Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenue
Total revenue	$ 3,219	$ 3,143
Expenses
Compensation and benefits	1,522	1,584
Information technology	111	117
Premises	73	87
Depreciation of fixed assets	41	40
Amortization of intangible assets	97	97
Other general expenses	342	346
Total operating expenses	2,186	2,271
Operating income	1,033	872
Interest income	2	2
Interest expense	(83)	(72)
Other income (expense)	29	0
Income from continuing operations before income taxes	981	802
Income tax expense	189	126
Net income from continuing operations	792	676
Net income (loss) from discontinued operations	(1)	0
Net income	791	676
Less: Net income attributable to noncontrolling interests	19	17
Net income attributable to Aon shareholders	$ 772	$ 659
Basic net income per share attributable to Aon shareholders
Continuing operations (in dollars per share)	$ 3.31	$ 2.72
Discontinued operations (in dollars per share)	0	0
Net income (in dollars per share)	3.31	2.72
Diluted net income per share attributable to Aon shareholders
Continuing operations (in dollars per share)	3.29	2.70
Discontinued operations (in dollars per share)	0	0
Net income (in dollars per share)	$ 3.29	$ 2.70
Weighted average ordinary shares outstanding - basic (in shares)	233.2	242.2
Weighted average ordinary shares outstanding - diluted (in shares)	234.5	243.7