Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenue
Commissions, fees and other	$ 11,605	$ 11,661	$ 12,019
Fiduciary investment income	22	21	26
Total revenue	11,627	11,682	12,045
Expenses
Compensation and benefits	6,914	6,837	7,014
Other general expenses	2,807	2,997	3,065
Total operating expenses	9,721	9,834	10,079
Operating income	1,906	1,848	1,966
Interest income	9	14	10
Interest expense	(282)	(273)	(255)
Other income	36	100	44
Income before income taxes	1,669	1,689	1,765
Income taxes	239	267	334
Net income	1,430	1,422	1,431
Less: Net income attributable to noncontrolling interests	34	37	34
Net income attributable to Aon shareholders	$ 1,396	$ 1,385	$ 1,397
Basic net income per share attributable to Aon shareholders (in dollars per share)	$ 5.21	$ 4.93	$ 4.73
Diluted net income per share attributable to Aon shareholders (in dollars per share)	5.16	4.88	4.66
Cash dividends per share paid on ordinary shares (in dollars per share)	$ 1.29	$ 1.15	$ 0.92
Weighted average ordinary shares outstanding - basic (in shares)	268.1	280.8	295.5
Weighted average ordinary shares outstanding - diluted (in shares)	270.3	283.8	299.6