Aon (AON) 10-Q 31 Jul 15 2015 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2015	Jul. 23, 2015
Document and Entity Information
Entity Registrant Name	Aon plc
Entity Central Index Key	315,293
Document Type	10-Q
Document Period End Date	Jun. 30, 2015
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		280,042,927
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q2

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Revenue
Commissions, fees and other	$ 2,800	$ 2,913	$ 5,642	$ 5,854
Fiduciary investment income	5	6	10	12
Total revenue	2,805	2,919	5,652	5,866
Expenses
Compensation and benefits	1,653	1,708	3,336	3,459
Other general expenses	875	766	1,598	1,493
Total operating expenses	2,528	2,474	4,934	4,952
Operating income	277	445	718	914
Interest income	4	2	7	4
Interest expense	(68)	(65)	(133)	(123)
Other income (expense)	1	(2)	43	(1)
Income before income taxes	214	380	635	794
Income taxes	26	67	106	145
Net income	188	313	529	649
Less: Net income attributable to noncontrolling interests	10	9	23	20
Net income attributable to Aon shareholders	$ 178	$ 304	$ 506	$ 629
Basic net income per share attributable to Aon shareholders	$ 0.63	$ 1.02	$ 1.78	$ 2.09
Diluted net income per share attributable to Aon shareholders	0.62	1.01	1.76	2.07
Cash dividends per share paid on ordinary shares	$ 0.30	$ 0.25	$ 0.55	$ 0.43
Weighted average ordinary shares outstanding - basic (in shares)	284.5	298.5	284.3	301
Weighted average ordinary shares outstanding - diluted (in shares)	286.7	301.6	286.9	304.4

Condensed Consolidated Stateme3

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 188	$ 313	$ 529	$ 649
Less: Net income attributable to noncontrolling interests	10	9	23	20
Net income attributable to Aon shareholders	178	304	506	629
Other comprehensive (loss) income, net of tax:
Change in fair value of financial instruments	(6)	10	(1)	20
Foreign currency translation adjustments	175	74	(147)	90
Post-retirement benefit obligation	21	18	44	44
Total other comprehensive (loss) income	190	102	(104)	154
Less: Other comprehensive (loss) income attributable to noncontrolling interests	(1)	0	(2)	(2)
Total other comprehensive (loss) income attributable to Aon shareholders	191	102	(102)	156
Comprehensive income attributable to Aon shareholders	$ 369	$ 406	$ 404	$ 785

Condensed Consolidated Stateme4

Condensed Consolidated Statements of Financial Position (Unaudited) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
CURRENT ASSETS
Cash and cash equivalents	$ 367	$ 374
Short-term investments	484	394
Receivables, net	2,684	2,815
Fiduciary assets	11,389	11,638
Other current assets	731	602
Total Current Assets	15,655	15,823
Goodwill	8,661	8,860
Intangible assets, net	2,350	2,520
Fixed assets, net	782	765
Other non-current assets	1,755	1,804
TOTAL ASSETS	29,203	29,772
CURRENT LIABILITIES
Fiduciary liabilities	11,389	11,638
Short-term debt and current portion of long-term debt	1,237	783
Accounts payable and accrued liabilities	1,368	1,805
Other current liabilities	845	788
Total Current Liabilities	14,839	15,014
Long-term debt	4,824	4,799
Pension, other post-retirement and post-employment liabilities	1,944	2,141
Other non-current liabilities	1,140	1,187
TOTAL LIABILITIES	22,747	23,141
EQUITY
Ordinary shares - $0.01 nominal value Authorized: 750 shares (issued: 2015 - 279.8; 2014 - 280.0)	3	3
Additional paid-in capital	5,226	5,097
Retained earnings	4,405	4,605
Accumulated other comprehensive loss	(3,236)	(3,134)
TOTAL AON SHAREHOLDERS' EQUITY	6,398	6,571
Noncontrolling interests	58	60
TOTAL EQUITY	6,456	6,631
TOTAL LIABILITIES AND EQUITY	$ 29,203	$ 29,772

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Financial Position (Unaudited) (Parenthetical) - $ / shares shares in Millions	Jun. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Common stock, nominal or par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, Authorized shares	750	750
Common stock, issued shares	279.8	280

Condensed Consolidated Stateme6

Condensed Consolidated Statement of Shareholders' Equity (Unaudited) - 6 months ended Jun. 30, 2015 - USD ($) shares in Millions, $ in Millions	Total	Ordinary Shares and Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive (Loss) Income, Net of Tax [Member]	Non-controlling Interests [Member]
Beginning Balance (in shares) at Dec. 31, 2014	280	280
Beginning Balance at Dec. 31, 2014	$ 6,631	$ 5,100	$ 4,605	$ (3,134)	$ 60
Increase (Decrease) in Shareholders' Equity
Net income	529		506		23
Shares issued - employee benefit plans (in shares)		0.2
Shares issued - employee benefit plans	15	$ 15
Shares issued - employee compensation (in shares)		5
Shares issued - employee compensation	(175)	$ (175)
Shares purchased (in shares)		(5.4)
Shares purchased	(550)		(550)
Tax benefit - employee benefit plans	124	$ 124
Share-based compensation expense	164	164
Dividends to shareholders	(156)		(156)
Net change in fair value of financial instruments	(1)			(1)
Net foreign currency translation adjustments	(147)			(145)	(2)
Net post-retirement benefit obligation	44			44
Purchases of shares from noncontrolling interests	(4)	$ 1			(5)
Dividends paid to noncontrolling interests on subsidiary common stock	$ (18)				(18)
Ending Balance (in shares) at Jun. 30, 2015	279.8	279.8
Ending Balance at Jun. 30, 2015	$ 6,456	$ 5,229	$ 4,405	$ (3,236)	$ 58

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 529	$ 649
Adjustments to reconcile net income to cash provided by operating activities:
Gain from sales of businesses and investments, net	(20)	(8)
Depreciation of fixed assets	113	122
Amortization of intangible assets	159	173
Share-based compensation expense	164	175
Deferred income taxes	16	18
Change in assets and liabilities:
Fiduciary receivables	(116)	(563)
Short-term investments — funds held on behalf of clients	52	(175)
Fiduciary liabilities	64	738
Receivables, net	59	115
Accounts payable and accrued liabilities	(537)	(492)
Restructuring reserves	(19)	(62)
Current income taxes	(152)	(145)
Pension, other post-retirement and other post-employment liabilities	(122)	(226)
Other assets and liabilities	175	14
CASH PROVIDED BY OPERATING ACTIVITIES	365	333
CASH FLOWS FROM INVESTING ACTIVITIES
Proceeds from sale of long-term investments	10	48
Purchases of long-term investments	(1)	(14)
Net (purchases) sales of short-term investments — non-fiduciary	(97)	217
Acquisition of businesses, net of cash acquired	(23)	(83)
Proceeds from sale of businesses	52	1
Capital expenditures	(142)	(115)
CASH (USED FOR) PROVIDED BY INVESTING ACTIVITIES	(201)	54
CASH FLOWS FROM FINANCING ACTIVITIES
Share repurchase	(550)	(1,250)
Issuance of shares for employee benefit plans	52	40
Issuance of debt	2,445	3,324
Repayment of debt	(1,896)	(1,745)
Deposit with trustee	0	(681)
Cash dividends to shareholders	(156)	(128)
(Purchases) sales of shares (from) to noncontrolling interests	(5)	1
Dividends paid to noncontrolling interests	18	10
CASH USED FOR FINANCING ACTIVITIES	(128)	(449)
EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS	(43)	3
NET DECREASE IN CASH AND CASH EQUIVALENTS	(7)	(59)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	374	477
CASH AND CASH EQUIVALENTS AT END OF PERIOD	367	418
Supplemental disclosures:
Interest paid	128	82
Income taxes paid, net of refunds	$ 118	$ 204

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited Condensed Consolidated Financial Statements and Notes thereto have been prepared in accordance with U.S. generally accepted accounting principles ("U.S. GAAP"). The Condensed Consolidated Financial Statements include the accounts of Aon plc and all of its controlled subsidiaries ("Aon" or the "Company"). All intercompany accounts and transactions have been eliminated. The Condensed Consolidated Financial Statements include, in the opinion of management, all adjustments (consisting of normal recurring adjustments and reclassifications) necessary to present fairly the Company's consolidated financial position, results of operations and cash flows for all periods presented. Certain information and footnote disclosures normally included in the financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. These Condensed Consolidated Financial Statements should be read in conjunction with the Consolidated Financial Statements and Notes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2014 . The results for the three and six months ended June 30, 2015 are not necessarily indicative of operating results that may be expected for the full year ending December 31, 2015 . Reclassification Certain amounts in prior years' Condensed Consolidated Financial Statements and related notes have been reclassified to conform to the 2015 presentation. In prior periods, long-term investments were included in Investments in the Condensed Consolidated Statement of Financial Position. These amounts are now included in Other non-current assets in the Condensed Consolidated Statement of Financial Position, as shown in Note 4 to these Condensed Consolidated Financial Statements. Long-term investments were $142 million at June 30, 2015 and $143 million at December 31, 2014. Use of Estimates The preparation of the accompanying Condensed Consolidated Financial Statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosures of contingent assets and liabilities at the date of the financial statements, and the reported amounts of reserves and expenses. These estimates and assumptions are based on management's best estimates and judgments. Management evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors, including the current economic environment. Management believes its estimates to be reasonable given the current facts available. Aon adjusts such estimates and assumptions when facts and circumstances dictate. Illiquid credit markets, volatile equity markets, and foreign currency movements increase the uncertainty inherent in such estimates and assumptions. As future events and their effects cannot be determined with precision, actual results could differ significantly from these estimates. Changes in estimates resulting from continuing changes in the economic environment will be reflected in the financial statements in future periods.

Accounting Principles and Pract

Accounting Principles and Practices	6 Months Ended
	Jun. 30, 2015
Accounting Policies [Abstract]
Accounting Principles and Practices	Accounting Principles and Practices New Accounting Pronouncements Debt Issuance Costs In April 2015, the Financial Accounting Standards Board ("FASB") issued new accounting guidance on the presentation of debt issuance costs, which requires debt issuance costs to be presented in the balance sheet as a direct deduction from the associated debt liability. The new guidance will be applied on a retrospective basis and is effective for the Company in the first quarter of 2016. The adoption of this guidance is not expected to have a material impact on the Company's Condensed Consolidated Financial Statements. Consolidations In February 2015, the FASB issued new accounting guidance on consolidations, which 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 will require re-evaluation of these entities under the revised guidance, which could change previous consolidation conclusions. The guidance is effective for the Company in the first quarter of 2016. The impact from the adoption of this guidance on the Company's Condensed Consolidated Financial Statements cannot be determined at this time. Revenue Recognition In May 2014, the FASB issued new accounting guidance on revenue from contracts with customers, which will supersede nearly all existing revenue recognition guidance under U.S. GAAP. The core principal of the 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. The guidance is effective for Aon in the first quarter of 2017 and early adoption is not permitted. 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. The impact from the adoption of this guidance on the Company's Condensed Consolidated Financial Statements cannot be determined at this time as the standard is still undergoing changes. The Company is also determining the appropriate method of transition to the guidance. Discontinued Operations In April 2014, the FASB issued new accounting guidance that increased the threshold for a disposal to qualify as a discontinued operation and requires new disclosures of both discontinued operations and certain other disposals that do not meet the definition of a discontinued operation. The guidance was effective for Aon in the first quarter of 2015. The adoption of this guidance did not have a material impact on the Company's Condensed Consolidated Financial Statements.

Cash and Cash Equivalents and S

Cash and Cash Equivalents and Short-term Investments	6 Months Ended
	Jun. 30, 2015
Cash, Cash Equivalents, and Short-term Investments [Abstract]
Cash and Cash Equivalents and Short-term Investments	Cash and Cash Equivalents and Short-term Investments Cash and cash equivalents include cash balances and all highly liquid investments with initial maturities of three months or less. Short-term investments include certificates of deposit, money market funds and highly liquid debt instruments purchased with initial maturities in excess of three months but less than one year and are carried at amortized cost, which approximates fair value. At June 30, 2015 , Cash and cash equivalents and Short-term investments were $851 million compared to $768 million at December 31, 2014 . Of the total balance, $117 million and $169 million was restricted as to its use at June 30, 2015 and December 31, 2014 , respectively. Included within that amount, the Company is required to hold £40.5 million of operating funds in the U.K. by the Financial Conduct Authority, a U.K.-based regulator, which were included in Short-term investments. These operating funds, when translated to U.S. dollars, were equal to $64 million and $63 million at June 30, 2015 and December 31, 2014 , respectively. In addition, Cash and cash equivalents included additional restricted balances of $53 million and $106 million at June 30, 2015 and December 31, 2014 , respectively. The restricted balances primarily relate to cash required to be held as collateral.

Other Financial Data

Other Financial Data	6 Months Ended
	Jun. 30, 2015
Other Financial Data [Abstract]
Other Financial Data	Other Financial Data Condensed Consolidated Statements of Income Information Other Income Other income (expense) consists of the following (in millions): Three months ended June 30, Six months ended June 30, 2015 2014 2015 2014 Foreign currency remeasurement (loss) gain (7 ) (15 ) $ 17 $ 4 Gain on disposal of business 1 — 20 — Equity earnings 4 1 6 6 Income (loss) on financial instruments 3 9 — (15 ) Other — 3 — 4 Total $ 1 $ (2 ) $ 43 $ (1 ) Condensed Consolidated Statements of Financial Position Information Allowance for Doubtful Accounts An analysis of the allowance for doubtful accounts is as follows (in millions): Three months ended June 30, Six months ended June 30, 2015 2014 2015 2014 Balance at beginning of period $ 70 $ 89 $ 74 $ 90 Provision charged to operations 3 4 11 8 Accounts written off, net of recoveries (13 ) (4 ) (22 ) (9 ) Foreign currency translation 5 (1 ) 2 (1 ) Balance at end of period $ 65 $ 88 $ 65 $ 88 Other Current Assets The components of Other current assets are as follows (in millions): June 30, 2015 December 31, 2014 Taxes receivable $ 220 $ 99 Deferred tax assets 204 212 Prepaid expenses 175 164 Deferred project costs 106 102 Other 26 25 Total $ 731 $ 602 Other Non-Current Assets The components of Other non-current assets are as follows (in millions): June 30, 2015 December 31, 2014 Prepaid pension $ 953 $ 933 Deferred project costs 232 250 Deferred tax assets 164 144 Investments 142 143 Taxes receivable 63 101 Other 201 233 Total $ 1,755 $ 1,804 Other Current Liabilities The components of Other current liabilities are as follows (in millions): June 30, 2015 December 31, 2014 Deferred revenue $ 425 $ 408 Taxes payable 24 64 Deferred tax liabilities 2 2 Other 394 314 Total $ 845 $ 788 Other Non-Current Liabilities The components of Other non-current liabilities are as follows (in millions): June 30, 2015 December 31, 2014 Deferred tax liabilities $ 322 $ 313 Taxes payable 208 210 Deferred revenue 187 167 Leases 167 184 Compensation and benefits 54 57 Other 202 256 Total $ 1,140 $ 1,187

Acquisitions and Dispositions

Acquisitions and Dispositions	6 Months Ended
	Jun. 30, 2015
Business Combinations [Abstract]
Acquisitions and Dispositions	Acquisitions and Dispositions Acquisitions During the three months ended June 30, 2015 , the Company completed the acquisition of one business in the Risk Solutions segment and one business in the HR Solutions segment. During the six months ended June 30, 2015 , the Company completed the acquisition of two businesses in the Risk Solutions segment and two businesses in the HR Solutions segment. During the three months ended June 30, 2014 , the Company completed the acquisition of two businesses in the Risk Solutions segment. During the six months ended June 30, 2014 , the Company completed the acquisition of three businesses in the Risk Solutions segment and one business in the HR Solutions segment. The following table includes the aggregate consideration transferred and the preliminary value of intangible assets recorded as a result of the Company's acquisitions (in millions): Six months ended June 30, 2015 2014 Consideration $ 23 $ 83 Intangible assets: Goodwill $ 16 $ 52 Other intangible assets 1 48 Total $ 17 $ 100 The results of operations of these acquisitions are included in the Condensed Consolidated Financial Statements as of the acquisition date. The results of operations of the Company would not have been materially different if these acquisitions had been reported from the beginning of the period in which they were acquired. Dispositions During the three months ended June 30, 2015 , the Company had no dispositions. A pretax gain of $1 million was recognized on prior period dispositions during the three months ended June 30, 2015 . During the six months ended June 30, 2015 , the Company completed the disposition of one business in the Risk Solutions segment and one business in the HR Solutions segment. A pretax gain of $20 million was recognized on these dispositions in the six months ended June 30, 2015 . During the three months ended June 30, 2014 , the Company had no dispositions of businesses. During the six months ended June 30, 2014 , the Company completed the disposition of one business in the Risk Solutions segment. A pretax gain of $1 million was recognized on this disposition in the six months ended June 30, 2014 . Gains and losses recognized as a result of a disposition are included in Other income (expense) in the Condensed Consolidated Statements of Income.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	6 Months Ended
	Jun. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets The changes in the net carrying amount of goodwill by reportable segment for the six months ended June 30, 2015 are as follows (in millions): Risk Solutions HR Solutions Total Balance as of January 1, 2015 $ 5,911 $ 2,949 $ 8,860 Goodwill related to current year acquisitions 1 15 16 Goodwill related to disposals — (13 ) (13 ) Goodwill related to prior year acquisitions (1 ) — (1 ) Foreign currency translation (189 ) (12 ) (201 ) Balance as of June 30, 2015 $ 5,722 $ 2,939 $ 8,661 Other intangible assets by asset class are as follows (in millions): June 30, 2015 December 31, 2014 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Intangible assets with indefinite lives: Tradenames $ 1,019 $ — $ 1,019 $ 1,019 $ — $ 1,019 Intangible assets with finite lives: Customer related and contract based 2,930 1,706 1,224 2,952 1,579 1,373 Technology and other 552 445 107 571 443 128 Total $ 4,501 $ 2,151 $ 2,350 $ 4,542 $ 2,022 $ 2,520 Amortization expense from finite lived intangible assets was $79 million and $159 million for the three and six months ended June 30, 2015 , respectively. Amortization expense from finite lived intangible assets was $87 million and $173 million for the three and six months ended June 30, 2014 , respectively. The estimated future amortization for finite lived intangible assets as of June 30, 2015 is as follows (in millions): Risk Solutions HR Solutions Total Remainder of 2015 $ 56 $ 103 $ 159 2016 104 172 276 2017 93 138 231 2018 78 92 170 2019 68 73 141 Thereafter 188 166 354 Total $ 587 $ 744 $ 1,331

Debt

Debt	6 Months Ended
	Jun. 30, 2015
Debt Disclosure [Abstract]
Debt	Debt Revolving Credit Facilities As of December 31, 2014, Aon plc had two primary committed credit facilities outstanding: its $400 million U.S. credit facility expiring in March 2017 (the "2017 Facility") and its €650 million ( $726 million based on exchange rates at June 30, 2015 ) European credit facility expiring in October 2015 (the "2015 Facility"). Aon Corporation entered into the 2015 Facility on October 15, 2010 (Aon plc became a borrower under such facility on April 29, 2013) and Aon plc entered into the 2017 Facility on March 20, 2012. On February 2, 2015, Aon plc replaced the 2015 Facility with a new $900 million multi-currency U.S. credit facility expiring in February 2020 (the "2020 Facility"). Each of these facilities included customary representations, warranties and covenants, including financial covenants that require Aon plc to maintain specified ratios of adjusted consolidated EBITDA to consolidated interest expense and consolidated debt to adjusted consolidated EBITDA, in each case, tested quarterly. At June 30, 2015 , Aon plc did not have borrowings under either the 2017 Facility or the 2020 Facility, and was in compliance with these financial covenants and all other covenants contained therein during the six months ended June 30, 2015. Commercial Paper Aon Corporation, a wholly-owned subsidiary of Aon plc, has established a U.S. commercial paper program, which provides for commercial paper to be issued in an aggregate principal amount of up to $900 million , and Aon plc has established a European multi-currency commercial paper program that provides for commercial paper to be issued in an aggregate principal amount of up to €300 million . The U.S. commercial paper program is fully and unconditionally guaranteed by Aon plc and the European commercial paper program is fully and unconditionally guaranteed by Aon Corporation. In the aggregate, the Company had $125 million and $168 million of commercial paper outstanding at June 30, 2015 and December 31, 2014 , respectively, which was included in Short-term debt and current portion of long-term debt in the Company's Condensed Consolidated Statements of Financial Position. The weighted average commercial paper outstanding for the three and six months ended June 30, 2015 was $359 million and $338 million , respectively. The weighted average interest rate of the commercial paper outstanding for the three and six months ended June 30, 2015 was 0.46% and 0.48% , respectively. Notes On May 20, 2015, the Aon plc issued $600 million of 4.750% Senior Notes due May 2045. The 4.750% Notes due May 2045 are fully and unconditionally guaranteed by Aon Corporation. The Company used the proceeds of the issuance for general corporate purposes.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The effective tax rate on net income was 12.2% and 16.8% for the three and six months ended June 30, 2015 , respectively. The effective tax rate on net income was 17.5% and 18.3% for the three and six months ended June 30, 2014 , respectively. The effective tax rate in the second quarter of 2015 was favorably impacted by changes in the geographical distribution of income, including a reduction in U.S. income resulting from the settlement of a legacy legal matter and the impact of certain discrete items. During the six months ended June 30, 2015, the Company's uncertain tax positions decreased by $10 million , excluding interest and penalties, as compared to the year ended December 31, 2014. The decrease in uncertain tax positions was primarily related to the settlement of certain issues related to the IRS audit for tax years 2008-2011. As of June 30, 2015, the Company's liability for uncertain tax positions was $197 million , which was included in Other non-current liabilities in the Condensed Consolidated Statement of Financial Position, including interest and penalties of $28 million and net of $12 million of tax attributes. The Company's liability for uncertain tax positions as of June 30, 2015 includes $144 million related to amounts that would impact the effective tax rate if recognized.

