein, are stated in millions unless otherwise indicated
Use of Estimates	The preparation of financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the reported amounts and disclosures in the financial statements. Actual results could differ from those estimates.
Recently Adopted Accounting Standards	Recently Adopted Accounting Standards During the quarter the Company adopted several new Accounting Standard Updates (“ASU”). While none of these ASUs had a significant impact on the Company’s Consolidated Financial Statements, the Company was required to update certain of its significant accounting policies. For a complete list of significant accounting policies, see the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2017. Revenue Recognition On January 1, 2018, the Company adopted ASU 2014-09, Revenue from Contracts with Customers (as amended), using a modified retrospective method and, as a result, updated its revenue recognition accounting policy as follows. Revenue primarily represents asset and performance based fees earned by the Company's Affiliates for managing the assets of clients. Substantially all of the Company’s Affiliate contracts contain a single performance obligation, which is investment management services. Investment management services are performed and consumed simultaneously and, therefore, the Company recognizes asset based fees ratably over time. Broker-dealer and administrative fees for services that are provided and consumed over time, and which are related to Affiliate sponsored investment products, are also included ratably in revenue. Revenue recognized by the Company is adjusted for any expense reimbursement arrangements. Performance based fees, including carried interests, are recognized only upon the satisfaction of performance obligations, resolution of any constraints and when it is improbable that there will be a significant reversal in the amount of revenue recognized. Performance based fees and carried interest may have a performance period that overlaps more than one reporting period. As such, any performance based fees or carried interest recognized in the current reporting period may relate to performance obligations satisfied in a previous reporting period. Revenue from investment management, broker-dealer and administrative services is typically based on the value of client assets over time, which are typically determined using observable market data. Services may be invoiced in advance or in arrears and are payable upon receipt. Any fees collected in advance are deferred and recognized as the services are performed and consumed. The Company and certain of its Affiliates have contractual arrangements with third parties to provide distribution-related services. Fees received and expenses incurred under these arrangements are primarily based on the value of client assets over time. Distribution-related fees are presented in revenue gross of any related expenses when the Company or its Affiliate is the principal in its role as primary obligor under its distribution-related services arrangements. Distribution-related expenses are presented within Selling, general and administrative expenses in the Consolidated Statements of Income. The Company and its Affiliates may enter into contracts for which the costs to obtain or fulfill the contract are based upon a percentage of the value of a client’s future assets under management. The Company and its Affiliates record these variable costs when incurred because they are subject to market volatility and are not estimable upon inception of a contract with a client. Any expenses paid in advance are capitalized and amortized on a systematic basis consistent with the transfer of services, which is the equivalent of recognizing the costs as incurred. Investments in Marketable Securities On January 1, 2018, the Company also adopted ASU 2016-01, Financial Instruments - Overall: Recognition and Measurement of Financial Assets and Financial Liabilities, using a modified retrospective method and, as a result, updated its Investments in marketable securities accounting policy as follows. Investments in marketable securities are carried at fair value and reported within Investments and other assets on the Consolidated Condensed Balance Sheets. Upon the adoption of ASU 2016-01, the Company no longer classifies these securities as either trading or available-for-sale securities. Realized and unrealized gains or losses on investments in marketable securities are reported within Investment and other income in the Consolidated Statements of Income. Realized gains and losses are recorded on the trade date on a specific identified basis. Recent Accounting Developments In February 2016, the Financial Accounting Standards Board (the “FASB”) issued ASU 2016-02, Leases, which requires lessees to record right-of-use assets and lease liabilities arising from most operating leases on the statement of financial position. The standard is effective for interim and annual periods beginning after December 15, 2018 for the Company and its consolidated Affiliates and for interim and annual periods beginning after December 15, 2019 for the Company’s equity method Affiliates. The standard must be adopted using a modified retrospective method. The Company is evaluating the impact of this standard on its Consolidated Financial Statements. In January 2017, the FASB issued ASU 2017-04, Intangibles - Goodwill and Other: Simplifying the Accounting for Goodwill Impairment. Under the new standard, a goodwill impairment will now be the amount by which a reporting unit’s carrying value exceeds its fair value. The standard is effective for interim and annual periods beginning after December 15, 2019. The Company will apply the standard prospectively upon adoption. The Company is evaluating the impact of this standard on its Consolidated Financial Statements.
Investments in Affiliates and Affiliate Sponsored Investments Products	Investments in Affiliates and Affiliate Sponsored Investment Products In evaluating whether an investment must be consolidated, the Company evaluates the risk, rewards and significant terms of each of its Affiliates and other investments to determine if an investment is considered a voting rights entity (“VRE”) or a variable interest entity (“VIE”). An entity is a VRE when the total equity investment at risk is sufficient to enable the entity to finance its activities independently and when the equity holders have the obligation to absorb losses, the right to receive residual returns and the right to direct the activities of the entity that most significantly impact its economic performance. An entity is a VIE when it lacks one or more of the characteristics of a VRE, which for the Company are Affiliates structured as partnerships (or similar entities) where the limited partners lack substantive kick-out or substantive participation rights over the general partner. Assessing whether an entity is a VRE or VIE involves judgment. Upon the occurrence of certain events, management reviews and reconsiders its previous conclusion regarding the status of an entity as a VRE or a VIE. The Company consolidates VREs when it has control over significant operating, financial and investing decisions of the investment. When the Company lacks such control, but is deemed to have significant influence, the Company accounts for the investment under the equity method. Other investments in which the Company does not have rights to exercise significant influence are recorded at fair value, with changes in fair value reflected within Investment and other income. The Company consolidates VIEs when it is the primary beneficiary of the entity, which is defined as having the power to direct the activities that most significantly impact the VIE’s economic performance and the obligation to absorb losses of or the right to receive benefits from the entity that could potentially be significant to the VIE. The Company applies the equity method of accounting to VIEs where the Company is not the primary beneficiary, but has the ability to exercise significant influence over operating and financial matters of the VIE. Investments in Affiliates Substantially all of the Company’s Affiliates are considered VIEs and are either consolidated or accounted for under the equity method. A limited number of the Company’s Affiliates are considered VREs and most of these are accounted for under the equity method. When an Affiliate is consolidated, the portion of the Affiliate’s management equity owners’ earnings attributable to Owners’ Allocation is included in Net income (non-controlling interests) in the Consolidated Statements of Income. Undistributed Operating and Owners’ Allocation attributable to Affiliate management equity owners, along with their share of any tangible or intangible net assets, are presented within Non-controlling interests on the Consolidated Condensed Balance Sheets. Affiliate equity interests where the holder has certain rights to demand settlement are presented, at their current redemption values, as Redeemable non-controlling interests on the Consolidated Condensed Balance Sheets. The Company periodically issues, sells and repurchases the equity of its consolidated Affiliates. Because these transactions take place between entities that are under common control, any gains or losses attributable to these transactions are required to be included within Additional paid-in capital, net of any related income tax effects in the period the transactions occur. When an Affiliate is accounted for under the equity method, the Company’s share of an Affiliate’s earnings or losses, net of amortization and impairments, is included in Equity method income (net) in the Consolidated Statements of Income and the Company’s interest in the Affiliate is reported in Equity method investments in Affiliates (net) in the Consolidated Condensed Balance Sheets. The Company’s share of income taxes incurred directly by Affiliates accounted for under the equity method is recorded within Income tax expense in the Consolidated Statements of Income. The Company periodically evaluates its equity method investments for impairment. In such impairment evaluations, the Company assesses whether or not the fair value of the investment has declined below its carrying value for a period considered to be other-than-temporary. If the Company determines that a decline in fair value below the carrying value of the investment is other-than-temporary, then the carrying value of the investment is reduced to its fair value and the reduction is recorded in Equity method income (net). Affiliate Sponsored Investment Products The Company’s Affiliates sponsor various investment products where they also act as the investment advisor. These investment products are typically owned primarily by third-party investors; however, certain products are funded with general partner and seed capital investments from the Company and its consolidated Affiliates. Investors in Affiliate sponsored investment products are generally entitled to substantially all of the economics of these products, except for the management and performance fees earned by consolidated Affiliates or any gains or losses attributable to the Company or its consolidated Affiliates’ investments in these products. As a result, the Company does not generally consolidate these products unless the Company and/or the Affiliate’s interest in the product is considered substantial. When the Affiliate’s interest is considered substantial and the products are consolidated, the Company retains the specialized investment company accounting principles of the underlying products, and all of the underlying investments are carried at fair value in Investments and other assets in the Consolidated Condensed Balance Sheets, with corresponding changes in the investments’ fair values reflected in Investment and other income in the Consolidated Statements of Income. Purchases and sales of securities are presented within purchases and sales by Affiliate sponsored consolidated products in the Consolidated Statements of Cash Flows. When Affiliates no longer control these products, due to a reduction in ownership or other reasons, the products are deconsolidated.
Fair Value Measurement	The following are descriptions of the financial assets and liabilities measured at fair value and the fair value methodologies used: Cash equivalents consist primarily of highly liquid investments in daily redeeming money market funds, without enacted liquidity fees or redemption gates that are valued at net asset value (“NAV”). Investments in marketable securities consist primarily of investments in publicly traded securities and funds advised by Affiliates that are valued at NAV. Publicly traded securities valued using unadjusted quoted market prices for identical instruments in active markets are classified as level 1. Publicly traded securities valued using quoted prices for similar instruments in active markets or quoted prices for identical or similar instruments in markets that are not active are classified as level 2. Investments in funds advised by Affiliates that are valued at NAV are classified as level 1. Contingent payment arrangements represent the present value of the expected future settlement of contingent payment arrangements related to the Company’s investments in consolidated Affiliates. The significant unobservable inputs that are used in the fair value measurement of these obligations are growth and discount rates. Increases in the growth rate result in a higher obligation while increases in the discount rate result in a lower obligation. Affiliate equity obligations include agreements to repurchase Affiliate equity. The significant unobservable inputs that are used in the fair value measurement of the agreements to repurchase Affiliate equity are growth and discount rates. Increases in the growth rate result in a higher obligation while increases in the discount rate result in a lower obligation. Foreign currency forward contracts use model-derived valuations in which all significant inputs are observable in active markets to determine fair value. It is the Company’s policy to value financial assets or liabilities transferred as of the beginning of the period in which the transfer occurs.

