Arthur J. Gallagher & Co. (AJG) 10-Q 28 Oct 16 2016 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	9 Months Ended
	Sep. 30, 2016shares
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q3
Trading Symbol	AJG
Entity Registrant Name	GALLAGHER ARTHUR J & CO
Entity Central Index Key	354,190
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding	177,941,000

Consolidated Statement of Earni

Consolidated Statement of Earnings (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Commissions	$ 612.9	$ 594.6	$ 1,842.3	$ 1,748.6
Fees	375	360.7	1,087.8	1,051.2
Supplemental commissions	35.3	29.2	106.8	90.9
Contingent commissions	16.4	14.5	96.7	81.8
Investment income	13.6	13.1	36.4	38.5
Gains on books of business sales	1.1	2.6	4.7	7
Revenues from clean coal activities	429.3	408.1	1,036	1,009
Other net revenues (losses)	(1.3)	32	(0.9)	30.5
Total revenues	1,482.3	1,454.8	4,209.8	4,057.5
Compensation	626.6	604.9	1,879.7	1,795.2
Operating	189.6	208.1	598.7	618.7
Cost of revenues from clean coal activities	449.7	418.9	1,079.1	1,035
Interest	28.5	25.6	81.5	77.2
Depreciation	25.7	23.8	76.4	68.1
Amortization	63.2	58.1	185.1	172.3
Change in estimated acquisition earnout payables	4.1	9.7	21.2	25.9
Total expenses	1,387.4	1,349.1	3,921.7	3,792.4
Earnings before income taxes	94.9	105.7	288.1	265.1
Benefit for income taxes	(35.5)	(35.2)	(55.9)	(55.8)
Net earnings	130.4	140.9	344	320.9
Net earnings attributable to noncontrolling interests	7.6	7.6	24.7	26.4
Net earnings attributable to controlling interests	$ 122.8	$ 133.3	$ 319.3	$ 294.5
Basic net earnings per share	$ 0.69	$ 0.76	$ 1.80	$ 1.73
Diluted net earnings per share	0.69	0.75	1.79	1.71
Dividends declared per common share	$ 0.38	$ 0.37	$ 1.14	$ 1.11

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Earnings (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net earnings	$ 130.4	$ 140.9	$ 344	$ 320.9
Change in pension liability, net of taxes	0.8	0.6	4.4	1.3
Foreign currency translation	(19.6)	(152.7)	(91.4)	(237.9)
Change in fair value of derivative investments, net of taxes	1.8	(5.5)	(11)	0.9
Comprehensive earnings (loss)	113.4	(16.7)	246	85.2
Comprehensive earnings attributable to noncontrolling interests	6.6	21.6	28.9	16.2
Comprehensive earnings (loss) attributable to controlling interests	$ 106.8	$ (38.3)	$ 217.1	$ 69

Consolidated Balance Sheet

Consolidated Balance Sheet - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Cash and cash equivalents	$ 531.8	$ 480.4
Restricted cash	1,397.1	1,412.1
Premiums and fees receivable	1,683.7	1,734
Other current assets	601.1	587.2
Total current assets	4,213.7	4,213.7
Fixed assets - net	213.9	202.7
Deferred income taxes	749.8	643.5
Other noncurrent assets	630.4	488.9
Goodwill - net	3,762.6	3,662.9
Amortizable intangible assets - net	1,629.9	1,698.8
Total assets	11,200.3	10,910.5
Premiums payable to insurance and reinsurance companies	2,866.9	2,877.1
Accrued compensation and other accrued liabilities	651.3	812.7
Unearned fees	83.7	61.3
Other current liabilities	55.9	54
Premium financing debt	133.1	137
Corporate related borrowings - current	608	245
Total current liabilities	4,398.9	4,187.1
Corporate related borrowings - noncurrent	2,044.6	2,071.7
Other noncurrent liabilities	1,015.6	963.5
Total liabilities	7,459.1	7,222.3
Stockholders' equity:
Common stock - issued and outstanding 177.9 shares in 2016 and 176.9 shares in 2015	177.9	176.9
Capital in excess of par value	3,239.3	3,209.4
Retained earnings	889.8	774.5
Accumulated other comprehensive loss	(620.5)	(522.5)
Stockholders' equity attributable to controlling interests	3,686.5	3,638.3
Stockholders' equity attributable to noncontrolling interests	54.7	49.9
Total stockholders' equity	3,741.2	3,688.2
Total liabilities and stockholders' equity	$ 11,200.3	$ 10,910.5

Consolidated Balance Sheet (Par

Consolidated Balance Sheet (Parenthetical) - shares shares in Millions	Sep. 30, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Common stock - issued shares	177.9	176.9
Common stock - outstanding shares	177.9	176.9

Consolidated Statement of Cash

Consolidated Statement of Cash Flows (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash flows from operating activities:
Net earnings	$ 344	$ 320.9
Adjustments to reconcile net earnings to net cash provided by operating activities:
Net gain on investments and other	(4.6)	(7)
Depreciation and amortization	261.5	240.4
Change in estimated acquisition earnout payables	21.2	25.9
Amortization of deferred compensation and restricted stock	21.6	16.8
Stock-based and other noncash compensation expense	10.9	8.2
Effect of changes in foreign exchange rates	1	0.2
Net change in restricted cash	(21.1)	15.3
Net change in premiums receivable	(26.7)	(86.3)
Net change in premiums payable	88.4	218.7
Net change in other current assets	(28.6)	(43.7)
Net change in accrued compensation and other accrued liabilities	(72.1)	37.4
Net change in fees receivable/unearned fees	12.3	(56)
Net change in income taxes payable	5.4	(11.7)
Net change in deferred income taxes	(123.6)	(111.4)
Net change in other noncurrent assets and liabilities	(53.8)	(91.4)
Unrealized foreign currency remeasurement loss	(47.4)	(149.8)
Net cash provided by operating activities	388.4	326.5
Cash flows from investing activities:
Net additions to fixed assets	(138.8)	(71.8)
Cash paid for acquisitions, net of cash acquired	(208.2)	(176.5)
Net proceeds from sales of operations/books of business	7.3	8.7
Net funding of investment transactions	(22.3)	(20.6)
Net cash used by investing activities	(362)	(260.2)
Cash flows from financing activities:
Proceeds from issuance of common stock	36.8	199
Tax impact from issuance of common stock	4.8	7.4
Repurchases of common stock	(101)
Payments to noncontrolling interests	(32.8)	(30.1)
Dividends paid	(204.3)	(192.5)
Net borrowings on premium financing debt facility	(10.9)	4.4
Borrowings on line of credit facility	1,619.5	534
Repayments on line of credit facility	(1,556.5)	(521)
Net borrowings of corporate related long-term debt	276
Net cash provided by financing activities	31.6	1.2
Effect of changes in foreign exchange rates on cash and cash equivalents	(6.6)	(12.2)
Net increase in cash and cash equivalents	51.4	55.3
Cash and cash equivalents at beginning of period	480.4	314.4
Cash and cash equivalents at end of period	531.8	369.7
Supplemental disclosures of cash flow information:
Interest paid	82.5	81
Income taxes paid	$ 52.2	$ 55.8

Consolidated Statement of Stock

Consolidated Statement of Stockholders' Equity (Unaudited) - 9 months ended Sep. 30, 2016 - USD ($) shares in Millions, $ in Millions	Total	Common Stock [Member]	Capital in Excess of Par Value [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Earnings (Loss) [Member]	Noncontrolling Interests [Member]
Beginning Balance at Dec. 31, 2015	$ 3,688.2	$ 176.9	$ 3,209.4	$ 774.5	$ (522.5)	$ 49.9
Beginning Balance (in shares) at Dec. 31, 2015		176.9
Net earnings	344			319.3		24.7
Dividends paid to noncontrolling interests	(24.1)					(24.1)
Change in pension liability, net of taxes	4.4				4.4
Foreign currency translation	(87.2)				(91.4)	4.2
Change in fair value of derivative instruments, net of taxes	(11)				(11)
Compensation expense related to stock option plan grants	10.9		10.9
Tax impact from issuance of common stock	4.8		4.8
Common stock issued in:
Seven purchase transactions	85.7	$ 1.9	83.8
Seven purchase transactions (in shares)		1.9
Stock option plans	$ 24.1	$ 0.9	23.2
Stock option plans (in shares)	0.9	0.9
Employee stock purchase plan	$ 12.7	$ 0.3	12.4
Employee stock purchase plan (in shares)		0.3
Deferred compensation and restricted stock	(6.3)	$ 0.2	(6.5)
Deferred compensation and restricted stock (in shares)		0.2
Common stock repurchases	(101)	$ (2.3)	(98.7)
Common stock repurchases (in shares)		(2.3)
Cash dividends declared on common stock	(204)			(204)
Ending Balance at Sep. 30, 2016	$ 3,741.2	$ 177.9	$ 3,239.3	$ 889.8	$ (620.5)	$ 54.7
Ending Balance (in shares) at Sep. 30, 2016		177.9

Consolidated Statement of Stoc8

Consolidated Statement of Stockholders' Equity (Unaudited) (Parenthetical) $ in Millions	9 Months Ended
	Sep. 30, 2016USD ($)
Statement of Stockholders' Equity [Abstract]
Tax effect on net change in pension liability	$ 2.9
Net change in fair value of derivative instruments, tax	$ 7.3

Nature of Operations and Basis

Nature of Operations and Basis of Presentation	9 Months Ended
	Sep. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations and Basis of Presentation	1. Nature of Operations and Basis of Presentation Arthur J. Gallagher & Co. and its subsidiaries, collectively referred to herein as we, our, us or the company, provide insurance brokerage and risk management services to a wide variety of commercial, industrial, institutional and governmental organizations through three reportable segments. Commission and fee revenue generated by the brokerage segment is primarily related to the negotiation and placement of insurance for our clients. Fee revenue generated by the risk management segment is primarily related to claims management, information management, risk control consulting (loss control) services and appraisals in the property/casualty market. Investment income and other revenue are generated from our premium financing operations and our investment portfolio, which includes invested cash and restricted funds, as well as clean energy and other investments. We are headquartered in Itasca, Illinois, have operations in 33 countries and offer client-service capabilities in more than 150 countries globally through a network of correspondent insurance brokers and consultants. We have prepared the accompanying unaudited consolidated financial statements pursuant to the rules and regulations of the Securities and Exchange Commission. Certain information and footnote disclosures normally included in annual financial statements have been omitted pursuant to such rules and regulations. The unaudited consolidated financial statements included herein are, in the opinion of management, prepared on a basis consistent with our audited consolidated financial statements for the year ended December 31, 2015, except as disclosed in Note 2, and include all normal recurring adjustments necessary for a fair presentation of the information set forth. The quarterly results of operations are not necessarily indicative of the results of operations to be reported for subsequent quarters or the full year. These unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2015. In the preparation of our unaudited consolidated financial statements as of September 30, 2016, management evaluated all material subsequent events or transactions that occurred after the balance sheet date through the date on which the financial statements were issued, for potential recognition or disclosure therein.

Effect of New Accounting Pronou

Effect of New Accounting Pronouncements	9 Months Ended
	Sep. 30, 2016
Accounting Changes and Error Corrections [Abstract]
Effect of New Accounting Pronouncements	2. Effect of New Accounting Pronouncements Cash Receipts and Cash Payments In August 2016, the Financial Accounting Standards Board (which we refer to as the FASB) issued Accounting Standards Update (which we refer to as ASU) No. 2016-15, Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force), (ASU 2016-15). The amendments in ASU 2016-15 address eight specific cash flow issues and apply to all entities that are required to present a statement of cash flows under ASC 230, Statement of Cash Flows. The amendments in ASU 2016-15 are effective for public business entities for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. We are currently reviewing the new guidance, and the impact from its adoption on our consolidated financial statements cannot be determined at this time. Leases In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). Under this new accounting guidance, an entity is required to recognize right-of-use assets and lease liabilities on its balance sheet and disclose key information about leasing arrangements. This new guidance offers specific accounting guidance for a lessee, a lessor and sale and leaseback transactions. Lessees and lessors are required to disclose qualitative and quantitative information about leasing arrangements to enable a user of the financial statements to assess the amount, timing and uncertainty of cash flows arising from leases. This new guidance is effective for first quarter 2019, and requires a modified retrospective adoption, with early adoption permitted. We are currently reviewing the new guidance, and the impact from its adoption on our consolidated financial statements cannot be determined at this time. Stock Compensation In March 2016, the FASB issued ASU No. 2016-09, Improvements to Employee Share-Based Payment Accounting. This new accounting guidance requires that all companies recognize the income tax effects of awards in the income statement when the awards vest or are settled, rather than maintaining an APIC pool and recognizing the tax benefits in excess of compensation costs through equity. As it relates to forfeitures, the guidance allows for companies to choose whether to continue to estimate forfeitures or account for forfeitures as they occur. ASU 2016-09 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2016. Early adoption is permitted and the new guidance may be applied either retrospectively or on a prospective basis. Management believes that the adoption of this guidance will not have a material impact on our consolidated financial statements. Consolidations In February 2015, the FASB issued ASU No. 2015-02, Amendments to the Consolidation Analysis. This new accounting guidance on consolidations eliminates the deferral granted to investment companies from applying the variable interest entities guidance and makes targeted amendments to the current consolidation guidance. The new guidance applies to all entities involved with limited partnerships or similar entities and required re-evaluation of these entities under the revised guidance, which could have changed previous consolidation conclusions. The new guidance was effective in first quarter 2016 and has been applied by us. The adoption of this guidance did not have a material impact on our consolidated financial statements. Debt Issuance Costs In April 2015, the FASB issued ASU No. 2015-03, Simplifying the Presentation of Debt Issuance Costs. The new accounting guidance requires debt issuance costs to be presented in the balance sheet as a direct deduction from the associated debt liability. The new guidance was effective in first quarter 2016 and has been applied by us on a retrospective basis. Accordingly, we have reclassified debt issuance costs of $3.3 million previously included in Other non-current Intangibles – Goodwill and Other In April 2015, the FASB issued ASU No. 2015-05, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement. This new guidance provides additional information to help entities determine whether a cloud computing arrangement contains a software license that should be accounted for as internal-use software or as a service contract. The new guidance was effective in first quarter 2016 and has been applied by us. The adoption of this guidance did not have a material impact on our consolidated financial statements. Business Combinations In September 2015, the FASB issued ASU No. 2015-16, Business Combinations (Topic 805): Simplifying the Accounting for Measurement-Period Adjustments. The new accounting guidance requires that measurement period adjustments be recognized in the reporting period in which the adjustment amount is determined rather than retrospectively applying the change to the acquisition date. The new guidance was effective in first quarter 2016 and was applied by us. The adoption of this guidance did not have a material impact on our consolidated financial statements. Income Taxes In November 2015, the FASB issued ASU No. 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes. The new accounting guidance requires that deferred tax assets and liabilities be classified as noncurrent on the balance sheet rather than being separated into current and noncurrent components. ASU 2015-17 is effective in first quarter 2017. Early adoption is permitted and the standard may be applied either retrospectively or on a prospective basis to all deferred tax assets and liabilities. We early adopted ASU 2015-17 during first quarter 2016 on a retrospective basis. Accordingly, we reclassified the current deferred taxes to noncurrent in our December 31, 2015 consolidated balance sheet, which increased Noncurrent deferred tax assets by $122.1 million and increased Other noncurrent liabilities by $4.6 million. Revenue Recognition In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers, as a new Topic, ASC 606, which will supersede nearly all existing revenue recognition guidance under U.S. GAAP. The core principal of the new accounting guidance is that an entity should recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The guidance also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to obtain or fulfill a contract. On July 9, 2015, the FASB decided to delay the effective date of the new revenue standard by one year. Reporting entities may choose to adopt the standard as of the original effective date. The FASB decided, based on its outreach to various stakeholders and the forthcoming amendments to the new revenue standard, that a deferral was necessary to provide adequate time to effectively implement the new revenue standard. This new guidance was originally effective for the first quarter 2017 and early adoption was not permitted. With the one year deferral date, this new guidance is now effective for the first quarter 2018, but it can be adopted earlier in first quarter 2017. We plan to adopt this new guidance in first quarter 2018. The guidance permits two methods of transition upon adoption; full retrospective and modified retrospective. Under the full retrospective method, prior periods would be restated under the new revenue standard, providing a comparable view across all periods presented. Under the modified retrospective method, prior periods would not be restated. Rather, revenues and other disclosures for pre-2017 periods would be provided in the notes to the financial statements as previously reported under the current revenue standard. We are currently reviewing the guidance, and the impact from its adoption on our consolidated financial statements cannot be determined at this time.