Shareholders' Equity

Shareholders' Equity	6 Months Ended
	Jun. 30, 2015
Equity [Abstract]
Shareholders' Equity	Shareholders' Equity Ordinary Shares In April 2012, the Company's Board of Directors authorized a share repurchase program under which up to $5.0 billion of Class A Ordinary Shares may be repurchased ("2012 Share Repurchase Program"). In November 2014, the Company's Board of Directors authorized a new $5.0 billion share repurchase program in addition to the existing program ("2014 Share Repurchase Program"). Under each program, shares may be repurchased through the open market or in privately negotiated transactions, from time to time, based on prevailing market conditions, and will be funded from available capital. In the three months ended June 30, 2015 , the Company repurchased 3.0 million shares at an average price per share of $100.92 for a total cost of approximately $300 million under the 2012 Share Repurchase Program. During the six months ended June 30, 2015 , the Company repurchased 5.5 million shares at an average price per share of $100.57 for a total cost of approximately $550 million under the 2012 Share Repurchase Program. In the three months ended June 30, 2014 , the Company repurchased 7.4 million shares at an average price per share of $87.67 for a total cost of $650 million under the 2012 Share Repurchase Program. During the six months ended June 30, 2014 , the Company repurchased 14.6 million shares at an average price per share of $85.59 for a total cost of $ 1.3 billion under the 2012 Share Repurchase Program. At June 30, 2015 , the remaining authorized amount for share repurchase under the 2012 Share Repurchase Program and 2014 Share Repurchase Program is $5.1 billion . Since the program's inception in 2012, the Company repurchased a total of 67.6 million shares for an aggregate cost of $4.9 billion . Net Income Per Share Unvested share-based payment awards that contain non-forfeitable rights to dividends or dividend equivalents, whether paid or unpaid, are participating securities, as defined, and therefore should be included in computing basic and diluted earnings per share using the two-class method. Certain of the Company's restricted share awards allow the holder to receive a non-forfeitable dividend equivalent. Weighted average shares outstanding are as follows (in millions): Three months ended June 30, Six months ended June 30, 2015 2014 2015 2014 Shares for basic earnings per share 284.5 298.5 284.3 301.0 Common stock equivalents 2.2 3.1 2.6 3.4 Shares for diluted earnings per share 286.7 301.6 286.9 304.4 Certain ordinary share equivalents may be excluded from the computation of diluted net income per share if their inclusion would be antidilutive. There were no shares excluded from the calculation for the three and six months ended June 30, 2015 and 2014 , respectively. Accumulated Other Comprehensive Loss Changes in Accumulated other comprehensive loss by component, net of related tax, are as follows (in millions): Change in Fair Value of Financial Instruments (1) Foreign Currency Translation Adjustments Post-Retirement Benefit Obligation (2) Total Balance at December 31, 2014 $ (17 ) $ (335 ) $ (2,782 ) $ (3,134 ) Other comprehensive income (loss) before reclassifications, net 5 (145 ) 3 (137 ) Amounts reclassified from accumulated other comprehensive loss: Amounts reclassified from accumulated other comprehensive loss 11 — 59 70 Tax benefit (17 ) — (18 ) (35 ) Amounts reclassified from accumulated other comprehensive loss, net (6 ) — 41 35 Net current period other comprehensive (loss) income (1 ) (145 ) 44 (102 ) Balance at June 30, 2015 $ (18 ) $ (480 ) $ (2,738 ) $ (3,236 ) ______________________________________________ (1) Reclassifications from this category included in Accumulated other comprehensive loss are recorded in Other income (expense) . (2) Reclassifications from this category included in Accumulated other comprehensive loss are recorded in Compensation and benefits.

Employee Benefits

Employee Benefits	6 Months Ended
	Jun. 30, 2015
Compensation and Retirement Disclosure [Abstract]
Employee Benefits	Employee Benefits The following table provides the components of the net periodic (benefit) cost recognized in the Condensed Consolidated Statements of Income in Compensation and benefits for Aon's material U.K., U.S., and other significant international pension plans located in the Netherlands and Canada (in millions): Three months ended June 30, U.K. U.S. Other 2015 2014 2015 2014 2015 2014 Service cost $ — $ — $ 1 $ — $ — $ — Interest cost 50 58 33 32 9 12 Expected return on plan assets (77 ) (83 ) (38 ) (39 ) (13 ) (15 ) Amortization of net actuarial loss 10 14 13 11 3 2 Net periodic (benefit) cost (17 ) (11 ) 9 4 (1 ) (1 ) Curtailment loss (gain) and other — — — — — — Total net periodic (benefit) cost $ (17 ) $ (11 ) $ 9 $ 4 $ (1 ) $ (1 ) Six months ended June 30, U.K. U.S. Other 2015 2014 2015 2014 2015 2014 Service cost $ — $ — $ 2 $ — $ — $ — Interest cost 99 116 66 64 17 24 Expected return on plan assets (152 ) (165 ) (77 ) (78 ) (25 ) (30 ) Amortization of net actuarial loss 20 27 27 21 6 4 Net periodic (benefit) cost (33 ) (22 ) 18 7 (2 ) (2 ) Curtailment loss (gain) and other — — (1 ) 1 — (3 ) Total net periodic (benefit) cost $ (33 ) $ (22 ) $ 17 $ 8 $ (2 ) $ (5 ) Based on current assumptions, in 2015 , the Company expects to contribute approximately $65 million , $132 million , and $23 million to its U.K., U.S. and other significant international pension plans, respectively. During the three months ended June 30, 2015 , contributions of $15 million , $28 million , and $4 million were made to the Company's U.K., U.S. and other significant international pension plans, respectively. During the six months ended June 30, 2015 , contributions of $34 million , $62 million , and $8 million were made to the Company's U.K., U.S. and other significant international pension plans, respectively. During the three months ended June 30, 2014 , contributions of $56 million , $33 million , and $4 million were made to the Company's U.K., U.S. and other significant international pension plans, respectively. During the six months ended June 30, 2014 , contributions of $121 million , $73 million , and $16 million were made to the Company's U.K., U.S. and other significant international pension plans, respectively.

Share-Based Compensation Plans

Share-Based Compensation Plans	6 Months Ended
	Jun. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation Plans	Share-Based Compensation Plans The following table summarizes share-based compensation expense recognized in the Condensed Consolidated Statements of Income in Compensation and benefits (in millions): Three months ended June 30, Six months ended June 30, 2015 2014 2015 2014 Restricted share units ("RSUs") $ 44 $ 43 $ 109 $ 103 Performance share awards ("PSAs") 28 28 49 67 Share options — — — — Employee share purchase plans 2 2 6 5 Total share-based compensation expense $ 74 $ 73 $ 164 $ 175 Restricted Share Units A summary of the status of the Company's RSUs is as follows (shares in thousands): Six months ended June 30, 2015 2014 Shares Fair Value (1) Shares Fair Value (1) Non-vested at beginning of period 8,381 $ 63 9,759 $ 51 Granted 2,144 98 2,498 84 Vested (3,037 ) 58 (3,320 ) 49 Forfeited (130 ) 67 (221 ) 54 Non-vested at end of period 7,358 76 8,716 61 ______________________________________________ (1) Represents per share weighted average fair value of award at date of grant. Performance Share Awards The vesting of PSAs is contingent upon meeting a cumulative level of earnings per share performance over a three -year period. The performance conditions are not considered in the determination of the grant date fair value for these awards. The fair value of PSAs is based upon the market price of an Aon ordinary share at the date of grant. Compensation expense is recognized over the performance period based on management's estimate of the number of units expected to vest. Compensation expense is adjusted to reflect the actual number of shares issued at the end of the programs. The actual issue of shares may range from 0 - 200% of the target number of PSAs granted, based on the terms of the plan and level of achievement of the related performance target. Dividend equivalents are not paid on PSAs. Information as of June 30, 2015 regarding the Company's target PSAs granted and shares that would be issued at current performance levels for PSAs granted during the six months ended June 30, 2015 and the years ended December 31, 2014 and 2013 , respectively, is as follows (shares in thousands, dollars in millions, except fair value): 2015 2014 2013 Target PSAs granted during period 993 816 1,135 Weighted average fair value per share at date of grant $ 96 $ 81 $ 58 Number of shares that would be issued based on current performance levels 992 1,201 2,197 Unamortized expense, based on current performance levels $ 85 $ 52 $ 23 Share Options The Company did not grant any share options during either the six months ended June 30, 2015 or the six months ended June 30, 2014 . A summary of the status of the Company's share options and related information is as follows (shares in thousands): Six months ended June 30, 2015 2014 Shares Weighted- Average Exercise Price Shares Weighted- Average Exercise Price Beginning outstanding 2,300 $ 32 3,462 $ 32 Granted — — — — Exercised (1,388 ) 27 (839 ) 32 Forfeited and expired (13 ) 39 (3 ) 37 Outstanding at end of period 899 39 2,620 32 Exercisable at end of period 899 39 2,572 32 The weighted average remaining contractual life, in years, of outstanding options was 2.7 years and 1.9 years at June 30, 2015 and 2014 , respectively. The aggregate intrinsic value represents the total pretax intrinsic value, based on options with an exercise price less than the Company's closing share price of $99.68 as of June 30, 2015 , which would have been received by the option holders had those option holders exercised their options as of that date. At June 30, 2015 , the aggregate intrinsic value of options outstanding, all of which were exercisable, was $54 million . Other information related to the Company's share options is as follows (in millions): Three months ended June 30, Six months ended June 30, 2015 2014 2015 2014 Aggregate intrinsic value of stock options exercised $ 6 $ 24 $ 100 $ 45 Cash received from the exercise of stock options 4 13 38 27 Tax benefit realized from the exercise of stock options 1 6 35 12 Unamortized deferred compensation expense, which includes both options and awards, amounted to $455 million as of June 30, 2015 , with a remaining weighted-average amortization period of approximately 2.2 years.

Derivatives and Hedging

Derivatives and Hedging	6 Months Ended
	Jun. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Hedging	Derivatives and Hedging The Company is exposed to market risks, including changes in foreign currency exchange rates and interest rates. To manage the risk related to these exposures, the Company enters into various derivative instruments that reduce these risks by creating offsetting exposures. The Company does not enter into derivative transactions for trading or speculative purposes. Foreign Exchange Risk Management The Company is exposed to foreign exchange risk when it earns revenues, pays expenses, or enters into monetary intercompany transfers denominated in a currency that differs from its functional currency, or other transactions that are denominated in a currency other than its functional currency. The Company uses foreign exchange derivatives, typically forward contracts, options and cross currency swaps, to reduce its overall exposure to the effects of currency fluctuations on cash flows. These exposures are hedged, on average, for less than two years. These derivatives are accounted for as hedges, and changes in fair value are recorded each period in Other comprehensive income (loss) in the Condensed Consolidated Statements of Comprehensive Income. The Company also uses foreign exchange derivatives, typically forward contracts and options to economically hedge the currency exposure of the Company's global liquidity profile, including monetary assets or liabilities that are denominated in a non-functional currency of an entity, typically in a rolling 30 day basis, but may be for up to one year in the future. These derivatives are not accounted for as hedges, and changes in fair value are recorded each period in Other income in the Condensed Consolidated Statements of Income. Interest Rate Risk Management The Company holds variable-rate short-term brokerage and other operating deposits. The Company uses interest rate derivatives, typically swaps, to reduce its exposure to the effects of interest rate fluctuations on the forecasted interest receipts from these deposits for up to two years in the future. Certain derivatives also give rise to credit risks from the possible non-performance by counterparties. The credit risk at the balance sheet date is generally limited to the fair value of those contracts that are favorable to the Company. The Company has reduced its credit risk by (1) using International Swaps and Derivatives Association master agreements, collateral and credit support arrangements, (2) entering into non-exchange-traded derivatives with highly-rated major financial institutions and (3) using exchange-traded instruments. The Company monitors the creditworthiness of, and exposure to, its counterparties. As of June 30, 2015 , all net derivative positions were free of credit risk contingent features. The Company had not received or pledged any collateral related to derivative arrangements as of June 30, 2015 . The notional and fair values of derivative instruments are as follows (in millions): Notional Amount Derivative Assets (1) Derivative Liabilities (2) June 30, December 31, June 30, December 31, June 30, December 31, Derivatives accounted for as hedges: Interest rate contracts $ — $ — $ — $ — $ — $ — Foreign exchange contracts 998 1,200 54 46 57 58 Total 998 1,200 54 46 57 58 Derivatives not accounted for as hedges: Foreign exchange contracts (3) 167 165 — — — — Total $ 1,165 $ 1,365 $ 54 $ 46 $ 57 $ 58 ______________________________________________ (1) Included within Other current assets ( $28 million at June 30, 2015 and $24 million at December 31, 2014 ) or Other non-current assets ( $26 million at June 30, 2015 and $22 million at December 31, 2014 ). (2) Included within Other current liabilities ( $47 million at June 30, 2015 and $52 million at December 31, 2014 ) or Other non-current liabilities ( $10 million at June 30, 2015 and $6 million at December 31, 2014 ). (3) These contracts typically are for 30 day durations and executed close to the last day of the most recent reporting month, thereby resulting in nominal fair values at the balance sheet date. Offsetting of financial assets and derivatives assets are as follows (in millions): Gross Amounts of Recognized Assets Gross Amounts Offset in the Statement of Financial Position Net Amounts of Assets Presented in the Statement of Financial Position (1) June 30, December 31, June 30, December 31, June 30, December 31, Derivatives accounted for as hedges: Interest rate contracts $ — $ — $ — $ — $ — $ — Foreign exchange contracts 54 46 (20 ) (14 ) 34 32 Total 54 46 (20 ) (14 ) 34 32 Derivatives not accounted for as hedges: Foreign exchange contracts — — — — — — Total $ 54 $ 46 $ (20 ) $ (14 ) $ 34 $ 32 ______________________________________________ (1) Included within Other current assets ( $17 million at June 30, 2015 and $12 million at December 31, 2014 ) or Other non-current assets ( $17 million at June 30, 2015 and $20 million at December 31, 2014 ). Offsetting of financial liabilities and derivative liabilities are as follows (in millions): Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Statement of Financial Position Net Amounts of Liabilities Presented in the Statement of Financial Position (1) June 30, December 31, June 30, December 31, June 30, December 31, Derivatives accounted for as hedges: Interest rate contracts $ — $ — $ — $ — $ — $ — Foreign exchange contracts 57 58 (20 ) (14 ) 37 44 Total 57 58 (20 ) (14 ) 37 44 Derivatives not accounted for as hedges: Foreign exchange contracts — — — — — — Total $ 57 $ 58 $ (20 ) $ (14 ) $ 37 $ 44 ______________________________________________ (1) Included within Other current liabilities ( $36 million at June 30, 2015 and $40 million at December 31, 2014 ) or Other non-current liabilities ( $1 million at June 30, 2015 and $4 million at December 31, 2014 ). The amounts of derivative gains (losses) recognized in the Condensed Consolidated Financial Statements for the three and six months ended June 30, 2015 and 2014 are as follows (in millions): Three Months Ended June 30, 2015 Location of future reclassification from Accumulated Other Comprehensive Loss Gain (Loss) recognized in Accumulated Other Comprehensive Loss: Compensation and Benefits Other General Expenses Interest Expense Other Income (Expense) Total Cash flow hedges: Interest rate contracts $ — $ — $ — $ — $ — Foreign exchange contracts 1 3 — 10 14 Total $ 1 $ 3 $ — $ 10 $ 14 Three Months Ended June 30, 2014 Location of future reclassification from Accumulated Other Comprehensive Loss Gain (Loss) recognized in Accumulated Other Comprehensive Loss: Compensation and Benefits Other General Expenses Interest Expense Other Income (Expense) Total Cash flow hedges: Interest rate contracts $ — $ — $ — $ — $ — Foreign exchange contracts 5 — — 10 15 Total $ 5 $ — $ — $ 10 $ 15 Six Months Ended June 30, 2015 Location of future reclassification from Accumulated Other Comprehensive Loss Gain (Loss) recognized in Accumulated Other Comprehensive Loss: Compensation and Benefits Other General Expenses Interest Expense Other Income (Expense) Total Cash flow hedges: Interest rate contracts $ — $ — $ — $ — $ — Foreign exchange contracts 6 1 — 6 13 Total $ 6 $ 1 $ — $ 6 $ 13 Six Months Ended June 30, 2014 Location of future reclassification from Accumulated Other Comprehensive Loss Gain (Loss) recognized in Accumulated Other Comprehensive Loss: Compensation and Benefits Other General Expenses Interest Expense Other Income (Expense) Total Cash flow hedges: Interest rate contracts $ — $ — $ — $ — $ — Foreign exchange contracts 16 — — (9 ) 7 Total $ 16 $ — $ — $ (9 ) $ 7 Three Months Ended June 30, 2015 Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion): Compensation and Benefits Other General Expenses Interest Expense Other Income (Expense) Total Cash flow hedges: Interest rate contracts $ — $ — $ — $ — Foreign exchange contracts 1 (1 ) (2 ) 5 3 Total $ 1 $ (1 ) $ (2 ) $ 5 $ 3 Three Months Ended June 30, 2014 Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion): Compensation and Benefits Other General Expenses Interest Expense Other Income (Expense) Total Cash flow hedges: Interest rate contracts $ — $ — $ — $ — $ — Foreign exchange contracts — — (3 ) 5 2 Total $ — $ — $ (3 ) $ 5 $ 2 Six Months Ended June 30, 2015 Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion): Compensation and Benefits Other General Expenses Interest Expense Other Income (Expense) Total Cash flow hedges: Interest rate contracts $ — $ — $ (1 ) $ — $ (1 ) Foreign exchange contracts 1 (1 ) (4 ) (3 ) (7 ) Total $ 1 $ (1 ) $ (5 ) $ (3 ) $ (8 ) Six Months Ended June 30, 2014 Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion): Compensation and Benefits Other General Expenses Interest Expense Other Income (Expense) Total Cash flow hedges: Interest rate contracts $ — $ — $ (1 ) $ — $ (1 ) Foreign exchange contracts (2 ) — (5 ) (12 ) (19 ) Total $ (2 ) $ — $ (6 ) $ (12 ) $ (20 ) The Company estimates that approximately $1 million of pretax losses currently included within Accumulated other comprehensive loss will be reclassified into earnings in the next twelve months. The amount of gain (loss) recognized in income on the ineffective portion of derivatives for the three and six months ended June 30, 2015 and 2014 was not material. During the three and six months ended June 30, 2015 , the Company recorded a gain of $2 million and $9 million , respectively, in Other income (expense) for foreign exchange derivatives not designated or qualifying as hedges. During the three and six months ended June 30, 2014, the Company recorded a gain of $4 million and a loss of $1 million , respectively, in Other income for foreign exchange derivatives not designated or qualifying as hedges.

Fair Value Measurements and Fin

Fair Value Measurements and Financial Instruments	6 Months Ended
	Jun. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements and Financial Instruments	Fair Value Measurements and Financial Instruments Accounting standards establish a three tier fair value hierarchy that prioritizes the inputs used in measuring fair values as follows: • Level 1 — observable inputs such as quoted prices for identical assets in active markets; • Level 2 — inputs other than quoted prices for identical assets in active markets, that are observable either directly or indirectly; and • Level 3 — unobservable inputs in which there is little or no market data which requires the use of valuation techniques and the development of assumptions. The following methods and assumptions are used to estimate the fair values of the Company's financial instruments: Money market funds and highly liquid debt securities are carried at cost and amortized cost, respectively, as an approximation of fair value. Based on market convention, the Company considers cost a practical and expedient measure of fair value. Equity investments consist of domestic and international equity securities valued using the closing stock price on a national securities exchange. The Company reviews the listing of Level 1 equity securities in the portfolio and agrees the closing stock prices to a national securities exchange, and on a sample basis, independently verifies the observable inputs for Level 2 equity securities. Fixed income investments consist of corporate and government bonds. Corporate and government bonds are valued by pricing vendors who estimate fair value using recently executed transactions and proprietary models based on observable inputs, such as interest rate spreads, yield curves and credit risk. The Company obtains a detailed understanding of the models, inputs, and assumptions used in developing prices provided by its vendors. This understanding includes discussions with valuation resources at the vendor. During these discussions, the Company uses a fair value measurement questionnaire, which is part of the Company's internal controls over financial reporting, to obtain the information necessary to assert the model, inputs and assumptions used to comply with U.S. GAAP, including disclosure requirements. The Company also obtains observable inputs from the pricing vendor and independently verifies the observable inputs, as well as assesses assumptions used for reasonableness based on relevant market conditions and internal Company guidelines. If an assumption is deemed unreasonable, based on the Company's guidelines, it is then reviewed by management and the fair value estimate provided by the vendor is adjusted, if deemed appropriate. These adjustments do not occur frequently and have historically not been material to the fair value estimates used in the Condensed Consolidated Financial Statements. Derivatives are carried at fair value, based upon industry standard valuation techniques that use, where possible, current market-based or independently sourced pricing inputs, such as interest rates, currency exchange rates, or implied volatilities. Debt is carried at outstanding principal balance, less any unamortized discount or premium. Fair value is based on quoted market prices or estimates using discounted cash flow analyses based on current borrowing rates for similar types of borrowing arrangements. The following tables present the categorization of the Company's assets and liabilities that are measured at fair value on a recurring basis at June 30, 2015 and December 31, 2014 (in millions): Fair Value Measurements Using Balance at June 30, 2015 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Money market funds and highly liquid debt securities (1) $ 1,895 $ 1,895 $ — $ — Other investments: Corporate bonds 1 — — 1 Government bonds 6 — 6 — Equity investments 10 6 4 — Derivatives: Interest rate contracts — — — — Foreign exchange contracts 54 — 54 — Liabilities: Derivatives: Foreign exchange contracts 57 — 57 — ______________________________________________ (1) Includes $ 1,895 million of money market funds that are classified as Fiduciary assets, Short-term investments or Cash and cash equivalents in the Condensed Consolidated Statements of Financial Position, depending on their nature and initial maturity. Fair Value Measurements Using Balance at December 31, 2014 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Money market funds and highly liquid debt securities (1) $ 1,850 $ 1,850 $ — $ — Other investments: Corporate bonds 1 — — 1 Government bonds 6 — 6 — Equity investments 11 6 5 — Derivatives: Interest rate contracts — — — — Foreign exchange contracts 46 — 46 — Liabilities: Derivatives: Foreign exchange contracts 58 — 58 — ______________________________________________ (1) Includes $1,850 million of money market funds that are classified as Fiduciary assets, Short-term investments or Cash and cash equivalents in the Condensed Consolidated Statements of Financial Position, depending on their nature and initial maturity. There were no transfers of assets or liabilities between fair value hierarchy levels in either the three and six months ended June 30, 2015 or 2014 . The Company recognized no realized or unrealized gains or losses in the Condensed Consolidated Statements of Income during either the three and six months ended June 30, 2015 or 2014 , related to assets and liabilities measured at fair value using unobservable inputs. The fair value of Long-term debt is classified as Level 2 of the fair value hierarchy. The following table discloses the Company's financial instruments where the carrying amounts and fair values differ (in millions): June 30, 2015 December 31, 2014 Carrying Value Fair Value Carrying Value Fair Value Long-term debt $ 4,824 $ 5,060 $ 4,799 $ 5,268