Investments in Marketable Sec27

Investments in Marketable Securities (Tables)	3 Months Ended
Investments in Marketable Securities (Tables)	Mar. 31, 2018
Marketable Securities [Abstract]
Schedule of Investments in Marketable Securities	The following is a summary of the cost, gross unrealized gains and losses and fair value of investments in marketable securities: December 31, March 31, Cost $ 67.1 $ 74.2 Unrealized gains 13.0 9.0 Unrealized losses (2.3 ) (2.2 ) Fair value $ 77.8 $ 81.0

Investments in Affiliates and28

Investments in Affiliates and Affiliate Sponsored Investment Products (Tables)	3 Months Ended
	Mar. 31, 2018
Variable Interest Entities
Schedule of Unconsolidated Assets and Liabilities of Equity Method Investments and Company's Risk of Loss	The net assets of unconsolidated VIEs attributable to Affiliate sponsored investment products, and the Company’s maximum risk of loss, were as follows: December 31, 2017 March 31, 2018 Unconsolidated VIE Net Assets Carrying Value and Maximum Exposure to Loss Unconsolidated VIE Net Assets Carrying Value and Maximum Exposure to Loss Affiliate sponsored investment products $ 2,154.6 $ 10.2 $ 2,291.5 $ 10.4 The unconsolidated assets, net of liabilities and non-controlling interests of equity method Affiliates considered VIEs, and the Company’s maximum risk of loss, were as follows: December 31, 2017 March 31, 2018 Unconsolidated Carrying Value and Unconsolidated Carrying Value and Affiliates accounted for under the equity method $ 1,594.4 $ 2,765.7 $ 1,285.7 $ 2,640.3