Business Combinations

Business Combinations	9 Months Ended
	Sep. 30, 2016
Business Combinations [Abstract]
Business Combinations	3. Business Combinations During the nine-month period ended September 30, 2016, we acquired substantially all of the net assets of the following firms in exchange for our common stock and/or cash. These acquisitions have been accounted for using the acquisition method for recording business combinations (in millions except share data): Name and Effective Date of Acquisition Common Common Cash Accrued Escrow Recorded Total Maximum (000s) Bomford, Couch & Wilson, Inc. February 1, 2016 — $ — $ 0.9 $ — $ — $ 1.4 $ 2.3 $ 2.1 White & Company Insurance, Inc. (WCI) February 1, 2016 494 17.4 — — 1.9 — 19.3 — Joseph Distel & Company, Inc. March 1, 2016 — — 1.3 — 0.2 — 1.5 — Vincent L. Braband Insurance, Inc. March 1, 2016 — — 3.0 — 0.3 0.4 3.7 1.1 Kane’s Insurance Management Operations (KIM) March 31, 2016 — — 30.8 — — — 30.8 — Capitol Benefits Group, Inc. April 1, 2016 — — 3.3 — 0.1 0.4 3.8 2.8 Charles Allen Agency, Inc. April 1, 2016 — — 2.8 — 0.2 0.2 3.2 0.7 Hagan Newkirk Financial Services, Inc. April 1, 2016 — — 4.3 — 0.1 0.9 5.3 3.1 Insurance Plans Agency, Inc. April 1, 2016 51 2.3 — — 0.1 0.2 2.6 1.5 KDC Associates, LLC (KDC) April 1, 2016 — — 20.7 — 1.8 3.9 26.4 7.5 Hogan Insurance Services, Inc. (HIS) May 1, 2016 172 7.4 — — 0.8 1.1 9.3 2.0 McNeary, Inc. (MNI) May 1, 2016 572 22.0 — — 5.0 0.4 27.4 5.5 Name and Effective Date of Acquisition Common Common Cash Accrued Escrow Recorded Total Maximum (000s) Ashmore & Associates Insurance Agency, LLC May 1, 2016 — $ — $ 7.7 $ — $ 0.4 $ 0.6 $ 8.7 $ 1.7 KRW Insurance Agency, Inc. June 1, 2016 139 5.9 — — 0.7 1.0 7.6 1.6 Buchholz Planning Corporation June 1, 2016 — — 3.9 — 0.1 2.5 6.5 6.0 Blue Horizon Insurance Services, Inc. July 1, 2016 — — 3.4 — 0.4 0.5 4.3 1.0 Brim AB (BRM) July 1, 2016 — — 23.5 6.5 — — 30.0 — Gabor Insurance Services, Inc. (GIS) July 1, 2016 — — 14.1 — 0.5 — 14.6 — Victory Insurance Agency, Inc. (VIA) July 1, 2016 422 20.9 — 2.3 — 3.3 26.5 4.5 Orb Financial Services Limited August 1, 2016 — — 3.1 — 0.4 2.0 5.5 2.7 Eight other acquisitions completed in 2016 — — 17.7 0.1 1.1 5.9 24.8 9.4 1,850 $ 75.9 $ 140.5 $ 8.9 $ 14.1 $ 24.7 $ 264.1 $ 53.2 Effective on September 1, 2016, we entered into a purchase agreement to acquire certain assets and an assembled workforce from one of our India-based outsourced service providers for approximately $4.6 million in cash. Prior to this transaction, most of our India-based workforce was provided by the third-party on a cost-pass-through basis. We now directly employ those associates thereby adding approximately 2,700 employees to our global workforce. Common shares issued in connection with acquisitions are valued at closing market prices as of the effective date of the applicable acquisition. We record escrow deposits that are returned to us as a result of adjustments to net assets acquired as reductions of goodwill when the escrows are settled. The maximum potential earnout payables disclosed in the foregoing table represent the maximum amount of additional consideration that could be paid pursuant to the terms of the purchase agreement for the applicable acquisition. The amounts recorded as earnout payables, which are primarily based upon the estimated future operating results of the acquired entities over a two- to three-year period subsequent to the acquisition date, are measured at fair value as of the acquisition date and are included on that basis in the recorded purchase price consideration in the foregoing table. We will record subsequent changes in these estimated earnout obligations, including the accretion of discount, in our consolidated statement of earnings when incurred. The fair value of these earnout obligations is based on the present value of the expected future payments to be made to the sellers of the acquired entities in accordance with the provisions outlined in the respective purchase agreements, which is a Level 3 fair value measurement. In determining fair value, we estimated the acquired entity’s future performance using financial projections developed by management for the acquired entity and market participant assumptions that were derived for revenue growth and/or profitability. Revenue growth rates generally ranged from 3.5% to 12.5% for our 2016 acquisitions. We estimated future payments using the earnout formula and performance targets specified in each purchase agreement and these financial projections. We then discounted these payments to present value using a risk-adjusted rate that takes into consideration market-based rates of return that reflect the ability of the acquired entity to achieve the targets. These discount rates generally ranged from 8.5% to 9.5% for all of our 2016 acquisitions. Changes in financial projections, market participant assumptions for revenue growth and/or profitability, or the risk-adjusted discount rate, would result in a change in the fair value of recorded earnout obligations. During the three-month periods ended September 30, 2016 and 2015, we recognized $4.3 million and $3.7 million, respectively, of expense in our consolidated statement of earnings related to the accretion of the discount recorded for earnout obligations in connection with our acquisitions. During the nine-month periods ended September 30, 2016 and 2015, we recognized $12.5 million and $12.2 million, respectively, of expense in our consolidated statement of earnings related to the accretion of the discount recorded for earnout obligations in connection with our acquisitions. In addition, during the three-month periods ended September 30, 2016 and 2015, we recognized $0.2 million of income and $6.0 million of expense, respectively, related to net adjustments in the estimated fair value of earnout obligations in connection with revised projections of future performance for 27 and 35 acquisitions, respectively. During the nine-month periods ended September 30, 2016 and 2015, we recognized $8.7 million and $13.7 million of expense, respectively, related to net adjustments in the estimated fair value of earnout obligations in connection with revised projections of future performance for 77 and 72 acquisitions, respectively. The aggregate amount of maximum earnout obligations related to acquisitions was $503.8 million as of September 30, 2016, of which $225.0 million was recorded in our consolidated balance sheet as of September 30, 2016, based on the estimated fair value of the expected future payments to be made. The following is a summary of the estimated fair values of the net assets acquired at the date of each acquisition made in the nine-month period ended September 30, 2016 (in millions): WCI KIM KDC HIS MNI BRM GIS VIA Twenty Total Cash $ — $ 2.2 $ 0.3 $ 0.2 $ 3.0 $ 0.5 $ 0.3 $ 0.2 $ 3.8 $ 10.5 Other current assets 2.8 1.8 9.3 0.2 1.7 36.0 3.9 2.1 4.5 62.3 Fixed assets 0.1 0.4 0.1 — 0.1 0.6 0.1 0.1 1.9 3.4 Noncurrent assets — 1.2 — — — — — — — 1.2 Goodwill 13.6 9.2 12.1 6.3 19.5 23.5 7.5 18.2 37.3 147.2 Expiration lists 8.1 20.0 13.8 4.9 13.8 10.4 6.6 13.2 40.7 131.5 Non-compete agreements 0.1 — 0.1 — 0.1 0.3 0.1 0.1 0.5 1.3 Trade names — — — — 0.1 — — — — 0.1 Total assets acquired 24.7 34.8 35.7 11.6 38.3 71.3 18.5 33.9 88.7 357.5 Current liabilities 2.2 3.9 8.9 0.4 2.2 33.3 3.9 2.2 4.4 61.4 Noncurrent liabilities 3.2 0.1 0.4 1.9 8.7 8.0 — 5.2 4.5 32.0 Total liabilities assumed 5.4 4.0 9.3 2.3 10.9 41.3 3.9 7.4 8.9 93.4 Total net assets acquired $ 19.3 $ 30.8 $ 26.4 $ 9.3 $ 27.4 $ 30.0 $ 14.6 $ 26.5 $ 79.8 $ 264.1 Among other things, these acquisitions allow us to expand into desirable geographic locations, further extend our presence in the retail and wholesale insurance brokerage services and risk management industries and increase the volume of general services currently provided. The excess of the purchase price over the estimated fair value of the tangible net assets acquired at the acquisition date was allocated to goodwill, expiration lists, non-compete agreements and trade names in the amounts of $147.2 million, $131.5 million, $1.3 million and $0.1 million, respectively, within the brokerage segment. Provisional estimates of fair value are established at the time of each acquisition and are subsequently reviewed within the first year of operations subsequent to the acquisition date to determine the necessity for adjustments. The fair value of the tangible assets and liabilities for each applicable acquisition at the acquisition date approximated their carrying values. The fair value of expiration lists was established using the excess earnings method, which is an income approach based on estimated financial projections developed by management for each acquired entity using market participant assumptions. Revenue growth and attrition rates generally ranged from 1.0% to 3.0% and 2.5% to 12.5%, respectively, for our 2015 acquisitions for which valuations were performed in 2016. We estimate the fair value as the present value of the benefits anticipated from ownership of the subject customer list in excess of returns required on the investment in contributory assets necessary to realize those benefits. The rate used to discount the net benefits was based on a risk-adjusted rate that takes into consideration market-based rates of return and reflects the risk of the asset relative to the acquired business. These discount rates generally ranged from 12.0% to 19.0% for our 2015 acquisitions for which valuations were performed in 2016. The fair value of non-compete agreements was established using the profit differential method, which is an income approach based on estimated financial projections developed by management for the acquired company using market participant assumptions and various non-compete scenarios. Expiration lists, non-compete agreements and trade names related to our acquisitions are amortized using the straight-line method over their estimated useful lives (three to fifteen years for expiration lists, three to five years for non-compete agreements and three to five years for trade names), while goodwill is not subject to amortization. We use the straight-line method to amortize these intangible assets because the pattern of their economic benefits cannot be reasonably determined with any certainty. We review all of our intangible assets for impairment periodically (at least annually) and whenever events or changes in business circumstances indicate that the carrying value of the assets may not be recoverable. In reviewing intangible assets, if the fair value were less than the carrying amount of the respective (or underlying) asset, an indicator of impairment would exist and further analysis would be required to determine whether or not a loss would need to be charged against current period earnings as a component of amortization expense. Of the $131.5 million of expiration lists, $1.3 million of non-compete agreements and $0.1 million of trade names related to our acquisitions made during the nine-month period ended September 30, 2016, $61.1 million, $0.7 million, and $0.1 million, respectively, is not expected to be deductible for income tax purposes. Accordingly, we recorded a deferred tax liability of $21.1 million, and a corresponding amount of goodwill, in the nine-month period ended September 30, 2016, related to nondeductible amortizable intangible assets. Our consolidated financial statements for the nine-month period ended September 30, 2016 include the operations of the acquired entities from their respective acquisition dates. The following is a summary of the unaudited pro forma historical results, as if these entities had been acquired at January 1, 2015 (in millions, except per share data): Three-month period Nine-month period 2016 2015 2016 2015 Total revenues $ 1,482.6 $ 1,480.1 $ 4,242.9 $ 4,132.4 Net earnings attributable to controlling interests 122.8 134.6 321.2 298.1 Basic net earnings per share 0.69 0.76 1.80 1.73 Diluted net earnings per share 0.69 0.75 1.79 1.72 The unaudited pro forma results above have been prepared for comparative purposes only and do not purport to be indicative of the results of operations which actually would have resulted had these acquisitions occurred at January 1, 2015, nor are they necessarily indicative of future operating results. Annualized revenues of entities acquired during the nine-month period ended September 30, 2016 totaled approximately $97.8 million. For the nine-month

Other Current Assets

Other Current Assets	9 Months Ended
	Sep. 30, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Other Current Assets	4. Other Current Assets Major classes of other current assets consist of the following (in millions): September 30, December 31, Premium finance advances and loans $ 255.6 $ 220.2 Accrued supplemental, direct bill and other receivables 145.6 181.1 Refined coal production related receivables 122.0 108.1 Prepaid expenses 77.9 77.8 Total other current assets $ 601.1 $ 587.2 The premium finance loans represent short-term loans which we make to many of our brokerage related clients and other non-brokerage

Intangible Assets

Intangible Assets	9 Months Ended
	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	5. Intangible Assets The carrying amount of goodwill at September 30, 2016 and December 31, 2015 allocated by domestic and foreign operations is as follows (in millions): Brokerage Risk Corporate Total At September 30, 2016 United States $ 2,065.1 $ 23.6 $ — $ 2,088.7 United Kingdom 684.2 4.5 — 688.7 Canada 298.3 — — 298.3 Australia 400.5 — — 400.5 New Zealand 216.5 0.3 — 216.8 Other foreign 69.6 — — 69.6 Total goodwill - net $ 3,734.2 $ 28.4 $ — $ 3,762.6 At December 31, 2015 United States $ 1,946.9 $ 23.5 $ — $ 1,970.4 United Kingdom 779.3 3.5 — 782.8 Canada 282.6 — — 282.6 Australia 380.1 — — 380.1 New Zealand 204.2 0.3 — 204.5 Other foreign 42.5 — — 42.5 Total goodwill - net $ 3,635.6 $ 27.3 $ — $ 3,662.9 The changes in the carrying amount of goodwill for the nine-month period ended September 30, 2016 are as follows (in millions): Brokerage Risk Corporate Total Balance as of December 31, 2015 $ 3,635.6 $ 27.3 $ — $ 3,662.9 Goodwill acquired during the period 147.2 — — 147.2 Goodwill adjustments due to appraisals and other acquisition adjustments 0.4 1.6 — 2.0 Foreign currency translation adjustments during the period (49.0 ) (0.5 ) — (49.5 ) Balance as of September 30, 2016 $ 3,734.2 $ 28.4 $ — $ 3,762.6 Major classes of amortizable intangible assets at September 30, 2016 and December 31, 2015 consist of the following (in millions): September 30, December 31, Expiration lists $ 2,713.1 $ 2,613.3 Accumulated amortization - expiration lists (1,097.3 ) (934.7 ) 1,615.8 1,678.6 Non-compete agreements 48.3 43.7 Accumulated amortization - non-compete agreements (40.9 ) (34.8 ) 7.4 8.9 Trade names 24.6 25.7 Accumulated amortization - trade names (17.9 ) (14.4 ) 6.7 11.3 Net amortizable assets $ 1,629.9 $ 1,698.8 Estimated aggregate amortization expense for each of the next five years is as follows: 2016 (remaining three months) $ 61.5 2017 233.1 2018 220.2 2019 206.5 2020 190.2 Total $ 911.5

Credit and Other Debt Agreement

Credit and Other Debt Agreements	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Credit and Other Debt Agreements	6. Credit and Other Debt Agreements The following is a summary of our corporate and other debt (in millions): September 30, December 31, Note Purchase Agreements: Semi-annual payments of interest, fixed rate of 6.44%, balloon due 2017 $ 300.0 $ 300.0 Semi-annual payments of interest, fixed rate of 5.85%, $50 million due in 2016, 2018 and 2019 150.0 150.0 Semi-annual payments of interest, fixed rate of 2.80%, balloon due 2018 50.0 50.0 Semi-annual payments of interest, fixed rate of 3.20%, balloon due 2019 50.0 50.0 Semi-annual payments of interest, fixed rate of 3.99%, balloon due 2020 50.0 50.0 Semi-annual payments of interest, fixed rate of 3.48%, balloon due 2020 50.0 50.0 Semi-annual payments of interest, fixed rate of 5.18%, balloon due 2021 75.0 75.0 Semi-annual payments of interest, fixed rate of 3.69%, balloon due 2022 200.0 200.0 Semi-annual payments of interest, fixed rate of 5.49%, balloon due 2023 50.0 50.0 Semi-annual payments of interest, fixed rate of 4.13%, balloon due 2023 200.0 200.0 Semi-annual payments of interest, fixed rate of 4.58%, balloon due 2024 325.0 325.0 Semi-annual payments of interest, fixed rate of 4.31%, balloon due 2025 200.0 200.0 Semi-annual payments of interest, fixed rate of 4.73%, balloon due 2026 175.0 175.0 Semi-annual payments of interest, fixed rate of 4.36%, balloon due 2026 150.0 150.0 Semi-annual payments of interest, fixed rate of 4.40%, balloon due 2026 175.0 — Semi-annual payments of interest, fixed rate of 4.55%, balloon due 2028 75.0 — Semi-annual payments of interest, fixed rate of 4.98%, balloon due 2029 100.0 100.0 Semi-annual payments of interest, fixed rate of 4.70%, balloon due 2031 25.0 — Total Note Purchase Agreements 2,400.0 2,125.0 Credit Agreement: Periodic payments of interest and principal, prime or LIBOR plus up to 1.45%, was to expire September 19, 2018, replaced with amended and restated facility on April 8, 2016 (see below) 258.0 195.0 Premium Financing Debt Facility - expires May 18, 2017: Periodic payments of interest and principal, Interbank rates plus 1.05% for Facility B; plus 0.55% for Facilities C and D Facility B AUD denominated tranche 113.1 101.2 NZD denominated tranche 9.1 8.5 Facility C and D AUD denominated tranche — 17.2 NZD denominated tranche 10.9 10.1 Total Premium Financing Debt Facility 133.1 137.0 Total corporate and other debt $ 2,791.1 $ 2,457.0 Note Purchase Agreements We are a party to a note purchase agreement dated November 30, 2009, with certain accredited institutional investors, pursuant to which we issued and sold $150.0 million in aggregate principal amount of our 5.85% Senior Notes, Series C, due in three equal installments on November 30, 2016, November 30, 2018 and November 30, 2019, in a private placement. These notes require semi-annual payments of interest that are due in May and November of each year. We are a party to a note purchase agreement dated February 10, 2011, with certain accredited institutional investors, pursuant to which we issued and sold $75.0 million in aggregate principal amount of our 5.18% Senior Notes, Series D, due February 10, 2021 and $50.0 million in aggregate principal amount of our 5.49% Senior Notes, Series E, due February 10, 2023, in a private placement. These notes require semi-annual payments of interest that are due in February and August of each year. We are a party to a note purchase agreement dated July 10, 2012, with certain accredited institutional investors, pursuant to which we issued and sold $50.0 million in aggregate principal amount of our 3.99% Senior Notes, Series F, due July 10, 2020, in a private placement. These notes require semi-annual payments of interest that are due in January and July of each year. We are a party to a note purchase agreement dated June 14, 2013, with certain accredited institutional investors, pursuant to which we issued and sold $200.0 million in aggregate principal amount of our 3.69% Senior Notes, Series G, due June 14, 2022, in a private placement. These notes require semi-annual payments of interest that are due in June and December of each year. We are a party to a note purchase agreement dated December 20, 2013, with certain accredited institutional investors, pursuant to which we issued and sold $325.0 million in aggregate principal amount of our 4.58% Senior Notes, Series H, due February 27, 2024, $175.0 million in aggregate principal amount of our 4.73% Senior Notes, Series I, due February 27, 2026 and $100.0 million in aggregate principal amount of our 4.98% Senior Notes, Series J, due February 27, 2029. These notes require semi-annual payments of interest that are due in February and August of each year. The funding of this note purchase agreement occurred on February 27, 2014. We incurred approximately $1.4 million of debt acquisition costs that was capitalized and will be amortized on a pro rata basis over the life of the debt. We are a party to a note purchase agreement dated June 24, 2014, with certain accredited institutional investors, pursuant to which we issued and sold $50.0 million in aggregate principal amount of our 2.80% Senior Notes, Series K, due June 24, 2018, $50.0 million in aggregate principal amount of our 3.20% Senior Notes, Series L, due June 24, 2019, $50.0 million in aggregate principal amount of our 3.48% Senior Notes, Series M, due June 24, 2020, $200.0 million in aggregate principal amount of our 4.13% Senior Notes, Series N, due June 24, 2023, $200.0 million in aggregate principal amount of our 4.31% Senior Notes, Series O, due June 24, 2025 and $150.0 million in aggregate principal amount of our 4.36% Senior Notes, Series P, due June 24, 2026. These notes require semi-annual payments of interest that are due in June and December of each year. We incurred approximately $2.6 million of debt acquisition costs that was capitalized and will be amortized on a pro rata basis over the life of the debt. We are a party to a note purchase agreement dated June 2, 2016, with certain accredited institutional investors, pursuant to which we issued and sold $175.0 million in aggregate principal amount of our 4.40% Senior Notes, Series Q, due June 2, 2026, $75.0 million in aggregate principal amount of our 4.55% Senior Notes, Series R, due June 2, 2028 and $25.0 million in aggregate principal amount of our 4.70% Senior Notes, Series S, due June 2, 2031. These notes require semi-annual payments of interest that are due in June and December of each year. We incurred approximately $1.2 million of debt acquisition costs that was capitalized and will be amortized on a pro rata basis over the life of the debt. In addition, we realized a cash gain of approximately $1.0 million on the hedging transaction that will be recognized on a pro rata basis as a reduction in our reported interest expense over the ten year life of the debt. Under the terms of the note purchase agreements described above, we may redeem the notes at any time, in whole or in part, at 100% of the principal amount of such notes being redeemed, together with accrued and unpaid interest and a “make-whole amount.” The “make-whole amount” is derived from a net present value computation of the remaining scheduled payments of principal and interest using a discount rate based on U.S. Treasury yields plus 0.5% and is designed to compensate the purchasers of the notes for their investment risk in the event prevailing interest rates at the time of prepayment are less favorable than the interest rates under the notes. We do not currently intend to prepay any of the notes. The note purchase agreements described above contain customary provisions for transactions of this type, including representations and warranties regarding us and our subsidiaries and various financial covenants, including covenants that require us to maintain specified financial ratios. We were in compliance with these covenants as of September 30, 2016. The note purchase agreements also provide customary events of default, generally with corresponding grace periods, including, without limitation, payment defaults with respect to the notes, covenant defaults, cross-defaults to other agreements evidencing our or our subsidiaries’ indebtedness, certain judgments against us or our subsidiaries and events of bankruptcy involving us or our material subsidiaries. The notes issued under the note purchase agreements are senior unsecured obligations of ours and rank equal in right of payment with our Credit Agreement discussed below. Credit Agreement The Credit Agreement provides that we may elect that each borrowing in U.S. dollars be either base rate loans or eurocurrency loans, each as defined in the Credit Agreement. However, the Credit Agreement provides that all loans denominated in currencies other than U.S. dollars will be eurocurrency loans. Interest rates on base rate loans and outstanding drawings on letters of credit in U.S. dollars under the Credit Agreement will be based on the base rate, as defined in the Credit Agreement, plus a margin of 0.00% to 0.45%, depending on the financial leverage ratio we maintain. Interest rates on eurocurrency loans or outstanding drawings on letters of credit in currencies other than U.S. dollars under the Credit Agreement will be based on adjusted LIBOR, as defined in the Credit Agreement, plus a margin of 0.85% to 1.45%, depending on the financial leverage ratio we maintain. Interest rates on swing loans will be based, at our election, on either the base rate or an alternate rate that may be quoted by the lead lender. The annual facility fee related to the Credit Agreement will be between 0.15% and 0.30% of the revolving credit commitment, depending on the financial leverage ratio we maintain. In connection with entering into the Credit Agreement, we incurred approximately $2.0 million of debt acquisition costs that were capitalized and will be amortized on a pro rata basis over the term of the Credit Agreement. The terms of the Credit Agreement include various financial covenants, including covenants that require us to maintain specified financial ratios. We were in compliance with these covenants as of September 30, 2016. The Credit Agreement also includes customary provisions for transactions of this type, including events of default, with corresponding grace periods and cross-defaults to other agreements evidencing our indebtedness. At September 30, 2016, $21.1 million of letters of credit (for which we had $12.0 million of liabilities recorded at September 30, 2016) were outstanding under the Credit Agreement. There were $258.0 million of borrowings outstanding under the Credit Agreement at September 30, 2016. Accordingly, as of September 30, 2016, $520.9 million remained available for potential borrowings under the Credit Agreement, of which $53.9 million was available for additional letters of credit. Premium Financing Debt Facility The interest rates on Facility B are Interbank rates, which vary by tranche, duration and currency, plus a margin of 1.05%. The interest rates on Facilities C and D are 30 day Interbank rates, plus a margin of 0.55%. The annual fee for Facility B is 0.4725% of the undrawn commitments for the two tranches of the facility. The annual fee for Facilities C and D is 0.50% of the total commitments of the facilities. The terms of our Premium Financing Debt Facility include various financial covenants, including covenants that require us to maintain specified financial ratios. We were in compliance with these covenants as of September 30, 2016. The Premium Financing Debt Facility also includes customary provisions for transactions of this type, including events of default, with corresponding grace periods and cross-defaults to other agreements evidencing our indebtedness. Facilities B, C and D are secured by the premium finance receivables of the Australian and New Zealand premium finance subsidiaries. At September 30, 2016, AU$149.0 million and NZ$12.5 million of borrowings were outstanding under Facility B, AU zero borrowings were outstanding under Facility C and NZ$14.9 million of borrowings were outstanding under Facility D. Accordingly, as of September 30, 2016, AU$1.0 million and NZ$22.5 million remained available for potential borrowing under Facility B, and AU$25.0 million and NZ$0.1 million under Facilities C and D, respectively. See Note 13 to these unaudited consolidated financial statements for additional discussion on our contractual obligations and commitments as of September 30, 2016. The aggregate estimated fair value of the $2,400.0 million in debt under the note purchase agreements at September 30, 2016 was $2,590.8 million due to the long-term duration and fixed interest rates associated with these debt obligations. No active or observable market exists for our private placement long-term debt. Therefore, the estimated fair value of this debt is based on discounted future cash flows, which is a Level 3 fair value measurement, using current interest rates available for debt with similar terms and remaining maturities. See Note 1, Fair Value of Financial Instruments, to our consolidated financial statements included in Item 8 of our Annual Report on Form 10-K

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Earnings Per Share	7. Earnings Per Share The following table sets forth the computation of basic and diluted net earnings per share (in millions, except per share data): Three-month period ended September 30, Nine-month period ended September 30, 2016 2015 2016 2015 Net earnings attributable to controlling interests $ 122.8 $ 133.3 $ 319.3 $ 294.5 Weighted average number of common shares outstanding 177.6 176.0 177.4 170.7 Dilutive effect of stock options using the treasury stock method 0.9 0.8 0.8 1.1 Weighted average number of common and common equivalent shares outstanding 178.5 176.8 178.2 171.8 Basic net earnings per share $ 0.69 $ 0.76 $ 1.80 $ 1.73 Diluted net earnings per share $ 0.69 $ 0.75 $ 1.79 $ 1.71 Options to purchase 4.5 million and 3.9 million shares of common stock were outstanding at September 30, 2016 and 2015, respectively, but were not included in the computation of the dilutive effect of stock options for the three-month nine-month