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Aon and its subsidiaries are subject to numerous claims, tax assessments, lawsuits and proceedings that arise in the ordinary course of business, which frequently include errors and omissions ("E&O") claims. The damages claimed in these matters are or may be substantial, including, in many instances, claims for punitive, treble or extraordinary damages. While Aon maintains meaningful E&O insurance and other insurance programs to provide protection against certain losses that arise in such matters, Aon has exhausted or materially depleted its coverage under some of the policies that protect the Company and, consequently, is self-insured or materially self-insured for some claims. Accruals for these exposures, and related insurance receivables, when applicable, are included in the Condensed Consolidated Statements of Financial Position and have been recognized in Other general expenses in the Condensed Consolidated Statements of Income to the extent that losses are deemed probable and are reasonably estimable. These amounts are adjusted from time to time as developments warrant. Matters that are not probable and estimable are not accrued for in the financial statements. We have included in the matters described below certain matters in which (1) loss is probable, (2) loss is reasonably possible; that is, more than remote but not probable, or (3) there exists the reasonable possibility of loss greater than the accrued amount. In addition, we may from time to time disclose matters for which the probability of loss could be remote but the claim amounts associated with such matters are potentially significant. The reasonably possible range of loss for the matters described below, in excess of amounts that are deemed probable and estimable and therefore already accrued, is estimated to be between $0 and $0.3 billion , exclusive of any insurance coverage. These estimates are based on currently available information. As available information changes, the matters for which Aon is able to estimate may change, and the estimates themselves may change. In addition, many estimates involve significant judgment and uncertainty. For example, at the time of making an estimate, Aon may only have limited information about the facts underlying the claim, and predictions and assumptions about future court rulings and outcomes may prove to be inaccurate. Although management at present believes that the ultimate outcome of all matters described below, individually or in the aggregate, will not have a material adverse effect on the consolidated financial position of Aon, legal proceedings are subject to inherent uncertainties and unfavorable rulings or other events. Unfavorable resolutions could include substantial monetary or punitive damages imposed on Aon or its subsidiaries. If unfavorable outcomes of these matters were to occur, future results of operations or cash flows for any particular quarterly or annual period could be materially adversely affected. A retail insurance brokerage subsidiary of Aon provided insurance brokerage services to Northrop Grumman Corporation ("Northrop"), including the placement of Northrop's property insurance program for the period covering 2005. In August 2005, Hurricane Katrina damaged Northrop's shipbuilding facilities in the Gulf States. Northrop's excess insurance carrier denied coverage for storm surge damage pursuant to a flood exclusion in the excess policy. Northrop sued that carrier but subsequently settled its claims. On January 27, 2011, Northrop filed suit against an Aon subsidiary in the Superior Court of the State of California, County of Los Angeles, asserting claims for negligence, breach of contract and negligent misrepresentation in connection with the placement of Northrop's property insurance program for the period covering 2005 and subsequently amended the complaint to add additional claims for intentional misrepresentation and concealment. Northrop sought compensatory damages of approximately $340 million , which included prejudgment interest and attorneys' fees, and punitive damages that were a multiple of the compensatory damages sought. On May 29, 2015, Aon and Huntington Ingalls Industries, Inc., successor to Northrop's claims in this matter ("HII"), entered into a settlement agreement pursuant to which, among other things, Aon agreed to pay HII $150 million in exchange for HII dismissing its lawsuit and releasing Aon from related claims. In June 2015, Aon paid $150 million due under the settlement agreement. Another retail insurance brokerage subsidiary of Aon was sued on September 14, 2010 in the Chancery Court for Davidson County, Tennessee, Twentieth Judicial District, at Nashville by a client, Opry Mills Mall Limited Partnership ("Opry Mills") that sustained flood damage to its property in May 2010. The lawsuit seeks $200 million in coverage from numerous insurers with whom this Aon subsidiary placed the client's property insurance coverage. The insurers contend that only $50 million in coverage (which has already been paid) is available for the loss because the flood event occurred on property in a high hazard flood zone. Opry Mills is seeking full coverage from the insurers for the loss and has sued this Aon subsidiary in the alternative for the same $150 million difference on various theories of professional liability if the court determines there is not full coverage. In addition, Opry Mills seeks prejudgment interest, attorneys' fees and enhanced damages which could substantially increase Aon's exposure. In March 2015, the trial court granted partial summary judgment in favor of plaintiffs and against the insurers, holding generally that the plaintiffs are entitled to $200 million in coverage under the language of the policies. Aon understands that the insurers intend to appeal this trial court decision. Aon believes it has meritorious defenses and intends to vigorously defend itself against these claims. A pensions consulting and administration subsidiary of Hewitt before its acquisition by Aon provided advisory services to the Trustees of the Philips UK pension fund and the relevant employer of fund beneficiaries. On January 2, 2014, Philips Pension Trustees Limited and Philips Electronics UK Limited (together, "Philips") sued Aon in the High Court, Chancery Division, London alleging negligence and breach of duty. The proceedings assert Philips' right to claim damages related to Philips' use of a credit default swap hedging strategy pursuant to the supply of the advisory services, which is said to have resulted in substantial damages to Philips. Philips is seeking approximately £189 million ( $298 million at June 30, 2015 exchange rates), plus interest and costs. In June 2015, the High Court ordered Philips to clarify several aspects of its claim. Aon believes that it has meritorious defenses and intends to vigorously defend itself against these allegations. On June 1, 2007, the International Road Transport Union ("IRU") sued Aon in the Geneva Tribunal of First Instance in Switzerland. IRU alleges, among other things, that, between 1995 and 2004, a business acquired by Aon and, later, an Aon subsidiary (1) accepted commissions for certain insurance placements that violated a fee agreement entered between the parties and (2) negligently failed to ask certain insurance carriers to contribute to the IRU's risk management costs. IRU seeks damages of approximately CHF 46 million ( $49 million at June 30, 2015 exchange rates) and $3 million , plus legal fees and interest of approximately $30 million . On December 2, 2014, the Geneva Tribunal of First Instance entered a judgment that accepted some, and rejected other, of IRU's claims. The judgment awarded IRU CHF 16.8 million ( $18 million at June 30, 2015 exchange rates) and $3.1 million , plus interest and adverse costs. The entire amount of the judgment, including interest through December 31, 2014, totals CHF 27.9 million ( $30 million at June 30, 2015 exchange rates) and $5 million . On January 26, 2015, in return for IRU agreeing not to appeal the bulk of its dismissed claims, the Aon subsidiary agreed not to appeal a part of the judgment and to pay IRU CHF 12.8 million ( $14 million at June 30, 2015 exchange rates) and $4.7 million without Aon admitting liability. The Aon subsidiary appealed those aspects of the judgment it retained the right to appeal. IRU did not appeal. The Aon subsidiary's maximum liability on appeal is limited to CHF 8.7 million ( $9 million at June 30, 2015 exchange rates) and $115,000 (plus interest and costs) beyond what the subsidiary has already paid. The appeal is now under submission. On December 27, 2012, AXA Versicherung Aktiengesellschaft ("AXA") started arbitral proceedings in Hamburg, Germany against an insurance and reinsurance brokerage subsidiary of Aon in Germany. Entities acquired by AXA granted entities acquired by Aon a mandate to underwrite non-proportional reinsurance business from 1975 through 1999. AXA alleges, among other things, that the Aon-related entities intentionally exceeded their mandate and that, if AXA had known of this intention, it would not have granted a mandate. AXA seeks damages of approximately €183 million ( $204 million at June 30, 2015 exchange rates). On June 24, 2015, the arbitral panel issued an award that rejected all of AXA's claims and ordered AXA to reimburse the Aon subsidiary for its legal fees and costs in the amount of €1.6 million ($ 2 million at June 30, 2015 exchange rates). A pensions consulting and administration subsidiary of Aon provided advisory services to the Trustees of the Gleeds pension fund in the United Kingdom and, on occasion, to the relevant employer of the fund. In April 2014, the High Court, Chancery Division, London found that certain governing documents of the fund that sought to alter the fund's benefit structure and that had been drafted by Aon were procedurally defective and therefore invalid. No lawsuit naming Aon as a party has been filed, although a tolling agreement has been entered. The High Court decision says that the additional liabilities in the pension fund resulting from the alleged defect in governing documents amount to approximately £45 million ( $71 million at June 30, 2015 exchange rates). In December 2014, the Court of Appeal granted the employer leave to appeal the High Court decision. The Court of Appeal hearing was set for October 2015, but has been postponed to permit the parties to discuss possible settlement. Aon believes that it has meritorious defenses and intends to vigorously defend itself against this potential claim. On June 29, 2015, Lyttelton Port Company Limited ("LPC") sued Aon New Zealand (Aon) in the Christchurch Registry of the High Court of New Zealand. LPC alleges, among other things, that Aon was negligent and in breach of contract in arranging LPC’s property insurance program for the period covering June 30, 2010, to June 30, 2011. LPC contends that acts and omissions by Aon caused LPC to recover less than it otherwise would have from insurers for losses suffered in the 2010/2011 Canterbury Earthquakes. LPC claims damages of approximately NZD 184 million ( $126.2 million at June 30, 2015 exchange rates) plus interest and costs. Aon believes that it has meritorious defenses and intends to vigorously defend itself against these claims. From time to time, Aon's clients may bring claims and take legal action pertaining to the performance of fiduciary responsibilities. Whether client claims and legal action related to the Company's performance of fiduciary responsibilities are founded or unfounded, if such claims and legal actions are resolved in a manner unfavorable to the Company, they may adversely affect Aon's financial results and materially impair the market perception of the Company and that of its products and services. Guarantees and Indemnifications In connection with the redomicile of Aon's headquarters (the "Redomestication"), the Company on April 2, 2012 entered into various agreements pursuant to which it agreed to guarantee the obligations of its subsidiaries arising under issued and outstanding debt securities. Those agreements included the (1) Amended and Restated Indenture, dated as of April 2, 2012, among Aon Corporation, Aon plc, and The Bank of New York Mellon Trust Company, N.A., as trustee (the "Trustee") (amending and restating the Indenture, dated as of September 10, 2010, between Aon Corporation and the Trustee), (2) Amended and Restated Indenture, dated as of April 2, 2012, among Aon Corporation, Aon plc and the Trustee (amending and restating the Indenture, dated as of December 16, 2002, between Aon Corporation and the Trustee), (3) Amended and Restated Indenture, dated as of April 2, 2012, among Aon Corporation, Aon plc and the Trustee (amending and restating the Indenture, dated as of January 13, 1997, as supplemented by the First Supplemental Indenture, dated as of January 13, 1997), and (4) First Supplemental Indenture, dated as of April 2, 2012, among Aon Finance N.S. 1, ULC, as issuer, Aon Corporation, as guarantor, Aon plc, as guarantor, and Computershare Trust Company of Canada, as trustee. The Company provides a variety of guarantees and indemnifications to its customers and others. The maximum potential amount of future payments represents the notional amounts that could become payable under the guarantees and indemnifications if there were a total default by the guaranteed parties, without consideration of possible recoveries under recourse provisions or other methods. These amounts may bear no relationship to the expected future payments, if any, for these guarantees and indemnifications. Any anticipated amounts payable are included in the Company's Condensed Consolidated Financial Statements, and are recorded at fair value. The Company expects that, as prudent business interests dictate, additional guarantees and indemnifications may be issued from time to time. Letters of Credit The Company had total letters of credit ("LOCs") outstanding of approximately $62 million at June 30, 2015 , compared to $95 million at December 31, 2014 . These letters of credit cover the beneficiaries related to certain of Aon's U.S. and Canadian non-qualified pension plan schemes and secure deductible retentions for Aon's own workers compensation program. The Company has also issued LOCs to cover contingent payments for taxes and other business obligations to third parties, and other guarantees for miscellaneous purposes at its international subsidiaries. Commitments The Company has provided commitments to fund certain limited partnerships in which it has an interest in the event that the general partners request funding. Some of these commitments have specific expiration dates and the maximum potential funding under these commitments was $12 million at June 30, 2015 compared to $14 million at December 31, 2014 . During the three and six months ended June 30, 2015 , the Company funded $0 million and $2 million of these commitments, respectively. Premium Payments The Company has certain contractual contingent guarantees for premium payments owed by clients to certain insurance companies. The maximum exposure with respect to such contractual contingent guarantees was approximately $91 million at June 30, 2015 compared to $112 million at December 31, 2014 .

Segment Information

Segment Information	6 Months Ended
	Jun. 30, 2015
Segment Reporting [Abstract]
Segment Information	Segment Information The Company has two reportable segments: Risk Solutions and HR Solutions. Unallocated income and expenses, when combined with the operating segments and after the elimination of intersegment revenues and expenses, equal the amounts in the Condensed Consolidated Financial Statements. Reportable operating segments have been determined using a management approach, which is consistent with the basis and manner in which Aon's chief operating decision-maker ("CODM") uses financial information for the purposes of allocating resources and evaluating performance. The CODM assesses performance based on operating income and generally accounts for inter-segment revenue as if the revenue were from third parties and at what management believes are current market prices. The Company does not present net assets by segment as this information is not reviewed by the CODM. Risk Solutions acts as an advisor and insurance and reinsurance broker, helping clients manage their risks, via consultation, as well as negotiation and placement of insurance risk with insurance carriers through Aon's global distribution network. HR Solutions partners with organizations to solve their most complex benefits, talent and related financial challenges, and improve business performance by designing, implementing, communicating and administering a wide range of human capital, retirement, investment management, health care, compensation and talent management strategies. Aon's total revenue is as follows (in millions): Three months ended June 30, Six months ended June 30, 2015 2014 2015 2014 Risk Solutions $ 1,833 $ 1,948 $ 3,728 $ 3,942 HR Solutions 979 982 1,949 1,947 Intersegment eliminations (7 ) (11 ) (25 ) (23 ) Total revenue $ 2,805 $ 2,919 $ 5,652 $ 5,866 Commissions, fees and other revenues by product are as follows (in millions): Three months ended June 30, Six months ended June 30, 2015 2014 2015 2014 Retail brokerage $ 1,498 $ 1,582 $ 3,011 $ 3,161 Reinsurance brokerage 330 360 707 769 Total Risk Solutions Segment 1,828 1,942 3,718 3,930 Consulting services 391 395 762 779 Outsourcing 599 595 1,203 1,184 Intrasegment (11 ) (8 ) (16 ) (16 ) Total HR Solutions Segment 979 982 1,949 1,947 Intersegment (7 ) (11 ) (25 ) (23 ) Total commissions, fees and other revenue $ 2,800 $ 2,913 $ 5,642 $ 5,854 Fiduciary investment income by segment is as follows (in millions): Three months ended June 30, Six months ended June 30, 2015 2014 2015 2014 Risk Solutions $ 5 $ 6 $ 10 $ 12 HR Solutions — — — — Total fiduciary investment income $ 5 $ 6 $ 10 $ 12 A reconciliation of segment operating income before tax to income before income taxes is as follows (in millions): Three months ended June 30, Six months ended June 30, 2015 2014 2015 2014 Risk Solutions $ 279 $ 417 $ 691 $ 862 HR Solutions 39 69 115 136 Segment income before income taxes 318 486 806 998 Unallocated expenses (41 ) (41 ) (88 ) (84 ) Interest income 4 2 7 4 Interest expense (68 ) (65 ) (133 ) (123 ) Other income (expense) 1 (2 ) 43 (1 ) Income before income taxes $ 214 $ 380 $ 635 $ 794 Unallocated expenses include administrative or other costs not attributable to the operating segments, such as corporate governance costs. Interest income represents income earned primarily on operating cash balances and certain income producing securities. Interest expense represents the cost of debt obligations. Other income consists of equity earnings, realized gains or losses on the sale of investments, gains or losses on the disposal of businesses, gains or losses on derivatives, and gains or losses on foreign currency transactions.

