Condensed Consolidated Statements of Income (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Revenue
Commissions, fees and other	$ 2,873		$ 2,786		$ 8,727		$ 8,585
Fiduciary investment income	7		8		19		21
Total revenue	2,880		2,794		8,746		8,606
Expenses
Compensation and benefits	1,707		1,666		5,166		5,103
Other general expenses	756		764		2,249		2,347
Total operating expenses	2,463		2,430		7,415		7,450
Operating income	417		364		1,331		1,156
Interest income	3		3		7		6
Interest expense	(65)		(53)		(188)		(153)
Other income	35		39		34		54
Income before income taxes	390		353		1,184		1,063
Income taxes	75		89		220		275
Net income	315		264		964		788
Less: Net income attributable to noncontrolling interests	6		8		26		30
Net income attributable to Aon shareholders	$ 309		$ 256		$ 938		$ 758
Basic net income per share attributable to Aon shareholders	$ 1.06		$ 0.83		$ 3.15		$ 2.42
Diluted net income per share attributable to Aon shareholders	$ 1.04		$ 0.82		$ 3.11		$ 2.39
Cash dividends per share paid on ordinary shares	$ 0.25		$ 0.18		$ 0.68		$ 0.51
Weighted average ordinary shares outstanding - basic (in shares)	292.3	[1]	309.5	[1]	298.1	[1]	313.2	[1]
Weighted average ordinary shares outstanding - diluted (in shares)	296.1		312.9		301.6		316.7

[1] Includes 2.9 million and 3.8 million of participating securities for the three months ended September 30, 2014 and 2013, respectively, and 3.1 million and 4.0 million of participating securities for the nine months ended September 30, 2014 and 2013, respectively.