Stock Option Plans

Stock Option Plans	9 Months Ended
	Sep. 30, 2016
Text Block [Abstract]
Stock Option Plans	8. Stock Option Plans On May 13, 2014, our stockholders approved the Arthur J. Gallagher 2014 Long-Term Incentive Plan (which we refer to as the LTIP), which replaced our previous stockholder-approved Arthur J. Gallagher & Co. 2011 Long-Term Incentive Plan (which we refer to as the 2011 LTIP). The LTIP term began May 13, 2014 and terminates on the date of the annual meeting of stockholders in 2021, unless terminated earlier by our board of directors. All of our officers, employees and non-employee directors are eligible to receive awards under the LTIP. The compensation committee of our board of directors determines the participants under the LTIP. The LTIP provides for non-qualified and incentive stock options, stock appreciation rights, restricted stock, restricted stock units and performance units, any or all of which may be made contingent upon the achievement of performance criteria. A stock appreciation right entitles the holder to receive, upon exercise and subject to withholding taxes, cash or shares of our common stock (which may be restricted stock) with a value equal to the difference between the fair market value of our common stock on the exercise date and the base price of the stock appreciation right. Subject to the LTIP limits, the compensation committee has the discretionary authority to determine the size of an award. Shares of our common stock available for issuance under the LTIP include authorized and unissued shares of common stock or authorized and issued shares of common stock reacquired and held as treasury shares or otherwise, or a combination thereof. The number of available shares will be reduced by the aggregate number of shares that become subject to outstanding awards granted under the LTIP. To the extent that shares subject to an outstanding award granted under either the LTIP or the 2011 LTIP are not issued or delivered by reason of the expiration, termination, cancellation or forfeiture of such award or by reason of the settlement of such award in cash, then such shares will again be available for grant under the LTIP. Shares withheld to satisfy tax withholding requirements upon the vesting of awards other than stock options and stock appreciation rights will also be available for grant under the LTIP. Shares that are subject to a stock appreciation right and were not issued upon the net settlement or net exercise of such stock appreciation right, shares that are used to pay the exercise price of an option, delivered to or withheld by us to pay withholding taxes related to stock options or stock appreciation rights, and shares that are purchased on the open market with the proceeds of an option exercise, may not again be made available for issuance. The maximum number of shares available under the LTIP for restricted stock, restricted stock unit awards and performance unit awards settled with stock (i.e., all awards other than stock options and stock appreciation rights) is 1.0 million at September 30, 2016. To the extent necessary to be qualified performance-based compensation under Section 162(m) of the Internal Revenue Code (which we refer to as the IRC): (i) the maximum number of shares with respect to which options or stock appreciation rights or a combination thereof that may be granted during any fiscal year to any person is 200,000; (ii) the maximum number of shares with respect to which performance-based restricted stock or restricted stock units that may be granted during any fiscal year to any person is 100,000; (iii) the maximum amount that may be payable with respect to cash-settled performance units granted during any fiscal year to any person is $5.0 million; and (iv) the maximum number of shares with respect to which stock-settled performance units may be granted during any fiscal year to any person is 100,000. The LTIP provides for the grant of stock options, which may be either tax-qualified incentive stock options or non-qualified options and stock appreciation rights. The compensation committee determines the period for the exercise of a non-qualified stock option, tax-qualified incentive stock option or stock appreciation right, provided that no option can be exercised later than seven years after its date of grant. The exercise price of a non-qualified stock option or tax-qualified incentive stock option and the base price of a stock appreciation right cannot be less than 100% of the fair market value of a share of our common stock on the date of grant, provided that the base price of a stock appreciation right granted in tandem with an option will be the exercise price of the related option. Upon exercise, the option exercise price may be paid in cash, by the delivery of previously owned shares of our common stock, through a net-exercise arrangement, or through a broker-assisted cashless exercise arrangement. The compensation committee determines all of the terms relating to the exercise, cancellation or other disposition of an option or stock appreciation right upon a termination of employment, whether by reason of disability, retirement, death or any other reason. Stock option and stock appreciation right awards under the LTIP are non-transferable. On March 17, 2016, the compensation committee granted 2,576,700 options under the 2014 LTIP to our officers and key employees that become exercisable at the rate of 34%, 33% and 33% on the anniversary date of the grant in 2019, 2020 and 2021, respectively. On March 11, 2015, the compensation committee granted 1,941,000 options under the 2014 LTIP to our officers and key employees that become exercisable at the rate of 34%, 33% and 33% on the anniversary date of the grant in 2018, 2019 and 2020, respectively. The 2016 and 2015 options expire seven years from the date of grant, or earlier in the event of certain terminations of employment. For certain of our executive officers age 55 or older, stock options awarded in 2016 and 2015 are no longer subject to forfeiture upon such officers’ departure from the company after two years from the date of grant. Our stock option plans provide for the immediate vesting of all outstanding stock option grants in the event of a change in control of our company, as defined in the applicable plan documents. During the three-month periods ended September 30, 2016 and 2015, we recognized $3.8 million and $3.1 million, respectively, of compensation expense related to our stock option grants. During the nine-month periods ended September 30, 2016 and 2015, we recognized $10.9 million and $8.2 million, respectively, of compensation expense related to our stock option grants. For purposes of expense recognition, the estimated fair values of the stock option grants are amortized to expense over the options’ vesting period. We estimated the fair value of stock options at the date of grant using the Black-Scholes option pricing model with the following weighted average assumptions: 2016 2015 Expected dividend yield 3.0 % 3.0 % Expected risk-free interest rate 1.6 % 1.8 % Volatility 27.7 % 28.2 % Expected life (in years) 5.5 5.5 Option valuation models require the input of highly subjective assumptions including the expected stock price volatility. The Black-Scholes option pricing model was developed for use in estimating the fair value of traded options which have no vesting restrictions and are fully transferable. Because our employee and director stock options have characteristics significantly different from those of traded options, and because changes in the selective input assumptions can materially affect the fair value estimate, in management’s opinion, the existing models do not necessarily provide a reliable single measure of the fair value of our employee and non-employee director stock options. The weighted average fair value per option for all options granted during the nine-month periods ended September 30, 2016 and 2015, as determined on the grant date using the Black-Scholes option pricing model, was $8.45 and $9.25, respectively. The following is a summary of our stock option activity and related information for 2016 (in millions, except exercise price and year data): Nine-month period ended September 30, 2016 Weighted Average Weighted Remaining Shares Average Contractual Aggregate Under Exercise Term Intrinsic Option Price (in years) Value Beginning balance 8.8 $ 39.25 Granted 2.6 43.72 Exercised (0.9 ) 29.28 Forfeited or canceled — — Ending balance 10.5 $ 41.18 4.34 $ 102.1 Exercisable at end of period 2.4 $ 32.19 1.95 $ 45.7 Ending vested and expected to vest 10.3 $ 41.11 4.32 $ 100.8 Options with respect to 4.4 million shares (less any shares of restricted stock issued under the LTIP - see Note 10 to these unaudited consolidated financial statements) were available for grant under the LTIP at September 30, 2016. The total intrinsic value of options exercised during the nine-month periods ended September 30, 2016 and 2015 was $14.9 million and $26.3 million, respectively. As of September 30, 2016, we had approximately $45.4 million of total unrecognized compensation expense related to nonvested options. We expect to recognize that cost over a weighted average period of approximately four years. Other information regarding stock options outstanding and exercisable at September 30, 2016 is summarized as follows (in millions, except exercise price and year data): Options Outstanding Options Exercisable Range of Exercise Prices Number Outstanding Weighted Average Remaining Contractual Term (in years) Weighted Average Exercise Price Number Exercisable Weighted Average Exercise Price $ 23.76 - $ 35.71 2.4 1.74 $ 31.36 1.9 $ 30.51 35.95 - 39.17 1.6 3.45 39.15 0.5 39.13 43.71 - 43.71 2.6 6.46 43.71 — — 46.16 - 49.55 3.9 4.95 46.53 — — $ 23.76 - $ 49.55 10.5 4.34 $ 41.18 2.4 $ 32.19

Deferred Compensation

Deferred Compensation	9 Months Ended
	Sep. 30, 2016
Compensation Related Costs [Abstract]
Deferred Compensation	9. Deferred Compensation We have a Deferred Equity Participation Plan (which we refer to as the DEPP), which is a non-qualified plan that generally provides for distributions to certain of our key executives when they reach age 62 (or the one-year anniversary of the date of the grant for participants over the age of 61 as of the grant date) or upon or after their actual retirement. Under the provisions of the DEPP, we typically contribute cash in an amount approved by the compensation committee to a rabbi trust on behalf of the executives participating in the DEPP, and instruct the trustee to acquire a specified number of shares of our common stock on the open market or in privately negotiated transactions based on participant elections. Distributions under the DEPP may not normally be made until the participant reaches age 62 (or the one-year anniversary of the date of the grant for participants over the age of 61 as of the grant date) and are subject to forfeiture in the event of voluntary termination of employment prior to then. DEPP awards are generally made annually in the first quarter. In the second quarter of 2016, we made awards under sub-plans of the DEPP for certain production staff, which generally provide for vesting and/or distributions no sooner than five years from the date of awards, although certain awards vest and/or distribute after the earlier of fifteen years or the participant reaching age 65. All contributions to the plan (including sub-plans) deemed to be invested in shares of our common stock are distributed in the form of our common stock and all other distributions are paid in cash. Our common stock that is issued to or purchased by the rabbi trust as a contribution under the DEPP is valued at historical cost, which equals its fair market value at the date of grant or date of purchase. When common stock is issued, we record an unearned deferred compensation obligation as a reduction of capital in excess of par value in the accompanying consolidated balance sheet, which is amortized to compensation expense ratably over the vesting period of the participants. Future changes in the fair market value of our common stock owed to the participants do not have any impact on the amounts recorded in our consolidated financial statements. In the first quarter of each of 2016 and 2015, the compensation committee approved $10.1 million and $8.9 million, respectively, of awards in the aggregate to certain key executives under the DEPP that were contributed to the rabbi trust in first quarter 2016 and 2015, respectively. We contributed cash to the rabbi trust and instructed the trustee to acquire a specified number of shares of our common stock on the open market to fund these 2016 and 2015 awards. During the three-month periods ended September 30, 2016 and 2015, we charged $2.1 million and $2.1 million, respectively, to compensation expense related to these awards. During the nine-month periods ended September 30, 2016 and 2015, we charged $5.5 million and $5.2 million, respectively, to compensation expense related to these awards. In the second quarter of 2016, the compensation committee approved $13.6 million of awards under the sub-plans referred to above, which were contributed to the rabbi trust in second quarter 2016. During the three-month and nine-month At September 30, 2016 and December 31, 2015, we recorded $49.7 million (related to 2.4 million shares) and $33.5 million (related to 2.1 million shares), respectively, of unearned deferred compensation as a reduction of capital in excess of par value in the accompanying consolidated balance sheet. The total intrinsic value of our unvested equity based awards under the plan at September 30, 2016 and December 31, 2015 was $122.7 million and $85.2 million, respectively. During the nine-month period ended September 30, 2016, cash and equity awards with an aggregate fair value of $7.0 million were vested and distributed to executives under the DEPP. We have a Deferred Cash Participation Plan (which we refer to as the DCPP), which is a non-qualified deferred compensation plan for certain key employees, other than executive officers, that generally provides for vesting and/or distributions no sooner than five years from the date of awards. Under the provisions of the DCPP, we typically contribute cash in an amount approved by compensation committee to the rabbi trust on behalf of the executives participating in the DCPP, and instruct the trustee to acquire a specified number of shares of our common stock on the open market or in privately negotiated transactions based on participant elections. In the first quarter of each of 2016 and 2015, the compensation committee approved $3.1 million and $2.7 million, respectively, of awards in the aggregate to certain key executives under the DCPP that were contributed to the rabbi trust in first quarter 2016 and 2015, respectively. During the three-month periods ended September 30, 2016 and 2015, we charged $0.4 million and $0.3 million, respectively, to compensation expense related to these awards. During the nine-month periods ended September 30, 2016 and 2015, we charged $1.1 million and $0.9 million, respectively, to compensation expense related to these awards. There were no distributions from the DCPP during the nine-month periods ended September 30, 2016 and 2015, respectively.

Restricted Stock, Performance S

Restricted Stock, Performance Share and Cash Awards	9 Months Ended
	Sep. 30, 2016
Text Block [Abstract]
Restricted Stock, Performance Share and Cash Awards	10. Restricted Stock, Performance Share and Cash Awards Restricted Stock Awards As discussed in Note 8 to these unaudited consolidated financial statements, on May 13, 2014, our stockholders approved the LTIP, which replaced our previous stockholder-approved 2011 LTIP. The LTIP provides for the grant of a stock award either as restricted stock or as restricted stock units. In either case, the compensation committee may determine that the award will be subject to the attainment of performance measures over an established performance period. Stock awards and the related dividend equivalents are non-transferable and subject to forfeiture if the holder does not remain continuously employed with us during the applicable restriction period or, in the case of a performance-based award, if applicable performance measures are not attained. The compensation committee will determine all of the terms relating to the satisfaction of performance measures and the termination of a restriction period, or the forfeiture and cancellation of a restricted stock award upon a termination of employment, whether by reason of disability, retirement, death or any other reason. The compensation committee may grant unrestricted shares of common stock or units representing the right to receive shares of common stock to employees who have attained age 62. The agreements awarding restricted stock units under the LTIP will specify whether such awards may be settled in shares of our common stock, cash or a combination of shares and cash and whether the holder will be entitled to receive dividend equivalents, on a current or deferred basis, with respect to such award. Prior to the settlement of a restricted stock unit, the holder of a restricted stock unit will have no rights as a stockholder of the company. The maximum number of shares available under the LTIP for restricted stock, restricted stock units and performance unit awards settled with stock (i.e., all awards other than stock options and stock appreciation rights) is 2.0 million. At September 30, 2016, 1.0 million shares were available for grant under the LTIP for such awards. In the first quarter of each of 2016 and 2015, we granted 466,600 and 362,600 restricted stock units, respectively, to employees under the LTIP, with an aggregate fair value of $20.4 million and $16.7 million, respectively, at the date of grant. These 2016 and 2015 awards of restricted stock units vest as follows: 466,600 units granted in first quarter 2016 and 362,600 units granted in first quarter 2015, vest in full based on continued employment through March 11, 2020 and March 11, 2019, respectively. For certain of our executive officers age 55 or older, restricted stock units awarded in 2016 and 2015 are no longer subject to forfeiture upon such officers’ departure from the company after two years from the date of grant. We account for restricted stock awards at historical cost, which equals its fair market value at the date of grant, which is amortized to compensation expense ratably over the vesting period of the participants. Future changes in the fair value of our common stock that is owed to the participants do not have any impact on the amounts recorded in our consolidated financial statements. During the three-month periods ended September 30, 2016 and 2015, we recognized $4.2 million and $3.2 million, respectively, to compensation expense related to restricted stock unit awards granted in 2007 through 2016. During the nine-month periods ended September 30, 2016 and 2015, we recognized $14.2 million and $10.7 million, respectively, to compensation expense related to restricted stock unit awards granted in 2007 through 2016. The total intrinsic value of unvested restricted stock units at September 30, 2016 and 2015 was $79.7 million and $57.3 million, respectively. During the nine-month periods ended September 30, 2016 and 2015, equity awards (including accrued dividends) with an aggregate fair value of $14.2 million and $10.2 million were vested and distributed to employees under this plan. Performance Share Awards On March 17, 2016 and March 11, 2015, pursuant to the LTIP, the compensation committee approved 72,900 and 53,900, respectively of provisional performance unit awards, with an aggregate fair value of $3.2 million and $2.5 million, respectively, for future grants to our officers. Each performance unit award was equivalent to the value of one share of our common stock on the date such provisional award was approved. These awards are subject to a one-year performance period based on our financial performance and a two-year vesting period. At the discretion of the compensation committee and determined based on our performance, the eligible officer will be granted a percentage of the provisional performance unit award that equates to the EBITAC growth achieved (as specified in the applicable grant agreement). At the end of the performance period, eligible participants will be granted a number of units based on achievement of the performance goal and subject to approval by the compensation committee. Granted units for the 2016 and 2015 provisional awards will fully vest based on continuous employment through January 1, 2019 and January 1, 2018, respectively, and will be settled in shares of our common stock on a one-for-one basis as soon as practicable in 2019 and 2018, respectively. For certain of our executive officers age 55 or older, awards granted in 2016 and 2015 are no longer subject to forfeiture upon such officers’ departure from the company after two years from the date of grant. If an eligible employee leaves us prior to the vesting date, the entire award will be forfeited. Cash Awards On March 17, 2016, pursuant to our Performance Unit Program (which we refer to as the Program), the compensation committee approved provisional cash awards of $17.4 million in the aggregate for future grants to our officers and key employees that are denominated in units (397,000 units in the aggregate), each of which was equivalent to the value of one share of our common stock on the date the provisional award was approved. The Program consists of a one-year performance period based on our financial performance and a two-year vesting period. At the discretion of the compensation committee and determined based on our performance, the eligible officer or key employee will be granted a percentage of the provisional cash award units that equates to the EBITAC growth achieved (as defined in the Program). At the end of the performance period, eligible participants will be granted a number of units based on achievement of the performance goal and subject to approval by the compensation committee. Granted units for the 2016 provisional award will fully vest based on continuous employment through January 1, 2019. For certain of our executive officers age 55 or older, awards granted under the Program in 2016 are no longer subject to forfeiture upon such officers’ departure from the company after two years from the date of the provisional award. The ultimate award value will be equal to the trailing twelve-month price of our common stock on December 31, 2018, multiplied by the number of units subject to the award, but limited to between 0.5 and 1.5 times the original value of the units determined as of the grant date. The fair value of the awarded units will be paid out in cash as soon as practicable in 2019. If an eligible employee leaves us prior to the vesting date, the entire award will be forfeited. We did not recognize any compensation expense during the nine-month period ended September 30, 2016 related to the 2016 provisional award under the Program. On March 11, 2015, pursuant to the Program, the compensation committee approved provisional cash awards of $14.6 million in the aggregate for future grant to our officers and key employees that are denominated in units (315,000 units in the aggregate), each of which was equivalent to the value of one share of our common stock on the date the provisional awards were approved. Terms of the 2015 provisional awards were similar to the terms of the 2016 provisional awards. Based on our performance for 2015, we granted 294,000 units under the Program in first quarter 2016 that will fully vest on January 1, 2018. During the three-month period ended September 30, 2016, we recognized $1.7 million to compensation expense related to these awards. During the nine-month period ended September 30, 2016, we recognized $4.9 million to compensation expense related to these awards. We did not recognize any compensation expense during 2015 related to the 2015 awards. On March 12, 2014, pursuant to the Program, the compensation committee approved provisional cash awards of $10.8 million in the aggregate for future grant to our officers and key employees that are denominated in units (229,000 units in the aggregate), each of which was equivalent to the value of one share of our common stock on the date the provisional awards were approved. Terms of the 2014 provisional awards were similar to the terms of the 2015 provisional awards. Based on our performance for 2014, we granted 220,000 units under the Program in first quarter 2015 that will fully vest on January 1, 2017. During the three-month periods ended September 30, 2016 and 2015, we recognized $1.2 million and $1.2 million, respectively, to compensation expense related to these awards. During the nine-month periods ended September 30, 2016 and 2015, we recognized $3.1 million and $3.7 million, respectively, to compensation expense related to these awards. On March 13, 2013, pursuant to the Program, the compensation committee approved provisional cash awards of $10.5 million in the aggregate for future grant to our officers and key employees that are denominated in units (269,000 units in the aggregate), each of which was equivalent to the value of one share of our common stock on the date the provisional awards were approved. Terms of the 2013 provisional awards were similar to the terms of the 2015 provisional awards. Based on our performance for 2013, we granted 263,000 units under the Program in first quarter 2014 that fully vested on January 1, 2016. During the three-month period ended September 30, 2015, we recognized $1.3 million to compensation expense related to the 2013 awards. During the nine-month period ended September 30, 2015, we recognized $4.3 million to compensation expense related to the 2013 awards. During the nine-month period ended September 30, 2016, cash awards related to the 2013 provisional award with an aggregate fair value of $11.2 million (0.2 million units in the aggregate) were vested and distributed to employees under the Program.

Retirement Plans

Retirement Plans	9 Months Ended
	Sep. 30, 2016
Compensation and Retirement Disclosure [Abstract]
Retirement Plans	11. Retirement Plans We have a noncontributory defined benefit pension plan that, prior to July 1, 2005, covered substantially all of our domestic employees who had attained a specified age and one year of employment. Benefits under the plan were based on years of service and salary history. In 2005, we amended our defined benefit pension plan to freeze the accrual of future benefits for all U.S. employees, effective on July 1, 2005. In the table below, the service cost component represents plan administration costs that are incurred directly by the plan. The components of the net periodic pension benefit cost for the plan consists of the following (in millions): Three-month period ended Nine-month period ended 2016 2015 2016 2015 Service cost $ 0.4 $ 0.3 $ 1.0 $ 0.8 Interest cost on benefit obligation 2.7 2.7 8.1 8.1 Expected return on plan assets (3.6 ) (3.8 ) (11.0 ) (11.5 ) Amortization of net actuarial loss 1.3 1.5 4.1 4.7 Net periodic benefit cost $ 0.8 $ 0.7 $ 2.2 $ 2.1 We are not required under the IRC to make any minimum contributions to the plan for the 2016 plan year nor were we required to make any minimum contributions to the plan for the 2015 plan year. This level of required funding is based on the plan being frozen and the aggregate amount of our historical funding. We did not make any discretionary contributions to the plan during the nine-month periods ended September 30, 2016 and 2015.

