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	301.0
Weighted average ordinary shares outstanding - diluted (in shares)	286.7	301.6	286.9	304.4