Guarantee of Registered Securit

Guarantee of Registered Securities	6 Months Ended
	Jun. 30, 2015
Guarantee of Registered Securities [Abstract]
Guarantee of Registered Securities	Guarantee of Registered Securities As described in Note 14, in connection with the Redomestication, Aon plc entered into various agreements pursuant to which it agreed to guarantee the obligations of Aon Corporation arising under issued and outstanding debt securities, including the 3.50% Notes due September 2015, the 3.125% Notes due May 2016, the 5.00% Notes due September 2020, the 8.205% Notes due January 2027 and the 6.25% Notes due September 2040. Aon Corporation is a 100% indirectly owned subsidiary of Aon plc. All guarantees of Aon plc are full and unconditional. There are no other subsidiaries of Aon plc that are guarantors of the debt. In addition, Aon Corporation entered into an agreement pursuant to which it agreed to guarantee the obligations of Aon plc arising under the 4.250% Notes due 2042 exchanged for Aon Corporation's outstanding 8.205% Notes due January 2027 and also agreed to guarantee the obligations of Aon plc arising under the 4.45% Notes due 2043, the 4.00% Notes due November 2023, the 2.875% Notes due May 2026, the 3.50% Notes due June 2024, the 4.60% Notes due June 2044, and the 4.75% Notes due May 2045. In each case, the guarantee of Aon Corporation is full and unconditional. There are no subsidiaries of Aon plc, other than Aon Corporation, that are guarantors of the 4.250% Notes due 2042, the 4.45% Notes due 2043, the 4.00% Notes due 2023, the 2.875% Notes due 2026, the 3.50% Notes due 2024, the 4.60% Notes due 2044, or the 4.75% Notes due 2045. As a result of the existence of these guarantees, the Company is required by Rule 3-10 of Regulation S-X to present the financial information set forth in this footnote. The following tables set forth condensed consolidating statements of income for the three and six months ended June 30, 2015 and 2014 , condensed consolidating statements of comprehensive income for the three and six months ended June 30, 2015 and 2014 , condensed consolidating statements of financial position as of June 30, 2015 and December 31, 2014 , and condensed consolidating statements of cash flows for the six months ended June 30, 2015 and 2014 in accordance with Rule 3-10 of Regulation S-X. The condensed consolidating financial information includes the accounts of Aon plc, the accounts of Aon Corporation, and the combined accounts of the non-guarantor subsidiaries. The condensed consolidating financial statements are presented in all periods as a merger under common control, with Aon plc presented as the parent company in all periods prior and subsequent to the Redomestication. The principal consolidating adjustments are to eliminate the investment in subsidiaries and intercompany balances and transactions. In January 2015, Aon plc transferred its ownership of all of its directly held subsidiaries to Aon Global Holdings Limited, an intermediate holding company. The financial results of Aon Global Holdings Limited are included in the Other Non-Guarantor Subsidiaries column of the Condensed Consolidating Financial Statements. The Company has reflected the transfer of Aon Corporation from Aon plc to Aon Global Holdings Limited below for all periods presented. Certain amounts in prior year's condensed consolidating statements of income have been reclassified and adjusted to conform to the 2015 presentation. In prior periods, other income (expense) from intercompany transactions were recognized in Compensation and benefits and Other general expenses. These amounts are now included in Intercompany other income (expense) in the Condensed Consolidating Statements of Income. The Company believes this provides greater clarity into the income generated from operations and intercompany transactions. Condensed Consolidating Statement of Income Three months ended June 30, 2015 Other Aon Aon Non-Guarantor Consolidating (millions) plc Corporation Subsidiaries Adjustments Consolidated Revenue Commissions, fees and other $ — $ — $ 2,800 $ — $ 2,800 Fiduciary investment income — — 5 — 5 Total revenue — — 2,805 — 2,805 Expenses Compensation and benefits 5 10 1,638 — 1,653 Other general expenses (4 ) 2 877 — 875 Total operating expenses 1 12 2,515 — 2,528 Operating (loss) income (1 ) (12 ) 290 — 277 Interest income (5 ) 4 5 — 4 Interest expense (29 ) (33 ) (6 ) — (68 ) Intercompany interest income (expense) 119 (116 ) (3 ) — — Intercompany other (expense) income (56 ) (15 ) 71 — — Other income (1 ) — 2 — 1 (Loss) income before taxes 27 (172 ) 359 — 214 Income tax (benefit) expense 6 (66 ) 86 — 26 (Loss) income before equity in earnings of subsidiaries 21 (106 ) 273 — 188 Equity in earnings of subsidiaries, net of tax 157 170 64 (391 ) — Net income 178 64 337 (391 ) 188 Less: Net income attributable to noncontrolling interests — — 10 — 10 Net income attributable to Aon shareholders $ 178 $ 64 $ 327 $ (391 ) $ 178 Condensed Consolidating Statement of Income Three months ended June 30, 2014 Other Aon Aon Non-Guarantor Consolidating (millions) plc Corporation Subsidiaries Adjustments Consolidated Revenue Commissions, fees and other $ — $ — $ 2,913 $ — $ 2,913 Fiduciary investment income — — 6 — 6 Total revenue — — 2,919 — 2,919 Expenses Compensation and benefits 6 6 1,696 — 1,708 Other general expenses 1 3 762 — 766 Total operating expenses 7 9 2,458 — 2,474 Operating (loss) income (7 ) (9 ) 461 — 445 Interest income (2 ) — 4 — 2 Interest expense (15 ) (32 ) (18 ) — (65 ) Intercompany interest income (expense) 111 (73 ) (38 ) — — Intercompany other (expense) income (54 ) (4 ) 58 — — Other income (1 ) 8 (9 ) — (2 ) Income (loss) before taxes 32 (110 ) 458 — 380 Income tax expense (benefit) 6 (42 ) 103 — 67 Income (loss) before equity in earnings of subsidiaries 26 (68 ) 355 — 313 Equity in earnings of subsidiaries, net of tax 278 288 220 (786 ) — Net income 304 220 575 (786 ) 313 Less: Net income attributable to noncontrolling interests — — 9 — 9 Net income attributable to Aon shareholders $ 304 $ 220 $ 566 $ (786 ) $ 304 Condensed Consolidating Statement of Income Six months ended June 30, 2015 Other Aon Aon Non-Guarantor Consolidating (millions) plc Corporation Subsidiaries Adjustments Consolidated Revenue Commissions, fees and other $ — $ — $ 5,642 $ — $ 5,642 Fiduciary investment income — — 10 — 10 Total revenue — — 5,652 — 5,652 Expenses Compensation and benefits 57 21 3,258 — 3,336 Other general expenses 9 4 1,585 — 1,598 Total operating expenses 66 25 4,843 — 4,934 Operating (loss) income (66 ) (25 ) 809 — 718 Interest income (9 ) 7 9 — 7 Interest expense (54 ) (68 ) (11 ) — (133 ) Intercompany interest income (expense) 239 (221 ) (18 ) — — Intercompany other (expense) income (106 ) (23 ) 129 — — Other income 1 8 34 — 43 (Loss) income before taxes 5 (322 ) 952 — 635 Income tax (benefit) expense 1 (117 ) 222 — 106 (Loss) income before equity in earnings of subsidiaries 4 (205 ) 730 — 529 Equity in earnings of subsidiaries, net of tax 502 571 366 (1,439 ) — Net income 506 366 1,096 (1,439 ) 529 Less: Net income attributable to noncontrolling interests — — 23 — 23 Net income attributable to Aon shareholders $ 506 $ 366 $ 1,073 $ (1,439 ) $ 506 Condensed Consolidating Statement of Income Six months ended June 30, 2014 Other Aon Aon Non-Guarantor Consolidating (millions) plc Corporation Subsidiaries Adjustments Consolidated Revenue Commissions, fees and other $ — $ — $ 5,854 $ — $ 5,854 Fiduciary investment income — — 12 — 12 Total revenue — — 5,866 — 5,866 Expenses Compensation and benefits 72 13 3,374 — 3,459 Other general expenses 6 5 1,482 — 1,493 Total operating expenses 78 18 4,856 — 4,952 Operating (loss) income (78 ) (18 ) 1,010 — 914 Interest income (4 ) 1 7 — 4 Interest expense (25 ) (63 ) (35 ) — (123 ) Intercompany interest income (expense) 222 (147 ) (75 ) — — Intercompany other (expense) income (72 ) (19 ) 91 — — Other income (1 ) 8 (8 ) — (1 ) (Loss) income before taxes 42 (238 ) 990 — 794 Income tax (benefit) expense 9 (92 ) 228 — 145 (Loss) income before equity in earnings of subsidiaries 33 (146 ) 762 — 649 Equity in earnings of subsidiaries, net of tax 596 621 475 (1,692 ) — Net income 629 475 1,237 (1,692 ) 649 Less: Net income attributable to noncontrolling interests — — 20 — 20 Net income attributable to Aon shareholders $ 629 $ 475 $ 1,217 $ (1,692 ) $ 629 Condensed Consolidating Statement of Comprehensive Income Three months ended June 30, 2015 Other Aon Aon Non-Guarantor Consolidating (millions) plc Corporation Subsidiaries Adjustments Consolidated Net income $ 178 $ 64 $ 337 $ (391 ) $ 188 Less: Net income attributable to noncontrolling interests — — 10 — 10 Net income attributable to Aon shareholders $ 178 $ 64 $ 327 $ (391 ) $ 178 Other comprehensive (loss) income, net of tax: Change in fair value of financial instruments — 2 (8 ) — (6 ) Foreign currency translation adjustments — 4 171 — 175 Post-retirement benefit obligation — 9 12 — 21 Total other comprehensive loss — 15 175 — 190 Equity in other comprehensive loss of subsidiaries, net of tax 191 173 188 (552 ) — Less: Other comprehensive income attributable to noncontrolling interests — — (1 ) — (1 ) Total other comprehensive loss attributable to Aon shareholders 191 188 364 (552 ) 191 Comprehensive income attributable to Aon shareholders $ 369 $ 252 $ 691 $ (943 ) $ 369 Condensed Consolidating Statement of Comprehensive Income Three months ended June 30, 2014 Other Aon Aon Non-Guarantor Consolidating (millions) plc Corporation Subsidiaries Adjustments Consolidated Net income $ 304 $ 220 $ 575 $ (786 ) $ 313 Less: Net income attributable to noncontrolling interests — — 9 — 9 Net income attributable to Aon shareholders $ 304 $ 220 $ 566 $ (786 ) $ 304 Other comprehensive income (loss), net of tax: Change in fair value of financial instruments — (1 ) 11 — 10 Foreign currency translation adjustments — 15 59 — 74 Post-retirement benefit obligation — 5 13 — 18 Total other comprehensive (loss) income — 19 83 — 102 Equity in other comprehensive income of subsidiaries, net of tax 102 73 — (175 ) — Less: Other comprehensive income attributable to noncontrolling interests — — — — — Total other comprehensive income attributable to Aon shareholders 102 92 83 (175 ) 102 Comprehensive income attributable to Aon Shareholders $ 406 $ 312 $ 649 $ (961 ) $ 406 Condensed Consolidating Statement of Comprehensive Income Six months ended June 30, 2015 Other Aon Aon Non-Guarantor Consolidating (millions) plc Corporation Subsidiaries Adjustments Consolidated Net income $ 506 $ 366 $ 1,096 $ (1,439 ) $ 529 Less: Net income attributable to noncontrolling interests — — 23 — 23 Net income attributable to Aon shareholders $ 506 $ 366 $ 1,073 $ (1,439 ) $ 506 Other comprehensive (loss) income, net of tax: Change in fair value of financial instruments — 1 (2 ) — (1 ) Foreign currency translation adjustments — (19 ) (128 ) — (147 ) Post-retirement benefit obligation — 17 27 — 44 Total other comprehensive loss — (1 ) (103 ) — (104 ) Equity in other comprehensive loss of subsidiaries, net of tax (102 ) (94 ) (95 ) 291 — Less: Other comprehensive income attributable to noncontrolling interests — — (2 ) — (2 ) Total other comprehensive loss attributable to Aon shareholders (102 ) (95 ) (196 ) 291 (102 ) Comprehensive income attributable to Aon shareholders $ 404 $ 271 $ 877 $ (1,148 ) $ 404 Condensed Consolidating Statement of Comprehensive Income Six months ended June 30, 2014 Other Aon Aon Non-Guarantor Consolidating (millions) plc Corporation Subsidiaries Adjustments Consolidated Net income $ 629 $ 475 $ 1,237 $ (1,692 ) $ 649 Less: Net income attributable to noncontrolling interests — — 20 — 20 Net income attributable to Aon shareholders $ 629 $ 475 $ 1,217 $ (1,692 ) $ 629 Other comprehensive (loss) income, net of tax: Change in fair value of financial instruments — — 20 — 20 Foreign currency translation adjustments — (2 ) 92 — 90 Post-retirement benefit obligation — 11 33 — 44 Total other comprehensive loss — 9 145 — 154 Equity in other comprehensive loss of subsidiaries, net of tax 156 142 — (298 ) — Less: Other comprehensive income attributable to noncontrolling interests — — (2 ) — (2 ) Total other comprehensive loss attributable to Aon shareholders 156 151 147 (298 ) 156 Comprehensive income attributable to Aon shareholders $ 785 $ 626 $ 1,364 $ (1,990 ) $ 785 Condensed Consolidating Statement of Financial Position As of June 30, 2015 Other Aon Aon Non-Guarantor Consolidating (millions) plc Corporation Subsidiaries Adjustments Consolidated ASSETS Cash and cash equivalents $ — $ 2,221 $ 707 $ (2,561 ) $ 367 Short-term investments — 125 359 — 484 Receivables, net — — 2,684 — 2,684 Fiduciary assets — — 11,389 — 11,389 Intercompany receivables 258 3,847 10,286 (14,391 ) — Other current assets 2 223 538 (32 ) 731 Total Current Assets 260 6,416 25,963 (16,984 ) 15,655 Goodwill — — 8,661 — 8,661 Intangible assets, net — — 2,350 — 2,350 Fixed assets, net — — 782 — 782 Intercompany receivables 7,379 581 1,621 (9,581 ) — Other non-current assets 189 693 1,656 (783 ) 1,755 Investment in subsidiary 4,488 15,799 542 (20,829 ) — TOTAL ASSETS $ 12,316 $ 23,489 $ 41,575 $ (48,177 ) $ 29,203 LIABILITIES AND EQUITY Fiduciary liabilities $ — $ — $ 11,389 $ — $ 11,389 Short-term debt and current portion of long-term debt — 1,225 12 — 1,237 Accounts payable and accrued liabilities 2,597 49 1,283 (2,561 ) 1,368 Intercompany payables 223 9,975 4,194 (14,392 ) — Other current liabilities — 55 822 (32 ) 845 Total Current Liabilities 2,820 11,304 17,700 (16,985 ) 14,839 Long-term debt 3,092 1,418 314 — 4,824 Pension, other post-retirement and other post-employment liabilities — 1,336 608 — 1,944 Intercompany payables — 8,787 794 (9,581 ) — Other non-current liabilities 6 102 1,814 (782 ) 1,140 TOTAL LIABILITIES 5,918 22,947 21,230 (27,348 ) 22,747 TOTAL AON SHAREHOLDERS' EQUITY 6,398 542 20,287 (20,829 ) 6,398 Noncontrolling interests — — 58 — 58 TOTAL EQUITY 6,398 542 20,345 (20,829 ) 6,456 TOTAL LIABILITIES AND EQUITY $ 12,316 $ 23,489 $ 41,575 $ (48,177 ) $ 29,203 Condensed Consolidating Statement of Financial Position As of December 31, 2014 Other Aon Aon Non-Guarantor Consolidating (millions) plc Corporation Subsidiaries Adjustments Consolidated ASSETS Cash and cash equivalents $ — $ 2,727 $ 1,361 $ (3,714 ) $ 374 Short-term investments — 165 229 — 394 Receivables, net — — 2,815 — 2,815 Fiduciary assets — — 11,638 — 11,638 Intercompany receivables 455 2,814 9,156 (12,425 ) — Other current assets 2 226 407 (33 ) 602 Total Current Assets 457 5,932 25,606 (16,172 ) 15,823 Goodwill — — 8,860 — 8,860 Intangible assets, net — — 2,520 — 2,520 Fixed assets, net — — 765 — 765 Intercompany receivables 7,399 600 111 (8,110 ) — Other non-current assets 179 697 1,718 (790 ) 1,804 Investment in subsidiary 4,962 15,200 1,880 (22,042 ) — TOTAL ASSETS $ 12,997 $ 22,429 $ 41,460 $ (47,114 ) $ 29,772 LIABILITIES AND EQUITY Fiduciary liabilities $ — $ — $ 11,638 $ — $ 11,638 Short-term debt and current portion of long-term debt — 767 16 — 783 Accounts payable and accrued liabilities 3,755 58 1,706 (3,714 ) 1,805 Intercompany payables 122 8,960 3,343 (12,425 ) — Other current liabilities — 49 772 (33 ) 788 Total Current Liabilities 3,877 9,834 17,475 (16,172 ) 15,014 Long-term debt 2,544 1,917 338 — 4,799 Pension, other post-retirement and other post-employment liabilities — 1,396 745 — 2,141 Intercompany payables — 7,277 833 (8,110 ) — Other non-current liabilities 5 125 1,847 (790 ) 1,187 TOTAL LIABILITIES 6,426 20,549 21,238 (25,072 ) 23,141 TOTAL AON SHAREHOLDERS' EQUITY 6,571 1,880 20,162 (22,042 ) 6,571 Noncontrolling interests — — 60 — 60 TOTAL EQUITY 6,571 1,880 20,222 (22,042 ) 6,631 TOTAL LIABILITIES AND EQUITY $ 12,997 $ 22,429 $ 41,460 $ (47,114 ) $ 29,772 Condensed Consolidating Statement of Cash Flows Six months ended June 30, 2015 Aon Aon Other Non-Guarantor Consolidating (millions) plc Corporation Subsidiaries Adjustments Consolidated CASH FLOWS FROM OPERATING ACTIVITIES CASH PROVIDED BY (USED FOR) OPERATING ACTIVITIES $ (120 ) $ (368 ) $ 853 $ — $ 365 CASH FLOWS FROM INVESTING ACTIVITIES Sales of long-term investments — — 10 — 10 Purchase of long-term investments — (1 ) — — (1 ) Net sales of short-term investments - non-fiduciary — 41 (138 ) — (97 ) Acquisition of businesses, net of cash acquired — — (23 ) — (23 ) Proceeds from sale of businesses — — 52 — 52 Capital expenditures — — (142 ) — (142 ) CASH PROVIDED BY (USED FOR) INVESTING ACTIVITIES — 40 (241 ) — (201 ) CASH FLOWS FROM FINANCING ACTIVITIES Share repurchase (550 ) — — — (550 ) Advances from (to) affiliates 172 (134 ) (1,191 ) 1,153 — Issuance of shares for employee benefit plans 52 — — — 52 Issuance of debt 712 1,732 1 — 2,445 Repayment of debt (110 ) (1,776 ) (10 ) — (1,896 ) Cash dividends to shareholders (156 ) — — — (156 ) Purchase of shares from noncontrolling interests — — (5 ) — (5 ) Dividends paid to noncontrolling interests — — (18 ) — (18 ) CASH (USED FOR) PROVIDED BY FINANCING ACTIVITIES 120 (178 ) (1,223 ) 1,153 (128 ) EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS — — (43 ) — (43 ) NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS — (506 ) (654 ) 1,153 (7 ) CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR — 2,727 1,361 (3,714 ) 374 CASH AND CASH EQUIVALENTS AT END OF PERIOD $ — $ 2,221 $ 707 $ (2,561 ) $ 367 Condensed Consolidating Statement of Cash Flows Six months ended June 30, 2014 Other Aon Aon Non-Guarantor Consolidating (millions) plc Corporation Subsidiaries Adjustments Consolidated CASH FLOWS FROM OPERATING ACTIVITIES CASH PROVIDED BY (USED FOR) OPERATING ACTIVITIES $ 265 $ (215 ) $ 283 $ — $ 333 CASH FLOWS FROM INVESTING ACTIVITIES Sales of long-term investments — 37 11 — 48 Purchase of long-term investments — (14 ) — — (14 ) Net sales of short-term investments - non-fiduciary — 27 190 — 217 Acquisition of businesses, net of cash acquired — — (83 ) — (83 ) Proceeds from sale of businesses — — 1 — 1 Capital expenditures — — (115 ) — (115 ) CASH PROVIDED BY INVESTING ACTIVITIES — 50 4 — 54 CASH FLOWS FROM FINANCING ACTIVITIES Share repurchase (1,250 ) — — — (1,250 ) Advances from (to) affiliates (522 ) 99 586 (163 ) — Issuance of shares for employee benefit plans 40 — — — 40 Issuance of debt 2,169 1,161 (6 ) — 3,324 Repayment of debt (574 ) (1,161 ) (10 ) — (1,745 ) Deposit with trustee — — (681 ) — (681 ) Cash dividends to shareholders (128 ) — — — (128 ) Purchase of shares from noncontrolling interests — — 1 — 1 Dividends paid to noncontrolling interests — — (10 ) — (10 ) CASH (USED FOR) PROVIDED BY FINANCING ACTIVITIES (265 ) 99 (120 ) (163 ) (449 ) EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS — — 3 — 3 NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS — (66 ) 170 (163 ) (59 ) CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR — 247 1,246 (1,016 ) 477 CASH AND CASH EQUIVALENTS AT END OF PERIOD $ — $ 181 $ 1,416 $ (1,179 ) $ 418

Other Financial Data (Tables)

Other Financial Data (Tables)	6 Months Ended
	Jun. 30, 2015
Other Financial Data [Abstract]
Schedule of Other Income (Expense)	Other income (expense) consists of the following (in millions): Three months ended June 30, Six months ended June 30, 2015 2014 2015 2014 Foreign currency remeasurement (loss) gain (7 ) (15 ) $ 17 $ 4 Gain on disposal of business 1 — 20 — Equity earnings 4 1 6 6 Income (loss) on financial instruments 3 9 — (15 ) Other — 3 — 4 Total $ 1 $ (2 ) $ 43 $ (1 )
Schedule of Allowance for Doubtful Accounts	An analysis of the allowance for doubtful accounts is as follows (in millions): Three months ended June 30, Six months ended June 30, 2015 2014 2015 2014 Balance at beginning of period $ 70 $ 89 $ 74 $ 90 Provision charged to operations 3 4 11 8 Accounts written off, net of recoveries (13 ) (4 ) (22 ) (9 ) Foreign currency translation 5 (1 ) 2 (1 ) Balance at end of period $ 65 $ 88 $ 65 $ 88
Schedule of Other Current Assets	The components of Other current assets are as follows (in millions): June 30, 2015 December 31, 2014 Taxes receivable $ 220 $ 99 Deferred tax assets 204 212 Prepaid expenses 175 164 Deferred project costs 106 102 Other 26 25 Total $ 731 $ 602
Schedule of Other Non-current Assets	The components of Other non-current assets are as follows (in millions): June 30, 2015 December 31, 2014 Prepaid pension $ 953 $ 933 Deferred project costs 232 250 Deferred tax assets 164 144 Investments 142 143 Taxes receivable 63 101 Other 201 233 Total $ 1,755 $ 1,804
Schedule of Other Current Liabilities	The components of Other current liabilities are as follows (in millions): June 30, 2015 December 31, 2014 Deferred revenue $ 425 $ 408 Taxes payable 24 64 Deferred tax liabilities 2 2 Other 394 314 Total $ 845 $ 788
Schedule of Other Non-current Liabilities	The components of Other non-current liabilities are as follows (in millions): June 30, 2015 December 31, 2014 Deferred tax liabilities $ 322 $ 313 Taxes payable 208 210 Deferred revenue 187 167 Leases 167 184 Compensation and benefits 54 57 Other 202 256 Total $ 1,140 $ 1,187

Acquisitions and Dispositions (

Acquisitions and Dispositions (Tables)	6 Months Ended
	Jun. 30, 2015
Business Combinations [Abstract]
Consideration transferred and preliminary value of intangible assets	The following table includes the aggregate consideration transferred and the preliminary value of intangible assets recorded as a result of the Company's acquisitions (in millions): Six months ended June 30, 2015 2014 Consideration $ 23 $ 83 Intangible assets: Goodwill $ 16 $ 52 Other intangible assets 1 48 Total $ 17 $ 100

Goodwill and Other Intangible26

Goodwill and Other Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of changes in the net carrying amount of goodwill by operating segment	The changes in the net carrying amount of goodwill by reportable segment for the six months ended June 30, 2015 are as follows (in millions): Risk Solutions HR Solutions Total Balance as of January 1, 2015 $ 5,911 $ 2,949 $ 8,860 Goodwill related to current year acquisitions 1 15 16 Goodwill related to disposals — (13 ) (13 ) Goodwill related to prior year acquisitions (1 ) — (1 ) Foreign currency translation (189 ) (12 ) (201 ) Balance as of June 30, 2015 $ 5,722 $ 2,939 $ 8,661
Schedule of other intangible assets by asset class	Other intangible assets by asset class are as follows (in millions): June 30, 2015 December 31, 2014 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Intangible assets with indefinite lives: Tradenames $ 1,019 $ — $ 1,019 $ 1,019 $ — $ 1,019 Intangible assets with finite lives: Customer related and contract based 2,930 1,706 1,224 2,952 1,579 1,373 Technology and other 552 445 107 571 443 128 Total $ 4,501 $ 2,151 $ 2,350 $ 4,542 $ 2,022 $ 2,520
Schedule of estimated future amortization expense on intangible assets	The estimated future amortization for finite lived intangible assets as of June 30, 2015 is as follows (in millions): Risk Solutions HR Solutions Total Remainder of 2015 $ 56 $ 103 $ 159 2016 104 172 276 2017 93 138 231 2018 78 92 170 2019 68 73 141 Thereafter 188 166 354 Total $ 587 $ 744 $ 1,331

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	6 Months Ended
	Jun. 30, 2015
Equity [Abstract]
Schedule of components of weighted average number of shares	Weighted average shares outstanding are as follows (in millions): Three months ended June 30, Six months ended June 30, 2015 2014 2015 2014 Shares for basic earnings per share 284.5 298.5 284.3 301.0 Common stock equivalents 2.2 3.1 2.6 3.4 Shares for diluted earnings per share 286.7 301.6 286.9 304.4
Components of Accumulated other comprehensive loss, net of related tax	Changes in Accumulated other comprehensive loss by component, net of related tax, are as follows (in millions): Change in Fair Value of Financial Instruments (1) Foreign Currency Translation Adjustments Post-Retirement Benefit Obligation (2) Total Balance at December 31, 2014 $ (17 ) $ (335 ) $ (2,782 ) $ (3,134 ) Other comprehensive income (loss) before reclassifications, net 5 (145 ) 3 (137 ) Amounts reclassified from accumulated other comprehensive loss: Amounts reclassified from accumulated other comprehensive loss 11 — 59 70 Tax benefit (17 ) — (18 ) (35 ) Amounts reclassified from accumulated other comprehensive loss, net (6 ) — 41 35 Net current period other comprehensive (loss) income (1 ) (145 ) 44 (102 ) Balance at June 30, 2015 $ (18 ) $ (480 ) $ (2,738 ) $ (3,236 ) ______________________________________________ (1) Reclassifications from this category included in Accumulated other comprehensive loss are recorded in Other income (expense) . (2) Reclassifications from this category included in Accumulated other comprehensive loss are recorded in Compensation and benefits

Employee Benefits (Tables)

Employee Benefits (Tables)	6 Months Ended
	Jun. 30, 2015
Compensation and Retirement Disclosure [Abstract]
Components of net periodic benefit cost for the pension plans	The following table provides the components of the net periodic (benefit) cost recognized in the Condensed Consolidated Statements of Income in Compensation and benefits for Aon's material U.K., U.S., and other significant international pension plans located in the Netherlands and Canada (in millions): Three months ended June 30, U.K. U.S. Other 2015 2014 2015 2014 2015 2014 Service cost $ — $ — $ 1 $ — $ — $ — Interest cost 50 58 33 32 9 12 Expected return on plan assets (77 ) (83 ) (38 ) (39 ) (13 ) (15 ) Amortization of net actuarial loss 10 14 13 11 3 2 Net periodic (benefit) cost (17 ) (11 ) 9 4 (1 ) (1 ) Curtailment loss (gain) and other — — — — — — Total net periodic (benefit) cost $ (17 ) $ (11 ) $ 9 $ 4 $ (1 ) $ (1 ) Six months ended June 30, U.K. U.S. Other 2015 2014 2015 2014 2015 2014 Service cost $ — $ — $ 2 $ — $ — $ — Interest cost 99 116 66 64 17 24 Expected return on plan assets (152 ) (165 ) (77 ) (78 ) (25 ) (30 ) Amortization of net actuarial loss 20 27 27 21 6 4 Net periodic (benefit) cost (33 ) (22 ) 18 7 (2 ) (2 ) Curtailment loss (gain) and other — — (1 ) 1 — (3 ) Total net periodic (benefit) cost $ (33 ) $ (22 ) $ 17 $ 8 $ (2 ) $ (5 )