Investments

Investments	9 Months Ended
	Sep. 30, 2016
Equity Method Investments and Joint Ventures [Abstract]
Investments	12. Investments The following is a summary of our investments and the related funding commitments (in millions): September 30, 2016 December 31, 2015 Assets Funding Commitments Assets Chem-Mod LLC $ 4.0 $ — $ 4.0 Chem-Mod International LLC 2.0 — 2.0 C-Quest Technologies LLC and C-Quest Technologies International LLC — — — Clean-coal investments: Controlling interest in six limited liability companies that own fourteen 2009 Era Clean Coal Plants 15.5 — 13.9 Non-controlling interest in one limited liability company that owns one 2011 Era Clean Coal Plant 0.7 — 0.8 Controlling interest in seventeen limited liability companies that own nineteen 2011 Era Clean Coal Plants 64.2 9.8 60.3 Other investments 2.6 2.2 2.6 Total investments $ 89.0 $ 12.0 $ 83.6 Chem-Mod LLC Chem-Mod™ coal-fired We believe that the application of The Chem-Mod™ Solution qualifies for refined coal tax credits under IRC Section 45 when used with refined coal production plants placed in service by December 31, 2011 or 2009. Chem-Mod Chem-Mod is determined to be a variable interest entity (which we refer to as a VIE). We are the manager (decision maker) of Chem-Mod and therefore consolidate its operations into our consolidated financial statements. At September 30, 2016, total assets and total liabilities of this VIE included in our consolidated balance sheet were $11.5 million and $0.7 million, respectively. At December 31, 2015, total assets and total liabilities of this VIE were $10.3 million and $0.9 million, respectively. For the nine-month period ended September 30, 2016, total revenues and expenses were $48.2 million and $1.8 million, respectively. For the nine-month period ended September 30, 2015, total revenues and expenses were $55.2 million and $2.2 million, respectively. We are under no obligation to fund Chem-Mod’s operations in the future. Chem-Mod International LLC C-Quest Technologies LLC and C-Quest Technologies International LLC (together, C-Quest) C-Quest’s C-Quest C-Quest C-Quest’s Clean Coal Investments - • We have investments in limited liability companies that own 34 refined coal production plants which produce refined coal using propriety technologies owned by Chem-Mod. We believe the production and sale of refined coal at these plants is qualified to receive refined coal tax credits under IRC Section 45. The fourteen plants placed in service prior to December 31, 2009 (which we refer to as the 2009 Era Plants) are eligible to receive tax credits through 2019 and the twenty plants placed in service prior to December 31, 2011 (which we refer to as the 2011 Era Plants) are eligible to receive tax credits through 2021. • On March 1, 2013, we purchased an additional ownership interest in twelve of the 2009 Era Plants from a co-investor. nine-months • On March 1, 2014, we purchased additional ownership interests from a co-investor in four limited liability companies that own seven 2009 Era Plants and five 2011 Era Plants. We recognized a gain of $25.6 million as a component of other net revenues in the accompanying unaudited consolidated statement of earnings, which included the increase in fair value of our prior equity interests in the limited liability companies upon the acquisition of the additional equity interests, and recorded $26.3 million of fixed and other amortizable intangible assets in connection with this transaction. The carrying value of our prior non-controlling interest in the limited liability company was $15.6 million as of the acquisition date. The fair value of our prior non-controlling • As of September 30, 2016: • Thirty-one of the plants have long-term production contracts. • The remaining three plants are in various stages of seeking and negotiating long-term • We have a non-controlling interest in one plant, which is owned by a limited liability company (which we refer to as a LLC). We have determined that this LLC is a VIE, for which we are not the primary beneficiary. At September 30, 2016, total assets and total liabilities of this VIE were $15.2 million and $12.8 million, respectively. For the nine-month period ended September 30, 2016, total revenues and expenses of this VIE were $38.8 million and $48.4 million, respectively. • We and our co-investors each fund our portion of the on-going operations of the limited liability companies in proportion to our investment ownership percentages. Other than our portion of the on-going operational funding, there are no additional amounts that we are committed to related to funding these investments. Other Investments -

Commitments, Contingencies and

Commitments, Contingencies and Off-Balance Sheet Arrangements	9 Months Ended
	Sep. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments, Contingencies and Off-Balance Sheet Arrangements	13. Commitments, Contingencies and Off-Balance Sheet Arrangements In connection with our investing and operating activities, we have entered into certain contractual obligations and commitments. See Notes 6 and 12 to these unaudited consolidated financial statements for additional discussion of these obligations and commitments. Our future minimum cash payments, including interest, associated with our contractual obligations pursuant to the note purchase agreements, Credit Agreement, Premium Financing Debt Facility, operating leases and purchase commitments at September 30, 2016 were as follows (in millions): Payments Due by Period Contractual Obligations 2016 2017 2018 2019 2020 Thereafter Total Note purchase agreements $ 50.0 $ 300.0 $ 100.0 $ 100.0 $ 100.0 $ 1,750.0 $ 2,400.0 Credit Agreement 258.0 — — — — — 258.0 Premium Financing Debt Facility 133.1 — — — — — 133.1 Interest on debt 28.8 109.8 89.8 85.5 80.9 340.3 735.1 Total debt obligations 469.9 409.8 189.8 185.5 180.9 2,090.3 3,526.2 Operating lease obligations 38.1 154.1 136.4 121.0 109.2 542.0 1,100.8 Less sublease arrangements (0.9 ) (0.6 ) (0.3 ) (0.1 ) (0.1 ) — (2.0 ) Outstanding purchase obligations 61.3 43.4 31.9 17.0 8.0 — 161.6 Total contractual obligations $ 568.4 $ 606.7 $ 357.8 $ 323.4 $ 298.0 $ 2,632.3 $ 4,786.6 The amounts presented in the table above may not necessarily reflect our actual future cash funding requirements, because the actual timing of future payments may vary from the stated contractual obligation. Outstanding purchase commitments in the table above include $43.2 million related to expenditures on our new corporate headquarters. Note Purchase Agreements, Credit Agreement and Premium Financing Debt Facility Operating Lease Obligations We generally operate in leased premises at our other locations. Certain of these leases have options permitting renewals for additional periods. In addition to minimum fixed rentals, a number of leases contain annual escalation clauses which are generally related to increases in an inflation index. We have leased certain office space to several non-affiliated tenants under operating sublease arrangements. In the normal course of business, we expect that certain of these leases will not be renewed or replaced. We adjust charges for real estate taxes and common area maintenance annually based on actual expenses, and we recognize the related revenues in the year in which the expenses are incurred. These amounts are not included in the minimum future rentals to be received in the contractual obligations table above. Outstanding Purchase Obligations Off-Balance Sheet Commitments Total Amounts Committed Amount of Commitment Expiration by Period Off-Balance Sheet Commitments 2016 2017 2018 2019 2020 Thereafter Letters of credit $ — $ — $ — $ — $ — $ 21.1 $ 21.1 Financial guarantees — 0.2 0.2 0.2 0.2 1.7 2.5 Funding commitments 12.6 0.5 — 1.3 — 0.9 15.3 Total commitments $ 12.6 $ 0.7 $ 0.2 $ 1.5 $ 0.2 $ 23.7 $ 38.9 Since commitments may expire unused, the amounts presented in the table above do not necessarily reflect our actual future cash funding requirements. See Note 12 to our unaudited consolidated financial statements for a discussion of our funding commitments related to our corporate segment and the Off-Balance Sheet Debt section below for a discussion of our letters of credit. All of the letters of credit represent multiple year commitments that have annual, automatic renewing provisions and are classified by the latest commitment date. In addition, funding commitments in the table above includes $3.3 million related to expenditures on our new corporate headquarters building. Since January 1, 2002, we have acquired 411 companies, all of which were accounted for using the acquisition method for recording business combinations. Substantially all of the purchase agreements related to these acquisitions contain provisions for potential earnout obligations. For all of our acquisitions made in the period from 2013 to 2016 that contain potential earnout obligations, such obligations are measured at fair value as of the acquisition date and are included on that basis in the recorded purchase price consideration for the respective acquisition. The amounts recorded as earnout payables are primarily based upon estimated future operating results of the acquired entities over a two- to three-year period subsequent to the acquisition date. The aggregate amount of the maximum earnout obligations related to these acquisitions was $503.8 million, of which $225.0 million was recorded in our consolidated balance sheet as of September 30, 2016 based on the estimated fair value of the expected future payments to be made. Off-Balance Sheet Debt - At September 30, 2016, we had posted two letters of credit totaling $9.3 million, in the aggregate, related to our self-insurance deductibles, for which we had a recorded liability of $12.0 million. We have an equity investment in a rent-a-captive facility, which we use as a placement facility for certain of our insurance brokerage operations. At September 30, 2016, we had posted seven letters of credit totaling $6.3 million to allow certain of our captive operations to meet minimum statutory surplus requirements and for additional collateral related to premium and claim funds held in a fiduciary capacity, one letter of credit totaling $5.0 million to support our potential obligation under a client’s insurance program and one letter of credit totaling $0.5 million as a security deposit for a 2015 acquisition’s lease. These letters of credit have never been drawn upon. Litigation, Regulatory and Taxation Matters - non-compete In July 2014, we were named in a lawsuit that asserts that we, our subsidiary, Gallagher Clean Energy, LLC, and Chem-Mod LLC are liable for infringement of a patent held by Nalco Company. The complaint sought a judgment of infringement, damages, costs and attorneys’ fees, and injunctive relief. Along with other defendants, we disputed the allegation of infringement and have defended this matter vigorously. We filed a motion to dismiss the complaint on behalf of all defendants, alleging no infringement of Nalco’s intellectual property. This motion, and similar motions attacking amended complaints filed by Nalco, were granted. On April 21, 2016, the court dismissed Nalco’s claims and disallowed leave to file any further amended complaint. Although Nalco has appealed this ruling, we believe that the probability of a material loss is remote. However, litigation is inherently uncertain and it is not possible for us to predict the ultimate disposition of this proceeding. Our micro-captive advisory services are under investigation by the Internal Revenue Service (IRS). Additionally, the IRS has initiated audits for the 2012 tax year of over 100 of the micro-captive insurance companies organized and/or managed by us. Among other matters, the IRS is investigating whether we have been acting as a tax shelter promoter in connection with these operations. While the IRS has not made specific allegations relating to our operations, if the IRS were to successfully assert that the micro-captives organized and/or managed by us do not meet the requirements of IRC Section 831(b), we could be held liable to pay monetary claims by the IRS and/or our micro-captive clients, and our future earnings from our micro-captive operations could be materially adversely affected, any of which events, could negatively impact the overall captive business and adversely affect our consolidated results of operations and financial condition. Due to the early stage of the investigation and the fact that the IRS has not made any allegation against us or completed its audits of our clients, we are not able to reasonably estimate the amount of any potential loss in connection with this investigation. Contingent Liabilities - Tax-advantaged Investments No Longer Held -

Accumulated Other Comprehensive

Accumulated Other Comprehensive Earnings (Loss)	9 Months Ended
	Sep. 30, 2016
Equity [Abstract]
Accumulated Other Comprehensive Earnings (Loss)	14. Accumulated Other Comprehensive Earnings (Loss) The after-tax components of our accumulated other comprehensive earnings (loss) attributable to controlling interests consist of the following: Pension Foreign Fair Value of Accumulated Balance as of December 31, 2015 $ (42.9 ) $ (477.4 ) $ (2.2 ) $ (522.5 ) Net change in period 4.4 (91.4 ) (11.0 ) (98.0 ) Balance as of September 30, 2016 $ (38.5 ) $ (568.8 ) $ (13.2 ) $ (620.5 ) The foreign currency translation during the nine-month period ended September 30, 2016 primarily relates to the net impact of changes in the value of the local currencies relative to the U.S. dollar for our operations in Australia, Canada, the Caribbean, India, New Zealand and the U.K. During the nine-month periods ended September 30, 2016 and 2015, $4.1 million and $4.7 million, respectively, of expense related to the pension liability was reclassified from accumulated other comprehensive earnings (loss) to compensation expense in the statement of earnings. During the nine-month periods ended September 30, 2016 and 2015, $0.2 million and $0.1 million of income, respectively, related to the fair value of derivative investments, was reclassified from accumulated other comprehensive earnings (loss) to the statement of earnings. During the nine-month periods ended September 30, 2016 and 2015, no amounts related to foreign currency translation were reclassified from accumulated other comprehensive earnings (loss) to the statement of earnings.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
Segment Information	15. Segment Information We have three reportable segments: brokerage, risk management and corporate. The brokerage segment is primarily comprised of our retail and wholesale insurance brokerage operations. The brokerage segment generates revenues through commissions paid by insurance underwriters and through fees charged to our clients. Our brokers, agents and administrators act as intermediaries between insurers and their customers and we do not assume underwriting risks. The risk management segment provides contract claim settlement and administration services for enterprises that choose to self-insure some or all of their property/casualty coverages and for insurance companies that choose to outsource some or all of their property/casualty claims departments. These operations also provide claims management, loss control consulting and insurance property appraisal services. Revenues are principally generated on a negotiated per-claim or per-service fee basis. The corporate segment manages our clean energy and other investments. In addition, the corporate segment reports the financial information related to our debt, and certain corporate and acquisition-related activities. Allocations of investment income and certain expenses are based on what management believes are reasonable assumptions and estimates primarily using revenue, headcount and other information. We allocate the provision for income taxes to the brokerage and risk management segments using the local country statutory rates. Reported operating results by segment would change if different methods were applied. Financial information relating to our segments for the three-month and nine-month periods ended September 30, 2016 and 2015 is as follows (in millions): Three-month period Nine-month period 2016 2015 2016 2015 Brokerage Total revenues $ 877.6 $ 835.5 $ 2,642.2 $ 2,472.2 Earnings before income taxes $ 149.1 $ 122.5 $ 427.3 $ 340.1 Identifiable assets at September 30, 2016 and 2015 $ 8,972.7 $ 8,638.2 Risk Management Total revenues $ 176.7 $ 179.2 $ 532.5 $ 545.8 Earnings before income taxes $ 21.5 $ 22.4 $ 67.9 $ 72.7 Identifiable assets at September 30, 2016 and 2015 $ 679.6 $ 640.4 Corporate Total revenues $ 428.0 $ 440.1 $ 1,035.1 $ 1,039.5 Loss before income taxes $ (75.7 ) $ (39.2 ) $ (207.1 ) $ (147.7 ) Identifiable assets at September 30, 2016 and 2015 $ 1,548.0 $ 1,231.8

Effect of New Accounting Pron24

Effect of New Accounting Pronouncements (Policies)	9 Months Ended
	Sep. 30, 2016
Accounting Changes and Error Corrections [Abstract]
Cash Receipts and Cash Payments	Cash Receipts and Cash Payments In August 2016, the Financial Accounting Standards Board (which we refer to as the FASB) issued Accounting Standards Update (which we refer to as ASU) No. 2016-15, Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force), (ASU 2016-15). The amendments in ASU 2016-15 address eight specific cash flow issues and apply to all entities that are required to present a statement of cash flows under ASC 230, Statement of Cash Flows. The amendments in ASU 2016-15 are effective for public business entities for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. We are currently reviewing the new guidance, and the impact from its adoption on our consolidated financial statements cannot be determined at this time.
Leases	Leases In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). Under this new accounting guidance, an entity is required to recognize right-of-use assets and lease liabilities on its balance sheet and disclose key information about leasing arrangements. This new guidance offers specific accounting guidance for a lessee, a lessor and sale and leaseback transactions. Lessees and lessors are required to disclose qualitative and quantitative information about leasing arrangements to enable a user of the financial statements to assess the amount, timing and uncertainty of cash flows arising from leases. This new guidance is effective for first quarter 2019, and requires a modified retrospective adoption, with early adoption permitted. We are currently reviewing the new guidance, and the impact from its adoption on our consolidated financial statements cannot be determined at this time.
Stock Compensation	Stock Compensation In March 2016, the FASB issued ASU No. 2016-09, Improvements to Employee Share-Based Payment Accounting. This new accounting guidance requires that all companies recognize the income tax effects of awards in the income statement when the awards vest or are settled, rather than maintaining an APIC pool and recognizing the tax benefits in excess of compensation costs through equity. As it relates to forfeitures, the guidance allows for companies to choose whether to continue to estimate forfeitures or account for forfeitures as they occur. ASU 2016-09 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2016. Early adoption is permitted and the new guidance may be applied either retrospectively or on a prospective basis. Management believes that the adoption of this guidance will not have a material impact on our consolidated financial statements.
Consolidations	Consolidations In February 2015, the FASB issued ASU No. 2015-02, Amendments to the Consolidation Analysis. This new accounting guidance on consolidations eliminates the deferral granted to investment companies from applying the variable interest entities guidance and makes targeted amendments to the current consolidation guidance. The new guidance applies to all entities involved with limited partnerships or similar entities and required re-evaluation of these entities under the revised guidance, which could have changed previous consolidation conclusions. The new guidance was effective in first quarter 2016 and has been applied by us. The adoption of this guidance did not have a material impact on our consolidated financial statements.
Debt Issuance Costs	Debt Issuance Costs In April 2015, the FASB issued ASU No. 2015-03, Simplifying the Presentation of Debt Issuance Costs. The new accounting guidance requires debt issuance costs to be presented in the balance sheet as a direct deduction from the associated debt liability. The new guidance was effective in first quarter 2016 and has been applied by us on a retrospective basis. Accordingly, we have reclassified debt issuance costs of $3.3 million previously included in Other non-current
Intangibles - Goodwill and Other	Intangibles – Goodwill and Other In April 2015, the FASB issued ASU No. 2015-05, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement. This new guidance provides additional information to help entities determine whether a cloud computing arrangement contains a software license that should be accounted for as internal-use software or as a service contract. The new guidance was effective in first quarter 2016 and has been applied by us. The adoption of this guidance did not have a material impact on our consolidated financial statements.
Business Combinations	Business Combinations In September 2015, the FASB issued ASU No. 2015-16, Business Combinations (Topic 805): Simplifying the Accounting for Measurement-Period Adjustments. The new accounting guidance requires that measurement period adjustments be recognized in the reporting period in which the adjustment amount is determined rather than retrospectively applying the change to the acquisition date. The new guidance was effective in first quarter 2016 and was applied by us. The adoption of this guidance did not have a material impact on our consolidated financial statements.
Income Taxes	Income Taxes In November 2015, the FASB issued ASU No. 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes. The new accounting guidance requires that deferred tax assets and liabilities be classified as noncurrent on the balance sheet rather than being separated into current and noncurrent components. ASU 2015-17 is effective in first quarter 2017. Early adoption is permitted and the standard may be applied either retrospectively or on a prospective basis to all deferred tax assets and liabilities. We early adopted ASU 2015-17 during first quarter 2016 on a retrospective basis. Accordingly, we reclassified the current deferred taxes to noncurrent in our December 31, 2015 consolidated balance sheet, which increased Noncurrent deferred tax assets by $122.1 million and increased Other noncurrent liabilities by $4.6 million.
Revenue Recognition	Revenue Recognition In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers, as a new Topic, ASC 606, which will supersede nearly all existing revenue recognition guidance under U.S. GAAP. The core principal of the new accounting guidance is that an entity should recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The guidance also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to obtain or fulfill a contract. On July 9, 2015, the FASB decided to delay the effective date of the new revenue standard by one year. Reporting entities may choose to adopt the standard as of the original effective date. The FASB decided, based on its outreach to various stakeholders and the forthcoming amendments to the new revenue standard, that a deferral was necessary to provide adequate time to effectively implement the new revenue standard. This new guidance was originally effective for the first quarter 2017 and early adoption was not permitted. With the one year deferral date, this new guidance is now effective for the first quarter 2018, but it can be adopted earlier in first quarter 2017. We plan to adopt this new guidance in first quarter 2018. The guidance permits two methods of transition upon adoption; full retrospective and modified retrospective. Under the full retrospective method, prior periods would be restated under the new revenue standard, providing a comparable view across all periods presented. Under the modified retrospective method, prior periods would not be restated. Rather, revenues and other disclosures for pre-2017 periods would be provided in the notes to the financial statements as previously reported under the current revenue standard. We are currently reviewing the guidance, and the impact from its adoption on our consolidated financial statements cannot be determined at this time.

