Employee Benefits

3 Months Ended

Mar. 31, 2013

Compensation and Retirement Disclosure [Abstract]

Employee Benefits

Employee Benefits

The following table provides the components of the net periodic benefit cost for Aon’s U.S. pension plans, along with its most significant international pension plans, which are located in the U.K., the Netherlands and Canada (in millions):

	Three months ended March 31,
	U.K. and Non-U.S.						U.S.
	2013			2012			2013			2012
Service cost	$	5		$	4		$	—		$	—
Interest cost	64			66			28			30
Expected return on plan assets	(90		)	(80		)	(34		)	(32		)
Amortization of net actuarial loss	18			14			13			11
Net periodic benefit cost	$	(3	)	$	4		$	7		$	9

Based on current assumptions, in 2013, Aon plans to contribute $167 million and $381 million to its U.S. and most significant international defined benefit pension plans, respectively.  During the three months ended March 31, 2013, contributions of $33 million were made to the Company’s U.S. pension plans and $167 million were made to its most significant international pension plans.