Share-Based Compensation Plans

Share-Based Compensation Plans (Tables)	6 Months Ended
	Jun. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-based compensation expense recognized in continuing operations	The following table summarizes share-based compensation expense recognized in the Condensed Consolidated Statements of Income in Compensation and benefits (in millions): Three months ended June 30, Six months ended June 30, 2015 2014 2015 2014 Restricted share units ("RSUs") $ 44 $ 43 $ 109 $ 103 Performance share awards ("PSAs") 28 28 49 67 Share options — — — — Employee share purchase plans 2 2 6 5 Total share-based compensation expense $ 74 $ 73 $ 164 $ 175
Restricted share unit activity	A summary of the status of the Company's RSUs is as follows (shares in thousands): Six months ended June 30, 2015 2014 Shares Fair Value (1) Shares Fair Value (1) Non-vested at beginning of period 8,381 $ 63 9,759 $ 51 Granted 2,144 98 2,498 84 Vested (3,037 ) 58 (3,320 ) 49 Forfeited (130 ) 67 (221 ) 54 Non-vested at end of period 7,358 76 8,716 61 ______________________________________________ (1) Represents per share weighted average fair value of award at date of grant.
Performance-based plans	Information as of June 30, 2015 regarding the Company's target PSAs granted and shares that would be issued at current performance levels for PSAs granted during the six months ended June 30, 2015 and the years ended December 31, 2014 and 2013 , respectively, is as follows (shares in thousands, dollars in millions, except fair value): 2015 2014 2013 Target PSAs granted during period 993 816 1,135 Weighted average fair value per share at date of grant $ 96 $ 81 $ 58 Number of shares that would be issued based on current performance levels 992 1,201 2,197 Unamortized expense, based on current performance levels $ 85 $ 52 $ 23
Share options and related information	A summary of the status of the Company's share options and related information is as follows (shares in thousands): Six months ended June 30, 2015 2014 Shares Weighted- Average Exercise Price Shares Weighted- Average Exercise Price Beginning outstanding 2,300 $ 32 3,462 $ 32 Granted — — — — Exercised (1,388 ) 27 (839 ) 32 Forfeited and expired (13 ) 39 (3 ) 37 Outstanding at end of period 899 39 2,620 32 Exercisable at end of period 899 39 2,572 32
Other information related to the company's share options	Other information related to the Company's share options is as follows (in millions): Three months ended June 30, Six months ended June 30, 2015 2014 2015 2014 Aggregate intrinsic value of stock options exercised $ 6 $ 24 $ 100 $ 45 Cash received from the exercise of stock options 4 13 38 27 Tax benefit realized from the exercise of stock options 1 6 35 12

Derivatives and Hedging (Tables

Derivatives and Hedging (Tables)	6 Months Ended
	Jun. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Notional and fair values of derivative instruments	The notional and fair values of derivative instruments are as follows (in millions): Notional Amount Derivative Assets (1) Derivative Liabilities (2) June 30, December 31, June 30, December 31, June 30, December 31, Derivatives accounted for as hedges: Interest rate contracts $ — $ — $ — $ — $ — $ — Foreign exchange contracts 998 1,200 54 46 57 58 Total 998 1,200 54 46 57 58 Derivatives not accounted for as hedges: Foreign exchange contracts (3) 167 165 — — — — Total $ 1,165 $ 1,365 $ 54 $ 46 $ 57 $ 58 ______________________________________________ (1) Included within Other current assets ( $28 million at June 30, 2015 and $24 million at December 31, 2014 ) or Other non-current assets ( $26 million at June 30, 2015 and $22 million at December 31, 2014 ). (2) Included within Other current liabilities ( $47 million at June 30, 2015 and $52 million at December 31, 2014 ) or Other non-current liabilities ( $10 million at June 30, 2015 and $6 million at December 31, 2014 ). (3) These contracts typically are for 30 day durations and executed close to the last day of the most recent reporting month, thereby resulting in nominal fair values at the balance sheet date. Offsetting of financial assets and derivatives assets are as follows (in millions): Gross Amounts of Recognized Assets Gross Amounts Offset in the Statement of Financial Position Net Amounts of Assets Presented in the Statement of Financial Position (1) June 30, December 31, June 30, December 31, June 30, December 31, Derivatives accounted for as hedges: Interest rate contracts $ — $ — $ — $ — $ — $ — Foreign exchange contracts 54 46 (20 ) (14 ) 34 32 Total 54 46 (20 ) (14 ) 34 32 Derivatives not accounted for as hedges: Foreign exchange contracts — — — — — — Total $ 54 $ 46 $ (20 ) $ (14 ) $ 34 $ 32 ______________________________________________ (1) Included within Other current assets ( $17 million at June 30, 2015 and $12 million at December 31, 2014 ) or Other non-current assets ( $17 million at June 30, 2015 and $20 million at December 31, 2014 ). Offsetting of financial liabilities and derivative liabilities are as follows (in millions): Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Statement of Financial Position Net Amounts of Liabilities Presented in the Statement of Financial Position (1) June 30, December 31, June 30, December 31, June 30, December 31, Derivatives accounted for as hedges: Interest rate contracts $ — $ — $ — $ — $ — $ — Foreign exchange contracts 57 58 (20 ) (14 ) 37 44 Total 57 58 (20 ) (14 ) 37 44 Derivatives not accounted for as hedges: Foreign exchange contracts — — — — — — Total $ 57 $ 58 $ (20 ) $ (14 ) $ 37 $ 44 ______________________________________________ (1) Included within Other current liabilities ( $36 million at June 30, 2015 and $40 million at December 31, 2014 ) or Other non-current liabilities ( $1 million at June 30, 2015 and $4 million at December 31, 2014 )
Derivative gains (losses)	The amounts of derivative gains (losses) recognized in the Condensed Consolidated Financial Statements for the three and six months ended June 30, 2015 and 2014 are as follows (in millions): Three Months Ended June 30, 2015 Location of future reclassification from Accumulated Other Comprehensive Loss Gain (Loss) recognized in Accumulated Other Comprehensive Loss: Compensation and Benefits Other General Expenses Interest Expense Other Income (Expense) Total Cash flow hedges: Interest rate contracts $ — $ — $ — $ — $ — Foreign exchange contracts 1 3 — 10 14 Total $ 1 $ 3 $ — $ 10 $ 14 Three Months Ended June 30, 2014 Location of future reclassification from Accumulated Other Comprehensive Loss Gain (Loss) recognized in Accumulated Other Comprehensive Loss: Compensation and Benefits Other General Expenses Interest Expense Other Income (Expense) Total Cash flow hedges: Interest rate contracts $ — $ — $ — $ — $ — Foreign exchange contracts 5 — — 10 15 Total $ 5 $ — $ — $ 10 $ 15 Six Months Ended June 30, 2015 Location of future reclassification from Accumulated Other Comprehensive Loss Gain (Loss) recognized in Accumulated Other Comprehensive Loss: Compensation and Benefits Other General Expenses Interest Expense Other Income (Expense) Total Cash flow hedges: Interest rate contracts $ — $ — $ — $ — $ — Foreign exchange contracts 6 1 — 6 13 Total $ 6 $ 1 $ — $ 6 $ 13 Six Months Ended June 30, 2014 Location of future reclassification from Accumulated Other Comprehensive Loss Gain (Loss) recognized in Accumulated Other Comprehensive Loss: Compensation and Benefits Other General Expenses Interest Expense Other Income (Expense) Total Cash flow hedges: Interest rate contracts $ — $ — $ — $ — $ — Foreign exchange contracts 16 — — (9 ) 7 Total $ 16 $ — $ — $ (9 ) $ 7 Three Months Ended June 30, 2015 Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion): Compensation and Benefits Other General Expenses Interest Expense Other Income (Expense) Total Cash flow hedges: Interest rate contracts $ — $ — $ — $ — Foreign exchange contracts 1 (1 ) (2 ) 5 3 Total $ 1 $ (1 ) $ (2 ) $ 5 $ 3 Three Months Ended June 30, 2014 Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion): Compensation and Benefits Other General Expenses Interest Expense Other Income (Expense) Total Cash flow hedges: Interest rate contracts $ — $ — $ — $ — $ — Foreign exchange contracts — — (3 ) 5 2 Total $ — $ — $ (3 ) $ 5 $ 2 Six Months Ended June 30, 2015 Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion): Compensation and Benefits Other General Expenses Interest Expense Other Income (Expense) Total Cash flow hedges: Interest rate contracts $ — $ — $ (1 ) $ — $ (1 ) Foreign exchange contracts 1 (1 ) (4 ) (3 ) (7 ) Total $ 1 $ (1 ) $ (5 ) $ (3 ) $ (8 ) Six Months Ended June 30, 2014 Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion): Compensation and Benefits Other General Expenses Interest Expense Other Income (Expense) Total Cash flow hedges: Interest rate contracts $ — $ — $ (1 ) $ — $ (1 ) Foreign exchange contracts (2 ) — (5 ) (12 ) (19 ) Total $ (2 ) $ — $ (6 ) $ (12 ) $ (20 )

Fair Value Measurements and F31

Fair Value Measurements and Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2015
Fair Value Disclosures [Abstract]
Schedule of assets and liabilities that are measured at fair value on a recurring basis	The following tables present the categorization of the Company's assets and liabilities that are measured at fair value on a recurring basis at June 30, 2015 and December 31, 2014 (in millions): Fair Value Measurements Using Balance at June 30, 2015 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Money market funds and highly liquid debt securities (1) $ 1,895 $ 1,895 $ — $ — Other investments: Corporate bonds 1 — — 1 Government bonds 6 — 6 — Equity investments 10 6 4 — Derivatives: Interest rate contracts — — — — Foreign exchange contracts 54 — 54 — Liabilities: Derivatives: Foreign exchange contracts 57 — 57 — ______________________________________________ (1) Includes $ 1,895 million of money market funds that are classified as Fiduciary assets, Short-term investments or Cash and cash equivalents in the Condensed Consolidated Statements of Financial Position, depending on their nature and initial maturity. Fair Value Measurements Using Balance at December 31, 2014 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Money market funds and highly liquid debt securities (1) $ 1,850 $ 1,850 $ — $ — Other investments: Corporate bonds 1 — — 1 Government bonds 6 — 6 — Equity investments 11 6 5 — Derivatives: Interest rate contracts — — — — Foreign exchange contracts 46 — 46 — Liabilities: Derivatives: Foreign exchange contracts 58 — 58 — ______________________________________________ (1) Includes $1,850 million of money market funds that are classified as Fiduciary assets, Short-term investments or Cash and cash equivalents in the Condensed Consolidated Statements of Financial Position, depending on their nature and initial maturity.
Schedule of financial instruments where the carrying amounts and fair values differ	The fair value of Long-term debt is classified as Level 2 of the fair value hierarchy. The following table discloses the Company's financial instruments where the carrying amounts and fair values differ (in millions): June 30, 2015 December 31, 2014 Carrying Value Fair Value Carrying Value Fair Value Long-term debt $ 4,824 $ 5,060 $ 4,799 $ 5,268

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
	Jun. 30, 2015
Segment Reporting [Abstract]
Schedule of total revenue by business segments	Aon's total revenue is as follows (in millions): Three months ended June 30, Six months ended June 30, 2015 2014 2015 2014 Risk Solutions $ 1,833 $ 1,948 $ 3,728 $ 3,942 HR Solutions 979 982 1,949 1,947 Intersegment eliminations (7 ) (11 ) (25 ) (23 ) Total revenue $ 2,805 $ 2,919 $ 5,652 $ 5,866
Schedule of commissions, fees and other revenues by products	Commissions, fees and other revenues by product are as follows (in millions): Three months ended June 30, Six months ended June 30, 2015 2014 2015 2014 Retail brokerage $ 1,498 $ 1,582 $ 3,011 $ 3,161 Reinsurance brokerage 330 360 707 769 Total Risk Solutions Segment 1,828 1,942 3,718 3,930 Consulting services 391 395 762 779 Outsourcing 599 595 1,203 1,184 Intrasegment (11 ) (8 ) (16 ) (16 ) Total HR Solutions Segment 979 982 1,949 1,947 Intersegment (7 ) (11 ) (25 ) (23 ) Total commissions, fees and other revenue $ 2,800 $ 2,913 $ 5,642 $ 5,854
Schedule of fiduciary investment income by business segments	Fiduciary investment income by segment is as follows (in millions): Three months ended June 30, Six months ended June 30, 2015 2014 2015 2014 Risk Solutions $ 5 $ 6 $ 10 $ 12 HR Solutions — — — — Total fiduciary investment income $ 5 $ 6 $ 10 $ 12
Schedule of reconciliation of segment income before tax to income from continuing operations before income taxes	A reconciliation of segment operating income before tax to income before income taxes is as follows (in millions): Three months ended June 30, Six months ended June 30, 2015 2014 2015 2014 Risk Solutions $ 279 $ 417 $ 691 $ 862 HR Solutions 39 69 115 136 Segment income before income taxes 318 486 806 998 Unallocated expenses (41 ) (41 ) (88 ) (84 ) Interest income 4 2 7 4 Interest expense (68 ) (65 ) (133 ) (123 ) Other income (expense) 1 (2 ) 43 (1 ) Income before income taxes $ 214 $ 380 $ 635 $ 794

Guarantee of Registered Secur33

Guarantee of Registered Securities (Tables)	6 Months Ended
	Jun. 30, 2015
Guarantee of Registered Securities [Abstract]
Condensed Consolidating Statements of Income	Condensed Consolidating Statement of Income Three months ended June 30, 2015 Other Aon Aon Non-Guarantor Consolidating (millions) plc Corporation Subsidiaries Adjustments Consolidated Revenue Commissions, fees and other $ — $ — $ 2,800 $ — $ 2,800 Fiduciary investment income — — 5 — 5 Total revenue — — 2,805 — 2,805 Expenses Compensation and benefits 5 10 1,638 — 1,653 Other general expenses (4 ) 2 877 — 875 Total operating expenses 1 12 2,515 — 2,528 Operating (loss) income (1 ) (12 ) 290 — 277 Interest income (5 ) 4 5 — 4 Interest expense (29 ) (33 ) (6 ) — (68 ) Intercompany interest income (expense) 119 (116 ) (3 ) — — Intercompany other (expense) income (56 ) (15 ) 71 — — Other income (1 ) — 2 — 1 (Loss) income before taxes 27 (172 ) 359 — 214 Income tax (benefit) expense 6 (66 ) 86 — 26 (Loss) income before equity in earnings of subsidiaries 21 (106 ) 273 — 188 Equity in earnings of subsidiaries, net of tax 157 170 64 (391 ) — Net income 178 64 337 (391 ) 188 Less: Net income attributable to noncontrolling interests — — 10 — 10 Net income attributable to Aon shareholders $ 178 $ 64 $ 327 $ (391 ) $ 178 Condensed Consolidating Statement of Income Three months ended June 30, 2014 Other Aon Aon Non-Guarantor Consolidating (millions) plc Corporation Subsidiaries Adjustments Consolidated Revenue Commissions, fees and other $ — $ — $ 2,913 $ — $ 2,913 Fiduciary investment income — — 6 — 6 Total revenue — — 2,919 — 2,919 Expenses Compensation and benefits 6 6 1,696 — 1,708 Other general expenses 1 3 762 — 766 Total operating expenses 7 9 2,458 — 2,474 Operating (loss) income (7 ) (9 ) 461 — 445 Interest income (2 ) — 4 — 2 Interest expense (15 ) (32 ) (18 ) — (65 ) Intercompany interest income (expense) 111 (73 ) (38 ) — — Intercompany other (expense) income (54 ) (4 ) 58 — — Other income (1 ) 8 (9 ) — (2 ) Income (loss) before taxes 32 (110 ) 458 — 380 Income tax expense (benefit) 6 (42 ) 103 — 67 Income (loss) before equity in earnings of subsidiaries 26 (68 ) 355 — 313 Equity in earnings of subsidiaries, net of tax 278 288 220 (786 ) — Net income 304 220 575 (786 ) 313 Less: Net income attributable to noncontrolling interests — — 9 — 9 Net income attributable to Aon shareholders $ 304 $ 220 $ 566 $ (786 ) $ 304 Condensed Consolidating Statement of Income Six months ended June 30, 2015 Other Aon Aon Non-Guarantor Consolidating (millions) plc Corporation Subsidiaries Adjustments Consolidated Revenue Commissions, fees and other $ — $ — $ 5,642 $ — $ 5,642 Fiduciary investment income — — 10 — 10 Total revenue — — 5,652 — 5,652 Expenses Compensation and benefits 57 21 3,258 — 3,336 Other general expenses 9 4 1,585 — 1,598 Total operating expenses 66 25 4,843 — 4,934 Operating (loss) income (66 ) (25 ) 809 — 718 Interest income (9 ) 7 9 — 7 Interest expense (54 ) (68 ) (11 ) — (133 ) Intercompany interest income (expense) 239 (221 ) (18 ) — — Intercompany other (expense) income (106 ) (23 ) 129 — — Other income 1 8 34 — 43 (Loss) income before taxes 5 (322 ) 952 — 635 Income tax (benefit) expense 1 (117 ) 222 — 106 (Loss) income before equity in earnings of subsidiaries 4 (205 ) 730 — 529 Equity in earnings of subsidiaries, net of tax 502 571 366 (1,439 ) — Net income 506 366 1,096 (1,439 ) 529 Less: Net income attributable to noncontrolling interests — — 23 — 23 Net income attributable to Aon shareholders $ 506 $ 366 $ 1,073 $ (1,439 ) $ 506 Condensed Consolidating Statement of Income Six months ended June 30, 2014 Other Aon Aon Non-Guarantor Consolidating (millions) plc Corporation Subsidiaries Adjustments Consolidated Revenue Commissions, fees and other $ — $ — $ 5,854 $ — $ 5,854 Fiduciary investment income — — 12 — 12 Total revenue — — 5,866 — 5,866 Expenses Compensation and benefits 72 13 3,374 — 3,459 Other general expenses 6 5 1,482 — 1,493 Total operating expenses 78 18 4,856 — 4,952 Operating (loss) income (78 ) (18 ) 1,010 — 914 Interest income (4 ) 1 7 — 4 Interest expense (25 ) (63 ) (35 ) — (123 ) Intercompany interest income (expense) 222 (147 ) (75 ) — — Intercompany other (expense) income (72 ) (19 ) 91 — — Other income (1 ) 8 (8 ) — (1 ) (Loss) income before taxes 42 (238 ) 990 — 794 Income tax (benefit) expense 9 (92 ) 228 — 145 (Loss) income before equity in earnings of subsidiaries 33 (146 ) 762 — 649 Equity in earnings of subsidiaries, net of tax 596 621 475 (1,692 ) — Net income 629 475 1,237 (1,692 ) 649 Less: Net income attributable to noncontrolling interests — — 20 — 20 Net income attributable to Aon shareholders $ 629 $ 475 $ 1,217 $ (1,692 ) $ 629
Condensed Consolidating Statements of Comprehensive Income	Condensed Consolidating Statement of Comprehensive Income Three months ended June 30, 2015 Other Aon Aon Non-Guarantor Consolidating (millions) plc Corporation Subsidiaries Adjustments Consolidated Net income $ 178 $ 64 $ 337 $ (391 ) $ 188 Less: Net income attributable to noncontrolling interests — — 10 — 10 Net income attributable to Aon shareholders $ 178 $ 64 $ 327 $ (391 ) $ 178 Other comprehensive (loss) income, net of tax: Change in fair value of financial instruments — 2 (8 ) — (6 ) Foreign currency translation adjustments — 4 171 — 175 Post-retirement benefit obligation — 9 12 — 21 Total other comprehensive loss — 15 175 — 190 Equity in other comprehensive loss of subsidiaries, net of tax 191 173 188 (552 ) — Less: Other comprehensive income attributable to noncontrolling interests — — (1 ) — (1 ) Total other comprehensive loss attributable to Aon shareholders 191 188 364 (552 ) 191 Comprehensive income attributable to Aon shareholders $ 369 $ 252 $ 691 $ (943 ) $ 369 Condensed Consolidating Statement of Comprehensive Income Three months ended June 30, 2014 Other Aon Aon Non-Guarantor Consolidating (millions) plc Corporation Subsidiaries Adjustments Consolidated Net income $ 304 $ 220 $ 575 $ (786 ) $ 313 Less: Net income attributable to noncontrolling interests — — 9 — 9 Net income attributable to Aon shareholders $ 304 $ 220 $ 566 $ (786 ) $ 304 Other comprehensive income (loss), net of tax: Change in fair value of financial instruments — (1 ) 11 — 10 Foreign currency translation adjustments — 15 59 — 74 Post-retirement benefit obligation — 5 13 — 18 Total other comprehensive (loss) income — 19 83 — 102 Equity in other comprehensive income of subsidiaries, net of tax 102 73 — (175 ) — Less: Other comprehensive income attributable to noncontrolling interests — — — — — Total other comprehensive income attributable to Aon shareholders 102 92 83 (175 ) 102 Comprehensive income attributable to Aon Shareholders $ 406 $ 312 $ 649 $ (961 ) $ 406 Condensed Consolidating Statement of Comprehensive Income Six months ended June 30, 2015 Other Aon Aon Non-Guarantor Consolidating (millions) plc Corporation Subsidiaries Adjustments Consolidated Net income $ 506 $ 366 $ 1,096 $ (1,439 ) $ 529 Less: Net income attributable to noncontrolling interests — — 23 — 23 Net income attributable to Aon shareholders $ 506 $ 366 $ 1,073 $ (1,439 ) $ 506 Other comprehensive (loss) income, net of tax: Change in fair value of financial instruments — 1 (2 ) — (1 ) Foreign currency translation adjustments — (19 ) (128 ) — (147 ) Post-retirement benefit obligation — 17 27 — 44 Total other comprehensive loss — (1 ) (103 ) — (104 ) Equity in other comprehensive loss of subsidiaries, net of tax (102 ) (94 ) (95 ) 291 — Less: Other comprehensive income attributable to noncontrolling interests — — (2 ) — (2 ) Total other comprehensive loss attributable to Aon shareholders (102 ) (95 ) (196 ) 291 (102 ) Comprehensive income attributable to Aon shareholders $ 404 $ 271 $ 877 $ (1,148 ) $ 404 Condensed Consolidating Statement of Comprehensive Income Six months ended June 30, 2014 Other Aon Aon Non-Guarantor Consolidating (millions) plc Corporation Subsidiaries Adjustments Consolidated Net income $ 629 $ 475 $ 1,237 $ (1,692 ) $ 649 Less: Net income attributable to noncontrolling interests — — 20 — 20 Net income attributable to Aon shareholders $ 629 $ 475 $ 1,217 $ (1,692 ) $ 629 Other comprehensive (loss) income, net of tax: Change in fair value of financial instruments — — 20 — 20 Foreign currency translation adjustments — (2 ) 92 — 90 Post-retirement benefit obligation — 11 33 — 44 Total other comprehensive loss — 9 145 — 154 Equity in other comprehensive loss of subsidiaries, net of tax 156 142 — (298 ) — Less: Other comprehensive income attributable to noncontrolling interests — — (2 ) — (2 ) Total other comprehensive loss attributable to Aon shareholders 156 151 147 (298 ) 156 Comprehensive income attributable to Aon shareholders $ 785 $ 626 $ 1,364 $ (1,990 ) $ 785
Condensed Consolidating Statements of Financial Position	Condensed Consolidating Statement of Financial Position As of June 30, 2015 Other Aon Aon Non-Guarantor Consolidating (millions) plc Corporation Subsidiaries Adjustments Consolidated ASSETS Cash and cash equivalents $ — $ 2,221 $ 707 $ (2,561 ) $ 367 Short-term investments — 125 359 — 484 Receivables, net — — 2,684 — 2,684 Fiduciary assets — — 11,389 — 11,389 Intercompany receivables 258 3,847 10,286 (14,391 ) — Other current assets 2 223 538 (32 ) 731 Total Current Assets 260 6,416 25,963 (16,984 ) 15,655 Goodwill — — 8,661 — 8,661 Intangible assets, net — — 2,350 — 2,350 Fixed assets, net — — 782 — 782 Intercompany receivables 7,379 581 1,621 (9,581 ) — Other non-current assets 189 693 1,656 (783 ) 1,755 Investment in subsidiary 4,488 15,799 542 (20,829 ) — TOTAL ASSETS $ 12,316 $ 23,489 $ 41,575 $ (48,177 ) $ 29,203 LIABILITIES AND EQUITY Fiduciary liabilities $ — $ — $ 11,389 $ — $ 11,389 Short-term debt and current portion of long-term debt — 1,225 12 — 1,237 Accounts payable and accrued liabilities 2,597 49 1,283 (2,561 ) 1,368 Intercompany payables 223 9,975 4,194 (14,392 ) — Other current liabilities — 55 822 (32 ) 845 Total Current Liabilities 2,820 11,304 17,700 (16,985 ) 14,839 Long-term debt 3,092 1,418 314 — 4,824 Pension, other post-retirement and other post-employment liabilities — 1,336 608 — 1,944 Intercompany payables — 8,787 794 (9,581 ) — Other non-current liabilities 6 102 1,814 (782 ) 1,140 TOTAL LIABILITIES 5,918 22,947 21,230 (27,348 ) 22,747 TOTAL AON SHAREHOLDERS' EQUITY 6,398 542 20,287 (20,829 ) 6,398 Noncontrolling interests — — 58 — 58 TOTAL EQUITY 6,398 542 20,345 (20,829 ) 6,456 TOTAL LIABILITIES AND EQUITY $ 12,316 $ 23,489 $ 41,575 $ (48,177 ) $ 29,203 Condensed Consolidating Statement of Financial Position As of December 31, 2014 Other Aon Aon Non-Guarantor Consolidating (millions) plc Corporation Subsidiaries Adjustments Consolidated ASSETS Cash and cash equivalents $ — $ 2,727 $ 1,361 $ (3,714 ) $ 374 Short-term investments — 165 229 — 394 Receivables, net — — 2,815 — 2,815 Fiduciary assets — — 11,638 — 11,638 Intercompany receivables 455 2,814 9,156 (12,425 ) — Other current assets 2 226 407 (33 ) 602 Total Current Assets 457 5,932 25,606 (16,172 ) 15,823 Goodwill — — 8,860 — 8,860 Intangible assets, net — — 2,520 — 2,520 Fixed assets, net — — 765 — 765 Intercompany receivables 7,399 600 111 (8,110 ) — Other non-current assets 179 697 1,718 (790 ) 1,804 Investment in subsidiary 4,962 15,200 1,880 (22,042 ) — TOTAL ASSETS $ 12,997 $ 22,429 $ 41,460 $ (47,114 ) $ 29,772 LIABILITIES AND EQUITY Fiduciary liabilities $ — $ — $ 11,638 $ — $ 11,638 Short-term debt and current portion of long-term debt — 767 16 — 783 Accounts payable and accrued liabilities 3,755 58 1,706 (3,714 ) 1,805 Intercompany payables 122 8,960 3,343 (12,425 ) — Other current liabilities — 49 772 (33 ) 788 Total Current Liabilities 3,877 9,834 17,475 (16,172 ) 15,014 Long-term debt 2,544 1,917 338 — 4,799 Pension, other post-retirement and other post-employment liabilities — 1,396 745 — 2,141 Intercompany payables — 7,277 833 (8,110 ) — Other non-current liabilities 5 125 1,847 (790 ) 1,187 TOTAL LIABILITIES 6,426 20,549 21,238 (25,072 ) 23,141 TOTAL AON SHAREHOLDERS' EQUITY 6,571 1,880 20,162 (22,042 ) 6,571 Noncontrolling interests — — 60 — 60 TOTAL EQUITY 6,571 1,880 20,222 (22,042 ) 6,631 TOTAL LIABILITIES AND EQUITY $ 12,997 $ 22,429 $ 41,460 $ (47,114 ) $ 29,772
Condensed Consolidating Statements of Cash Flows	Condensed Consolidating Statement of Cash Flows Six months ended June 30, 2015 Aon Aon Other Non-Guarantor Consolidating (millions) plc Corporation Subsidiaries Adjustments Consolidated CASH FLOWS FROM OPERATING ACTIVITIES CASH PROVIDED BY (USED FOR) OPERATING ACTIVITIES $ (120 ) $ (368 ) $ 853 $ — $ 365 CASH FLOWS FROM INVESTING ACTIVITIES Sales of long-term investments — — 10 — 10 Purchase of long-term investments — (1 ) — — (1 ) Net sales of short-term investments - non-fiduciary — 41 (138 ) — (97 ) Acquisition of businesses, net of cash acquired — — (23 ) — (23 ) Proceeds from sale of businesses — — 52 — 52 Capital expenditures — — (142 ) — (142 ) CASH PROVIDED BY (USED FOR) INVESTING ACTIVITIES — 40 (241 ) — (201 ) CASH FLOWS FROM FINANCING ACTIVITIES Share repurchase (550 ) — — — (550 ) Advances from (to) affiliates 172 (134 ) (1,191 ) 1,153 — Issuance of shares for employee benefit plans 52 — — — 52 Issuance of debt 712 1,732 1 — 2,445 Repayment of debt (110 ) (1,776 ) (10 ) — (1,896 ) Cash dividends to shareholders (156 ) — — — (156 ) Purchase of shares from noncontrolling interests — — (5 ) — (5 ) Dividends paid to noncontrolling interests — — (18 ) — (18 ) CASH (USED FOR) PROVIDED BY FINANCING ACTIVITIES 120 (178 ) (1,223 ) 1,153 (128 ) EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS — — (43 ) — (43 ) NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS — (506 ) (654 ) 1,153 (7 ) CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR — 2,727 1,361 (3,714 ) 374 CASH AND CASH EQUIVALENTS AT END OF PERIOD $ — $ 2,221 $ 707 $ (2,561 ) $ 367 Condensed Consolidating Statement of Cash Flows Six months ended June 30, 2014 Other Aon Aon Non-Guarantor Consolidating (millions) plc Corporation Subsidiaries Adjustments Consolidated CASH FLOWS FROM OPERATING ACTIVITIES CASH PROVIDED BY (USED FOR) OPERATING ACTIVITIES $ 265 $ (215 ) $ 283 $ — $ 333 CASH FLOWS FROM INVESTING ACTIVITIES Sales of long-term investments — 37 11 — 48 Purchase of long-term investments — (14 ) — — (14 ) Net sales of short-term investments - non-fiduciary — 27 190 — 217 Acquisition of businesses, net of cash acquired — — (83 ) — (83 ) Proceeds from sale of businesses — — 1 — 1 Capital expenditures — — (115 ) — (115 ) CASH PROVIDED BY INVESTING ACTIVITIES — 50 4 — 54 CASH FLOWS FROM FINANCING ACTIVITIES Share repurchase (1,250 ) — — — (1,250 ) Advances from (to) affiliates (522 ) 99 586 (163 ) — Issuance of shares for employee benefit plans 40 — — — 40 Issuance of debt 2,169 1,161 (6 ) — 3,324 Repayment of debt (574 ) (1,161 ) (10 ) — (1,745 ) Deposit with trustee — — (681 ) — (681 ) Cash dividends to shareholders (128 ) — — — (128 ) Purchase of shares from noncontrolling interests — — 1 — 1 Dividends paid to noncontrolling interests — — (10 ) — (10 ) CASH (USED FOR) PROVIDED BY FINANCING ACTIVITIES (265 ) 99 (120 ) (163 ) (449 ) EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS — — 3 — 3 NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS — (66 ) 170 (163 ) (59 ) CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR — 247 1,246 (1,016 ) 477 CASH AND CASH EQUIVALENTS AT END OF PERIOD $ — $ 181 $ 1,416 $ (1,179 ) $ 418