Business Combinations (Tables)

Business Combinations (Tables)	9 Months Ended
	Sep. 30, 2016
Business Combinations [Abstract]
Acquisition Method for Recording Business Combinations	During the nine-month period ended September 30, 2016, we acquired substantially all of the net assets of the following firms in exchange for our common stock and/or cash. These acquisitions have been accounted for using the acquisition method for recording business combinations (in millions except share data): Name and Effective Date of Acquisition Common Common Cash Accrued Escrow Recorded Total Maximum (000s) Bomford, Couch & Wilson, Inc. February 1, 2016 — $ — $ 0.9 $ — $ — $ 1.4 $ 2.3 $ 2.1 White & Company Insurance, Inc. (WCI) February 1, 2016 494 17.4 — — 1.9 — 19.3 — Joseph Distel & Company, Inc. March 1, 2016 — — 1.3 — 0.2 — 1.5 — Vincent L. Braband Insurance, Inc. March 1, 2016 — — 3.0 — 0.3 0.4 3.7 1.1 Kane’s Insurance Management Operations (KIM) March 31, 2016 — — 30.8 — — — 30.8 — Capitol Benefits Group, Inc. April 1, 2016 — — 3.3 — 0.1 0.4 3.8 2.8 Charles Allen Agency, Inc. April 1, 2016 — — 2.8 — 0.2 0.2 3.2 0.7 Hagan Newkirk Financial Services, Inc. April 1, 2016 — — 4.3 — 0.1 0.9 5.3 3.1 Insurance Plans Agency, Inc. April 1, 2016 51 2.3 — — 0.1 0.2 2.6 1.5 KDC Associates, LLC (KDC) April 1, 2016 — — 20.7 — 1.8 3.9 26.4 7.5 Hogan Insurance Services, Inc. (HIS) May 1, 2016 172 7.4 — — 0.8 1.1 9.3 2.0 McNeary, Inc. (MNI) May 1, 2016 572 22.0 — — 5.0 0.4 27.4 5.5 Name and Effective Date of Acquisition Common Common Cash Accrued Escrow Recorded Total Maximum (000s) Ashmore & Associates Insurance Agency, LLC May 1, 2016 — $ — $ 7.7 $ — $ 0.4 $ 0.6 $ 8.7 $ 1.7 KRW Insurance Agency, Inc. June 1, 2016 139 5.9 — — 0.7 1.0 7.6 1.6 Buchholz Planning Corporation June 1, 2016 — — 3.9 — 0.1 2.5 6.5 6.0 Blue Horizon Insurance Services, Inc. July 1, 2016 — — 3.4 — 0.4 0.5 4.3 1.0 Brim AB (BRM) July 1, 2016 — — 23.5 6.5 — — 30.0 — Gabor Insurance Services, Inc. (GIS) July 1, 2016 — — 14.1 — 0.5 — 14.6 — Victory Insurance Agency, Inc. (VIA) July 1, 2016 422 20.9 — 2.3 — 3.3 26.5 4.5 Orb Financial Services Limited August 1, 2016 — — 3.1 — 0.4 2.0 5.5 2.7 Eight other acquisitions completed in 2016 — — 17.7 0.1 1.1 5.9 24.8 9.4 1,850 $ 75.9 $ 140.5 $ 8.9 $ 14.1 $ 24.7 $ 264.1 $ 53.2
Summary of Estimated Fair Values of Net Assets Acquired	The following is a summary of the estimated fair values of the net assets acquired at the date of each acquisition made in the nine-month period ended September 30, 2016 (in millions): WCI KIM KDC HIS MNI BRM GIS VIA Twenty Total Cash $ — $ 2.2 $ 0.3 $ 0.2 $ 3.0 $ 0.5 $ 0.3 $ 0.2 $ 3.8 $ 10.5 Other current assets 2.8 1.8 9.3 0.2 1.7 36.0 3.9 2.1 4.5 62.3 Fixed assets 0.1 0.4 0.1 — 0.1 0.6 0.1 0.1 1.9 3.4 Noncurrent assets — 1.2 — — — — — — — 1.2 Goodwill 13.6 9.2 12.1 6.3 19.5 23.5 7.5 18.2 37.3 147.2 Expiration lists 8.1 20.0 13.8 4.9 13.8 10.4 6.6 13.2 40.7 131.5 Non-compete agreements 0.1 — 0.1 — 0.1 0.3 0.1 0.1 0.5 1.3 Trade names — — — — 0.1 — — — — 0.1 Total assets acquired 24.7 34.8 35.7 11.6 38.3 71.3 18.5 33.9 88.7 357.5 Current liabilities 2.2 3.9 8.9 0.4 2.2 33.3 3.9 2.2 4.4 61.4 Noncurrent liabilities 3.2 0.1 0.4 1.9 8.7 8.0 — 5.2 4.5 32.0 Total liabilities assumed 5.4 4.0 9.3 2.3 10.9 41.3 3.9 7.4 8.9 93.4 Total net assets acquired $ 19.3 $ 30.8 $ 26.4 $ 9.3 $ 27.4 $ 30.0 $ 14.6 $ 26.5 $ 79.8 $ 264.1
Summary of Unaudited Pro Forma Historical Results	The following is a summary of the unaudited pro forma historical results, as if these entities had been acquired at January 1, 2015 (in millions, except per share data): Three-month period Nine-month period 2016 2015 2016 2015 Total revenues $ 1,482.6 $ 1,480.1 $ 4,242.9 $ 4,132.4 Net earnings attributable to controlling interests 122.8 134.6 321.2 298.1 Basic net earnings per share 0.69 0.76 1.80 1.73 Diluted net earnings per share 0.69 0.75 1.79 1.72

Other Current Assets (Tables)

Other Current Assets (Tables)	9 Months Ended
	Sep. 30, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Summary of Major Classes of Other Current Assets	Major classes of other current assets consist of the following (in millions): September 30, December 31, Premium finance advances and loans $ 255.6 $ 220.2 Accrued supplemental, direct bill and other receivables 145.6 181.1 Refined coal production related receivables 122.0 108.1 Prepaid expenses 77.9 77.8 Total other current assets $ 601.1 $ 587.2

Intangible Assets (Tables)

Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Carrying Amount of Goodwill Allocated by Domestic and Foreign Operations	The carrying amount of goodwill at September 30, 2016 and December 31, 2015 allocated by domestic and foreign operations is as follows (in millions): Brokerage Risk Corporate Total At September 30, 2016 United States $ 2,065.1 $ 23.6 $ — $ 2,088.7 United Kingdom 684.2 4.5 — 688.7 Canada 298.3 — — 298.3 Australia 400.5 — — 400.5 New Zealand 216.5 0.3 — 216.8 Other foreign 69.6 — — 69.6 Total goodwill - net $ 3,734.2 $ 28.4 $ — $ 3,762.6 At December 31, 2015 United States $ 1,946.9 $ 23.5 $ — $ 1,970.4 United Kingdom 779.3 3.5 — 782.8 Canada 282.6 — — 282.6 Australia 380.1 — — 380.1 New Zealand 204.2 0.3 — 204.5 Other foreign 42.5 — — 42.5 Total goodwill - net $ 3,635.6 $ 27.3 $ — $ 3,662.9
Changes in Carrying Amount of Goodwill	The changes in the carrying amount of goodwill for the nine-month period ended September 30, 2016 are as follows (in millions): Brokerage Risk Corporate Total Balance as of December 31, 2015 $ 3,635.6 $ 27.3 $ — $ 3,662.9 Goodwill acquired during the period 147.2 — — 147.2 Goodwill adjustments due to appraisals and other acquisition adjustments 0.4 1.6 — 2.0 Foreign currency translation adjustments during the period (49.0 ) (0.5 ) — (49.5 ) Balance as of September 30, 2016 $ 3,734.2 $ 28.4 $ — $ 3,762.6
Major Classes of Amortizable Intangible Assets	Major classes of amortizable intangible assets at September 30, 2016 and December 31, 2015 consist of the following (in millions): September 30, December 31, Expiration lists $ 2,713.1 $ 2,613.3 Accumulated amortization - expiration lists (1,097.3 ) (934.7 ) 1,615.8 1,678.6 Non-compete agreements 48.3 43.7 Accumulated amortization - non-compete agreements (40.9 ) (34.8 ) 7.4 8.9 Trade names 24.6 25.7 Accumulated amortization - trade names (17.9 ) (14.4 ) 6.7 11.3 Net amortizable assets $ 1,629.9 $ 1,698.8
Estimated Aggregate Amortization Expense	Estimated aggregate amortization expense for each of the next five years is as follows: 2016 (remaining three months) $ 61.5 2017 233.1 2018 220.2 2019 206.5 2020 190.2 Total $ 911.5

Credit and Other Debt Agreeme28

Credit and Other Debt Agreements (Tables)	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Summary of Corporate and Other Debt	The following is a summary of our corporate and other debt (in millions): September 30, December 31, Note Purchase Agreements: Semi-annual payments of interest, fixed rate of 6.44%, balloon due 2017 $ 300.0 $ 300.0 Semi-annual payments of interest, fixed rate of 5.85%, $50 million due in 2016, 2018 and 2019 150.0 150.0 Semi-annual payments of interest, fixed rate of 2.80%, balloon due 2018 50.0 50.0 Semi-annual payments of interest, fixed rate of 3.20%, balloon due 2019 50.0 50.0 Semi-annual payments of interest, fixed rate of 3.99%, balloon due 2020 50.0 50.0 Semi-annual payments of interest, fixed rate of 3.48%, balloon due 2020 50.0 50.0 Semi-annual payments of interest, fixed rate of 5.18%, balloon due 2021 75.0 75.0 Semi-annual payments of interest, fixed rate of 3.69%, balloon due 2022 200.0 200.0 Semi-annual payments of interest, fixed rate of 5.49%, balloon due 2023 50.0 50.0 Semi-annual payments of interest, fixed rate of 4.13%, balloon due 2023 200.0 200.0 Semi-annual payments of interest, fixed rate of 4.58%, balloon due 2024 325.0 325.0 Semi-annual payments of interest, fixed rate of 4.31%, balloon due 2025 200.0 200.0 Semi-annual payments of interest, fixed rate of 4.73%, balloon due 2026 175.0 175.0 Semi-annual payments of interest, fixed rate of 4.36%, balloon due 2026 150.0 150.0 Semi-annual payments of interest, fixed rate of 4.40%, balloon due 2026 175.0 — Semi-annual payments of interest, fixed rate of 4.55%, balloon due 2028 75.0 — Semi-annual payments of interest, fixed rate of 4.98%, balloon due 2029 100.0 100.0 Semi-annual payments of interest, fixed rate of 4.70%, balloon due 2031 25.0 — Total Note Purchase Agreements 2,400.0 2,125.0 Credit Agreement: Periodic payments of interest and principal, prime or LIBOR plus up to 1.45%, was to expire September 19, 2018, replaced with amended and restated facility on April 8, 2016 (see below) 258.0 195.0 Premium Financing Debt Facility - expires May 18, 2017: Periodic payments of interest and principal, Interbank rates plus 1.05% for Facility B; plus 0.55% for Facilities C and D Facility B AUD denominated tranche 113.1 101.2 NZD denominated tranche 9.1 8.5 Facility C and D AUD denominated tranche — 17.2 NZD denominated tranche 10.9 10.1 Total Premium Financing Debt Facility 133.1 137.0 Total corporate and other debt $ 2,791.1 $ 2,457.0

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Computation of Basic and Diluted Net EPS	The following table sets forth the computation of basic and diluted net earnings per share (in millions, except per share data): Three-month period ended September 30, Nine-month period ended September 30, 2016 2015 2016 2015 Net earnings attributable to controlling interests $ 122.8 $ 133.3 $ 319.3 $ 294.5 Weighted average number of common shares outstanding 177.6 176.0 177.4 170.7 Dilutive effect of stock options using the treasury stock method 0.9 0.8 0.8 1.1 Weighted average number of common and common equivalent shares outstanding 178.5 176.8 178.2 171.8 Basic net earnings per share $ 0.69 $ 0.76 $ 1.80 $ 1.73 Diluted net earnings per share $ 0.69 $ 0.75 $ 1.79 $ 1.71

Stock Option Plans (Tables)

Stock Option Plans (Tables)	9 Months Ended
	Sep. 30, 2016
Text Block [Abstract]
Black-Scholes Option Pricing Model with Weighted Average	For purposes of expense recognition, the estimated fair values of the stock option grants are amortized to expense over the options’ vesting period. We estimated the fair value of stock options at the date of grant using the Black-Scholes option pricing model with the following weighted average assumptions: 2016 2015 Expected dividend yield 3.0 % 3.0 % Expected risk-free interest rate 1.6 % 1.8 % Volatility 27.7 % 28.2 % Expected life (in years) 5.5 5.5
Stock Option Activity and Related Information	The following is a summary of our stock option activity and related information for 2016 (in millions, except exercise price and year data): Nine-month period ended September 30, 2016 Weighted Average Weighted Remaining Shares Average Contractual Aggregate Under Exercise Term Intrinsic Option Price (in years) Value Beginning balance 8.8 $ 39.25 Granted 2.6 43.72 Exercised (0.9 ) 29.28 Forfeited or canceled — — Ending balance 10.5 $ 41.18 4.34 $ 102.1 Exercisable at end of period 2.4 $ 32.19 1.95 $ 45.7 Ending vested and expected to vest 10.3 $ 41.11 4.32 $ 100.8
Other Information Regarding Stock Options Outstanding and Exercisable	Other information regarding stock options outstanding and exercisable at September 30, 2016 is summarized as follows (in millions, except exercise price and year data): Options Outstanding Options Exercisable Range of Exercise Prices Number Outstanding Weighted Average Remaining Contractual Term (in years) Weighted Average Exercise Price Number Exercisable Weighted Average Exercise Price $ 23.76 - $ 35.71 2.4 1.74 $ 31.36 1.9 $ 30.51 35.95 - 39.17 1.6 3.45 39.15 0.5 39.13 43.71 - 43.71 2.6 6.46 43.71 — — 46.16 - 49.55 3.9 4.95 46.53 — — $ 23.76 - $ 49.55 10.5 4.34 $ 41.18 2.4 $ 32.19

Retirement Plans (Tables)

Retirement Plans (Tables)	9 Months Ended
	Sep. 30, 2016
Compensation and Retirement Disclosure [Abstract]
Components of Net Periodic Pension Benefit Cost	The components of the net periodic pension benefit cost for the plan consists of the following (in millions): Three-month period ended Nine-month period ended 2016 2015 2016 2015 Service cost $ 0.4 $ 0.3 $ 1.0 $ 0.8 Interest cost on benefit obligation 2.7 2.7 8.1 8.1 Expected return on plan assets (3.6 ) (3.8 ) (11.0 ) (11.5 ) Amortization of net actuarial loss 1.3 1.5 4.1 4.7 Net periodic benefit cost $ 0.8 $ 0.7 $ 2.2 $ 2.1

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2016
Equity Method Investments and Joint Ventures [Abstract]
Investments Reported in Other Current and Non-Current Assets	The following is a summary of our investments and the related funding commitments (in millions): September 30, 2016 December 31, 2015 Assets Funding Commitments Assets Chem-Mod LLC $ 4.0 $ — $ 4.0 Chem-Mod International LLC 2.0 — 2.0 C-Quest Technologies LLC and C-Quest Technologies International LLC — — — Clean-coal investments: Controlling interest in six limited liability companies that own fourteen 2009 Era Clean Coal Plants 15.5 — 13.9 Non-controlling interest in one limited liability company that owns one 2011 Era Clean Coal Plant 0.7 — 0.8 Controlling interest in seventeen limited liability companies that own nineteen 2011 Era Clean Coal Plants 64.2 9.8 60.3 Other investments 2.6 2.2 2.6 Total investments $ 89.0 $ 12.0 $ 83.6

Commitments, Contingencies an33

Commitments, Contingencies and Off-Balance Sheet Arrangements (Tables)	9 Months Ended
	Sep. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Contractual Obligations	Our future minimum cash payments, including interest, associated with our contractual obligations pursuant to the note purchase agreements, Credit Agreement, Premium Financing Debt Facility, operating leases and purchase commitments at September 30, 2016 were as follows (in millions): Payments Due by Period Contractual Obligations 2016 2017 2018 2019 2020 Thereafter Total Note purchase agreements $ 50.0 $ 300.0 $ 100.0 $ 100.0 $ 100.0 $ 1,750.0 $ 2,400.0 Credit Agreement 258.0 — — — — — 258.0 Premium Financing Debt Facility 133.1 — — — — — 133.1 Interest on debt 28.8 109.8 89.8 85.5 80.9 340.3 735.1 Total debt obligations 469.9 409.8 189.8 185.5 180.9 2,090.3 3,526.2 Operating lease obligations 38.1 154.1 136.4 121.0 109.2 542.0 1,100.8 Less sublease arrangements (0.9 ) (0.6 ) (0.3 ) (0.1 ) (0.1 ) — (2.0 ) Outstanding purchase obligations 61.3 43.4 31.9 17.0 8.0 — 161.6 Total contractual obligations $ 568.4 $ 606.7 $ 357.8 $ 323.4 $ 298.0 $ 2,632.3 $ 4,786.6
Off-Balance Sheet Commitments	Off-Balance Sheet Commitments Total Amounts Committed Amount of Commitment Expiration by Period Off-Balance Sheet Commitments 2016 2017 2018 2019 2020 Thereafter Letters of credit $ — $ — $ — $ — $ — $ 21.1 $ 21.1 Financial guarantees — 0.2 0.2 0.2 0.2 1.7 2.5 Funding commitments 12.6 0.5 — 1.3 — 0.9 15.3 Total commitments $ 12.6 $ 0.7 $ 0.2 $ 1.5 $ 0.2 $ 23.7 $ 38.9

Accumulated Other Comprehensi34

Accumulated Other Comprehensive Earnings (Loss) (Tables)	9 Months Ended
	Sep. 30, 2016
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Earnings (Loss) Attributable to Controlling Interests	The after-tax components of our accumulated other comprehensive earnings (loss) attributable to controlling interests consist of the following: Pension Foreign Fair Value of Accumulated Balance as of December 31, 2015 $ (42.9 ) $ (477.4 ) $ (2.2 ) $ (522.5 ) Net change in period 4.4 (91.4 ) (11.0 ) (98.0 ) Balance as of September 30, 2016 $ (38.5 ) $ (568.8 ) $ (13.2 ) $ (620.5 )

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
Schedule of Segment Reporting Information by Segment	Financial information relating to our segments for the three-month and nine-month periods ended September 30, 2016 and 2015 is as follows (in millions): Three-month period Nine-month period 2016 2015 2016 2015 Brokerage Total revenues $ 877.6 $ 835.5 $ 2,642.2 $ 2,472.2 Earnings before income taxes $ 149.1 $ 122.5 $ 427.3 $ 340.1 Identifiable assets at September 30, 2016 and 2015 $ 8,972.7 $ 8,638.2 Risk Management Total revenues $ 176.7 $ 179.2 $ 532.5 $ 545.8 Earnings before income taxes $ 21.5 $ 22.4 $ 67.9 $ 72.7 Identifiable assets at September 30, 2016 and 2015 $ 679.6 $ 640.4 Corporate Total revenues $ 428.0 $ 440.1 $ 1,035.1 $ 1,039.5 Loss before income taxes $ (75.7 ) $ (39.2 ) $ (207.1 ) $ (147.7 ) Identifiable assets at September 30, 2016 and 2015 $ 1,548.0 $ 1,231.8

Nature of Operations and Basi36

Nature of Operations and Basis of Presentation - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2016CountrySegment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of countries in which the company has operations	33
Number of countries in which the company does business through a network of correspondent brokers and consultants	150
Number of reportable segments | Segment	3

Effect of New Accounting Pron37

Effect of New Accounting Pronouncements - Additional Information (Detail) - Reclassification [Member] $ in Millions	9 Months Ended
	Sep. 30, 2016USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Debt issuance costs	$ 3.3
Amount of noncurrent deferred tax assets increased	122.1
Amount other noncurrent liabilities increased	$ 4.6

Business Combinations - Acquisi

Business Combinations - Acquisition Method for Recording Business Combinations (Detail) - USD ($) shares in Thousands	Sep. 01, 2016	Sep. 30, 2016
Business Acquisition [Line Items]
Common Shares Issued		1,850
Common Share Value		$ 75,900,000
Cash Paid	$ 4,600,000	140,500,000
Accrued Liability		8,900,000
Escrow Deposited		14,100,000
Recorded Earnout Payable		24,700,000
Total Recorded Purchase Price		264,100,000
Maximum Potential Earnout Payable		53,200,000
Bomford, Couch & Wilson, Inc. [Member]
Business Acquisition [Line Items]
Cash Paid		900,000
Recorded Earnout Payable		1,400,000
Total Recorded Purchase Price		2,300,000
Maximum Potential Earnout Payable		$ 2,100,000
White & Company Insurance, Inc. (WCI) [Member]
Business Acquisition [Line Items]
Common Shares Issued		494
Common Share Value		$ 17,400,000
Escrow Deposited		1,900,000
Total Recorded Purchase Price		19,300,000
Joseph Distel & Company, Inc. [Member]
Business Acquisition [Line Items]
Cash Paid		1,300,000
Escrow Deposited		200,000
Total Recorded Purchase Price		1,500,000
Vincent L. Braband Insurance, Inc. [Member]
Business Acquisition [Line Items]
Cash Paid		3,000,000
Escrow Deposited		300,000
Recorded Earnout Payable		400,000
Total Recorded Purchase Price		3,700,000
Maximum Potential Earnout Payable		1,100,000
Kane's Insurance Management Operations (KIM) [Member]
Business Acquisition [Line Items]
Cash Paid		30,800,000
Total Recorded Purchase Price		30,800,000
Capitol Benefits Group, Inc. [Member]
Business Acquisition [Line Items]
Cash Paid		3,300,000
Escrow Deposited		100,000
Recorded Earnout Payable		400,000
Total Recorded Purchase Price		3,800,000
Maximum Potential Earnout Payable		2,800,000
Charles Allen Agency, Inc. [Member]
Business Acquisition [Line Items]
Cash Paid		2,800,000
Escrow Deposited		200,000
Recorded Earnout Payable		200,000
Total Recorded Purchase Price		3,200,000
Maximum Potential Earnout Payable		700,000
Hagan Newkirk Financial Services, Inc. [Member]
Business Acquisition [Line Items]
Cash Paid		4,300,000
Escrow Deposited		100,000
Recorded Earnout Payable		900,000
Total Recorded Purchase Price		5,300,000
Maximum Potential Earnout Payable		$ 3,100,000
Insurance Plans Agency, Inc. [Member]
Business Acquisition [Line Items]
Common Shares Issued		51
Common Share Value		$ 2,300,000
Escrow Deposited		100,000
Recorded Earnout Payable		200,000
Total Recorded Purchase Price		2,600,000
Maximum Potential Earnout Payable		1,500,000
KDC Associates, LLC (KDC) [Member]
Business Acquisition [Line Items]
Cash Paid		20,700,000
Escrow Deposited		1,800,000
Recorded Earnout Payable		3,900,000
Total Recorded Purchase Price		26,400,000
Maximum Potential Earnout Payable		$ 7,500,000
Hogan Insurance Services, Inc. (HIS) [Member]
Business Acquisition [Line Items]
Common Shares Issued		172
Common Share Value		$ 7,400,000
Escrow Deposited		800,000
Recorded Earnout Payable		1,100,000
Total Recorded Purchase Price		9,300,000
Maximum Potential Earnout Payable		$ 2,000,000
McNeary, Inc. (MNI) [Member]
Business Acquisition [Line Items]
Common Shares Issued		572
Common Share Value		$ 22,000,000
Escrow Deposited		5,000,000
Recorded Earnout Payable		400,000
Total Recorded Purchase Price		27,400,000
Maximum Potential Earnout Payable		5,500,000
Ashmore & Associates Insurance Agency, LLC (AAI) [Member]
Business Acquisition [Line Items]
Cash Paid		7,700,000
Escrow Deposited		400,000
Recorded Earnout Payable		600,000
Total Recorded Purchase Price		8,700,000
Maximum Potential Earnout Payable		$ 1,700,000
KRW Insurance Agency, Inc. (KRW) [Member]
Business Acquisition [Line Items]
Common Shares Issued		139
Common Share Value		$ 5,900,000
Escrow Deposited		700,000
Recorded Earnout Payable		1,000,000
Total Recorded Purchase Price		7,600,000
Maximum Potential Earnout Payable		1,600,000
Buchholz Planning Corporation (BPC) [Member]
Business Acquisition [Line Items]
Cash Paid		3,900,000
Escrow Deposited		100,000
Recorded Earnout Payable		2,500,000
Total Recorded Purchase Price		6,500,000
Maximum Potential Earnout Payable		6,000,000
Blue Horizon Insurance Services Inc [Member]
Business Acquisition [Line Items]
Cash Paid		3,400,000
Escrow Deposited		400,000
Recorded Earnout Payable		500,000
Total Recorded Purchase Price		4,300,000
Maximum Potential Earnout Payable		1,000,000
Brim AB [Member]
Business Acquisition [Line Items]
Cash Paid		23,500,000
Accrued Liability		6,500,000
Total Recorded Purchase Price		30,000,000
Gabor Insurance Services Inc [Member]
Business Acquisition [Line Items]
Cash Paid		14,100,000
Escrow Deposited		500,000
Total Recorded Purchase Price		$ 14,600,000
Victory Insurance Agency Inc [Member]
Business Acquisition [Line Items]
Common Shares Issued		422
Common Share Value		$ 20,900,000
Accrued Liability		2,300,000
Recorded Earnout Payable		3,300,000
Total Recorded Purchase Price		26,500,000
Maximum Potential Earnout Payable		4,500,000
Orb Financial Services Limited [Member]
Business Acquisition [Line Items]
Cash Paid		3,100,000
Escrow Deposited		400,000
Recorded Earnout Payable		2,000,000
Total Recorded Purchase Price		5,500,000
Maximum Potential Earnout Payable		2,700,000
Eight Other Acquisitions [Member]
Business Acquisition [Line Items]
Cash Paid		17,700,000
Accrued Liability		100,000
Escrow Deposited		1,100,000
Recorded Earnout Payable		5,900,000
Total Recorded Purchase Price		24,800,000
Maximum Potential Earnout Payable		$ 9,400,000

