Restructuring	9 Months Ended
Sep. 30, 2014
Restructuring and Related Activities [Abstract]
Restructuring	Restructuring Aon Hewitt Restructuring Plan On October 14, 2010, the Company announced a global restructuring plan ("Aon Hewitt Plan") in connection with the acquisition of Hewitt Associates, Inc. The Aon Hewitt Plan was intended to streamline operations across the combined Aon Hewitt organization. The Company incurred all remaining costs for the Aon Hewitt Plan and the plan was closed in the fourth quarter of 2013. For the three and nine months ended September 30, 2014, no charges were taken under the Aon Hewitt Plan. For the three months ended September 30, 2013, $30 million of restructuring expenses were charged, of which $24 million and $6 million were in the Risk Solutions segment and HR Solutions segment, respectively. For the nine months ended September 30, 2013, $109 million of restructuring expenses were charged, of which $52 million and $57 million were in the Risk Solutions segment and HR Solutions segment, respectively. As of December 31, 2013, the remaining liabilities for the Company's restructuring plans were $166 million. During the nine months ended September 30, 2014, the Company made cash payments of $70 million, resulting in remaining restructuring liabilities of $90 million as of September 30, 2014. The remaining $6 million reduction in the liability is due fluctuation in foreign exchange rates.

Restructuring

9 Months Ended

Sep. 30, 2014

Restructuring and Related Activities [Abstract]

Aon Hewitt Restructuring Plan

On October 14, 2010, the Company announced a global restructuring plan ("Aon Hewitt Plan") in connection with the acquisition of Hewitt Associates, Inc. The Aon Hewitt Plan was intended to streamline operations across the combined Aon Hewitt organization. The Company incurred all remaining costs for the Aon Hewitt Plan and the plan was closed in the fourth quarter of 2013. For the three and nine months ended September 30, 2014, no charges were taken under the Aon Hewitt Plan. For the three months ended September 30, 2013, $30 million of restructuring expenses were charged, of which $24 million and $6 million were in the Risk Solutions segment and HR Solutions segment, respectively. For the nine months ended September 30, 2013, $109 million of restructuring expenses were charged, of which $52 million and $57 million were in the Risk Solutions segment and HR Solutions segment, respectively.

As of December 31, 2013, the remaining liabilities for the Company's restructuring plans were $166 million. During the nine months ended September 30, 2014, the Company made cash payments of $70 million, resulting in remaining restructuring liabilities of $90 million as of September 30, 2014. The remaining $6 million reduction in the liability is due fluctuation in foreign exchange rates.