Basis of Presentation Basis of

Basis of Presentation Basis of Presentation (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Investments	$ 142	$ 143

Cash and Cash Equivalents (Deta

Cash and Cash Equivalents (Details) £ in Millions, $ in Millions	6 Months Ended
	Jun. 30, 2015GBP (£)	Jun. 30, 2015USD ($)	Dec. 31, 2014USD ($)
Cash, Cash Equivalents, and Short-term Investments [Abstract]
Short-term investment, minimum maturity period	3 months
Short-term investment, maximum maturity period	1 year
Cash and Cash Equivalents and Short-Term Investments		$ 851	$ 768
Restricted Cash and Investments, Current		117	169
Operating funds in U.K.	£ 40.5	64	63
Cash and cash equivalents, restricted		$ 53	$ 106

Other Financial Data - Schedule

Other Financial Data - Schedule of Other Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Other (Expense) Income
Foreign currency remeasurement (loss) gain	$ (7)	$ (15)	$ 17	$ 4
Gain on disposal of business	1	0	20	0
Equity earnings	4	1	6	6
Income (loss) on financial instruments	3	9	0	(15)
Other	0	3	0	4
Total	$ 1	$ (2)	$ 43	$ (1)

Other Financial Data Schedule o

Other Financial Data Schedule of Allowance for Doubtful Accounts (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at beginning of period	$ 70	$ 89	$ 74	$ 90
Provision charged to operations	3	4	11	8
Accounts written off, net of recoveries	(13)	(4)	(22)	(9)
Foreign currency translation	5	(1)	2	(1)
Balance at end of period	$ 65	$ 88	$ 65	$ 88

Other Financial Data Schedule38

Other Financial Data Schedule of Other Current Assets (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Other Financial Data [Abstract]
Taxes receivable	$ 220	$ 99
Deferred tax assets	204	212
Prepaid expenses	175	164
Deferred project costs	106	102
Other	26	25
Total	$ 731	$ 602

Other Financial Data Schedule39

Other Financial Data Schedule of Non-current Assets (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Other Financial Data [Abstract]
Prepaid pension	$ 953	$ 933
Deferred project costs	232	250
Deferred tax assets	164	144
Investments	142	143
Taxes receivable	63	101
Other	201	233
Total	$ 1,755	$ 1,804

Other Financial Data Schedule40

Other Financial Data Schedule of Other Current Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Other Financial Data [Abstract]
Deferred revenue	$ 425	$ 408
Taxes payable	24	64
Deferred tax liabilities	2	2
Other	394	314
Total	$ 845	$ 788

Other Financial Data Schedule41

Other Financial Data Schedule of Other Non-current Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Other Financial Data [Abstract]
Deferred tax liabilities	$ 322	$ 313
Taxes payable	208	210
Deferred revenue	187	167
Leases	167	184
Compensation and benefits	54	57
Other	202	256
Total	$ 1,140	$ 1,187

Acquisitions and Dispositions -

Acquisitions and Dispositions - Acquisitions (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015USD ($)business	Jun. 30, 2014USD ($)business	Jun. 30, 2015USD ($)business	Jun. 30, 2014USD ($)business	Dec. 31, 2014USD ($)
Intangible assets:
Goodwill	$ 8,661		$ 8,661		$ 8,860
Business Acquisition 1 [Member]
Business Acquisition
Consideration	23	$ 83	23	$ 83
Intangible assets:
Goodwill	16	52	16	52
Other intangible assets	1	48	1	48
Total	$ 17	$ 100	$ 17	$ 100
Risk Solutions [Member]
Business Acquisition
Number of business acquired under business combination | business	1	2	2	3
Intangible assets:
Goodwill	$ 5,722		$ 5,722		5,911
HR Solutions [Member]
Business Acquisition
Number of business acquired under business combination | business	1		2	1
Intangible assets:
Goodwill	$ 2,939		$ 2,939		$ 2,949

Acquisitions and Dispositions43

Acquisitions and Dispositions - Dispositions (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015USD ($)business	Jun. 30, 2014USD ($)business	Jun. 30, 2015USD ($)business	Jun. 30, 2014USD ($)business
Dispositions
Number of dispositions	0	0
Gain on disposal of business | $	$ 1	$ 0	$ 20	$ 0
Risk Solutions [Member]
Dispositions
Number of dispositions			1	1
Gain on disposal of business | $		$ 1
HR Solutions [Member]
Dispositions
Number of dispositions			1

Goodwill and Other Intangible44

Goodwill and Other Intangible Assets (Details) $ in Millions	6 Months Ended
	Jun. 30, 2015USD ($)
Changes in the net carrying amount of goodwill by operating segment (in millions)
Beginning balance	$ 8,860
Goodwill related to current year acquisitions	16
Goodwill related to disposals	(13)
Goodwill related to prior year acquisitions	(1)
Foreign currency translation	(201)
Ending balance	8,661
Risk Solutions [Member]
Changes in the net carrying amount of goodwill by operating segment (in millions)
Beginning balance	5,911
Goodwill related to current year acquisitions	1
Goodwill related to disposals	0
Goodwill related to prior year acquisitions	(1)
Foreign currency translation	(189)
Ending balance	5,722
HR Solutions [Member]
Changes in the net carrying amount of goodwill by operating segment (in millions)
Beginning balance	2,949
Goodwill related to current year acquisitions	15
Goodwill related to disposals	(13)
Goodwill related to prior year acquisitions	0
Foreign currency translation	(12)
Ending balance	$ 2,939

Goodwill and Other Intangible45

Goodwill and Other Intangible Assets (Details 2) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Intangible assets with indefinite lives
Tradenames	$ 1,019		$ 1,019		$ 1,019
Intangible assets with finite lives
Intangible assets with finite lives, Gross Carrying Amount	4,501		4,501		4,542
Intangible assets with finite lives, Accumulated Amortization	2,151		2,151		2,022
Intangible assets, Net Carrying Amount	2,350		2,350		2,520
Amortization expense on intangible assets	79	$ 87	159	$ 173
Estimated amortization for intangible assets
Remainder of 2015	159		159
2,016	276		276
2,017	231		231
2,018	170		170
2,019	141		141
Thereafter	354		354
Total	1,331		1,331
Risk Solutions [Member]
Estimated amortization for intangible assets
Remainder of 2015	56		56
2,016	104		104
2,017	93		93
2,018	78		78
2,019	68		68
Thereafter	188		188
Total	587		587
HR Solutions [Member]
Estimated amortization for intangible assets
Remainder of 2015	103		103
2,016	172		172
2,017	138		138
2,018	92		92
2,019	73		73
Thereafter	166		166
Total	744		744
Customer related and contract based [Member]
Intangible assets with finite lives
Intangible assets with finite lives, Gross Carrying Amount	2,930		2,930		2,952
Intangible assets with finite lives, Accumulated Amortization	1,706		1,706		1,579
Intangible assets, Net Carrying Amount	1,224		1,224		1,373
Marketing, technology and other [Member]
Intangible assets with finite lives
Intangible assets with finite lives, Gross Carrying Amount	552		552		571
Intangible assets with finite lives, Accumulated Amortization	445		445		443
Intangible assets, Net Carrying Amount	$ 107		$ 107		$ 128

Debt (Details)

Debt (Details)	3 Months Ended	6 Months Ended
	Jun. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Jun. 30, 2015EUR (€)	May. 20, 2015USD ($)	Feb. 02, 2015USD ($)	Dec. 31, 2014USD ($)credit_facility
Debt Instrument [Line Items]
Number Of Credit Facilities | credit_facility						2
Commercial paper [Member]
Debt Instrument [Line Items]
Total debt	$ 125,000,000	$ 125,000,000				$ 168,000,000
Weighted average commercial paper outstanding	$ 359,000,000	$ 338,000,000
Weighted-average interest rates (as a percent)	0.46%	0.48%
4.750% Senior Notes Due May 2045 [Member] | Notes Payable, Other Payables [Member]
Debt Instrument [Line Items]
Face amount of debt				$ 600,000,000
Debt interest rate percentage				4.75%
Domestic Line of Credit [Member] | 2017 Facility [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity						$ 400,000,000
Foreign Line of Credit [Member] | 2015 Facility [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 726,000,000	$ 726,000,000	€ 650,000,000
Foreign Line of Credit [Member] | 2020 Facility [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity					$ 900,000,000
Commercial paper [Member] | US Commercial Paper Program [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 900,000,000	$ 900,000,000
Commercial paper [Member] | European Multi Currency Paper Program [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity | €			€ 300,000,000

Income Taxes Income Taxes (Deta

Income Taxes Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Tax Contingency [Line Items]
Effective income tax rate	12.20%	17.50%	16.80%	18.30%
Decrease in uncertain tax positions			$ 10
Amount of liability for uncertain tax positions that would impact the effective tax rate if recognized	$ 144		144
Other Noncurrent Liabilities [Member]
Income Tax Contingency [Line Items]
Liability for uncertain tax positions, noncurrent	197		197
Liability for uncertain tax positions, interest	28		28
Liability for uncertain tax positions, penalties	$ 12		$ 12

Shareholders' Equity (Details)

Shareholders' Equity (Details) - USD ($)	3 Months Ended		6 Months Ended		39 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Nov. 30, 2014	Apr. 30, 2012
Common Stock Programs
Total cost of shares purchased			$ 550,000,000
Weighted average shares outstanding
Shares for basic earnings per share (in shares)	284,500,000	298,500,000	284,300,000	301,000,000
Common stock equivalents (in shares)	2,200,000	3,100,000	2,600,000	3,400,000
Shares for diluted earnings per share (in shares)	286,700,000	301,600,000	286,900,000	304,400,000
Number of shares excluded from the calculation of diluted earnings per share	0	0
2012 - Share Repurchase Program [Member]
Common Stock Programs
Share repurchase authorization limit							$ 5,000,000,000
Shares purchased (in shares)	3,000,000	7,400,000	5,500,000	14,600,000	67,600,000
Average price per share of stock repurchased	$ 100.92	$ 87.67	$ 100.57	$ 85.59
Total cost of shares purchased	$ 300,000,000	$ 650,000,000	$ 550,000,000	$ 1,300,000,000	$ 4,900,000,000
Share repurchase, remaining authorization limit	$ 5,100,000,000		$ 5,100,000,000		$ 5,100,000,000
Share Repurchase Program of 2014 [Member]
Common Stock Programs
Share repurchase authorization limit						$ 5,000,000,000

Shareholders' Equity (Details 2

Shareholders' Equity (Details 2) $ in Millions		6 Months Ended
		Jun. 30, 2015USD ($)
Changes in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		$ (3,134)
Other comprehensive income (loss) before reclassifications, net		(137)
Amounts reclassified from accumulated other comprehensive loss:
Amounts reclassified from accumulated other comprehensive loss		70
Tax benefit		(35)
Amounts reclassified from accumulated other comprehensive loss, net		35
Net current period other comprehensive (loss) income		(102)
Ending balance		(3,236)
Change in Fair Value of Financial Instruments [Member]
Changes in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	[1]	(17)
Other comprehensive income (loss) before reclassifications, net	[1]	5
Amounts reclassified from accumulated other comprehensive loss:
Amounts reclassified from accumulated other comprehensive loss	[1]	11
Tax benefit	[1]	(17)
Amounts reclassified from accumulated other comprehensive loss, net	[1]	(6)
Net current period other comprehensive (loss) income	[1]	(1)
Ending balance	[1]	(18)
Foreign Currency Translation Adjustments [Member]
Changes in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		(335)
Other comprehensive income (loss) before reclassifications, net		(145)
Amounts reclassified from accumulated other comprehensive loss:
Amounts reclassified from accumulated other comprehensive loss		0
Tax benefit		0
Amounts reclassified from accumulated other comprehensive loss, net		0
Net current period other comprehensive (loss) income		(145)
Ending balance		(480)
Post-Retirement Benefit Obligation [Member]
Changes in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	[2]	(2,782)
Other comprehensive income (loss) before reclassifications, net	[2]	3
Amounts reclassified from accumulated other comprehensive loss:
Amounts reclassified from accumulated other comprehensive loss	[2]	59
Tax benefit	[2]	(18)
Amounts reclassified from accumulated other comprehensive loss, net	[2]	41
Net current period other comprehensive (loss) income	[2]	44
Ending balance	[2]	$ (2,738)
[1]	Reclassifications from this category included in Accumulated other comprehensive loss are recorded in Other income (expense).
[2]	Reclassifications from this category included in Accumulated other comprehensive loss are recorded in Compensation and benefits.

Employee Benefits (Details)

Employee Benefits (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
U.K. [Member]
Defined Benefit Plan Disclosure
Service cost	$ 0	$ 0	$ 0	$ 0
Interest cost	50	58	99	116
Expected return on plan assets	(77)	(83)	(152)	(165)
Amortization of net actuarial loss	10	14	20	27
Net periodic (benefit) cost	(17)	(11)	(33)	(22)
Curtailment loss (gain) and other	0	0	0	0
Total net periodic (benefit) cost	(17)	(11)	(33)	(22)
Estimate of contributions to defined benefit pension plans for the current fiscal year	65		65
Contributions made to defined benefit pension plans	15	56	34	121
U.S. [Member]
Defined Benefit Plan Disclosure
Service cost	1	0	2	0
Interest cost	33	32	66	64
Expected return on plan assets	(38)	(39)	(77)	(78)
Amortization of net actuarial loss	13	11	27	21
Net periodic (benefit) cost	9	4	18	7
Curtailment loss (gain) and other	0	0	(1)	1
Total net periodic (benefit) cost	9	4	17	8
Estimate of contributions to defined benefit pension plans for the current fiscal year	132		132
Contributions made to defined benefit pension plans	28	33	62	73
Other [Member]
Defined Benefit Plan Disclosure
Service cost	0	0	0	0
Interest cost	9	12	17	24
Expected return on plan assets	(13)	(15)	(25)	(30)
Amortization of net actuarial loss	3	2	6	4
Net periodic (benefit) cost	(1)	(1)	(2)	(2)
Curtailment loss (gain) and other	0	0	0	(3)
Total net periodic (benefit) cost	(1)	(1)	(2)	(5)
Estimate of contributions to defined benefit pension plans for the current fiscal year	23		23
Contributions made to defined benefit pension plans	$ 4	$ 4	$ 8	$ 16

Share-Based Compensation Plan51

Share-Based Compensation Plans Share-based compensation expenses recognized (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 74	$ 73	$ 164	$ 175
Restricted share units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	44	43	109	103
Performance share awards (“PSAs”) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	28	28	49	67
Share options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	0	0	0	0
Employee share purchase plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 2	$ 2	$ 6	$ 5

Share-Based Compensation Plan52

Share-Based Compensation Plans Restricted share unit activity (Details) - Restricted share units (RSUs) [Member] - $ / shares shares in Thousands		6 Months Ended		12 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Non-vested share awards (in shares)
Non-vested at beginning of period		8,381	9,759	9,759
Granted		2,144	2,498
Vested		(3,037)	(3,320)
Forfeited		(130)	(221)
Non-vested at end of period		7,358	8,716	8,381
Weighted Average Fair value (in dollars per share)
Non-vested at beginning of period	[1]	$ 63	$ 51	$ 51
Granted	[1]	98	84
Vested	[1]	58	49
Forfeited	[1]	67	54
Non-vested at end of period	[1]	$ 76	$ 61	$ 63
[1]	Represents per share weighted average fair value of award at date of grant.