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
Fair Value Measurements (Tables)	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Schedule of Fair Value of Assets and Liabilities Measured on a Recurring Basis	The following tables summarize the Company’s financial assets and liabilities that are measured at fair value on a recurring basis: Fair Value Measurements December 31, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial Assets Cash equivalents $ 40.4 $ 40.4 $ — $ — Investments in marketable securities (1) 77.8 77.8 — — Foreign currency forward contracts (1) 0.2 — 0.2 — Financial Liabilities (2) Contingent payment arrangements $ 9.4 $ — $ — $ 9.4 Affiliate equity obligations 49.2 — — 49.2 Foreign currency forward contracts 0.6 — 0.6 — Fair Value Measurements March 31, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial Assets Cash equivalents $ 33.3 $ 33.3 $ — $ — Investments in marketable securities (1) 81.0 81.0 — — Foreign currency forward contracts (1) 1.2 — 1.2 — Financial Liabilities (2) Contingent payment arrangements $ 9.8 $ — $ — $ 9.8 Affiliate equity obligations 79.4 — — 79.4 Foreign currency forward contracts 1.3 — 1.3 — __________________________ (1) Amounts are presented within Investments and other assets. (2) Amounts are presented within Other liabilities.
Schedule of Changes in Level 3 Assets and Liabilities	The following table presents the changes in level 3 liabilities: For the Three Months Ended March 31, 2017 2018 Contingent Payment Arrangements Affiliate Equity Obligations Contingent Payment Arrangements Affiliate Equity Obligations Balance, beginning of period $ 8.6 $ 12.1 $ 9.4 $ 49.2 Net realized and unrealized losses (1) 0.3 — 0.4 — Purchases and issuances (2) — 99.6 — 45.6 Settlements and reductions — (20.2 ) — (15.4 ) Balance, end of period $ 8.9 $ 91.5 $ 9.8 $ 79.4 Net change in unrealized losses relating to instruments still held at the reporting date $ 0.3 $ — $ 0.4 $ — ___________________________ (1) Accretion and changes in the expected value of the Company’s contingent payment arrangements and Affiliate equity obligations are recorded in Other expenses (net). (2) Includes transfers from Redeemable non-controlling interests.
Schedule of Quantitative Information used in Valuing Level 3 Liabilities	The following table presents certain quantitative information about the significant unobservable inputs used in valuing the Company’s level 3 financial liabilities: Quantitative Information About Level 3 Fair Value Measurements Valuation Techniques Unobservable Input Fair Value at Range at Fair Value at March 31, 2018 Range at March 31, 2018 Contingent payment arrangements Discounted cash flow Growth rates $ 9.4 7% - 8% $ 9.8 7% - 8% Discount rates 15% - 16% 15% - 16% Affiliate equity obligations Discounted cash flow Growth rates 49.2 0% - 11% 79.4 0% - 11% Discount rates 12% - 16% 12% - 16%
Schedule of Investments in Certain Entities that Calculate Net Asset Value	The following table summarizes the nature of the Company’s investments, unfunded commitments and any related liquidity restrictions or other factors that may impact the ultimate value realized: December 31, 2017 March 31, 2018 Category of Investment Fair Value Unfunded Commitments Fair Value Unfunded Commitments Private equity funds (1) $ 156.1 $ 98.8 $ 171.7 $ 120.4 Other funds (2) 8.9 — 8.2 — Other investments (3) $ 165.0 $ 98.8 $ 179.9 $ 120.4 ___________________________ (1) The Company uses NAV as a practical expedient one quarter in arrears (adjusted for current period calls and distributions) to determine the fair value. These funds primarily invest in a broad range of private equity funds, as well as making direct investments. Distributions will be received as the underlying assets are liquidated over the life of the funds, which is generally up to 15 years . (2) These are multi-disciplinary funds that invest across various asset classes and strategies, including long/short equity, credit and real estate. Investments are generally redeemable on a daily, monthly or quarterly basis. (3) Fair value attributable to the controlling interest was $80.1 million and $99.0 million as of December 31, 2017 and March 31, 2018, respectively.
Schedule of Financial Assets and Liabilities Not Carried at Fair Value	The following table summarizes the Company’s other financial liabilities not carried at fair value: December 31, 2017 March 31, 2018 Carrying Value Fair Value Carrying Value Fair Value Fair Value Hierarchy Senior notes (1) $ 745.7 $ 765.2 $ 745.8 $ 753.4 Level 2 Convertible securities 309.9 549.8 310.5 534.2 Level 2 ___________________________ (1) The carrying value of the senior notes is reported in Senior debt.

Goodwill and Acquired Client 30

Goodwill and Acquired Client Relationships (Tables)	3 Months Ended
Goodwill and Acquired Client Relationships (Tables)	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Changes in Goodwill	The following tables present the changes in the Company’s consolidated Affiliates’ Goodwill and components of Acquired client relationships (net): Goodwill Total Balance, as of December 31, 2017 $ 2,662.5 Foreign currency translation 4.8 Balance, as of March 31, 2018 $ 2,667.3
Schedule of Changes in the Components of Acquired Client Relationships	Acquired Client Relationships (Net) Definite-lived Indefinite-lived Total Gross Book Value Accumulated Amortization Net Book Value Net Book Value Net Book Value Balance, as of December 31, 2017 $ 1,295.5 $ (874.5 ) $ 421.0 $ 1,028.7 $ 1,449.7 Intangible amortization and impairments — (23.2 ) (23.2 ) — (23.2 ) Foreign currency translation 2.2 — 2.2 14.4 16.6 Balance, as of March 31, 2018 $ 1,297.7 $ (897.7 ) $ 400.0 $ 1,043.1 $ 1,443.1

Equity Method Investments in 31

Equity Method Investments in Affiliates (Tables)	3 Months Ended
Equity Method Investments in Affiliates (Tables)	Mar. 31, 2018
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Changes in Equity Method Investments in Affiliates	The following table presents the change in Equity method investments in Affiliates (net): Total Balance, as of December 31, 2017 $ 3,304.7 Equity method earnings 126.3 Equity method intangible amortization (30.0 ) Distributions of earnings from equity method investments (225.7 ) Foreign currency translation 11.6 Other (9.9 ) Balance, as of March 31, 2018 $ 3,177.0