Business Combinations - Acqui39

Business Combinations - Acquisition Method for Recording Business Combinations (Parenthetical) (Detail)	9 Months Ended
	Sep. 30, 2016
Bomford, Couch & Wilson, Inc. [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition	Feb. 1, 2016
White & Company Insurance, Inc. (WCI) [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition	Feb. 1, 2016
Joseph Distel & Company, Inc. [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition	Mar. 1, 2016
Vincent L. Braband Insurance, Inc. [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition	Mar. 1, 2016
Kane's Insurance Management Operations (KIM) [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition	Mar. 31, 2016
Capitol Benefits Group, Inc. [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition	Apr. 1, 2016
Charles Allen Agency, Inc. [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition	Apr. 1, 2016
Hagan Newkirk Financial Services, Inc. [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition	Apr. 1, 2016
Insurance Plans Agency, Inc. [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition	Apr. 1, 2016
KDC Associates, LLC (KDC) [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition	Apr. 1, 2016
Hogan Insurance Services, Inc. (HIS) [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition	May 1, 2016
McNeary, Inc. (MNI) [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition	May 1, 2016
Ashmore & Associates Insurance Agency, LLC (AAI) [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition	May 1, 2016
KRW Insurance Agency, Inc. (KRW) [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition	Jun. 1, 2016
Buchholz Planning Corporation (BPC) [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition	Jun. 1, 2016
Blue Horizon Insurance Services Inc [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition	Jul. 1, 2016
Brim AB [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition	Jul. 1, 2016
Gabor Insurance Services Inc [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition	Jul. 1, 2016
Victory Insurance Agency Inc [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition	Jul. 1, 2016
Orb Financial Services Limited [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition	Aug. 1, 2016
Eight Other Acquisitions [Member]
Business Acquisition [Line Items]
Effective Year of Acquisition	2,016

Business Combinations - Additio

Business Combinations - Additional Information (Detail)	Sep. 01, 2016USD ($)	Sep. 30, 2016USD ($)Entity	Sep. 30, 2015USD ($)Entity	Sep. 30, 2016USD ($)EntityEmployees	Sep. 30, 2015USD ($)Entity	Sep. 30, 2016USD ($)Entity
Business Acquisition [Line Items]
Cash payments to acquire business	$ 4,600,000			$ 140,500,000
Number of employees at office of acquired entity | Employees				2,700
Accretion of the discount on acquisition		$ 4,300,000	$ 3,700,000	$ 12,500,000	$ 12,200,000
Number of companies acquired | Entity		27	35	77	72	411
Aggregate amount of maximum earnout obligations related to acquisitions		$ 503,800,000		$ 503,800,000
Aggregate amount of maximum earnout obligations related to acquisitions, recorded in consolidated balance sheet		225,000,000		225,000,000
Income (expense) related to net adjustments to estimated fair value of liability for earnout obligations		200,000	$ (6,000,000)	8,700,000	$ 13,700,000
Goodwill		147,200,000		147,200,000		$ 147,200,000
Expiration lists		131,500,000		131,500,000		131,500,000
Non-compete agreements		1,300,000		1,300,000		1,300,000
Trade names		100,000		100,000		100,000
Total revenues related to acquisitions in the aggregate		1,482,600,000	$ 1,480,100,000	4,242,900,000	$ 4,132,400,000
Brokerage and Risk Management [Member]
Business Acquisition [Line Items]
Goodwill		147,200,000		147,200,000		147,200,000
Expiration lists		131,500,000		131,500,000		131,500,000
Non-compete agreements		1,300,000		1,300,000		1,300,000
Trade names		100,000		$ 100,000		100,000
Expiration Lists [Member] | Minimum [Member]
Business Acquisition [Line Items]
Estimated useful lives of intangibles assets, years				3 years
Expiration Lists [Member] | Maximum [Member]
Business Acquisition [Line Items]
Estimated useful lives of intangibles assets, years				15 years
Non-Compete Agreements [Member] | Minimum [Member]
Business Acquisition [Line Items]
Estimated useful lives of intangibles assets, years				3 years
Non-Compete Agreements [Member] | Maximum [Member]
Business Acquisition [Line Items]
Estimated useful lives of intangibles assets, years				5 years
Trade Names [Member] | Minimum [Member]
Business Acquisition [Line Items]
Estimated useful lives of intangibles assets, years				3 years
Trade Names [Member] | Maximum [Member]
Business Acquisition [Line Items]
Estimated useful lives of intangibles assets, years				5 years
2016 Acquisitions [Member] | Market Approach Valuation Technique [Member] | Minimum [Member]
Business Acquisition [Line Items]
Revenue growth rate				3.50%
Discount rate				8.50%
2016 Acquisitions [Member] | Market Approach Valuation Technique [Member] | Maximum [Member]
Business Acquisition [Line Items]
Revenue growth rate				12.50%
Discount rate				9.50%
2015 Acquisitions [Member] | Income Approach Valuation Technique [Member] | Minimum [Member]
Business Acquisition [Line Items]
Revenue growth rate				1.00%
Discount rate				12.00%
Attrition rate				3.00%
2015 Acquisitions [Member] | Income Approach Valuation Technique [Member] | Maximum [Member]
Business Acquisition [Line Items]
Revenue growth rate				2.50%
Discount rate				19.00%
Attrition rate				12.50%
Business Acquisition [Member]
Business Acquisition [Line Items]
Annualized revenue of business acquisitions				$ 97,800,000
Total revenues related to acquisitions in the aggregate				39,000,000
Net earnings				1,900,000
Business Acquisition [Member] | Brokerage [Member]
Business Acquisition [Line Items]
Expiration lists		131,500,000		131,500,000		131,500,000
Non-compete agreements		1,300,000		1,300,000		1,300,000
Trade names		100,000		100,000		100,000
Deferred tax liability		21,100,000		21,100,000		21,100,000
Goodwill related to nondeductible amortizable intangible assets				21,100,000
Business Acquisition [Member] | Expiration Lists [Member] | Brokerage [Member]
Business Acquisition [Line Items]
Business acquisition not deductible for income tax purposes		61,100,000		61,100,000		61,100,000
Business Acquisition [Member] | Non-Compete Agreements [Member] | Brokerage [Member]
Business Acquisition [Line Items]
Business acquisition not deductible for income tax purposes		$ 700,000		$ 700,000		$ 700,000

Business Combinations - Summary

Business Combinations - Summary of Estimated Fair Values of Net Assets Acquired (Detail) $ in Millions	Sep. 30, 2016USD ($)
Business Acquisition Actual Revenue And Pre Tax Income Loss [Line Items]
Cash	$ 10.5
Other current assets	62.3
Fixed assets	3.4
Noncurrent assets	1.2
Goodwill	147.2
Expiration lists	131.5
Non-compete agreements	1.3
Trade names	0.1
Total assets acquired	357.5
Current liabilities	61.4
Noncurrent liabilities	32
Total liabilities assumed	93.4
Total net assets acquired	264.1
White & Company Insurance, Inc. (WCI) [Member]
Business Acquisition Actual Revenue And Pre Tax Income Loss [Line Items]
Other current assets	2.8
Fixed assets	0.1
Goodwill	13.6
Expiration lists	8.1
Non-compete agreements	0.1
Total assets acquired	24.7
Current liabilities	2.2
Noncurrent liabilities	3.2
Total liabilities assumed	5.4
Total net assets acquired	19.3
Kane's Insurance Management Operations (KIM) [Member]
Business Acquisition Actual Revenue And Pre Tax Income Loss [Line Items]
Cash	2.2
Other current assets	1.8
Fixed assets	0.4
Noncurrent assets	1.2
Goodwill	9.2
Expiration lists	20
Total assets acquired	34.8
Current liabilities	3.9
Noncurrent liabilities	0.1
Total liabilities assumed	4
Total net assets acquired	30.8
KDC Associates, LLC (KDC) [Member]
Business Acquisition Actual Revenue And Pre Tax Income Loss [Line Items]
Cash	0.3
Other current assets	9.3
Fixed assets	0.1
Goodwill	12.1
Expiration lists	13.8
Non-compete agreements	0.1
Total assets acquired	35.7
Current liabilities	8.9
Noncurrent liabilities	0.4
Total liabilities assumed	9.3
Total net assets acquired	26.4
Hogan Insurance Services, Inc. (HIS) [Member]
Business Acquisition Actual Revenue And Pre Tax Income Loss [Line Items]
Cash	0.2
Other current assets	0.2
Goodwill	6.3
Expiration lists	4.9
Total assets acquired	11.6
Current liabilities	0.4
Noncurrent liabilities	1.9
Total liabilities assumed	2.3
Total net assets acquired	9.3
McNeary, Inc. (MNI) [Member]
Business Acquisition Actual Revenue And Pre Tax Income Loss [Line Items]
Cash	3
Other current assets	1.7
Fixed assets	0.1
Goodwill	19.5
Expiration lists	13.8
Non-compete agreements	0.1
Trade names	0.1
Total assets acquired	38.3
Current liabilities	2.2
Noncurrent liabilities	8.7
Total liabilities assumed	10.9
Total net assets acquired	27.4
Ashmore & Associates Insurance Agency, LLC (AAI) [Member]
Business Acquisition Actual Revenue And Pre Tax Income Loss [Line Items]
Cash	0.5
Other current assets	36
Fixed assets	0.6
Goodwill	23.5
Expiration lists	10.4
Non-compete agreements	0.3
Total assets acquired	71.3
Current liabilities	33.3
Noncurrent liabilities	8
Total liabilities assumed	41.3
Total net assets acquired	30
KRW Insurance Agency, Inc. (KRW) [Member]
Business Acquisition Actual Revenue And Pre Tax Income Loss [Line Items]
Cash	0.3
Other current assets	3.9
Fixed assets	0.1
Goodwill	7.5
Expiration lists	6.6
Non-compete agreements	0.1
Total assets acquired	18.5
Current liabilities	3.9
Total liabilities assumed	3.9
Total net assets acquired	14.6
Buchholz Planning Corporation (BPC) [Member]
Business Acquisition Actual Revenue And Pre Tax Income Loss [Line Items]
Cash	0.2
Other current assets	2.1
Fixed assets	0.1
Goodwill	18.2
Expiration lists	13.2
Non-compete agreements	0.1
Total assets acquired	33.9
Current liabilities	2.2
Noncurrent liabilities	5.2
Total liabilities assumed	7.4
Total net assets acquired	26.5
Twenty Other Acquisitions [Member]
Business Acquisition Actual Revenue And Pre Tax Income Loss [Line Items]
Cash	3.8
Other current assets	4.5
Fixed assets	1.9
Goodwill	37.3
Expiration lists	40.7
Non-compete agreements	0.5
Total assets acquired	88.7
Current liabilities	4.4
Noncurrent liabilities	4.5
Total liabilities assumed	8.9
Total net assets acquired	$ 79.8

Business Combinations - Summa42

Business Combinations - Summary of Unaudited Pro Forma Historical Results (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Business Combinations [Abstract]
Total revenues	$ 1,482.6	$ 1,480.1	$ 4,242.9	$ 4,132.4
Net earnings attributable to controlling interests	$ 122.8	$ 134.6	$ 321.2	$ 298.1
Basic net earnings per share	$ 0.69	$ 0.76	$ 1.80	$ 1.73
Diluted net earnings per share	$ 0.69	$ 0.75	$ 1.79	$ 1.72

Other Current Assets - Summary

Other Current Assets - Summary of Major Classes of Other Current Assets (Detail) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Premium finance advances and loans	$ 255.6	$ 220.2
Accrued supplemental, direct bill and other receivables	145.6	181.1
Refined coal production related receivables	122	108.1
Prepaid expenses	77.9	77.8
Total other current assets	$ 601.1	$ 587.2

Other Current Assets - Addition

Other Current Assets - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Collateralized delinquency period of receivables	7 days

Intangible Assets - Carrying Am

Intangible Assets - Carrying Amount of Goodwill Allocated by Domestic and Foreign Operations (Detail) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Goodwill [Line Items]
Total goodwill - net	$ 3,762.6	$ 3,662.9
Unites States [Member]
Goodwill [Line Items]
Total goodwill - net	2,088.7	1,970.4
United Kingdom [Member]
Goodwill [Line Items]
Total goodwill - net	688.7	782.8
Canada [Member]
Goodwill [Line Items]
Total goodwill - net	298.3	282.6
Australia [Member]
Goodwill [Line Items]
Total goodwill - net	400.5	380.1
New Zealand [Member]
Goodwill [Line Items]
Total goodwill - net	216.8	204.5
Other Foreign [Member]
Goodwill [Line Items]
Total goodwill - net	69.6	42.5
Brokerage [Member]
Goodwill [Line Items]
Total goodwill - net	3,734.2	3,635.6
Brokerage [Member] | Unites States [Member]
Goodwill [Line Items]
Total goodwill - net	2,065.1	1,946.9
Brokerage [Member] | United Kingdom [Member]
Goodwill [Line Items]
Total goodwill - net	684.2	779.3
Brokerage [Member] | Canada [Member]
Goodwill [Line Items]
Total goodwill - net	298.3	282.6
Brokerage [Member] | Australia [Member]
Goodwill [Line Items]
Total goodwill - net	400.5	380.1
Brokerage [Member] | New Zealand [Member]
Goodwill [Line Items]
Total goodwill - net	216.5	204.2
Brokerage [Member] | Other Foreign [Member]
Goodwill [Line Items]
Total goodwill - net	69.6	42.5
Risk Management [Member]
Goodwill [Line Items]
Total goodwill - net	28.4	27.3
Risk Management [Member] | Unites States [Member]
Goodwill [Line Items]
Total goodwill - net	23.6	23.5
Risk Management [Member] | United Kingdom [Member]
Goodwill [Line Items]
Total goodwill - net	4.5	3.5
Risk Management [Member] | New Zealand [Member]
Goodwill [Line Items]
Total goodwill - net	$ 0.3	$ 0.3

Intangible Assets - Changes in

Intangible Assets - Changes in Carrying Amount of Goodwill (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2016USD ($)
Goodwill [Line Items]
Beginning Balance	$ 3,662.9
Goodwill acquired during the period	147.2
Goodwill adjustments due to appraisals and other acquisition adjustments	2
Foreign currency translation adjustments during the period	(49.5)
Balance as of September 30, 2016	3,762.6
Brokerage [Member]
Goodwill [Line Items]
Beginning Balance	3,635.6
Goodwill acquired during the period	147.2
Goodwill adjustments due to appraisals and other acquisition adjustments	0.4
Foreign currency translation adjustments during the period	(49)
Balance as of September 30, 2016	3,734.2
Risk Management [Member]
Goodwill [Line Items]
Beginning Balance	27.3
Goodwill adjustments due to appraisals and other acquisition adjustments	1.6
Foreign currency translation adjustments during the period	(0.5)
Balance as of September 30, 2016	$ 28.4

Intangible Assets - Major Class

Intangible Assets - Major Classes of Amortizable Intangible Assets (Detail) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, net	$ 1,629.9	$ 1,698.8
Expiration Lists [Member]
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, gross	2,713.1	2,613.3
Accumulated amortization	(1,097.3)	(934.7)
Amortizable intangible assets, net	1,615.8	1,678.6
Non-Compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, gross	48.3	43.7
Accumulated amortization	(40.9)	(34.8)
Amortizable intangible assets, net	7.4	8.9
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, gross	24.6	25.7
Accumulated amortization	(17.9)	(14.4)
Amortizable intangible assets, net	$ 6.7	$ 11.3

Intangible Assets - Estimated A

Intangible Assets - Estimated Aggregate Amortization Expense (Detail) $ in Millions	Sep. 30, 2016USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2016 (remaining three months)	$ 61.5
2,017	233.1
2,018	220.2
2,019	206.5
2,020	190.2
Total	$ 911.5

Credit and Other Debt Agreeme49

Credit and Other Debt Agreements - Summary of Corporate and Other Debt (Detail) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Semi-annual payments of interest	$ 2,791.1	$ 2,457
Premium Financing Debt Facility [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	133.1	137
Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	2,400	2,125
Fixed Rate of 6.44%, Balloon Due 2017 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	300	300
Fixed Rate of 5.85%, $50.0 Million Due in 2016, 2018 and 2019 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	150	150
Fixed Rate of 2.80%, Balloon Due 2018 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	50	50
Fixed Rate of 3.20%, Balloon Due 2019 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	50	50
Fixed Rate of 3.99%, Balloon Due 2020 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	50	50
Fixed Rate of 3.48%, Balloon Due 2020 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	50	50
Fixed Rate of 5.18%, Balloon Due 2021 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	75	75
Fixed rate of 3.69%, Balloon Due 2022 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	200	200
Fixed Rate of 5.49%, Balloon Due 2023 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	50	50
Fixed Rate of 4.13%, Balloon Due 2023 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	200	200
Fixed Rate of 4.58% Balloon Due 2024 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	325	325
Fixed Rate of 4.31%, Balloon Due 2025 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	200	200
Fixed Rate of 4.73% Balloon Due 2026 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	175	175
Fixed Rate of 4.36%, Balloon Due 2026 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	150	150
Fixed Rate of 4.40%, Balloon Due 2026 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	175
Fixed Rate of 4.55%, Balloon Due 2028 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	75
Fixed Rate of 4.98% Balloon Due 2029 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	100	100
Fixed Rate of 4.70%, Balloon Due 2031 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	25
Prime or LIBOR plus up to 1.45%, expires April 8, 2016 [Member] | Multi Currency Credit Agreement [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	258	195
Interbank rates plus 1.05%, Expires May 18, 2017 [Member] | AUD denominated tranche [Member] | Facility B [Member] | Premium Financing Debt Facility [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	113.1	101.2
Interbank rates plus 1.05%, Expires May 18, 2017 [Member] | NZD denominated tranche [Member] | Facility B [Member] | Premium Financing Debt Facility [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	9.1	8.5
Interbank rates plus 0.55%, Expires May 18, 2017 [Member] | AUD denominated tranche [Member] | Facility C and D [Member] | Premium Financing Debt Facility [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest		17.2
Interbank rates plus 0.55%, Expires May 18, 2017 [Member] | NZD denominated tranche [Member] | Facility C and D [Member] | Premium Financing Debt Facility [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	$ 10.9	$ 10.1

Credit and Other Debt Agreeme50

Credit and Other Debt Agreements - Summary of Corporate and Other Debt (Parenthetical) (Detail) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Premium Financing Debt Facility [Member]
Debt Instrument [Line Items]
Periodic payments of interest and principal, expiry date	May 18, 2017	May 18, 2017
Fixed Rate of 6.44%, Balloon Due 2017 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	6.44%	6.44%
Principal payments, year due	2,017	2,017
Fixed Rate of 5.85%, $50.0 Million Due in 2016, 2018 and 2019 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	5.85%	5.85%
Long-Term debt maturities repayments in 2016	$ 50	$ 50
Long-Term debt maturities repayments in 2018	50	50
Long-Term debt maturities repayments in 2019	$ 50	$ 50
Fixed Rate of 2.80%, Balloon Due 2018 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	2.80%	2.80%
Principal payments, year due	2,018	2,018
Fixed Rate of 3.20%, Balloon Due 2019 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	3.20%	3.20%
Principal payments, year due	2,019	2,019
Fixed Rate of 3.99%, Balloon Due 2020 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	3.99%	3.99%
Principal payments, year due	2,020	2,020
Fixed Rate of 3.48%, Balloon Due 2020 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	3.48%	3.48%
Principal payments, year due	2,020	2,020
Fixed Rate of 5.18%, Balloon Due 2021 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	5.18%	5.18%
Principal payments, year due	2,021	2,021
Fixed rate of 3.69%, Balloon Due 2022 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	3.69%	3.69%
Principal payments, year due	2,022	2,022
Fixed Rate of 5.49%, Balloon Due 2023 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	5.49%	5.49%
Principal payments, year due	2,023	2,023
Fixed Rate of 4.13%, Balloon Due 2023 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	4.13%	4.13%
Principal payments, year due	2,023	2,023
Fixed Rate of 4.58% Balloon Due 2024 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	4.58%	4.58%
Principal payments, year due	2,024	2,024
Fixed Rate of 4.31%, Balloon Due 2025 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	4.31%	4.31%
Principal payments, year due	2,025	2,025
Fixed Rate of 4.73% Balloon Due 2026 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	4.73%	4.73%
Principal payments, year due	2,026	2,026
Fixed Rate of 4.36%, Balloon Due 2026 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	4.36%	4.36%
Principal payments, year due	2,026	2,026
Fixed Rate of 4.40%, Balloon Due 2026 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	4.40%	4.40%
Principal payments, year due	2,026	2,026
Fixed Rate of 4.55%, Balloon Due 2028 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	4.55%	4.55%
Principal payments, year due	2,028	2,028
Fixed Rate of 4.98% Balloon Due 2029 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	4.98%	4.98%
Principal payments, year due	2,029	2,029
Fixed Rate of 4.70%, Balloon Due 2031 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	4.70%	4.70%
Principal payments, year due	2,031	2,031
Prime or LIBOR plus up to 1.45%, expires April 8, 2016 [Member] | Credit Agreement [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	1.45%	1.45%
Periodic payments of interest and principal, expiry date	Apr. 8, 2016	Apr. 8, 2016
First Installment [Member] | Fixed Rate of 5.85%, $50.0 Million Due in 2016, 2018 and 2019 [Member]
Debt Instrument [Line Items]
Principal payments, year due	2,016	2,016
Second Installment [Member] | Fixed Rate of 5.85%, $50.0 Million Due in 2016, 2018 and 2019 [Member]
Debt Instrument [Line Items]
Principal payments, year due	2,018	2,018
Third Installment [Member] | Fixed Rate of 5.85%, $50.0 Million Due in 2016, 2018 and 2019 [Member]
Debt Instrument [Line Items]
Principal payments, year due	2,019	2,019
Facility B [Member] | Interbank rates plus 1.05%, Expires May 18, 2017 [Member] | Premium Financing Debt Facility [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	1.05%	1.05%
Facility C and D [Member] | Interbank rates plus 0.55%, Expires May 18, 2017 [Member] | Premium Financing Debt Facility [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	0.55%	0.55%

