Employee Benefits (Tables)

6 Months Ended

Jun. 30, 2014

Compensation and Retirement Disclosure [Abstract]

Components of net periodic benefit cost for the pension plans

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

	Three months ended June 30,
	U.K.						U.S.						Other
	2014			2013			2014			2013			2014			2013
Service cost	$	—		$	—		$	—		$	—		$	—		$	4
Interest cost	58			51			32			28			12			11
Expected return on plan assets	(83		)	(74		)	(39		)	(35		)	(15		)	(14		)
Amortization of net actuarial loss	14			12			11			13			2			7
Total net periodic (benefit) cost	$	(11	)	$	(11	)	$	4		$	6		$	(1	)	$	8

	Six months ended June 30,
	U.K.						U.S.						Other
	2014			2013			2014			2013			2014			2013
Service cost	$	—		$	—		$	—		$	—		$	—		$	9
Interest cost	116			104			64			56			24			22
Expected return on plan assets	(165		)	(149		)	(78		)	(69		)	(30		)	(29		)
Amortization of net actuarial loss	27			24			21			26			4			13
Net periodic (benefit) cost	(22		)	(21		)	7			13			(2		)	15
Curtailment loss (gain) and other	—			—			1			—			(3		)	—
Total net periodic (benefit) cost	$	(22	)	$	(21	)	$	8		$	13		$	(5	)	$	15