Share-Based Compensation (Table

Share-Based Compensation (Tables)	3 Months Ended
Share-Based Compensation (Tables)	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Share-Based Compensation	The following table presents share-based compensation expense: For the Three Months Ended March 31, 2017 2018 Share-based compensation $ 9.4 $ 10.7 Tax benefit 3.6 2.7
Schedule of Company Stock Option Transactions	The following table summarizes transactions in the Company’s stock options: Stock Options Weighted Average Exercise Price Weighted Average Remaining Contractual Life (years) Unexercised options outstanding - December 31, 2017 0.6 $ 122.04 Options granted 0.0 203.22 Options exercised (0.0 ) 98.69 Options forfeited — — Unexercised options outstanding - March 31, 2018 0.6 124.49 3.8 Exercisable at March 31, 2018 0.2 120.03 2.0
Schedule of Fair Value of Options Granted and Assumptions	The weighted average grant date assumptions used to estimate the fair value of options granted were as follows: For the Three Months Ended March 31, 2017 2018 Dividend yield 0.5 % 0.7 % Expected volatility 30.1 % 24.6 % Risk-free interest rate 2.2 % 2.6 % Expected life of options (in years) 5.7 5.7 Forfeiture rate — % — %
Schedule of Company Restricted Stock Unit Transactions	The following table summarizes transactions in the Company’s restricted stock units: Restricted Stock Units Weighted Average Grant Date Value Unvested units - December 31, 2017 0.4 $ 162.32 Units granted 0.2 203.23 Units vested (0.0 ) 204.40 Units forfeited (0.0 ) 173.41 Unvested units - March 31, 2018 0.6 172.59

Redeemable Non-Controlling In33

Redeemable Non-Controlling Interests (Tables)	3 Months Ended
Redeemable Non-Controlling Interests (Tables)	Mar. 31, 2018
Noncontrolling Interest [Abstract]
Schedule of Changes in Redeemable Non-Controlling Interests	The following table presents the changes in Redeemable non-controlling interests: Redeemable Non-controlling interests Balance, as of December 31, 2017 $ 811.9 Changes attributable to consolidated products 1.9 Transfers to Other liabilities (45.6 ) Transfers from Non-controlling interests 4.9 Changes in redemption value 168.5 Balance, as of March 31, 2018 $ 941.6

Affiliate Equity (Tables)

Affiliate Equity (Tables)	3 Months Ended
Affiliate Equity (Tables)	Mar. 31, 2018
Affiliate Equity [Abstract]
Schedule of Affiliate Equity Compensation	The following table presents Affiliate equity expense: For the Three Months Ended March 31, 2017 2018 Controlling interest $ 4.0 $ 2.6 Non-controlling interests 12.6 16.8 Total $ 16.6 $ 19.4
Schedule of Affiliate Equity Unrecognized Compensation Expense [Table Text Block]	The following table presents unrecognized Affiliate equity expense: Controlling Interest Remaining Life Non-controlling Interests Remaining Life December 31, 2017 $ 33.3 5 years $ 95.9 6 years March 31, 2018 39.1 5 years 115.5 6 years
Schedule of Changes in the Company's Interest in its Affiliates on the Controlling Interest's Equity	While the Company presents the current redemption value of Affiliate equity within Redeemable non-controlling interests, with changes in the current redemption value increasing or decreasing the controlling interest’s equity over time, the following table presents the cumulative effect that ownership changes had on the controlling interest’s equity related only to Affiliate equity transactions that settled during the applicable periods: For the Three Months Ended March 31, 2017 2018 Net income (controlling interest) $ 122.5 $ 153.0 Decrease in controlling interest paid-in capital from Affiliate equity issuances (1.2 ) (1.0 ) Decrease in controlling interest paid-in capital from Affiliate equity repurchases (52.6 ) (33.1 ) Net income (controlling interest) including net impact of Affiliate equity transactions $ 68.7 $ 118.9

Income Taxes (Tables)

Income Taxes (Tables)	3 Months Ended
Income Taxes (Tables)	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Schedule of Income Tax Provisions by Controlling and Noncontrolling Interests	The following table presents the consolidated provision for income taxes: For the Three Months Ended March 31, 2017 2018 Controlling interest: Current tax $ 22.4 $ 47.3 Intangible-related deferred taxes 19.8 13.2 Other deferred taxes 15.6 0.3 Total controlling interest 57.8 60.8 Non-controlling interests: Current tax $ 2.0 $ 2.8 Deferred taxes (0.1 ) (0.1 ) Total non-controlling interests 1.9 2.7 Provision for income taxes $ 59.7 $ 63.5 Income before income taxes (controlling interest) $ 180.3 $ 213.8 Effective tax rate (controlling interest) (1) 32.1 % 28.4 % __________________________ (1) Taxes attributable to the controlling interest divided by Income before income taxes (controlling interest).

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
Earnings Per Share (Tables)	Mar. 31, 2018
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Earnings Per Share	The following is a reconciliation of the numerator and denominator used in the calculation of basic and diluted earnings per share available to common stockholders: For the Three Months Ended March 31, 2017 2018 Numerator Net income (controlling interest) $ 122.5 $ 153.0 Interest expense on convertible securities, net of taxes 3.8 4.7 Net income (controlling interest), as adjusted $ 126.3 $ 157.7 Denominator Average shares outstanding (basic) 56.7 54.6 Effect of dilutive instruments: Stock options and restricted stock units 0.3 0.2 Convertible securities 2.2 2.2 Average shares outstanding (diluted) 59.2 57.0
Schedule of Shares Excluded from Calculation of Basic and Diluted Earnings Per Share	Average shares outstanding (diluted) in the table above excludes share-based awards that have not satisfied performance conditions and the anti-dilutive effect of the following share-based awards: For the Three Months Ended March 31, 2017 2018 Stock options and restricted stock units 0.2 0.1

Comprehensive Income (Tables)

Comprehensive Income (Tables)	3 Months Ended
Comprehensive Income (Tables)	Mar. 31, 2018
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of Tax Effects Allocated to Each Component of Other Comprehensive Income	The following table presents the tax effects allocated to each component of Other comprehensive income (loss): For the Three Months Ended March 31, 2017 2018 Pre-Tax Tax Benefit Net of Tax Pre-Tax Tax Benefit Net of Tax Foreign currency translation adjustment $ 12.2 $ — $ 12.2 $ 29.1 $ — $ 29.1 Change in net realized and unrealized gain (loss) on derivative securities (0.3 ) 0.0 (0.3 ) 0.3 — 0.3 Change in net unrealized gain (loss) on investment securities 7.3 (2.4 ) 4.9 — — — Other comprehensive income (loss) $ 19.2 $ (2.4 ) $ 16.8 $ 29.4 $ — $ 29.4
Schedule of Components of Accumulated Other Comprehensive Income	The components of accumulated other comprehensive income (loss), net of taxes, were as follows: Foreign Currency Translation Adjustment Realized and Unrealized Gains (Losses) on Derivative Securities Unrealized Gains (Losses) on Investment Securities (1) Total Balance, as of December 31, 2017 $ (85.9 ) $ (0.4 ) $ 2.1 $ (84.2 ) Other comprehensive income before reclassifications 29.1 0.0 — 29.1 Amounts reclassified — 0.3 (2.1 ) (1.8 ) Net other comprehensive income (loss) 29.1 0.3 (2.1 ) 27.3 Balance, as of March 31, 2018 $ (56.8 ) $ (0.1 ) $ — $ (56.9 ) __________________________ (1) In connection with the Company’s adoption of ASU 2016-01, the unrealized losses on investment securities, which related to the non-controlling interests, were reclassified to Non-controlling interests on the Consolidated Condensed Balance Sheets.