Credit and Other Debt Agreeme51

Credit and Other Debt Agreements - Note Purchase Agreements - Additional information (Detail) - Note Purchase Agreements [Member] $ in Millions	9 Months Ended
	Sep. 30, 2016USD ($)
Debt Instrument [Line Items]
Cash gain realized from hedging transaction	$ 1
Interest expense expiration period	10 years
Amount payable to redeem the notes, percent of the principal amount	100.00%
Discount rate used to compute the remaining scheduled payments of principal and interest	U.S. Treasury yields plus 0.5%
6.44% Senior Notes, Series B [Member]
Debt Instrument [Line Items]
Notes issued and sold	$ 300
Note payable, semi-annual payments of interest, fixed rate	6.44%
Debt instrument, maturity date	Aug. 3, 2017
5.85% Senior Notes, Series C [Member]
Debt Instrument [Line Items]
Notes issued and sold	$ 150
Note payable, semi-annual payments of interest, fixed rate	5.85%
5.85% Senior Notes, Series C [Member] | First Installment [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Nov. 30, 2016
5.85% Senior Notes, Series C [Member] | Second Installment [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Nov. 30, 2018
5.85% Senior Notes, Series C [Member] | Third Installment [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Nov. 30, 2019
5.18% Senior Notes, Series D [Member]
Debt Instrument [Line Items]
Notes issued and sold	$ 75
Note payable, semi-annual payments of interest, fixed rate	5.18%
Debt instrument, maturity date	Feb. 10, 2021
5.49% Senior Notes, Series E [Member]
Debt Instrument [Line Items]
Notes issued and sold	$ 50
Note payable, semi-annual payments of interest, fixed rate	5.49%
Debt instrument, maturity date	Feb. 10, 2023
3.99% Senior Notes, Series F [Member]
Debt Instrument [Line Items]
Notes issued and sold	$ 50
Note payable, semi-annual payments of interest, fixed rate	3.99%
Debt instrument, maturity date	Jul. 10, 2020
3.69% Senior Notes Series G [Member] | Private Placement [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Jun. 14, 2022
Private placement debt, additional amount committed to borrow	$ 200
Interest rate	3.69%
4.58% Senior Notes, Series H [Member]
Debt Instrument [Line Items]
Notes issued and sold	$ 325
Note payable, semi-annual payments of interest, fixed rate	4.58%
Debt instrument, maturity date	Feb. 27, 2024
4.73% Senior Notes, Series I [Member]
Debt Instrument [Line Items]
Notes issued and sold	$ 175
Note payable, semi-annual payments of interest, fixed rate	4.73%
Debt instrument, maturity date	Feb. 27, 2026
4.98% Senior Notes, Series J [Member]
Debt Instrument [Line Items]
Notes issued and sold	$ 100
Note payable, semi-annual payments of interest, fixed rate	4.98%
Debt instrument, maturity date	Feb. 27, 2029
Senior Notes Series H, I & J [Member]
Debt Instrument [Line Items]
Debt acquisition costs	$ 1.4
2.80% Senior Notes, Series K [Member]
Debt Instrument [Line Items]
Notes issued and sold	$ 50
Note payable, semi-annual payments of interest, fixed rate	2.80%
Debt instrument, maturity date	Jun. 24, 2018
3.20% Senior Notes, Series L [Member]
Debt Instrument [Line Items]
Notes issued and sold	$ 50
Note payable, semi-annual payments of interest, fixed rate	3.20%
Debt instrument, maturity date	Jun. 24, 2019
3.48% Senior Notes, Series M [Member]
Debt Instrument [Line Items]
Notes issued and sold	$ 50
Note payable, semi-annual payments of interest, fixed rate	3.48%
Debt instrument, maturity date	Jun. 24, 2020
4.13% Senior Notes, Series N [Member]
Debt Instrument [Line Items]
Notes issued and sold	$ 200
Note payable, semi-annual payments of interest, fixed rate	4.13%
Debt instrument, maturity date	Jun. 24, 2023
4.31% Senior Notes, Series O [Member]
Debt Instrument [Line Items]
Notes issued and sold	$ 200
Note payable, semi-annual payments of interest, fixed rate	4.31%
Debt instrument, maturity date	Jun. 24, 2025
4.36% Senior Notes, Series P [Member]
Debt Instrument [Line Items]
Notes issued and sold	$ 150
Note payable, semi-annual payments of interest, fixed rate	4.36%
Debt instrument, maturity date	Jun. 24, 2026
Senior Notes Series K, L, M, N, O & P [Member]
Debt Instrument [Line Items]
Debt acquisition costs	$ 2.6
4.40% Senior Notes, Series Q [Member]
Debt Instrument [Line Items]
Notes issued and sold	$ 175
Note payable, semi-annual payments of interest, fixed rate	4.40%
Debt instrument, maturity date	Jun. 2, 2026
4.55% Senior Notes, Series R [Member]
Debt Instrument [Line Items]
Notes issued and sold	$ 75
Note payable, semi-annual payments of interest, fixed rate	4.55%
Debt instrument, maturity date	Jun. 2, 2028
4.70% Senior Notes, Series S [Member]
Debt Instrument [Line Items]
Notes issued and sold	$ 25
Note payable, semi-annual payments of interest, fixed rate	4.70%
Debt instrument, maturity date	Jun. 2, 2031
Senior Notes Series Q, R & S [Member]
Debt Instrument [Line Items]
Debt acquisition costs	$ 1.2

Credit and Other Debt Agreeme52

Credit and Other Debt Agreements - Credit Agreement - Additional information (Detail) NZD in Millions	Apr. 08, 2016USD ($)Institution	Sep. 30, 2016USD ($)	Sep. 30, 2016AUD	Sep. 30, 2016NZD	Sep. 30, 2015USD ($)	Sep. 30, 2016AUD	Sep. 30, 2016NZD	Dec. 31, 2015USD ($)
Debt Instrument [Line Items]
Liabilities		$ 7,459,100,000						$ 7,222,300,000
Line of credit facility, increase in additional borrowings		$ 1,619,500,000			$ 534,000,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Date of expire		May 18, 2017	May 18, 2017	May 18, 2017
Interest rate for facility		The interest rates on Facility B are Interbank rates, which vary by tranche, duration and currency, plus a margin of 1.05%. The interest rates on Facilities C and D are 30 day Interbank rates, plus a margin of 0.55%. The annual fee for Facility B is 0.4725% of the undrawn commitments for the two tranches of the facility. The annual fee for Facilities C and D is 0.50% of the total commitments of the facilities.	The interest rates on Facility B are Interbank rates, which vary by tranche, duration and currency, plus a margin of 1.05%. The interest rates on Facilities C and D are 30 day Interbank rates, plus a margin of 0.55%. The annual fee for Facility B is 0.4725% of the undrawn commitments for the two tranches of the facility. The annual fee for Facilities C and D is 0.50% of the total commitments of the facilities.	The interest rates on Facility B are Interbank rates, which vary by tranche, duration and currency, plus a margin of 1.05%. The interest rates on Facilities C and D are 30 day Interbank rates, plus a margin of 0.55%. The annual fee for Facility B is 0.4725% of the undrawn commitments for the two tranches of the facility. The annual fee for Facilities C and D is 0.50% of the total commitments of the facilities.
Debt instrument fair value amount		$ 133,100,000
Credit Facility Two [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, amount outstanding						AUD 149,000,000	NZD 12.5
Line of credit facility, remaining borrowing capacity						1,000,000	22.5
Net borrowings on premium financing debt facility			AUD 150,000,000	NZD 35
Additional margin percentage on interest rate		1.05%	1.05%	1.05%
Annual fee percentage		0.4725%	0.4725%	0.4725%
Credit Facility Three [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, amount outstanding | AUD						0
Line of credit facility, remaining borrowing capacity						25,000,000	0.1
Net borrowings on premium financing debt facility | AUD			AUD 25,000,000
Additional margin percentage on interest rate		0.55%	0.55%	0.55%
Annual fee percentage		0.50%	0.50%	0.50%
Credit Facility Four [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, amount outstanding | NZD							14.9
Line of credit facility, remaining borrowing capacity						AUD 25,000,000	NZD 0.1
Net borrowings on premium financing debt facility | NZD				NZD 15
Additional margin percentage on interest rate		0.55%	0.55%	0.55%
Annual fee percentage		0.50%	0.50%	0.50%
Multi Currency Credit Agreement [Member]
Debt Instrument [Line Items]
Number of financial institutions entered in unsecured multicurrency credit agreement | Institution	15
Line of credit facility, maximum amount outstanding during period		$ 1,100,000,000
Debt acquisition costs		2,000,000
Estimated fair value of outstanding borrowings		$ 258,000,000
Multi Currency Credit Agreement [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Sep. 19, 2018
Line of credit facility, maximum borrowing capacity	$ 600,000,000
Interest rates on base rate loans		0.00%	0.00%	0.00%
Fixed rate over LIBOR		0.85%	0.85%	0.85%
Annual facility fee of revolving credit facility		0.15%	0.15%	0.15%
Multi Currency Credit Agreement [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Apr. 8, 2021
Line of credit facility, maximum borrowing capacity	$ 800,000,000
Interest rates on base rate loans		0.45%	0.45%	0.45%
Fixed rate over LIBOR		1.45%	1.45%	1.45%
Annual facility fee of revolving credit facility		0.30%	0.30%	0.30%
Multi Currency Credit Agreement [Member] | Swing Loan [Member]
Debt Instrument [Line Items]
Long-term debt, gross		$ 75,000,000
Multi Currency Credit Agreement [Member] | Standby Letters of Credit [Member]
Debt Instrument [Line Items]
Long-term debt, gross		75,000,000
Line of credit facility, amount outstanding		21,100,000
Liabilities		12,000,000
Line of credit facility, fair value of amount outstanding		258,000,000
Line of credit facility, remaining borrowing capacity		520,900,000
Line of credit facility, increase in additional borrowings		53,900,000
Note Purchase Agreements [Member] | Level 3 [Member]
Debt Instrument [Line Items]
Line of credit facility, fair value of amount outstanding		2,590,800,000
Long-term debt		$ 2,400,000,000

Earnings Per Share - Computatio

Earnings Per Share - Computation of Basic and Diluted Net EPS (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Net earnings attributable to controlling interests	$ 122.8	$ 133.3	$ 319.3	$ 294.5
Weighted average number of common shares outstanding	177.6	176	177.4	170.7
Dilutive effect of stock options using the treasury stock method	0.9	0.8	0.8	1.1
Weighted average number of common and common equivalent shares outstanding	178.5	176.8	178.2	171.8
Basic net earnings per share	$ 0.69	$ 0.76	$ 1.80	$ 1.73
Diluted net earnings per share	$ 0.69	$ 0.75	$ 1.79	$ 1.71

Earnings Per Share - Additional

Earnings Per Share - Additional information (Detail) - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Options to purchase common stock shares outstanding	4.5	3.9	5.8	3.4

Stock Option Plans - Additional

Stock Option Plans - Additional information (Detail) - USD ($)	Mar. 17, 2016	Mar. 11, 2015	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Stock Option Plans [Line Items]
Maximum number of shares granted during any fiscal year to any person					200,000
Compensation expense related to stock option grants			$ 3,800,000	$ 3,100,000	$ 10,900,000	$ 8,200,000
Total intrinsic value of options exercised					14,900,000	$ 26,300,000
Total unrecognized compensation cost related to nonvested options			$ 45,400,000		$ 45,400,000
Weighted average period, years					4 years
Long Term Incentive Plan [Member]
Stock Option Plans [Line Items]
Maximum number of shares available					1,000,000
Shares available for grant			4,400,000		4,400,000
Number of years options expire, maximum					7 years	7 years
Long Term Incentive Plan [Member] | Officer and Key Employees [Member]
Stock Option Plans [Line Items]
Shares available for grant	2,576,700	1,941,000
Stock options granted, exercise percentage, on the third anniversary date of the grant	34.00%	34.00%
Stock options granted, exercise percentage, on the fourth anniversary date of the grant	33.00%	33.00%
Stock options granted, exercise percentage, on the fifth anniversary date of the grant	33.00%	33.00%
Performance-Based Restricted Stock [Member]
Stock Option Plans [Line Items]
Maximum number of shares granted during any fiscal year to any person					100,000
Cash Settled Performance Shares [Member] | Performance-Based Restricted Stock [Member]
Stock Option Plans [Line Items]
Maximum amount payable for the shares granted during any fiscal year to any person					$ 5,000,000
Stock Settled Performance Shares [Member] | Performance-Based Restricted Stock [Member]
Stock Option Plans [Line Items]
Maximum number of shares granted during any fiscal year to any person					100,000
Maximum [Member]
Stock Option Plans [Line Items]
Maximum period for the exercise of stock options, years					7 years
Minimum [Member]
Stock Option Plans [Line Items]
Minimum exercise price of stock options, percent of fair market value of a share of common stock on the date of grant					100.00%
Minimum [Member] | Long Term Incentive Plan [Member]
Stock Option Plans [Line Items]
Period of Service from Grant Date Stock Options Awarded Not Subject to Forfeiture					2 years
Minimum [Member] | Long Term Incentive Plan [Member] | Executive Officer [Member]
Stock Option Plans [Line Items]
Minimum age of employee with not subject to award forfeiture on condition compliance					55 years
Black-Scholes Option Pricing Model [Member]
Stock Option Plans [Line Items]
Weighted average fair value per option for all options					$ 8.45	$ 9.25

Stock Option Plans - Black-Scho

Stock Option Plans - Black-Scholes Option Pricing Model with Weighted Average (Detail)	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Expected dividend yield	3.00%	3.00%
Expected risk-free interest rate	1.60%	1.80%
Volatility	27.70%	28.20%
Expected life (in years)	5 years 6 months	5 years 6 months

Stock Option Plans - Stock Opti

Stock Option Plans - Stock Option Activity and Related Information (Detail) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2016USD ($)$ / sharesshares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Shares Under Option, Beginning balance | shares	8,800,000
Shares Under Option, Granted | shares	2,600,000
Shares Under Option, Exercised | shares	(900,000)
Shares Under Option, Forfeited or canceled | shares	0
Shares Under Option, Ending balance | shares	10,500,000
Shares Under Option, Exercisable at end of period | shares	2,400,000
Shares Under Option, Ending vested and expected to vest | shares	10,300,000
Weighted Average Exercise Price, Beginning balance | $ / shares	$ 39.25
Weighted Average Exercise Price, Granted | $ / shares	43.72
Weighted Average Exercise Price, Exercised | $ / shares	29.28
Weighted Average Exercise Price, Forfeited or canceled | $ / shares	0
Weighted Average Exercised Price, Ending balance | $ / shares	41.18
Weighted Average Exercise Price, Exercisable at end of period | $ / shares	32.19
Weighted Average Exercise price, Ending vested and expected to vest | $ / shares	$ 41.11
Weighted Average Remaining Contractual Term (in years), Ending balance	4 years 4 months 2 days
Weighted Average Remaining Contractual Term (in years), Exercisable at end of period	1 year 11 months 12 days
Weighted Average Remaining Contractual Term (in years), Ending vested and expected to vest	4 years 3 months 26 days
Aggregate Intrinsic Value, Ending Balance | $	$ 102.1
Aggregate Intrinsic Value, Exercisable at end of period | $	45.7
Aggregate Intrinsic Value, Ending vested and expected to vest | $	$ 100.8

Stock Option Plans - Stock Op58

Stock Option Plans - Stock Options Outstanding and Exercisable (Detail) - $ / shares shares in Millions	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, minimum	$ 23.76
Range of Exercise Prices, maximum	$ 49.55
Option Outstanding, Number Outstanding	10.5
Option Outstanding, Weighted Average Remaining Contractual Term (in years)	4 years 4 months 2 days
Option Outstanding, Weighted Average Exercise Price	$ 41.18	$ 39.25
Options Exercisable, Number Exercisable	2.4
Option Exercisable, Weighted Average Exercise Price	$ 32.19
Exercise Prices Range $ 23.76 - $ 35.71 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, minimum	23.76
Range of Exercise Prices, maximum	$ 35.71
Option Outstanding, Number Outstanding	2.4
Option Outstanding, Weighted Average Remaining Contractual Term (in years)	1 year 8 months 27 days
Option Outstanding, Weighted Average Exercise Price	$ 31.36
Options Exercisable, Number Exercisable	1.9
Option Exercisable, Weighted Average Exercise Price	$ 30.51
Exercise Prices Range $ 35.95 - $ 39.17 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, minimum	35.95
Range of Exercise Prices, maximum	$ 39.17
Option Outstanding, Number Outstanding	1.6
Option Outstanding, Weighted Average Remaining Contractual Term (in years)	3 years 5 months 12 days
Option Outstanding, Weighted Average Exercise Price	$ 39.15
Options Exercisable, Number Exercisable	0.5
Option Exercisable, Weighted Average Exercise Price	$ 39.13
Exercise Prices Range $ 43.71 - $ 43.71 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, minimum	43.71
Range of Exercise Prices, maximum	$ 43.71
Option Outstanding, Number Outstanding	2.6
Option Outstanding, Weighted Average Remaining Contractual Term (in years)	6 years 5 months 16 days
Option Outstanding, Weighted Average Exercise Price	$ 43.71
Exercise Prices Range $ 46.16 - $ 49.55 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, minimum	46.16
Range of Exercise Prices, maximum	$ 49.55
Option Outstanding, Number Outstanding	3.9
Option Outstanding, Weighted Average Remaining Contractual Term (in years)	4 years 11 months 12 days
Option Outstanding, Weighted Average Exercise Price	$ 46.53

Deferred Compensation - Additio

Deferred Compensation - Additional information (Detail) - USD ($) shares in Millions	3 Months Ended					9 Months Ended		12 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2015	Mar. 31, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Investments And Employee Deferred Compensation Plan [Line Items]
Deferred Equity Participation Plan, distributions to key executives, age						Age 62 (or the one-year anniversary of the date of the grant for participants over the age of 61 as of the grant date) or upon or after their actual retirement
Deferred Equity Participation Sub-plans, distributions to key executives, age						Age 65
Deferred Equity Participation Sub-plans, distributions requisite service description						we made awards under sub-plans of the DEPP for certain production staff, which generally provide for vesting and/or distributions no sooner than five years from the date of awards, although certain awards vest and/or distribute after the earlier of fifteen years or the participant reaching age 65.
Deferred Equity Participation Plan (DEPP) [Member]
Investments And Employee Deferred Compensation Plan [Line Items]
Awards approved by committee, value			$ 10,100,000		$ 8,900,000
Charge to compensation expenses related to awards	$ 2,100,000			$ 2,100,000		$ 5,500,000	$ 5,200,000
Cash and equity awards with aggregate fair value vested and distributed to participants						7,000,000
Unearned deferred compensation, value						$ 49,700,000		$ 33,500,000
Unearned deferred compensation, shares						2.4		2.1
Total intrinsic value of unvested equity based awards						$ 122,700,000		$ 85,200,000
Deferred Cash Participation Plan (DCPP) [Member]
Investments And Employee Deferred Compensation Plan [Line Items]
Awards approved by committee, value			$ 3,100,000		$ 2,700,000
Charge to compensation expenses related to awards	400,000			$ 300,000		1,100,000	900,000
Cash and equity awards with aggregate fair value vested and distributed to participants						0	$ 0
Deferred Equity Participation Plan Sub Plans [Member]
Investments And Employee Deferred Compensation Plan [Line Items]
Awards approved by committee, value		$ 13,600,000
Charge to compensation expenses related to awards	$ 400,000					800,000
Cash and equity awards with aggregate fair value vested and distributed to participants						$ 0

