Commitments and Contingencies	9 Months Ended
Sep. 30, 2014
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. Aon has historically purchased E&O insurance and other insurance 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. Included in the matters described below are matters in which (1) loss is probable (2) loss is reasonably possible but not probable or (3) there exists the reasonable possibility of loss greater than the accrued amount. 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 $0.7 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 will change, and the estimates themselves will 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 predecessor of a retail insurance brokerage subsidiary of Aon provided insurance brokerage services to Northrop Grumman Corporation ("Northrop"). This subsidiary placed Northrop's property insurance program for the period covering 2005. Northrop suffered a substantial loss in August 2005 when Hurricane Katrina damaged Northrop's shipbuilding facilities in the Gulf States. Northrop's excess insurance carrier, Factory Mutual Insurance Company ("Factory Mutual"), denied coverage for storm surge damage pursuant to a flood exclusion in the excess policy. Northrop sued Factory Mutual in the United States District Court for the Central District of California. The district court granted summary judgment in Northrop's favor in August 2007. In August 2008, the United State Court of Appeals for the Ninth Circuit reversed the district court's ruling and held that the flood exclusion applied to storm surge damage. Northrop thereafter sought to join Aon's subsidiary as a defendant in the action against Factory Mutual, asserting that if Northrop's policy with Factory Mutual does not cover the Northrop storm surge losses, then the Aon subsidiary will be responsible for Northrop's losses. In August 2010, the court granted in large part Factory Mutual's motion for partial summary judgment regarding the applicability of the flood exclusion and denied Northrop's motion to add the Aon subsidiary as a defendant in the federal lawsuit. On January 27, 2011, Northrop filed suit against the 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. Northrop later settled its claims with Factory Mutual. In January 2014, Northrop filed an amended complaint, adding additional claims against the Aon subsidiary for intentional misrepresentation and concealment. Northrop seeks compensatory damages of approximately $340 million, which includes prejudgment interest and attorneys' fees, and punitive damages that are a multiple of the compensatory damages sought. Aon asserts several defenses, including, but not limited to, that it committed no error or omission in placing the Factory Mutual excess policy for Northrop and that Northrop did not suffer any damages as a result of Aon's conduct. 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 from numerous insurers with whom this Aon subsidiary placed the client's property insurance coverage. The insurers contend that only $50 million in coverage 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. 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 ($307 million at September 30, 2014 exchange rates), plus interest and costs. Aon believes that it has meritorious defenses and intends to vigorously defend itself against these allegations. On December 21, 2012, Mazeikiu Nafta ("MN"), which operates an oil refinery in Lithuania, sued an insurance brokerage subsidiary of Aon in the High Court of Justice in England & Wales, Queen's Bench Division, Commercial Court. Aon placed property damage and business interruption coverage for MN. There was a fire at the refinery in 2006. MN settled with insurers in November 2011. The claim was for $125 million, which was the shortfall alleged by MN to have been caused by Aon's failure to obtain appropriate business interruption coverage. On October 27, 2014, following 11 days of trial, the case was settled for $5 million with no admission of liability on the part of Aon. 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 predecessor of 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 ($48 million at September 30, 2014 exchange rates) and $3 million, plus legal fees and interest of approximately $30 million. Aon believes that it has meritorious defenses and intends to vigorously defend itself against these claims. 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. Predecessors of AXA granted predecessors of the Aon subsidiary 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 ($232 million at September 30, 2014 exchange rates). Aon believes that it has meritorious defenses and intends to vigorously defend itself against these claims. 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 ($73 million at September 30, 2014 exchange rates). Aon believes that it has meritorious defenses and intends to vigorously defend itself against this potential claim. 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 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) (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, and (5) Amended and Restated Trust Deed, among Aon Corporation, Aon plc, Aon Services Luxembourg & Co S.C.A. (formerly known as Aon Financial Services Luxembourg S.A.) ("Aon Luxembourg") and BNY Mellon Corporate Trustee Services Limited, as trustee (the "Luxembourg Trustee") (amending and restating the Trust Deed, dated as of July 1, 2009, as amended and restated on January 12, 2011, among Aon Delaware, Aon Luxembourg and the Luxembourg Trustee). Effective as of the same date, the Company also entered into agreements pursuant to which it agreed to guarantee the obligations of its subsidiaries arising under the (1) $450,000,000 Term Credit Agreement dated June 15, 2011, among Aon Corporation, as borrower, Bank of America, N.A., as administrative agent and the other agents and lenders party thereto, (2) $400,000,000 Five-Year Agreement dated March 20, 2012, among Aon Corporation, as borrower, Citibank, N.A., as administrative agent and the other agents and lenders party thereto and (3) €650,000,000 Facility Agreement, dated October 15, 2010, among Aon Corporation, the subsidiaries of Aon Corporation party thereto as borrowers, Citibank International plc, as agent, and the other agents and lenders party thereto, as amended on July 18, 2011. 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 for approximately $97 million at September 30, 2014, compared to $71 million at December 31, 2013. 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. Amounts are accrued in the Condensed Consolidated Financial Statements, and are recorded at fair value. 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 $16 million at September 30, 2014 compared to $34 million at December 31, 2013. During the three and nine months ended September 30, 2014, the Company funded $4 million and $18 million of these commitments, respectively. Premium Payments The Company has certain contractual contingent guarantees for premium payments owed by clients to certain insurance companies. Costs associated with these guarantees, to the extent estimable and probable, are provided in Aon's allowance for doubtful accounts. The maximum exposure with respect to such contractual contingent guarantees was approximately $83 million at September 30, 2014 compared to $98 million at December 31, 2013.