Investments in Marketable Sec38

Investments in Marketable Securities - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Investments in marketable securities	$ 81	$ 77.8	$ 77.8
Proceeds received from sales of marketable securities	13.8	37.3
Net realized gains on sale of marketable securities	$ 2.8	$ 6.7

Investments in Marketable Sec39

Investments in Marketable Securities - Cost, Gross Unrealized Gains and Losses and Fair Value (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Marketable Securities [Abstract]
Cost			$ 74.2	$ 67.1
Unrealized gains	$ 9	$ 13
Unrealized losses	(2.2)	(2.3)
Fair value	$ 81	$ 77.8	$ 77.8

Investments in Affiliates and40

Investments in Affiliates and Affiliate Sponsored Investment Products - Affiliated Accounted For Under Equity Method (Details) - Affiliates accounted for under the equity method - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Variable Interest Entities
Unconsolidated VIE Net Assets	$ 1,285.7	$ 1,594.4
Carrying Value and Maximum Exposure to Loss	$ 2,640.3	$ 2,765.7

Investments in Affiliates and41

Investments in Affiliates and Affiliate Sponsored Investment Products - Affiliated Sponsored Investment Products (Details) - Affiliate sponsored investment products - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Variable Interest Entities
Unconsolidated VIE Net Assets	$ 2,291.5	$ 2,154.6
Carrying Value and Maximum Exposure to Loss	$ 10.4	$ 10.2

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($)	Dec. 31, 2018	Mar. 31, 2018
Commitments and Contingencies
Co-investment commitments in partnership		$ 120,400,000
Consolidated Affiliates
Commitments and Contingencies
Contingent liability		18,200,000
Expected payments of contingent liability		10,200,000
Present value of expected payments of contingent liabilities		9,800,000
Consolidated Affiliates \| Scenario, Forecast
Commitments and Contingencies
Expected payments of contingent liability	$ 8,200,000
Equity Method Investee
Commitments and Contingencies
Contingent liability		$ 170,000,000
Equity Method Investee \| Scenario, Forecast
Commitments and Contingencies
Expected payments of contingent liability	$ 0

Senior Debt (Details)

Senior Debt (Details) - Unsecured Debt $ in Millions	Mar. 31, 2018USD ($)
Revolver
Long-term debt
Maximum borrowing capacity	$ 1,450
Maximum borrowing capacity, additional amount	350
Term Loan
Long-term debt
Principal amount at maturity	385
Maximum borrowing capacity, additional amount	$ 65

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured on a Recurring Basis (Details) - Fair Value Measured On A Recurring Basis - USD ($) $ in Millions		Mar. 31, 2018		Dec. 31, 2017
Financial Assets
Cash equivalents		$ 33.3		$ 40.4
Investments in marketable securities	[1]	81		77.8
Foreign currency forward contracts		1.2	[2]	0.2	[1]
Financial Liabilities
Contingent payment arrangements	[2]	9.8		9.4
Affiliate equity obligations	[2]	79.4		49.2
Foreign currency forward contracts	[2]	1.3		0.6
Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial Assets
Cash equivalents		33.3		40.4
Investments in marketable securities	[1]	81		77.8
Foreign currency forward contracts		0	[2]	0	[1]
Financial Liabilities
Contingent payment arrangements	[2]	0		0
Affiliate equity obligations	[2]	0		0
Foreign currency forward contracts	[2]	0		0
Significant Other Observable Inputs (Level 2)
Financial Assets
Cash equivalents		0		0
Investments in marketable securities	[1]	0		0
Foreign currency forward contracts		1.2	[2]	0.2	[1]
Financial Liabilities
Contingent payment arrangements	[2]	0		0
Affiliate equity obligations	[2]	0		0
Foreign currency forward contracts	[2]	1.3		0.6
Significant Unobservable Inputs (Level 3)
Financial Assets
Cash equivalents		0		0
Investments in marketable securities	[1]	0		0
Foreign currency forward contracts		0	[2]	0	[1]
Financial Liabilities
Contingent payment arrangements	[2]	9.8		9.4
Affiliate equity obligations	[2]	79.4		49.2
Foreign currency forward contracts	[2]	$ 0		$ 0

[1]	Amounts are presented within Investments and other assets.
[2]	Amounts are presented within Other liabilities.

Fair Value Measurements - Chang

Fair Value Measurements - Changes in Level 3 Assets and Liabilities (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Contingent Payment Arrangements
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period		$ 9.4	$ 8.6
Net realized and unrealized losses	[1]	0.4	0.3
Purchases and issuances	[2]	0	0
Settlements and reductions		0	0
Balance, end of period		9.8	8.9
Net change in unrealized losses relating to instruments still held at the reporting date		0.4	0.3
Affiliate Equity Obligations
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period		49.2	12.1
Net realized and unrealized losses	[1]	0	0
Purchases and issuances	[2]	45.6	99.6
Settlements and reductions		(15.4)	(20.2)
Balance, end of period		79.4	91.5
Net change in unrealized losses relating to instruments still held at the reporting date		$ 0	$ 0

[1]	Accretion and changes in the expected value of the Company’s contingent payment arrangements and Affiliate equity obligations are recorded in Other expenses (net).
[2]	Includes transfers from Redeemable non-controlling interests.