Restricted Stock, Performance60

Restricted Stock, Performance Share and Cash Awards - Additional Information (Detail)	Mar. 17, 2016USD ($)shares	Mar. 11, 2015USD ($)shares	Sep. 30, 2016USD ($)shares	Mar. 31, 2016USD ($)shares	Sep. 30, 2015USD ($)	Mar. 31, 2015USD ($)shares	Sep. 30, 2016USD ($)Timesshares	Sep. 30, 2015USD ($)	Dec. 31, 2015shares	Mar. 31, 2014shares	Mar. 12, 2014USD ($)shares	Mar. 13, 2013USD ($)shares
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Share-based compensation, shares outstanding | shares			10,500,000				10,500,000		8,800,000
Restricted Stock Units (RSUs) [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Share-based compensation, shares outstanding, Value			$ 2,000,000				$ 2,000,000
Share-based compensation, shares outstanding | shares			1,000,000				1,000,000
Share based payment award vesting date				Mar. 11, 2020		Mar. 11, 2019
Restricted stock or unit expense			$ 4,200,000		$ 3,200,000		$ 14,200,000	$ 10,700,000
Restricted Stock Units (RSUs) [Member] | Minimum [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Period of Service from Grant Date Stock Options Awarded Not Subject to Forfeiture				2 years		2 years
Restricted Stock Units (RSUs) [Member] | Executive Officer [Member] | Minimum [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Minimum age of employee with not subject to award forfeiture on condition compliance				55 years		55 years
Restricted Stock Plan [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Shares granted in the period | shares				466,600		362,600
Fair value of grants in period				$ 20,400,000		$ 16,700,000
Unvested Restricted Stock [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Total intrinsic value			79,700,000		57,300,000		79,700,000	57,300,000
Equity awards with an aggregate fair value							$ 14,200,000	10,200,000
Performance Shares [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Shares authorized | shares	72,900	53,900
Performance unit awards approved, Fair value	$ 3,200,000	$ 2,500,000
Provisional awards, terms							Granted units for the 2016 and 2015 provisional awards will fully vest based on continuous employment through January 1, 2019 and January 1, 2018, respectively, and will be settled in shares of our common stock on a one-for-one basis as soon as practicable in 2019 and 2018, respectively.
Performance period, years							1 year
Vesting period, years							2 years
Cash Awards [Member] | Officer and Key Employees [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Provisional awards, terms							For certain of our executive officers age 55 or older, awards granted under the Program in 2015 are no longer subject to forfeiture upon such officers’ departure from the company after two years from the date of the provisional award. The ultimate award value will be equal to the trailing twelve-month stock price on December 31, 2017, multiplied by the number of units subject to the award, but limited to between 0.5 and 1.5 times the original value of the units determined as of the grant date.
Performance period, years							1 year
Vesting period, years							2 years
Provisional compensation cash awards approved for future grant by compensation committee, value	$ 17,400,000	$ 14,600,000									$ 10,800,000	$ 10,500,000
Provisional compensation cash award approved for future grant by compensation committee, units | shares	397,000	315,000		294,000		220,000				263,000	229,000	269,000
Ultimate award value, multiples of original value of the units, minimum | Times							0.5
Ultimate award value, multiples of original value of the units, maximum | Times							1.5
2016 Provisional Cash Awards [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Cash-based compensation awards, expenses							$ 0
2015 Provisional Cash Awards [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Cash-based compensation awards, expenses			1,700,000				4,900,000	0
2014 Provisional Cash Awards [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Cash-based compensation awards, expenses			$ 1,200,000		1,200,000		$ 3,100,000	3,700,000
2013 Provisional Cash Awards [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Provisional compensation cash award approved for future grant by compensation committee, units | shares			200,000				200,000
Cash-based compensation awards, expenses					$ 1,300,000			$ 4,300,000
Grants vested in period fair value			$ 11,200,000				$ 11,200,000

Retirement Plans - Components o

Retirement Plans - Components of Net Periodic Pension Benefit Cost (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Compensation and Retirement Disclosure [Abstract]
Service cost	$ 0.4	$ 0.3	$ 1	$ 0.8
Interest cost on benefit obligation	2.7	2.7	8.1	8.1
Expected return on plan assets	(3.6)	(3.8)	(11)	(11.5)
Amortization of net actuarial loss	1.3	1.5	4.1	4.7
Net periodic benefit cost	$ 0.8	$ 0.7	$ 2.2	$ 2.1

Retirement Plans - Additional I

Retirement Plans - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Compensation and Retirement Disclosure [Abstract]
Discretionary contributions by employer	$ 0	$ 0
Minimum contribution by employer	$ 0	$ 0

Investments - Investments Repor

Investments - Investments Reported in Other Current and Non-Current Assets (Detail) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Schedule of Equity Method Investments [Line Items]
Assets	$ 89	$ 83.6
Funding Commitments	12
Chem-Mod LLC [Member]
Schedule of Equity Method Investments [Line Items]
Assets	4	4
Chem-Mod International LLC [Member]
Schedule of Equity Method Investments [Line Items]
Assets	2	2
Clean-Coal Investments [Member] | Controlling Interest [Member] | Fourteen 2009 Era Clean Coal Plants [Member]
Schedule of Equity Method Investments [Line Items]
Assets	15.5	13.9
Clean-Coal Investments [Member] | Controlling Interest [Member] | Nineteen 2011 Era Clean Coal Plants [Member]
Schedule of Equity Method Investments [Line Items]
Assets	64.2	60.3
Funding Commitments	9.8
Clean-Coal Investments [Member] | Noncontrolling Interests [Member] | One 2011 Era Clean Coal Plant [Member]
Schedule of Equity Method Investments [Line Items]
Assets	0.7	0.8
Other Investments [Member]
Schedule of Equity Method Investments [Line Items]
Assets	2.6	$ 2.6
Funding Commitments	$ 2.2

Investments - Investments Rep64

Investments - Investments Reported in Other Current and Non-Current Assets (Parenthetical) (Detail) - Clean-Coal Investments [Member]	9 Months Ended	12 Months Ended
	Sep. 30, 2016EntityPlant	Dec. 31, 2015EntityPlant
Schedule of Equity Method Investments [Line Items]
Number of variable interest entities	1
Fourteen 2009 Era Clean Coal Plants [Member] | Controlling Interest [Member]
Schedule of Equity Method Investments [Line Items]
Number of coal plants | Plant	14	14
Number of variable interest entities	6	6
One 2011 Era Clean Coal Plant [Member] | Noncontrolling Interests [Member]
Schedule of Equity Method Investments [Line Items]
Number of coal plants | Plant	1	1
Number of variable interest entities	1	1
Nineteen 2011 Era Clean Coal Plants [Member] | Controlling Interest [Member]
Schedule of Equity Method Investments [Line Items]
Number of coal plants | Plant	19	19
Number of variable interest entities	17	17

Investments - Additional Inform

Investments - Additional Information (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Chem-Mod Clean-Coal Venture [Member]
Schedule of Equity Method Investments [Line Items]
Total assets of variable interest entities	$ 11.5		$ 10.3
Total liabilities of variable interest entities	0.7		$ 0.9
Total revenues of limited liability companies	48.2	$ 55.2
Total expenses of limited liability companies	$ 1.8	$ 2.2
Chem-Mod Clean-Coal Venture - U.S. and Canadian Operations [Member]
Schedule of Equity Method Investments [Line Items]
Ownership interest held	46.50%
Chem-Mod International LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership interest held	31.50%
C-Quest Technologies LLC and C-Quest Technologies International LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership interest held	12.00%
Option to acquire additional interest, percent	15.00%
Option to acquire additional interest, total price	$ 7.5
End date for acquiring additional interest	Aug. 1, 2017

Investments - Clean Coal Invest

Investments - Clean Coal Investments - Additional Information (Detail) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016USD ($)Entity	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)EntityPlant	Sep. 30, 2015USD ($)	Mar. 01, 2014USD ($)Plant	Mar. 01, 2013Plant
Schedule of Equity Method Investments [Line Items]
Total revenues	$ 1,482.3	$ 1,454.8	$ 4,209.8	$ 4,057.5
Number of clean coal production plants seeking and negotiating for long term production contract | Plant			3
Limited Liability Company [Member]
Schedule of Equity Method Investments [Line Items]
Ownership interest acquired in a limited liability company	50.00%		50.00%
Carrying value of prior non-controlling interest in limited liability company on acquisition date					$ 15.6
2009 Era Plants [Member]
Schedule of Equity Method Investments [Line Items]
Number of additional plants acquired | Plant					7	12
Number of additional plants acquired with ownership interest range one | Plant						9
Number of additional plants acquired with ownership interest range two | Plant						3
Ownership interest before additional nine plants acquired						24.50%
Ownership interest after additional nine plants acquired						49.50%
Ownership interest before additional three plants acquired						25.00%
Ownership interest after additional three plants acquired						60.00%
Total revenues			$ 138.1	186.5
Total expenses			142	191
Ownership interest before additional seven plants acquired					49.50%
Ownership interest after additional seven plants acquired					100.00%
2011 Era Plants [Member]
Schedule of Equity Method Investments [Line Items]
Number of additional plants acquired | Plant					5
Total revenues			275.2	404.4
Total expenses			$ 299.4	$ 428.8
Ownership interest before additional one plant acquired					48.80%
Ownership interest after additional one plant acquired					90.00%
Ownership interest before additional three plants acquired					49.00%
Ownership interest after additional three plants acquired					100.00%
Ownership interest before additional one plant acquired					98.00%
Ownership interest after additional one plant acquired					100.00%
Gain on purchase of additional interest					$ 25.6
Fixed assets and other amortizable intangible assets acquired upon acquisition					$ 26.3
Chem-Mod LLC [Member]
Schedule of Equity Method Investments [Line Items]
Number of clean coal production plants owned | Plant			34
Chem-Mod LLC [Member] | 2009 Era Plants [Member]
Schedule of Equity Method Investments [Line Items]
Number of clean coal production plants owned | Plant			14
Chem-Mod LLC [Member] | 2011 Era Plants [Member]
Schedule of Equity Method Investments [Line Items]
Number of clean coal production plants owned | Plant			20
Long Term Production Contracts [Member]
Schedule of Equity Method Investments [Line Items]
Number of clean coal production plants owned | Plant			31
Clean-Coal Investments [Member]
Schedule of Equity Method Investments [Line Items]
Number of variable interest entities | Entity	1		1
Clean-Coal Investments [Member] | VIE [Member]
Schedule of Equity Method Investments [Line Items]
Total assets of limited liability companies	$ 15.2		$ 15.2
Total liability of limited liability companies	$ 12.8		12.8
Total revenues of limited liability companies			38.8
Total expenses of limited liability companies			$ 48.4

Investments - Other Investments

Investments - Other Investments - Additional Information (Detail)	Sep. 30, 2016USD ($)InvestmentVenture	Dec. 31, 2015USD ($)
Schedule of Equity Method Investments [Line Items]
Assets	$ 89,000,000	$ 83,600,000
Non controlling interest certified low-income housing developments | Investment	12
Non controlling interest in real estate entities | Investment	2
Carrying value of investments in real estate entities	$ 0
Other Investments [Member]
Schedule of Equity Method Investments [Line Items]
Assets	2,600,000	$ 2,600,000
Other Investments [Member] | Four Venture Capital Funds [Member]
Schedule of Equity Method Investments [Line Items]
Assets	$ 2,100,000
Non controlling interest in venture capital funds number | Venture	4
Other Investments [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Schedule of Equity Method Investments [Line Items]
Assets	$ 60,000,000
Debt	20,000,000
Other Investments [Member] | Variable Interest Entity, Not Primary Beneficiary [Member] | Twelve Certified Low-Income Housing Developments [Member]
Schedule of Equity Method Investments [Line Items]
Carrying value of investments	$ 0
Investment Management Company [Member]
Schedule of Equity Method Investments [Line Items]
Ownership interest held	13.70%
Cost of acquiring equity interest	$ 500,000

Commitments, Contingencies an68

Commitments, Contingencies and Off-Balance Sheet Arrangements - Contractual Obligations (Detail) $ in Millions	Sep. 30, 2016USD ($)
Note Purchase Agreements [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, 2016	$ 50
Contractual Obligations, Payments Due by Period, 2017	300
Contractual Obligations, Payments Due by Period, 2018	100
Contractual Obligations, Payments Due by Period, 2019	100
Contractual Obligations, Payments Due by Period, 2020	100
Contractual Obligations, Payments Due by Period, Thereafter	1,750
Contractual Obligations, Payments Due by Period, Total	2,400
Multi Currency Credit Agreement [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, 2016	258
Contractual Obligations, Payments Due by Period, Total	258
Premium Financing Debt Facility [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, 2016	133.1
Contractual Obligations, Payments Due by Period, Total	133.1
Interest On Debt [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, 2016	28.8
Contractual Obligations, Payments Due by Period, 2017	109.8
Contractual Obligations, Payments Due by Period, 2018	89.8
Contractual Obligations, Payments Due by Period, 2019	85.5
Contractual Obligations, Payments Due by Period, 2020	80.9
Contractual Obligations, Payments Due by Period, Thereafter	340.3
Contractual Obligations, Payments Due by Period, Total	735.1
Total Debt Obligations [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, 2016	469.9
Contractual Obligations, Payments Due by Period, 2017	409.8
Contractual Obligations, Payments Due by Period, 2018	189.8
Contractual Obligations, Payments Due by Period, 2019	185.5
Contractual Obligations, Payments Due by Period, 2020	180.9
Contractual Obligations, Payments Due by Period, Thereafter	2,090.3
Contractual Obligations, Payments Due by Period, Total	3,526.2
Operating Lease Obligations [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, 2016	38.1
Contractual Obligations, Payments Due by Period, 2017	154.1
Contractual Obligations, Payments Due by Period, 2018	136.4
Contractual Obligations, Payments Due by Period, 2019	121
Contractual Obligations, Payments Due by Period, 2020	109.2
Contractual Obligations, Payments Due by Period, Thereafter	542
Contractual Obligations, Payments Due by Period, Total	1,100.8
Less Sublease Arrangements [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, 2016	(0.9)
Contractual Obligations, Payments Due by Period, 2017	(0.6)
Contractual Obligations, Payments Due by Period, 2018	(0.3)
Contractual Obligations, Payments Due by Period, 2019	(0.1)
Contractual Obligations, Payments Due by Period, 2020	(0.1)
Contractual Obligations, Payments Due by Period, Total	(2)
Outstanding Purchase Obligations [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, 2016	61.3
Contractual Obligations, Payments Due by Period, 2017	43.4
Contractual Obligations, Payments Due by Period, 2018	31.9
Contractual Obligations, Payments Due by Period, 2019	17
Contractual Obligations, Payments Due by Period, 2020	8
Contractual Obligations, Payments Due by Period, Total	161.6
Total Contractual Obligations [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, 2016	568.4
Contractual Obligations, Payments Due by Period, 2017	606.7
Contractual Obligations, Payments Due by Period, 2018	357.8
Contractual Obligations, Payments Due by Period, 2019	323.4
Contractual Obligations, Payments Due by Period, 2020	298
Contractual Obligations, Payments Due by Period, Thereafter	2,632.3
Contractual Obligations, Payments Due by Period, Total	$ 4,786.6

Commitments, Contingencies an69

Commitments, Contingencies and Off-Balance Sheet Arrangements - Additional Information (Detail)	3 Months Ended		9 Months Ended		177 Months Ended
	Sep. 30, 2016USD ($)ft²Entity	Sep. 30, 2015Entity	Sep. 30, 2016USD ($)ft²EntityEmployeesLetterOfCredit	Sep. 30, 2015Entity	Sep. 30, 2016USD ($)ft²Entity
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Acquired property through lease area, sqft | ft²			306,000
Acquired property through lease percentage of building			60.00%
Operating lease commitment, expiration date			Feb. 28, 2018
Number of square feet | ft²	360,000		360,000		360,000
Number of employees will accommodate at new facility | Employees			2,000
Number of companies acquired | Entity	27	35	77	72	411
Aggregate amount of maximum earnout obligations related to acquisitions	$ 503,800,000		$ 503,800,000
Aggregate amount of maximum earnout obligations related to acquisitions, recorded in consolidated balance sheet	225,000,000		225,000,000
Funding Commitments [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Expenditures related to our new business locations			$ 3,300,000
Self-Insurance Deductibles [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Number of letters of credit issued | LetterOfCredit			2
Rent-A-Captive Facility [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Number of letters of credit issued | LetterOfCredit			7
Letter of Credit [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Debt	5,000,000		$ 5,000,000		$ 5,000,000
Number of letters of credit issued | LetterOfCredit			1
Letter of Credit [Member] | Security Deposit [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Debt	500,000		$ 500,000		500,000
Number of letters of credit issued | LetterOfCredit			1
Letter of Credit [Member] | Self-Insurance Deductibles [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Liabilities recorded on self-insurance	9,300,000		$ 9,300,000		9,300,000
Debt	12,000,000		12,000,000		12,000,000
Letter of Credit [Member] | Rent-A-Captive Facility [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Debt	$ 6,300,000		$ 6,300,000		$ 6,300,000
Tax Increment Financing [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Property tax credit expect to receive period			15 years
Minimum [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Ownership interest	1.00%		1.00%		1.00%
Minimum [Member] | Tax Increment Financing [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Property tax credit expect to receive	$ 60,000,000		$ 60,000,000		$ 60,000,000
Maximum [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Ownership interest	50.00%		50.00%		50.00%
Maximum [Member] | Tax Increment Financing [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Property tax credit expect to receive	$ 80,000,000		$ 80,000,000		$ 80,000,000
Outstanding Purchase Obligations Related to New Corporate Headquarters [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, Total	$ 43,200,000		$ 43,200,000		$ 43,200,000

Commitments, Contingencies an70

Commitments, Contingencies and Off-Balance Sheet Arrangements - Off-Balance Sheet Commitments (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2016USD ($)
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Amount of Commitment Expiration by Period - 2016	$ 12.6
Amount of Commitment Expiration by Period - 2017	0.7
Amount of Commitment Expiration by Period - 2018	0.2
Amount of Commitment Expiration by Period - 2019	1.5
Amount of Commitment Expiration by Period - 2020	0.2
Amount of Commitment Expiration by Period - Thereafter	23.7
Total Amounts Committed	38.9
Letters of Credit [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Amount of Commitment Expiration by Period - Thereafter	21.1
Total Amounts Committed	21.1
Financial Guarantees [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Amount of Commitment Expiration by Period - 2017	0.2
Amount of Commitment Expiration by Period - 2018	0.2
Amount of Commitment Expiration by Period - 2019	0.2
Amount of Commitment Expiration by Period - 2020	0.2
Amount of Commitment Expiration by Period - Thereafter	1.7
Total Amounts Committed	2.5
Funding Commitments [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Amount of Commitment Expiration by Period - 2016	12.6
Amount of Commitment Expiration by Period - 2017	0.5
Amount of Commitment Expiration by Period - 2019	1.3
Amount of Commitment Expiration by Period - Thereafter	0.9
Total Amounts Committed	$ 15.3

Commitments, Contingencies an71

Commitments, Contingencies and Off-Balance Sheet Arrangements - Litigation, Regulatory and Taxation Matters- Additional Information (Detail)	9 Months Ended
	Sep. 30, 2016Companies
Minimum [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Number of micro-captive insurance companies organized or managed	100

Commitments, Contingencies an72

Commitments, Contingencies and Off-Balance Sheet Arrangements - Contingent Liabilities - Additional Information (Detail) - Errors and Omissions [Member]	9 Months Ended
	Sep. 30, 2016USD ($)
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Insurance claims, amount retained	$ 5,000,000
Amount of losses in excess of retained amounts	175,000,000
Maximum [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Actuarial range value	1,100,000
Minimum [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Actuarial range value	$ 7,900,000

Commitments, Contingencies an73

Commitments, Contingencies and Off-Balance Sheet Arrangements - Tax - advantaged Investments No Longer Held - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2016USD ($)
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Income tax credits and adjustments	$ 109
Tax-Advantaged Investments No Longer Held [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Total indemnifications	$ 32

Accumulated Other Comprehensi74

Accumulated Other Comprehensive Earnings (Loss) - Schedule of Accumulated Other Comprehensive Earnings (Loss) Attributable to Controlling Interests (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2016USD ($)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ (522.5)
Ending Balance	(620.5)
Pension Liability [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(42.9)
Net change in period	4.4
Ending Balance	(38.5)
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(477.4)
Net change in period	(91.4)
Ending Balance	(568.8)
Fair Value of Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(2.2)
Net change in period	(11)
Ending Balance	(13.2)
Accumulated Other Comprehensive Earnings (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(522.5)
Net change in period	(98)
Ending Balance	$ (620.5)

Accumulated Other Comprehensi75

Accumulated Other Comprehensive Earnings (Loss) - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Expense related to pension liability reclassified from accumulated other comprehensive earnings	$ 4,100,000	$ 4,700,000
Income related to fair value of derivative investments reclassified from accumulated other comprehensive earnings	200,000	100,000
Foreign currency translation reclassified from accumulated other comprehensive earnings	$ 0	$ 0

Segment Information - Additiona

Segment Information - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2016Segment
Segment Reporting [Abstract]
Number of reportable segments	3

Segment Information - Schedule

Segment Information - Schedule of Segment Reporting Information by Segment (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Segment Reporting Information [Line Items]
Total revenues	$ 1,482.3	$ 1,454.8	$ 4,209.8	$ 4,057.5
Earnings before income taxes	94.9	105.7	288.1	265.1
Identifiable assets at September 30, 2016 and 2015	11,200.3		11,200.3		$ 10,910.5
Operating Segments [Member] | Brokerage [Member]
Segment Reporting Information [Line Items]
Total revenues	877.6	835.5	2,642.2	2,472.2
Earnings before income taxes	149.1	122.5	427.3	340.1
Identifiable assets at September 30, 2016 and 2015	8,972.7	8,638.2	8,972.7	8,638.2
Operating Segments [Member] | Risk Management [Member]
Segment Reporting Information [Line Items]
Total revenues	176.7	179.2	532.5	545.8
Earnings before income taxes	21.5	22.4	67.9	72.7
Identifiable assets at September 30, 2016 and 2015	679.6	640.4	679.6	640.4
Operating Segments [Member] | Corporate [Member]
Segment Reporting Information [Line Items]
Total revenues	428	440.1	1,035.1	1,039.5
Earnings before income taxes	(75.7)	(39.2)	(207.1)	(147.7)
Identifiable assets at September 30, 2016 and 2015	$ 1,548	$ 1,231.8	$ 1,548	$ 1,231.8