Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenue
Commissions, fees and other	$ 2,740	$ 2,736	$ 8,288	$ 8,378
Fiduciary investment income	6	6	16	16
Total revenue	2,746	2,742	8,304	8,394
Expenses
Compensation and benefits	1,611	1,644	4,948	4,980
Other general expenses	713	685	2,079	2,283
Total operating expenses	2,324	2,329	7,027	7,263
Operating income	422	413	1,277	1,131
Interest income	1	3	6	10
Interest expense	(70)	(72)	(212)	(205)
Other income	9	8	27	51
Income before income taxes	362	352	1,098	987
Income taxes	48	49	177	155
Net income	314	303	921	832
Less: Net income attributable to noncontrolling interests	7	8	27	31
Net income attributable to Aon shareholders	$ 307	$ 295	$ 894	$ 801
Basic net income per share attributable to Aon shareholders (in dollars per share)	$ 1.15	$ 1.05	$ 3.32	$ 2.83
Diluted net income per share attributable to Aon shareholders (in dollars per share)	1.14	1.04	3.30	2.80
Cash dividends per share paid on ordinary shares (in dollars per share)	$ 0.33000000	$ 0.3	$ 0.961	$ 0.85
Weighted average ordinary shares outstanding - basic (in shares)	267.5	280.9	269.1	283.2
Weighted average ordinary shares outstanding - diluted (in shares)	269.6	283.8	271.0	285.9