Fair Value Measurements - Quant

Fair Value Measurements - Quantitative Information used in Valuing Level 3 Liabilities (Details) - Discounted Cash Flow - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Contingent Payment Arrangements
Quantitative information for Level 3 Fair Value Measurements Liabilities
Fair value liabilities	$ 9.8	$ 9.4
Contingent Payment Arrangements \| Minimum
Quantitative information for Level 3 Fair Value Measurements Liabilities
Growth rate (as a percent)	7.00%	7.00%
Discount rate (as a percent)	15.00%	15.00%
Contingent Payment Arrangements \| Maximum
Quantitative information for Level 3 Fair Value Measurements Liabilities
Growth rate (as a percent)	8.00%	8.00%
Discount rate (as a percent)	16.00%	16.00%
Affiliate Equity Obligations
Quantitative information for Level 3 Fair Value Measurements Liabilities
Fair value liabilities	$ 79.4	$ 49.2
Affiliate Equity Obligations \| Minimum
Quantitative information for Level 3 Fair Value Measurements Liabilities
Growth rate (as a percent)	0.00%	0.00%
Discount rate (as a percent)	12.00%	12.00%
Affiliate Equity Obligations \| Maximum
Quantitative information for Level 3 Fair Value Measurements Liabilities
Growth rate (as a percent)	11.00%	11.00%
Discount rate (as a percent)	16.00%	16.00%

Fair Value Measurements - Inves

Fair Value Measurements - Investments Measured at Net Asset Value as Practical Expedient (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Dec. 31, 2017
NAV of investments at fair value
Life of funds (in years)		15 years
Other Investments
NAV of investments at fair value
Fair Value	[1]	$ 179.9	$ 165
Unfunded Commitments		120.4	98.8
Other Investments \| Controlling Interest
NAV of investments at fair value
Fair Value		99	80.1
Private Equity Funds
NAV of investments at fair value
Fair Value	[2]	171.7	156.1
Unfunded Commitments	[2]	120.4	98.8
Other Funds
NAV of investments at fair value
Fair Value	[3]	8.2	8.9
Unfunded Commitments	[3]	$ 0	$ 0

[1]	Fair value attributable to the controlling interest was $80.1 million and $99.0 million as of December 31, 2017 and March 31, 2018, respectively.
[2]	The Company uses NAV as a practical expedient one quarter in arrears (adjusted for current period calls and distributions) to determine the fair value. These funds primarily invest in a broad range of private equity funds, as well as making direct investments. Distributions will be received as the underlying assets are liquidated over the life of the funds, which is generally up to 15 years.
[3]	These are multi-disciplinary funds that invest across various asset classes and strategies, including long/short equity, credit and real estate. Investments are generally redeemable on a daily, monthly or quarterly basis.

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets and Liabilities Not Carried at Fair Value (Details) - Level 2 - USD ($) $ in Millions		Mar. 31, 2018	Dec. 31, 2017
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Senior notes(1)	[1]	$ 745.8	$ 745.7
Convertible securities		310.5	309.9
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Senior notes(1)		753.4	765.2
Convertible securities		$ 534.2	$ 549.8

[1]	The carrying value of the senior notes is reported in Senior debt.

Goodwill and Acquired Client 49

Goodwill and Acquired Client Relationships - Schedule of Changes in Goodwill (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Goodwill [Roll Forward]
Balance, as of December 31, 2017	$ 2,662.5
Foreign currency translation	4.8
Balance, as of March 31, 2018	$ 2,667.3

Goodwill and Acquired Client 50

Goodwill and Acquired Client Relationships - Schedule of Changes in the Components of Acquired Client Relationships (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Total
Beginning balance, net book value	$ 1,449.7
Ending balance, net book value	1,443.1
Acquired Client Relationships
Definite-lived
Beginning balance, gross book value	1,295.5
Beginning balance, accumulated amortization	(874.5)
Beginning balance, net book value	421
Amortization and impairments	(23.2)
Foreign currency translation	2.2
Ending balance, gross book value	1,297.7
Ending balance, accumulated amortization	(897.7)
Ending balance, net book value	400
Indefinite-lived
Beginning balance, net book value	1,028.7
Intangible amortization and impairments	0
Foreign currency translation	14.4
Ending balance, net book value	1,043.1
Total
Beginning balance, net book value	1,449.7
Amortization and impairments	(23.2)
Foreign currency translation	16.6
Ending balance, net book value	$ 1,443.1

Goodwill and Acquired Client 51

Goodwill and Acquired Client Relationships - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Intangible Assets
Amortization and impairment expenses of intangible assets	$ 23.2	$ 21.9
Acquired Client Relationships
Finite-Lived Intangible Assets, Net, Amortization Expense, Rolling Maturity [Abstract]
Finite-lived intangible, future amortization expense in 2018	90
Finite-lived intangible, future amortization expense in 2019	90
Finite-lived intangible, future amortization expense in 2020	65
Finite-lived intangible, future amortization expense in 2021	40
Finite-lived intangible, future amortization expense in 2022	40
Acquired Client Relationships \| Intangible amortization and impairments
Intangible Assets
Amortization and impairment expenses of intangible assets	$ 23.2	$ 21.9

Equity Method Investments in 52

Equity Method Investments in Affiliates - Change in Equity Method Investments (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Change in Equity Method Investments in Affiliates [Roll Forward]
Balance, as of December 31, 2017	$ 3,304.7
Distributions of earnings from equity method investments	(225.7)	$ (189.9)
Balance, as of March 31, 2018	3,177
Equity Method Investee
Change in Equity Method Investments in Affiliates [Roll Forward]
Balance, as of December 31, 2017	3,304.7
Equity method earnings	126.3
Equity method intangible amortization	(30)
Distributions of earnings from equity method investments	(225.7)
Foreign currency translation	11.6
Other	(9.9)
Balance, as of March 31, 2018	$ 3,177

Equity Method Investments in 53

Equity Method Investments in Affiliates - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Schedule of Equity Method Investments [Line Items]
Amortization expense during the period	$ 23.2	$ 21.9
Acquired Client Relationships
Schedule of Equity Method Investments [Line Items]
Finite-lived intangible, future amortization expense in 2018	90
Finite-lived intangible, future amortization expense in 2019	90
Finite-lived intangible, future amortization expense in 2020	65
Finite-lived intangible, future amortization expense in 2021	40
Finite-lived intangible, future amortization expense in 2022	40
Equity Method Investee
Schedule of Equity Method Investments [Line Items]
Revenue from equity method investments	310.7	265.6
Net income from equity method investments	169.6	148.6
Equity Method Investee \| Acquired Client Relationships
Schedule of Equity Method Investments [Line Items]
Amortization expense during the period	30	$ 21.7
Finite-lived intangible, future amortization expense in 2018	100
Finite-lived intangible, future amortization expense in 2019	90
Finite-lived intangible, future amortization expense in 2020	90
Finite-lived intangible, future amortization expense in 2021	90
Finite-lived intangible, future amortization expense in 2022	$ 90