Share-Based Compensation Plan53

Share-Based Compensation Plans Performance Share Awards Narrative (Details) - Jun. 30, 2015 - Performance Shares [Member]	Total
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting conditions period	3 years
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued, percent	0.00%
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued, percent	200.00%

Share-Based Compensation Plan54

Share-Based Compensation Plans Schedule of Performance-based plans (Details) - Performance Shares [Member] - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Target PSAs granted during period	993	816	1,135
Weighted average fair value per share at date of grant	$ 96	$ 81	$ 58
Number of shares that would be issued based on current performance levels	992	1,201	2,197
Unamortized expense, based on current performance levels	$ 85	$ 52	$ 23

Share-Based Compensation Plan55

Share-Based Compensation Plans Share options activity (Details) - Share options [Member] - $ / shares shares in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Share Options (in shares)
Beginning outstanding	2,300	3,462
Granted	0	0
Exercised	(1,388)	(839)
Forfeited and expired	(13)	(3)
Outstanding at end of period	899	2,620
Exercisable at end of period	899	2,572
Weighted-Average Exercise Price (in dollars per share)
Beginning outstanding	$ 32	$ 32
Granted	0	0
Exercised	27	32
Forfeited and expired	39	37
Outstanding at end of period	39	32
Exercisable at end of period	$ 39	$ 32

Share-Based Compensation Plan56

Share-Based Compensation Plans Stock Option Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Closing share price (in dollars per share)	$ 99.68
Aggregate intrinsic value of options outstanding	$ 54
Unamortized deferred compensation expense	$ 455
Remaining weighted-average amortization period	2 years 2 months 12 days
Share options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average remaining contractual life	2 years 8 months 6 days	1 year 10 months 18 days

Share-Based Compensation Plan57

Share-Based Compensation Plans Other information related to the company's share options (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Aggregate intrinsic value of stock options exercised	$ 6	$ 24	$ 100	$ 45
Cash received from the exercise of stock options	4	13	38	27
Tax benefit realized from the exercise of stock options	$ 1	$ 6	$ 35	$ 12

Derivatives and Hedging Foreign

Derivatives and Hedging Foreign Exchange Risk Management Narrative (Details)	6 Months Ended
	Jun. 30, 2015
Cash Flow Hedging [Member]
Derivative [Line Items]
Foreign currency exposures, maximum average hedging period	2 years
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Foreign currency exposures, maximum hedging period	1 year

Derivatives and Hedging Interes

Derivatives and Hedging Interest Rate Management Risk Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Derivative [Line Items]
Estimated pretax losses currently included within Accumulated Other Comprehensive Loss that will be reclassified to earnings in next twelve months	$ 1		$ 1
Not Designated as Hedging Instrument [Member] | Foreign exchange contracts [Member]
Derivative [Line Items]
Derivative gain (loss)	$ 2	$ 4	$ 9	$ (1)
Cash Flow Hedging [Member]
Derivative [Line Items]
Interest rate fluctuations, maximum hedging period			2 years

Derivatives and Hedging Notiona

Derivatives and Hedging Notional and fair values of derivative instruments (Details) - USD ($) $ in Millions		6 Months Ended
		Jun. 30, 2015	Dec. 31, 2014
Derivatives, Fair Value
Notional Amount		$ 1,165	$ 1,365
Derivative Assets	[1]	54	46
Derivative Liabilities	[2]	$ 57	58
Term of derivative contract		30 days
Gross Amounts Offset in the Statement of Financial Position		$ (20)	(14)
Net Amounts of Assets Presented in the Statement of Financial Position	[3]	34	32
Gross Amounts Offset in the Statement of Financial Position		(20)	(14)
Net Amounts of Liabilities Presented in the Statement of Financial Position	[4]	37	44
Other Current Assets [Member]
Derivatives, Fair Value
Derivative Assets		28	24
Net Amounts of Assets Presented in the Statement of Financial Position		17	12
Other Noncurrent Assets [Member]
Derivatives, Fair Value
Derivative Assets		26	22
Net Amounts of Assets Presented in the Statement of Financial Position		17	20
Other Current Liabilities [Member]
Derivatives, Fair Value
Derivative Liabilities		47	52
Net Amounts of Liabilities Presented in the Statement of Financial Position		36	40
Other Noncurrent Liabilities [Member]
Derivatives, Fair Value
Derivative Liabilities		10	6
Net Amounts of Liabilities Presented in the Statement of Financial Position		1	4
Derivatives accounted for as hedges [Member]
Derivatives, Fair Value
Notional Amount		998	1,200
Derivative Assets	[1]	54	46
Derivative Liabilities	[2]	57	58
Gross Amounts Offset in the Statement of Financial Position		(20)	(14)
Net Amounts of Assets Presented in the Statement of Financial Position	[3]	34	32
Gross Amounts Offset in the Statement of Financial Position		(20)	(14)
Net Amounts of Liabilities Presented in the Statement of Financial Position	[4]	37	44
Derivatives accounted for as hedges [Member] | Interest rate contracts [Member]
Derivatives, Fair Value
Notional Amount		0	0
Derivative Assets		0	0
Derivative Liabilities		0	0
Gross Amounts Offset in the Statement of Financial Position		0	0
Net Amounts of Assets Presented in the Statement of Financial Position	[3]	0	0
Gross Amounts Offset in the Statement of Financial Position		0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	[4]	0	0
Derivatives accounted for as hedges [Member] | Foreign exchange contracts [Member]
Derivatives, Fair Value
Notional Amount		998	1,200
Derivative Assets		54	46
Derivative Liabilities		57	58
Gross Amounts Offset in the Statement of Financial Position		(20)	(14)
Net Amounts of Assets Presented in the Statement of Financial Position	[3]	34	32
Gross Amounts Offset in the Statement of Financial Position		(20)	(14)
Net Amounts of Liabilities Presented in the Statement of Financial Position	[4]	37	44
Not Designated as Hedging Instrument [Member] | Foreign exchange contracts [Member]
Derivatives, Fair Value
Notional Amount	[5]	167	165
Derivative Assets		0	0
Derivative Liabilities		0	0
Gross Amounts Offset in the Statement of Financial Position		0	0
Net Amounts of Assets Presented in the Statement of Financial Position	[3]	0	0
Gross Amounts Offset in the Statement of Financial Position		0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	[4]	$ 0	$ 0
[1]	Included within Other current assets ($28 million at June 30, 2015 and $24 million at December 31, 2014) or Other non-current assets ($26 million at June 30, 2015 and $22 million at December 31, 2014).
[2]	Included within Other current liabilities ($47 million at June 30, 2015 and $52 million at December 31, 2014) or Other non-current liabilities ($10 million at June 30, 2015 and $6 million at December 31, 2014).
[3]	Included within Other current assets ($17 million at June 30, 2015 and $12 million at December 31, 2014) or Other non-current assets ($17 million at June 30, 2015 and $20 million at December 31, 2014).
[4]	Included within Other current liabilities ($36 million at June 30, 2015 and $40 million at December 31, 2014) or Other non-current liabilities ($1 million at June 30, 2015 and $4 million at December 31, 2014).
[5]	These contracts typically are for 30 day durations and executed close to the last day of the most recent reporting month, thereby resulting in nominal fair values at the balance sheet date.

Derivatives and Hedging - Sched

Derivatives and Hedging - Schedule of amounts of derivative gains (losses) recognized in the Consolidated Financial Statements (Details) - Cash Flow Hedging [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Derivative [Line Items]
Gain (loss) recognized in accumulated other comprehensive income	$ 14	$ 15	$ 13	$ 7
Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion):	3	2	(8)	(20)
Interest rate contracts [Member]
Derivative [Line Items]
Gain (loss) recognized in accumulated other comprehensive income	0	0	0	0
Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion):	0	0	(1)	(1)
Foreign exchange contracts [Member]
Derivative [Line Items]
Gain (loss) recognized in accumulated other comprehensive income	14	15	13	7
Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion):	3	2	(7)	(19)
Compensation and Benefits [Member]
Derivative [Line Items]
Gain (loss) recognized in accumulated other comprehensive income	1	5	6	16
Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion):	1	0	1	(2)
Compensation and Benefits [Member] | Interest rate contracts [Member]
Derivative [Line Items]
Gain (loss) recognized in accumulated other comprehensive income	0	0	0	0
Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion):	0	0	0	0
Compensation and Benefits [Member] | Foreign exchange contracts [Member]
Derivative [Line Items]
Gain (loss) recognized in accumulated other comprehensive income	1	5	6	16
Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion):	1	0	1	(2)
Other General Expenses [Member]
Derivative [Line Items]
Gain (loss) recognized in accumulated other comprehensive income	3	0	1	0
Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion):	(1)	0	(1)	0
Other General Expenses [Member] | Interest rate contracts [Member]
Derivative [Line Items]
Gain (loss) recognized in accumulated other comprehensive income	0	0	0	0
Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion):	0	0	0	0
Other General Expenses [Member] | Foreign exchange contracts [Member]
Derivative [Line Items]
Gain (loss) recognized in accumulated other comprehensive income	3	0	1	0
Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion):	(1)	0	(1)	0
Interest Expense [Member]
Derivative [Line Items]
Gain (loss) recognized in accumulated other comprehensive income	0	0	0	0
Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion):	(2)	(3)	(5)	(6)
Interest Expense [Member] | Interest rate contracts [Member]
Derivative [Line Items]
Gain (loss) recognized in accumulated other comprehensive income	$ 0	0	0	0
Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion):		0	(1)	(1)
Interest Expense [Member] | Foreign exchange contracts [Member]
Derivative [Line Items]
Gain (loss) recognized in accumulated other comprehensive income	$ 0	0	0	0
Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion):	(2)	(3)	(4)	(5)
Other Income [Member]
Derivative [Line Items]
Gain (loss) recognized in accumulated other comprehensive income	10	10	6	(9)
Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion):	5	5	(3)	(12)
Other Income [Member] | Interest rate contracts [Member]
Derivative [Line Items]
Gain (loss) recognized in accumulated other comprehensive income	0	0	0	0
Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion):	0	0	0	0
Other Income [Member] | Foreign exchange contracts [Member]
Derivative [Line Items]
Gain (loss) recognized in accumulated other comprehensive income	10	10	6	(9)
Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion):	$ 5	$ 5	$ (3)	$ (12)

Fair Value Measurements and F62

Fair Value Measurements and Financial Instruments Schedule of assets and liabilities that are measured at fair value on a recurring basis (Details) - Recurring [Member] - USD ($) $ in Millions	Jun. 30, 2015		Dec. 31, 2014
Money market funds and highly liquid debt securities
Assets:
Money market funds and highly liquid debt securities	$ 1,895	[1]	$ 1,850	[2]
Money market funds [Member]
Assets:
Money market funds and highly liquid debt securities	1,895		1,850
Corporate bonds [Member]
Assets:
Other investments	1		1
Government bonds [Member]
Assets:
Other investments	6		6
Equity investments [Member]
Assets:
Other investments	10		11
Interest rate contracts [Member]
Assets:
Derivatives	0		0
Foreign exchange contracts [Member]
Assets:
Derivatives	54		46
Liabilities:
Derivatives	57		58
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Money market funds and highly liquid debt securities
Assets:
Money market funds and highly liquid debt securities	1,895	[1]	1,850	[2]
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Corporate bonds [Member]
Assets:
Other investments	0		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Government bonds [Member]
Assets:
Other investments	0		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity investments [Member]
Assets:
Other investments	6		6
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Interest rate contracts [Member]
Assets:
Derivatives	0		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Foreign exchange contracts [Member]
Assets:
Derivatives	0		0
Liabilities:
Derivatives	0		0
Significant Other Observable Inputs (Level 2) [Member] | Money market funds and highly liquid debt securities
Assets:
Money market funds and highly liquid debt securities	0	[1]	0	[2]
Significant Other Observable Inputs (Level 2) [Member] | Corporate bonds [Member]
Assets:
Other investments	0		0
Significant Other Observable Inputs (Level 2) [Member] | Government bonds [Member]
Assets:
Other investments	6		6
Significant Other Observable Inputs (Level 2) [Member] | Equity investments [Member]
Assets:
Other investments	4		5
Significant Other Observable Inputs (Level 2) [Member] | Interest rate contracts [Member]
Assets:
Derivatives	0		0
Significant Other Observable Inputs (Level 2) [Member] | Foreign exchange contracts [Member]
Assets:
Derivatives	54		46
Liabilities:
Derivatives	57		58
Significant Unobservable Inputs (Level 3) [Member] | Money market funds and highly liquid debt securities
Assets:
Money market funds and highly liquid debt securities	0	[1]	0	[2]
Significant Unobservable Inputs (Level 3) [Member] | Corporate bonds [Member]
Assets:
Other investments	1		1
Significant Unobservable Inputs (Level 3) [Member] | Government bonds [Member]
Assets:
Other investments	0		0
Significant Unobservable Inputs (Level 3) [Member] | Equity investments [Member]
Assets:
Other investments	0		0
Significant Unobservable Inputs (Level 3) [Member] | Interest rate contracts [Member]
Assets:
Derivatives	0		0
Significant Unobservable Inputs (Level 3) [Member] | Foreign exchange contracts [Member]
Assets:
Derivatives	0		0
Liabilities:
Derivatives	$ 0		$ 0
[1]	Includes $1,895 million of money market funds that are classified as Fiduciary assets, Short-term investments or Cash and cash equivalents in the Condensed Consolidated Statements of Financial Position, depending on their nature and initial maturity.
[2]	Includes $1,850 million of money market funds that are classified as Fiduciary assets, Short-term investments or Cash and cash equivalents in the Condensed Consolidated Statements of Financial Position, depending on their nature and initial maturity.

Fair Value Measurements and F63

Fair Value Measurements and Financial Instruments Schedule of financial instruments where the carrying amounts and fair values differ (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Fair value of financial instrument
Carrying value of total debt	$ 4,824	$ 4,799
Fair value of total debt	$ 5,060	$ 5,268

Commitments and Contingencies (

Commitments and Contingencies (Details) € in Millions, £ in Millions, SFr in Millions, NZD in Millions

Jun. 29, 2015USD ($)

Jun. 29, 2015NZD

Jun. 24, 2015USD ($)

Jun. 24, 2015EUR (€)

May. 29, 2015USD ($)

Jan. 26, 2015USD ($)

Jan. 26, 2015CHF (SFr)

Dec. 02, 2014USD ($)

Dec. 02, 2014CHF (SFr)

Jan. 02, 2014GBP (£)

Jan. 02, 2014USD ($)

Dec. 27, 2012USD ($)

Dec. 27, 2012EUR (€)

Jan. 27, 2011USD ($)

Sep. 14, 2010USD ($)

Jun. 01, 2007USD ($)

Jun. 01, 2007CHF (SFr)

Jun. 30, 2015USD ($)

Mar. 31, 2015USD ($)

Dec. 31, 2014USD ($)

Dec. 31, 2014CHF (SFr)

Jun. 30, 2015USD ($)

Jun. 30, 2015USD ($)

Apr. 30, 2014GBP (£)

Apr. 30, 2014USD ($)

Legal, Guarantees and Indemnifications

Range of possible loss, minimum

$ 0

$ 0

$ 0

Range of possible loss, maximum

300,000,000

300,000,000

300,000,000

Maximum potential funding under commitments

91,000,000

$ 112,000,000

91,000,000

91,000,000

Letters of credit outstanding

62,000,000

95,000,000

62,000,000

62,000,000

Potential Claim for Pension Advisory Services [Member]

Legal, Guarantees and Indemnifications

Estimate of possible loss

£ 45

$ 71,000,000

Commitments to fund certain limited partnerships or subsidiaries [Member]

Legal, Guarantees and Indemnifications

Maximum potential funding under commitments

12,000,000

14,000,000

12,000,000

12,000,000

Commitments funded

$ 0

$ 2,000,000

Northrop Grumman Corporation [Member]

Legal, Guarantees and Indemnifications

Damages sought

$ 340,000,000

Case settlement amount

$ 150,000,000

Payments for legal settlements

$ 150,000,000

Opry Mills Mall Limited Partnership [Member]

Legal, Guarantees and Indemnifications

Damages sought

$ 200,000,000

Amount of coverage for damages contended by the insurers

50,000,000

Difference amount of damages sought by the client

$ 150,000,000

Damages awarded

$ 200,000,000

Philips [Member]

Legal, Guarantees and Indemnifications

Damages sought

£ 189

$ 298,000,000

International Road Transport Union [Member] | Litigation Award [Member]

Legal, Guarantees and Indemnifications

Damages sought

$ 49,000,000

SFr 46

Damages awarded excluding interest and costs

$ 18,000,000

SFr 16.8

Damages awarded

30,000,000

SFr 27.9

Case settlement amount

$ 14,000,000

SFr 12.8

Settlement, maximum liability

9,000,000

SFr 8.7

International Road Transport Union [Member] | Litigation USD Denominated Award [Member]

Legal, Guarantees and Indemnifications

Damages sought

3,000,000

Damages awarded excluding interest and costs

$ 3,100,000

Damages awarded

$ 5,000,000

Case settlement amount

4,700,000

Settlement, maximum liability

$ 115,000

International Road Transport Union [Member] | Litigation Expenses and Interest [Member]

Legal, Guarantees and Indemnifications

Damages sought

$ 30,000,000

Versicherung Aktiengesellschaft [Member] | Litigation Award [Member]

Legal, Guarantees and Indemnifications

Damages sought

$ 204,000,000

€ 183

Case settlement amount

$ 2,000,000

€ 1.6

Pending Litigation [Member] | Lyttleton Port Company Limited [Member]

Legal, Guarantees and Indemnifications

Damages sought

$ 126,200,000

NZD 184

Segment Information (Details)

Segment Information (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015USD ($)	Jun. 30, 2014USD ($)	Jun. 30, 2015USD ($)segment	Jun. 30, 2014USD ($)
Segment Reporting Information
Number of reportable segments | segment			2
Total revenue	$ 2,805	$ 2,919	$ 5,652	$ 5,866
Total commissions, fees and other revenue	2,800	2,913	5,642	5,854
Total fiduciary investment income	5	6	10	12
Operating income before income tax	277	445	718	914
Interest income	4	2	7	4
Interest expense	(68)	(65)	(133)	(123)
Other income (expense)	1	(2)	43	(1)
Income before income taxes	214	380	635	794
Total operating segments [Member]
Segment Reporting Information
Operating income before income tax	318	486	806	998
Risk Solutions [Member]
Segment Reporting Information
Total revenue	1,833	1,948	3,728	3,942
Total commissions, fees and other revenue	1,828	1,942	3,718	3,930
Total fiduciary investment income	5	6	10	12
Operating income before income tax	279	417	691	862
Retail brokerage [Member]
Segment Reporting Information
Total commissions, fees and other revenue	1,498	1,582	3,011	3,161
Reinsurance brokerage [Member]
Segment Reporting Information
Total commissions, fees and other revenue	330	360	707	769
HR Solutions [Member]
Segment Reporting Information
Total revenue	979	982	1,949	1,947
Total commissions, fees and other revenue	979	982	1,949	1,947
Total fiduciary investment income	0	0	0	0
Operating income before income tax	39	69	115	136
Consulting services [Member]
Segment Reporting Information
Total commissions, fees and other revenue	391	395	762	779
Outsourcing [Member]
Segment Reporting Information
Total commissions, fees and other revenue	599	595	1,203	1,184
Intrasegment [Member]
Segment Reporting Information
Total commissions, fees and other revenue	(11)	(8)	(16)	(16)
Intersegment elimination [Member]
Segment Reporting Information
Total revenue	(7)	(11)	(25)	(23)
Total commissions, fees and other revenue	(7)	(11)	(25)	(23)
Unallocated Expense [Member]
Segment Reporting Information
Operating income before income tax	$ (41)	$ (41)	$ (88)	$ (84)

Guarantee of Registered Secur66

Guarantee of Registered Securities (Narrative) (Details)	Jun. 30, 2015
Aon plc [Member]
Condensed Financial Statements, Captions [Line Items]
Parent company's percentage ownership of guarantors	100.00%
3.50% senior notes due September 2015 [Member]
Condensed Financial Statements, Captions [Line Items]
Debt interest rate percentage	3.50%
3.125% Senior notes due 2016 [Member]
Condensed Financial Statements, Captions [Line Items]
Debt interest rate percentage	3.125%
5.00% Senior notes due September 2020 [Member]
Condensed Financial Statements, Captions [Line Items]
Debt interest rate percentage	5.00%
8.205% Junior subordinated deferrable interest debentures due January 2027 [Member]
Condensed Financial Statements, Captions [Line Items]
Debt interest rate percentage	8.205%
6.25% Senior notes due September 2040 [Member]
Condensed Financial Statements, Captions [Line Items]
Debt interest rate percentage	6.25%
4.250% Senior notes due 2042 [Member]
Condensed Financial Statements, Captions [Line Items]
Debt interest rate percentage	4.25%
4.45% notes due 2043 [Member]
Condensed Financial Statements, Captions [Line Items]
Debt interest rate percentage	4.45%
4.00% notes due 2023 [Member]
Condensed Financial Statements, Captions [Line Items]
Debt interest rate percentage	4.00%
2.875% notes due 2026 [Member]
Condensed Financial Statements, Captions [Line Items]
Debt interest rate percentage	2.875%
3.50% Notes due June 2024 [Member]
Condensed Financial Statements, Captions [Line Items]
Debt interest rate percentage	3.50%
4.60% notes due May 2044 [Member]
Condensed Financial Statements, Captions [Line Items]
Debt interest rate percentage	4.60%
4.75% Notes Due May 2045 [Member]
Condensed Financial Statements, Captions [Line Items]
Debt interest rate percentage	4.75%
3.50% notes due 2024 [Member]
Condensed Financial Statements, Captions [Line Items]
Debt interest rate percentage	3.50%
4.60% notes due 2044 [Member]
Condensed Financial Statements, Captions [Line Items]
Debt interest rate percentage	4.60%
4.75% Notes Due 2045 [Member]
Condensed Financial Statements, Captions [Line Items]
Debt interest rate percentage	4.75%