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. Aon has historically purchased E&O insurance and other insurance 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. Included in the matters described below are matters in which (1) loss is probable (2) loss is reasonably possible but not probable or (3) there exists the reasonable possibility of loss greater than the accrued amount. 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 $0.7 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 will change, and the estimates themselves will 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 predecessor of a retail insurance brokerage subsidiary of Aon provided insurance brokerage services to Northrop Grumman Corporation ("Northrop"). This subsidiary placed Northrop's property insurance program for the period covering 2005. Northrop suffered a substantial loss in August 2005 when Hurricane Katrina damaged Northrop's shipbuilding facilities in the Gulf States. Northrop's excess insurance carrier, Factory Mutual Insurance Company ("Factory Mutual"), denied coverage for storm surge damage pursuant to a flood exclusion in the excess policy. Northrop sued Factory Mutual in the United States District Court for the Central District of California. The district court granted summary judgment in Northrop's favor in August 2007. In August 2008, the United State Court of Appeals for the Ninth Circuit reversed the district court's ruling and held that the flood exclusion applied to storm surge damage. Northrop thereafter sought to join Aon's subsidiary as a defendant in the action against Factory Mutual, asserting that if Northrop's policy with Factory Mutual does not cover the Northrop storm surge losses, then the Aon subsidiary will be responsible for Northrop's losses. In August 2010, the court granted in large part Factory Mutual's motion for partial summary judgment regarding the applicability of the flood exclusion and denied Northrop's motion to add the Aon subsidiary as a defendant in the federal lawsuit. On January 27, 2011, Northrop filed suit against the 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. Northrop later settled its claims with Factory Mutual. In January 2014, Northrop filed an amended complaint, adding additional claims against the Aon subsidiary for intentional misrepresentation and concealment. Northrop seeks compensatory damages of approximately $340 million, which includes prejudgment interest and attorneys' fees, and punitive damages that are a multiple of the compensatory damages sought. Aon asserts several defenses, including, but not limited to, that it committed no error or omission in placing the Factory Mutual excess policy for Northrop and that Northrop did not suffer any damages as a result of Aon's conduct.

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 from numerous insurers with whom this Aon subsidiary placed the client's property insurance coverage. The insurers contend that only $50 million in coverage 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. 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 ($307 million at September 30, 2014 exchange rates), plus interest and costs. Aon believes that it has meritorious defenses and intends to vigorously defend itself against these allegations.

On December 21, 2012, Mazeikiu Nafta ("MN"), which operates an oil refinery in Lithuania, sued an insurance brokerage subsidiary of Aon in the High Court of Justice in England & Wales, Queen's Bench Division, Commercial Court. Aon placed property damage and business interruption coverage for MN. There was a fire at the refinery in 2006. MN settled with insurers in November 2011. The claim was for $125 million, which was the shortfall alleged by MN to have been caused by Aon's failure to obtain appropriate business interruption coverage. On October 27, 2014, following 11 days of trial, the case was settled for $5 million with no admission of liability on the part of Aon.

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 predecessor of 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 ($48 million at September 30, 2014 exchange rates) and $3 million, plus legal fees and interest of approximately $30 million. Aon believes that it has meritorious defenses and intends to vigorously defend itself against these claims.

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. Predecessors of AXA granted predecessors of the Aon subsidiary 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 ($232 million at September 30, 2014 exchange rates). Aon believes that it has meritorious defenses and intends to vigorously defend itself against these claims.

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 ($73 million at September 30, 2014 exchange rates). Aon believes that it has meritorious defenses and intends to vigorously defend itself against this potential claim.

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 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) (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, and (5) Amended and Restated Trust Deed, among Aon Corporation, Aon plc, Aon Services Luxembourg & Co S.C.A. (formerly known as Aon Financial Services Luxembourg S.A.) ("Aon Luxembourg") and BNY Mellon Corporate Trustee Services Limited, as trustee (the "Luxembourg Trustee") (amending and restating the Trust Deed, dated as of July 1, 2009, as amended and restated on January 12, 2011, among Aon Delaware, Aon Luxembourg and the Luxembourg Trustee).

Effective as of the same date, the Company also entered into agreements pursuant to which it agreed to guarantee the obligations of its subsidiaries arising under the (1) $450,000,000 Term Credit Agreement dated June 15, 2011, among Aon Corporation, as borrower, Bank of America, N.A., as administrative agent and the other agents and lenders party thereto, (2) $400,000,000 Five-Year Agreement dated March 20, 2012, among Aon Corporation, as borrower, Citibank, N.A., as administrative agent and the other agents and lenders party thereto and (3) €650,000,000 Facility Agreement, dated October 15, 2010, among Aon Corporation, the subsidiaries of Aon Corporation party thereto as borrowers, Citibank International plc, as agent, and the other agents and lenders party thereto, as amended on July 18, 2011.

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 for approximately $97 million at September 30, 2014, compared to $71 million at December 31, 2013. 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. Amounts are accrued in the Condensed Consolidated Financial Statements, and are recorded at fair value.

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 $16 million at September 30, 2014 compared to $34 million at December 31, 2013. During the three and nine months ended September 30, 2014, the Company funded $4 million and $18 million of these commitments, respectively.

Premium Payments

The Company has certain contractual contingent guarantees for premium payments owed by clients to certain insurance companies. Costs associated with these guarantees, to the extent estimable and probable, are provided in Aon's allowance for doubtful accounts. The maximum exposure with respect to such contractual contingent guarantees was approximately $83 million at September 30, 2014 compared to $98 million at December 31, 2013.