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Related Party Transactions
Other liabilities	$ 216.3	$ 182.4
Prior Owner \| Private Equity Investment Partnerships of Affiliate
Related Party Transactions
Other liabilities	57	61.2
Affiliated Entity \| Other Liabilities
Related Party Transactions
Contingent payment arrangements liability	$ 9.8	$ 9.4

Share-Based Compensation - Summ

Share-Based Compensation - Summary of Share-Based Compensation (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-based compensation	$ 10.7	$ 9.4
Tax benefit	2.7	$ 3.6
Compensation expense related to share-based compensation	$ 89.7		$ 63.5
Weighted average period over which compensation expense will be recognized	2 years

Share-Based Compensation - Sche

Share-Based Compensation - Schedule of the Transactions of the Company's Stock Options (Details) - Stock Options shares in Millions	3 Months Ended
	Mar. 31, 2018$ / sharesshares
Stock Options
Unexercised options outstanding at the beginning of the period (in shares) \| shares	0.6
Options granted (in shares) \| shares	0
Options exercised (in shares) \| shares	0
Options forfeited (in shares) \| shares	0
Unexercised options outstanding at the end of the period (in shares) \| shares	0.6
Exercisable at the end of the period (in shares) \| shares	0.2
Weighted Average Exercise Price
Unexercised options outstanding at the beginning of the period (in dollars per share) \| $ / shares	$ 122.04
Options granted (in dollars per share) \| $ / shares	203.22
Options exercised (in dollars per share) \| $ / shares	98.69
Options forfeited (in dollars per share) \| $ / shares	0
Unexercised options outstanding at the end of the period (in dollars per share) \| $ / shares	124.49
Exercisable at the end of the period (in dollars per share) \| $ / shares	$ 120.03
Weighted Average Remaining Contractual Life
Unexercised options outstanding at the end of the period (in years)	3 years 9 months 12 days
Exercisable at the end of the period (in years)	2 years

Share-Based Compensation - Sc57

Share-Based Compensation - Schedule of Fair Value Options Granted and Assumptions (Details) - Stock Options - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Share-based Compensation
Stock options granted, fair value	$ 0.5	$ 0.4
Stock options, expiration period (in years)	7 years
Stock options granted, weighted average fair value (in dollar per share)	$ 53.81	$ 46.49
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Dividend yield	0.70%	0.50%
Expected volatility	24.60%	30.10%
Risk-fee interest rate	2.60%	2.20%
Expected life of options (in years)	5 years 8 months 12 days	5 years 8 months 12 days
Forfeiture rate	0.00%	0.00%
Minimum
Share-based Compensation
Stock options, vesting period (in years)	3 years
Maximum
Share-based Compensation
Stock options, vesting period (in years)	4 years

Share-Based Compensation - Sc58

Share-Based Compensation - Schedule of Company Restricted Stock Unit Transactions (Details) - Restricted Stock - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Restricted Stock Units
Unvested units at the beginning of the period (in shares)	0.4
Units granted (in shares)	0.2
Units vested (in shares)	0
Units forfeited (in shares)	0
Unvested units at the end of the period (in shares)	0.6
Weighted Average Grant Date Value
Unvested units at the beginning of the period (in dollars per share)	$ 162.32
Units granted (in dollars per share)	203.23
Units vested (in dollars per share)	204.40
Units forfeited (in dollars per share)	173.41
Unvested units at the end of the period (in dollars per share)	$ 172.59
Restricted stocks granted, fair value	$ 36.7	$ 36.4
Minimum
Weighted Average Grant Date Value
Restricted stock, vesting period (in years)	3 years
Maximum
Weighted Average Grant Date Value
Restricted stock, vesting period (in years)	4 years

Redeemable Non-Controlling In59

Redeemable Non-Controlling Interests (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Redeemable Noncontrolling Interest [Roll Forward]
Balance, as of December 31, 2017	$ 811.9
Changes attributable to consolidated products	1.9
Transfers to Other liabilities	(45.6)
Transfers from Non-controlling interests	4.9	$ 25.7
Changes in redemption value	168.5
Balance, as of March 31, 2018	$ 941.6
Minimum
Noncontrolling Interest [Line Items]
Term of conditional right to put interest	5 years
Maximum
Noncontrolling Interest [Line Items]
Term of conditional right to put interest	15 years

Affiliated Equity - Additional

Affiliated Equity - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Affiliate Equity [Line Items]
Distributions paid to affiliate partners	$ 112.4	$ 92
Payments to acquire interest in affiliates	14.5	23.6
Issuance of interest in affiliates	6.2	$ 6
Other Assets
Affiliate Equity [Line Items]
Due from affiliates	17.2		$ 12.4
Other Liabilities
Affiliate Equity [Line Items]
Due to affiliates	$ 79.4		$ 49.2

Affiliate Equity - Summary of A

Affiliate Equity - Summary of Affiliate Recognized and Unrecognized Expense (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Affiliate Equity [Line Items]
Affiliate equity expense	$ 19.4	$ 16.6
Non-controlling Interests
Affiliate Equity [Line Items]
Non-controlling interests	$ 16.8	12.6
Unrecognized Affiliate Equity Expense [Abstract]
Remaining Life (in years)	6 years		6 years
Non-Controlling Interest	$ 115.5		$ 95.9
Affiliated Entity
Affiliate Equity [Line Items]
Controlling interest	2.6	$ 4
Unrecognized Affiliate Equity Expense [Abstract]
Controlling Interest	$ 39.1		$ 33.3
Remaining Life (in years)	5 years		5 years