Guarantee of Registered Secur67

Guarantee of Registered Securities - Condensed Consolidating Statement of Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Revenue
Commissions, fees and other	$ 2,800	$ 2,913	$ 5,642	$ 5,854
Fiduciary investment income	5	6	10	12
Total revenue	2,805	2,919	5,652	5,866
Expenses
Compensation and benefits	1,653	1,708	3,336	3,459
Other general expenses	875	766	1,598	1,493
Total operating expenses	2,528	2,474	4,934	4,952
Operating income	277	445	718	914
Interest income	4	2	7	4
Interest expense	(68)	(65)	(133)	(123)
Intercompany interest income (expense)	0	0	0	0
Intercompany other (expense) income	0	0	0	0
Other income (expense)	1	(2)	43	(1)
Income before income taxes	214	380	635	794
Income tax (benefit) expense	26	67	106	145
(Loss) income before equity in earnings of subsidiaries	188	313	529	649
Equity in earnings of subsidiaries, net of tax	0	0	0	0
Net income	188	313	529	649
Less: Net income attributable to noncontrolling interests	10	9	23	20
Net income attributable to Aon shareholders	178	304	506	629
Aon plc [Member]
Revenue
Commissions, fees and other	0	0	0	0
Fiduciary investment income	0	0	0	0
Total revenue	0	0	0	0
Expenses
Compensation and benefits	5	6	57	72
Other general expenses	(4)	1	9	6
Total operating expenses	1	7	66	78
Operating income	(1)	(7)	(66)	(78)
Interest income	(5)	(2)	(9)	(4)
Interest expense	(29)	(15)	(54)	(25)
Intercompany interest income (expense)	119	111	239	222
Intercompany other (expense) income	(56)	(54)	(106)	(72)
Other income (expense)	(1)	(1)	1	(1)
Income before income taxes	27	32	5	42
Income tax (benefit) expense	6	6	1	9
(Loss) income before equity in earnings of subsidiaries	21	26	4	33
Equity in earnings of subsidiaries, net of tax	157	278	502	596
Net income	178	304	506	629
Less: Net income attributable to noncontrolling interests	0	0	0	0
Net income attributable to Aon shareholders	178	304	506	629
Aon Corporation [Member]
Revenue
Commissions, fees and other	0	0	0	0
Fiduciary investment income	0	0	0	0
Total revenue	0	0	0	0
Expenses
Compensation and benefits	10	6	21	13
Other general expenses	2	3	4	5
Total operating expenses	12	9	25	18
Operating income	(12)	(9)	(25)	(18)
Interest income	4	0	7	1
Interest expense	(33)	(32)	(68)	(63)
Intercompany interest income (expense)	(116)	(73)	(221)	(147)
Intercompany other (expense) income	(15)	(4)	(23)	(19)
Other income (expense)	0	8	8	8
Income before income taxes	(172)	(110)	(322)	(238)
Income tax (benefit) expense	(66)	(42)	(117)	(92)
(Loss) income before equity in earnings of subsidiaries	(106)	(68)	(205)	(146)
Equity in earnings of subsidiaries, net of tax	170	288	571	621
Net income	64	220	366	475
Less: Net income attributable to noncontrolling interests	0	0	0	0
Net income attributable to Aon shareholders	64	220	366	475
Other Non-Guarantor Subsidiaries [Member]
Revenue
Commissions, fees and other	2,800	2,913	5,642	5,854
Fiduciary investment income	5	6	10	12
Total revenue	2,805	2,919	5,652	5,866
Expenses
Compensation and benefits	1,638	1,696	3,258	3,374
Other general expenses	877	762	1,585	1,482
Total operating expenses	2,515	2,458	4,843	4,856
Operating income	290	461	809	1,010
Interest income	5	4	9	7
Interest expense	(6)	(18)	(11)	(35)
Intercompany interest income (expense)	(3)	(38)	(18)	(75)
Intercompany other (expense) income	71	58	129	91
Other income (expense)	2	(9)	34	(8)
Income before income taxes	359	458	952	990
Income tax (benefit) expense	86	103	222	228
(Loss) income before equity in earnings of subsidiaries	273	355	730	762
Equity in earnings of subsidiaries, net of tax	64	220	366	475
Net income	337	575	1,096	1,237
Less: Net income attributable to noncontrolling interests	10	9	23	20
Net income attributable to Aon shareholders	327	566	1,073	1,217
Consolidating Adjustments [Member]
Revenue
Commissions, fees and other	0	0	0	0
Fiduciary investment income	0	0	0	0
Total revenue	0	0	0	0
Expenses
Compensation and benefits	0	0	0	0
Other general expenses	0	0	0	0
Total operating expenses	0	0	0	0
Operating income	0	0	0	0
Interest income	0	0	0	0
Interest expense	0	0	0	0
Intercompany interest income (expense)	0	0	0	0
Intercompany other (expense) income	0	0	0	0
Other income (expense)	0	0	0	0
Income before income taxes	0	0	0	0
Income tax (benefit) expense	0	0	0	0
(Loss) income before equity in earnings of subsidiaries	0	0	0	0
Equity in earnings of subsidiaries, net of tax	(391)	(786)	(1,439)	(1,692)
Net income	(391)	(786)	(1,439)	(1,692)
Less: Net income attributable to noncontrolling interests	0	0	0	0
Net income attributable to Aon shareholders	$ (391)	$ (786)	$ (1,439)	$ (1,692)

Guarantee of Registered Secur68

Guarantee of Registered Securities - Condensed Consolidating Statement of Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Condensed Financial Statements, Captions [Line Items]
Net income	$ 188	$ 313	$ 529	$ 649
Less: Net income attributable to noncontrolling interests	10	9	23	20
Net income attributable to Aon shareholders	178	304	506	629
Change in fair value of financial instruments	(6)	10	(1)	20
Foreign currency translation adjustments	175	74	(147)	90
Post-retirement benefit obligation	21	18	44	44
Total other comprehensive (loss) income	190	102	(104)	154
Equity in other comprehensive loss of subsidiaries, net of tax	0	0	0	0
Less: Other comprehensive (loss) income attributable to noncontrolling interests	(1)	0	(2)	(2)
Total other comprehensive (loss) income attributable to Aon shareholders	191	102	(102)	156
Comprehensive income attributable to Aon shareholders	369	406	404	785
Aon plc [Member]
Condensed Financial Statements, Captions [Line Items]
Net income	178	304	506	629
Less: Net income attributable to noncontrolling interests	0	0	0	0
Net income attributable to Aon shareholders	178	304	506	629
Change in fair value of financial instruments	0	0	0	0
Foreign currency translation adjustments	0	0	0	0
Post-retirement benefit obligation	0	0	0	0
Total other comprehensive (loss) income	0	0	0	0
Equity in other comprehensive loss of subsidiaries, net of tax	191	102	(102)	156
Less: Other comprehensive (loss) income attributable to noncontrolling interests	0	0	0	0
Total other comprehensive (loss) income attributable to Aon shareholders	191	102	(102)	156
Comprehensive income attributable to Aon shareholders	369	406	404	785
Aon Corporation [Member]
Condensed Financial Statements, Captions [Line Items]
Net income	64	220	366	475
Less: Net income attributable to noncontrolling interests	0	0	0	0
Net income attributable to Aon shareholders	64	220	366	475
Change in fair value of financial instruments	2	(1)	1	0
Foreign currency translation adjustments	4	15	(19)	(2)
Post-retirement benefit obligation	9	5	17	11
Total other comprehensive (loss) income	15	19	(1)	9
Equity in other comprehensive loss of subsidiaries, net of tax	173	73	(94)	142
Less: Other comprehensive (loss) income attributable to noncontrolling interests	0	0	0	0
Total other comprehensive (loss) income attributable to Aon shareholders	188	92	(95)	151
Comprehensive income attributable to Aon shareholders	252	312	271	626
Other Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net income	337	575	1,096	1,237
Less: Net income attributable to noncontrolling interests	10	9	23	20
Net income attributable to Aon shareholders	327	566	1,073	1,217
Change in fair value of financial instruments	(8)	11	(2)	20
Foreign currency translation adjustments	171	59	(128)	92
Post-retirement benefit obligation	12	13	27	33
Total other comprehensive (loss) income	175	83	(103)	145
Equity in other comprehensive loss of subsidiaries, net of tax	188	0	(95)	0
Less: Other comprehensive (loss) income attributable to noncontrolling interests	(1)	0	(2)	(2)
Total other comprehensive (loss) income attributable to Aon shareholders	364	83	(196)	147
Comprehensive income attributable to Aon shareholders	691	649	877	1,364
Consolidating Adjustments [Member]
Condensed Financial Statements, Captions [Line Items]
Net income	(391)	(786)	(1,439)	(1,692)
Less: Net income attributable to noncontrolling interests	0	0	0	0
Net income attributable to Aon shareholders	(391)	(786)	(1,439)	(1,692)
Change in fair value of financial instruments	0	0	0	0
Foreign currency translation adjustments	0	0	0	0
Post-retirement benefit obligation	0	0	0	0
Total other comprehensive (loss) income	0	0	0	0
Equity in other comprehensive loss of subsidiaries, net of tax	(552)	(175)	291	(298)
Less: Other comprehensive (loss) income attributable to noncontrolling interests	0	0	0	0
Total other comprehensive (loss) income attributable to Aon shareholders	(552)	(175)	291	(298)
Comprehensive income attributable to Aon shareholders	$ (943)	$ (961)	$ (1,148)	$ (1,990)

Guarantee of Registered Secur69

Guarantee of Registered Securities - Condensed Consolidating Statement of Financial Position (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2013
CURRENT ASSETS :
Cash and cash equivalents	$ 367	$ 374	$ 418	$ 477
Short-term investments	484	394
Receivables, net	2,684	2,815
Fiduciary assets	11,389	11,638
Intercompany receivables	0	0
Other current assets	731	602
Total Current Assets	15,655	15,823
Goodwill	8,661	8,860
Intangible assets, net	2,350	2,520
Fixed assets, net	782	765
Intercompany receivables	0	0
Other non-current assets	1,755	1,804
Investment in subsidiary	0	0
TOTAL ASSETS	29,203	29,772
CURRENT LIABILITIES
Fiduciary liabilities	11,389	11,638
Short-term debt and current portion of long-term debt	1,237	783
Accounts payable and accrued liabilities	1,368	1,805
Intercompany payables	0	0
Other current liabilities	845	788
Total Current Liabilities	14,839	15,014
Long-term debt	4,824	4,799
Pension, other post-retirement and post-employment liabilities	1,944	2,141
Intercompany payables	0	0
Other non-current liabilities	1,140	1,187
TOTAL LIABILITIES	22,747	23,141
TOTAL AON SHAREHOLDERS' EQUITY	6,398	6,571
Noncontrolling interests	58	60
TOTAL EQUITY	6,456	6,631
TOTAL LIABILITIES AND EQUITY	29,203	29,772
Aon plc [Member]
CURRENT ASSETS :
Cash and cash equivalents	0	0	0	0
Short-term investments	0	0
Receivables, net	0	0
Fiduciary assets	0	0
Intercompany receivables	258	455
Other current assets	2	2
Total Current Assets	260	457
Goodwill	0	0
Intangible assets, net	0	0
Fixed assets, net	0	0
Intercompany receivables	7,379	7,399
Other non-current assets	189	179
Investment in subsidiary	4,488	4,962
TOTAL ASSETS	12,316	12,997
CURRENT LIABILITIES
Fiduciary liabilities	0	0
Short-term debt and current portion of long-term debt	0	0
Accounts payable and accrued liabilities	2,597	3,755
Intercompany payables	223	122
Other current liabilities	0	0
Total Current Liabilities	2,820	3,877
Long-term debt	3,092	2,544
Pension, other post-retirement and post-employment liabilities	0	0
Intercompany payables	0	0
Other non-current liabilities	6	5
TOTAL LIABILITIES	5,918	6,426
TOTAL AON SHAREHOLDERS' EQUITY	6,398	6,571
Noncontrolling interests	0	0
TOTAL EQUITY	6,398	6,571
TOTAL LIABILITIES AND EQUITY	12,316	12,997
Aon Corporation [Member]
CURRENT ASSETS :
Cash and cash equivalents	2,221	2,727	181	247
Short-term investments	125	165
Receivables, net	0	0
Fiduciary assets	0	0
Intercompany receivables	3,847	2,814
Other current assets	223	226
Total Current Assets	6,416	5,932
Goodwill	0	0
Intangible assets, net	0	0
Fixed assets, net	0	0
Intercompany receivables	581	600
Other non-current assets	693	697
Investment in subsidiary	15,799	15,200
TOTAL ASSETS	23,489	22,429
CURRENT LIABILITIES
Fiduciary liabilities	0	0
Short-term debt and current portion of long-term debt	1,225	767
Accounts payable and accrued liabilities	49	58
Intercompany payables	9,975	8,960
Other current liabilities	55	49
Total Current Liabilities	11,304	9,834
Long-term debt	1,418	1,917
Pension, other post-retirement and post-employment liabilities	1,336	1,396
Intercompany payables	8,787	7,277
Other non-current liabilities	102	125
TOTAL LIABILITIES	22,947	20,549
TOTAL AON SHAREHOLDERS' EQUITY	542	1,880
Noncontrolling interests	0	0
TOTAL EQUITY	542	1,880
TOTAL LIABILITIES AND EQUITY	23,489	22,429
Other Non-Guarantor Subsidiaries [Member]
CURRENT ASSETS :
Cash and cash equivalents	707	1,361	1,416	1,246
Short-term investments	359	229
Receivables, net	2,684	2,815
Fiduciary assets	11,389	11,638
Intercompany receivables	10,286	9,156
Other current assets	538	407
Total Current Assets	25,963	25,606
Goodwill	8,661	8,860
Intangible assets, net	2,350	2,520
Fixed assets, net	782	765
Intercompany receivables	1,621	111
Other non-current assets	1,656	1,718
Investment in subsidiary	542	1,880
TOTAL ASSETS	41,575	41,460
CURRENT LIABILITIES
Fiduciary liabilities	11,389	11,638
Short-term debt and current portion of long-term debt	12	16
Accounts payable and accrued liabilities	1,283	1,706
Intercompany payables	4,194	3,343
Other current liabilities	822	772
Total Current Liabilities	17,700	17,475
Long-term debt	314	338
Pension, other post-retirement and post-employment liabilities	608	745
Intercompany payables	794	833
Other non-current liabilities	1,814	1,847
TOTAL LIABILITIES	21,230	21,238
TOTAL AON SHAREHOLDERS' EQUITY	20,287	20,162
Noncontrolling interests	58	60
TOTAL EQUITY	20,345	20,222
TOTAL LIABILITIES AND EQUITY	41,575	41,460
Consolidating Adjustments [Member]
CURRENT ASSETS :
Cash and cash equivalents	(2,561)	(3,714)	$ (1,179)	$ (1,016)
Short-term investments	0	0
Receivables, net	0	0
Fiduciary assets	0	0
Intercompany receivables	(14,391)	(12,425)
Other current assets	(32)	(33)
Total Current Assets	(16,984)	(16,172)
Goodwill	0	0
Intangible assets, net	0	0
Fixed assets, net	0	0
Intercompany receivables	(9,581)	(8,110)
Other non-current assets	(783)	(790)
Investment in subsidiary	(20,829)	(22,042)
TOTAL ASSETS	(48,177)	(47,114)
CURRENT LIABILITIES
Fiduciary liabilities	0	0
Short-term debt and current portion of long-term debt	0	0
Accounts payable and accrued liabilities	(2,561)	(3,714)
Intercompany payables	(14,392)	(12,425)
Other current liabilities	(32)	(33)
Total Current Liabilities	(16,985)	(16,172)
Long-term debt	0	0
Pension, other post-retirement and post-employment liabilities	0	0
Intercompany payables	(9,581)	(8,110)
Other non-current liabilities	(782)	(790)
TOTAL LIABILITIES	(27,348)	(25,072)
TOTAL AON SHAREHOLDERS' EQUITY	(20,829)	(22,042)
Noncontrolling interests	0	0
TOTAL EQUITY	(20,829)	(22,042)
TOTAL LIABILITIES AND EQUITY	$ (48,177)	$ (47,114)

Guarantee of Registered Secur70

Guarantee of Registered Securities - Condensed Consolidating Statement of Cash Flows (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
CASH FLOWS FROM OPERATING ACTIVITIES
CASH PROVIDED BY (USED FOR) OPERATING ACTIVITIES	$ 365	$ 333
CASH FLOWS FROM INVESTING ACTIVITIES
Proceeds from sale of long-term investments	10	48
Purchases of long-term investments	(1)	(14)
Net sales of short-term investments - non-fiduciary	(97)	217
Acquisition of businesses, net of cash acquired	(23)	(83)
Proceeds from sale of businesses	52	1
Capital expenditures	(142)	(115)
CASH (USED FOR) PROVIDED BY INVESTING ACTIVITIES	(201)	54
CASH FLOWS FROM FINANCING ACTIVITIES
Share repurchase	(550)	(1,250)
Advances from (to) affiliates	0	0
Issuance of shares for employee benefit plans	52	40
Issuance of debt	2,445	3,324
Repayment of debt	(1,896)	(1,745)
Deposit with trustee	0	681
Cash dividends to shareholders	(156)	(128)
Purchase of shares from noncontrolling interests	(5)	1
Dividends paid to noncontrolling interests	(18)	(10)
CASH USED FOR FINANCING ACTIVITIES	(128)	(449)
EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS	(43)	3
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	(7)	(59)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	374	477
CASH AND CASH EQUIVALENTS AT END OF PERIOD	367	418
Aon plc [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
CASH PROVIDED BY (USED FOR) OPERATING ACTIVITIES	(120)	265
CASH FLOWS FROM INVESTING ACTIVITIES
Proceeds from sale of long-term investments	0	0
Purchases of long-term investments	0	0
Net sales of short-term investments - non-fiduciary	0	0
Acquisition of businesses, net of cash acquired	0	0
Proceeds from sale of businesses	0	0
Capital expenditures	0	0
CASH (USED FOR) PROVIDED BY INVESTING ACTIVITIES	0	0
CASH FLOWS FROM FINANCING ACTIVITIES
Share repurchase	(550)	(1,250)
Advances from (to) affiliates	172	(522)
Issuance of shares for employee benefit plans	52	40
Issuance of debt	712	2,169
Repayment of debt	(110)	(574)
Deposit with trustee		0
Cash dividends to shareholders	(156)	(128)
Purchase of shares from noncontrolling interests	0	0
Dividends paid to noncontrolling interests	0	0
CASH USED FOR FINANCING ACTIVITIES	120	(265)
EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS	0	0
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	0	0
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	0	0
CASH AND CASH EQUIVALENTS AT END OF PERIOD	0	0
Aon Corporation [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
CASH PROVIDED BY (USED FOR) OPERATING ACTIVITIES	(368)	(215)
CASH FLOWS FROM INVESTING ACTIVITIES
Proceeds from sale of long-term investments	0	37
Purchases of long-term investments	(1)	(14)
Net sales of short-term investments - non-fiduciary	41	27
Acquisition of businesses, net of cash acquired	0	0
Proceeds from sale of businesses	0	0
Capital expenditures	0	0
CASH (USED FOR) PROVIDED BY INVESTING ACTIVITIES	40	50
CASH FLOWS FROM FINANCING ACTIVITIES
Share repurchase	0	0
Advances from (to) affiliates	(134)	99
Issuance of shares for employee benefit plans	0	0
Issuance of debt	1,732	1,161
Repayment of debt	(1,776)	(1,161)
Deposit with trustee		0
Cash dividends to shareholders	0	0
Purchase of shares from noncontrolling interests	0	0
Dividends paid to noncontrolling interests	0	0
CASH USED FOR FINANCING ACTIVITIES	(178)	99
EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS	0	0
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	(506)	(66)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	2,727	247
CASH AND CASH EQUIVALENTS AT END OF PERIOD	2,221	181
Other Non-Guarantor Subsidiaries [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
CASH PROVIDED BY (USED FOR) OPERATING ACTIVITIES	853	283
CASH FLOWS FROM INVESTING ACTIVITIES
Proceeds from sale of long-term investments	10	11
Purchases of long-term investments	0	0
Net sales of short-term investments - non-fiduciary	(138)	190
Acquisition of businesses, net of cash acquired	(23)	(83)
Proceeds from sale of businesses	52	1
Capital expenditures	(142)	(115)
CASH (USED FOR) PROVIDED BY INVESTING ACTIVITIES	(241)	4
CASH FLOWS FROM FINANCING ACTIVITIES
Share repurchase	0	0
Advances from (to) affiliates	(1,191)	586
Issuance of shares for employee benefit plans	0	0
Issuance of debt	1	(6)
Repayment of debt	(10)	(10)
Deposit with trustee		681
Cash dividends to shareholders	0	0
Purchase of shares from noncontrolling interests	(5)	1
Dividends paid to noncontrolling interests	(18)	(10)
CASH USED FOR FINANCING ACTIVITIES	(1,223)	(120)
EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS	(43)	3
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	(654)	170
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	1,361	1,246
CASH AND CASH EQUIVALENTS AT END OF PERIOD	707	1,416
Consolidating Adjustments [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
CASH PROVIDED BY (USED FOR) OPERATING ACTIVITIES	0	0
CASH FLOWS FROM INVESTING ACTIVITIES
Proceeds from sale of long-term investments	0	0
Purchases of long-term investments	0	0
Net sales of short-term investments - non-fiduciary	0	0
Acquisition of businesses, net of cash acquired	0	0
Proceeds from sale of businesses	0	0
Capital expenditures	0	0
CASH (USED FOR) PROVIDED BY INVESTING ACTIVITIES	0	0
CASH FLOWS FROM FINANCING ACTIVITIES
Share repurchase	0	0
Advances from (to) affiliates	1,153	(163)
Issuance of shares for employee benefit plans	0	0
Issuance of debt	0	0
Repayment of debt	0	0
Deposit with trustee		0
Cash dividends to shareholders	0	0
Purchase of shares from noncontrolling interests	0	0
Dividends paid to noncontrolling interests	0	0
CASH USED FOR FINANCING ACTIVITIES	1,153	(163)
EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS	0	0
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	1,153	(163)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	(3,714)	(1,016)
CASH AND CASH EQUIVALENTS AT END OF PERIOD	$ (2,561)	$ (1,179)