Affiliate Equity - Schedule of

Affiliate Equity - Schedule of Changes in the Company's Interest in its Affiliates on the Controlling Interest's Equity (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Affiliate Equity [Abstract]
Net income (controlling interest)	$ 153	$ 122.5
Decrease in controlling interest paid-in capital from Affiliate equity issuances	(1)	(1.2)
Decrease in controlling interest paid-in capital from Affiliate equity repurchases	(33.1)	(52.6)
Net income (controlling interest) including net impact of Affiliate equity transactions	$ 118.9	$ 68.7

Income Taxes (Details)

Income Taxes (Details) - USD ($)	3 Months Ended	12 Months Ended
Income Taxes (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Provisional one-time net benefit from changes in U.S. tax laws		$ 194,100,000
Changes in provisional amount of initial one-time benefit recorded resulting from change in U.S. tax laws	$ 0

Income Taxes - Schedule of Inco

Income Taxes - Schedule of Income Tax Provisions by Controlling and Noncontrolling Interests (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Income Tax Provision
Deferred taxes		$ 13.4	$ 35.3
Provision for income taxes		63.5	59.7
Non-controlling Interests
Income Tax Provision
Current tax		2.8	2
Deferred taxes		(0.1)	(0.1)
Provision for income taxes		2.7	1.9
Controlling Interest
Income Tax Provision
Current tax		47.3	22.4
Intangible-related deferred taxes		13.2	19.8
Other deferred taxes		0.3	15.6
Provision for income taxes		60.8	57.8
Income before income taxes (controlling interest)		$ 213.8	$ 180.3
Effective tax rate (controlling interest)	[1]	28.40%	32.10%

[1]	Taxes attributable to the controlling interest divided by Income before income taxes (controlling interest).

Earnings Per Share - Schedule o

Earnings Per Share - Schedule of Basic and Diluted Earnings Per Share (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Numerator
Net income (controlling interest)	$ 153	$ 122.5
Interest expense on convertible securities, net of taxes	4.7	3.8
Net income (controlling interest), as adjusted	$ 157.7	$ 126.3
Denominator
Average shares outstanding—basic (in shares)	54.6	56.7
Effect of dilutive instruments:
Stock options and restricted stock (in shares)	0.2	0.3
Convertible securities (in shares)	2.2	2.2
Average shares outstanding—diluted (in shares)	57	59.2

Earnings Per Share - Schedule66

Earnings Per Share - Schedule of Shares Excluded from Calculation of Basic and Diluted Earnings Per Share (Details) - shares shares in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Stock options and restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	0.1	0.2

Earnings Per Share - Additional

Earnings Per Share - Additional Information (Details) shares in Millions	3 Months Ended
	Mar. 31, 2018$ / sharesshares
Earnings Per Share [Abstract]
Number or shares repurchased during period (in shares) \| shares	0.8
Average price of shares repurchased during period (in dollars per share) \| $ / shares	$ 192.70

Comprehensive Income - Summary

Comprehensive Income - Summary of the Tax Effects Allocated to Each Component of Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018		Mar. 31, 2017
Accumulated Other Comprehensive Income (Loss)
Pre-Tax	$ 29.4		$ 19.2
Tax Benefit (Expense)	0		(2.4)
Other comprehensive income	29.4		16.8
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss)
Pre-Tax	29.1		12.2
Tax Benefit (Expense)	0		0
Other comprehensive income	29.1		12.2
Change in net realized and unrealized gain (loss) on derivative securities
Accumulated Other Comprehensive Income (Loss)
Pre-Tax	0.3		(0.3)
Tax Benefit (Expense)	0		0
Other comprehensive income	0.3		(0.3)
Change in net unrealized gain (loss) on investment securities
Accumulated Other Comprehensive Income (Loss)
Pre-Tax			7.3
Tax Benefit (Expense)			(2.4)
Other comprehensive income	(2.1)	[1]	$ 4.9
Change in net unrealized gain (loss) on investment securities attributable to noncontrolling interest
Accumulated Other Comprehensive Income (Loss)
Pre-Tax	0
Tax Benefit (Expense)	0
Other comprehensive income	$ 0

[1]	In connection with the Company’s adoption of ASU 2016-01, the unrealized losses on investment securities, which related to the non-controlling interests, were reclassified to Non-controlling interests on the Consolidated Condensed Balance Sheets.

Comprehensive Income - Schedule

Comprehensive Income - Schedule of Components of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018		Mar. 31, 2017
Components of Accumulated other comprehensive income, net of taxes
Beginning Balance		$ 4,578.5		$ 4,426.5
Other comprehensive income		29.4		16.8
Ending Balance		4,422.6		4,369
Foreign Currency Translation Adjustment
Components of Accumulated other comprehensive income, net of taxes
Beginning Balance		(85.9)
Other comprehensive income before reclassifications		29.1
Amounts reclassified		0
Other comprehensive income		29.1		12.2
Ending Balance		(56.8)
Realized and Unrealized Gains (Losses) on Derivative Securities
Components of Accumulated other comprehensive income, net of taxes
Beginning Balance		(0.4)
Other comprehensive income before reclassifications		0
Amounts reclassified		0.3
Other comprehensive income		0.3		(0.3)
Ending Balance		(0.1)
Change in net unrealized gain (loss) on investment securities
Components of Accumulated other comprehensive income, net of taxes
Beginning Balance	[1]	2.1
Other comprehensive income before reclassifications	[1]	0
Amounts reclassified	[1]	(2.1)
Other comprehensive income		(2.1)	[1]	$ 4.9
Ending Balance	[1]	0
Total
Components of Accumulated other comprehensive income, net of taxes
Beginning Balance		(84.2)
Other comprehensive income before reclassifications		29.1
Amounts reclassified		(1.8)
Other comprehensive income		27.3
Ending Balance		$ (56.9)

[1]	In connection with the Company’s adoption of ASU 2016-01, the unrealized losses on investment securities, which related to the non-controlling interests, were reclassified to Non-controlling interests on the Consolidated Condensed Balance Sheets.

Subsequent Events (Details)

Subsequent Events (Details) - $ / shares shares in Millions	May 02, 2018	Mar. 31, 2018
Subsequent Event [Line Items]
Number or shares repurchased during period (in shares)		0.8
Average price of shares repurchased during period (in dollars per share)		$ 192.70
Subsequent Event
Subsequent Event [Line Items]
Number or shares repurchased during period (in shares)	0.2
Average price of shares repurchased during period (in dollars per share)	$ 162.32