Benefit Plans

The components of net periodic benefit cost for the three months ended September 30 were as follows ($ in millions):



	Pension benefits						Other retirement benefits					Total
	2013			2012			2013			2012		2013			2012
Service cost	$	2.3		$	2.1		$	0.1		$	0.3	$	2.4		$	2.4
Interest cost	3.6			3.7			—			0.3		3.6			4.0
Expected return on assets	(4.3		)	(4.0		)	—			—		(4.3		)	(4.0		)
Amortization of prior service credit	(0.3		)	(0.3		)	—			—		(0.3		)	(0.3		)
Recognized actuarial losses	2.2			1.9			(0.5		)	—		1.7			1.9
Net periodic benefit cost	$	3.5		$	3.4		$	(0.4	)	$	0.6	$	3.1		$	4.0

The components of net periodic benefit cost for the nine months ended September 30 were as follows ($ in millions):



	Pension benefits						Other retirement benefits					Total
	2013			2012			2013			2012		2013			2012
Service cost	$	7.3		$	6.7		$	0.8		$	1.0	$	8.1		$	7.7
Interest cost	11.0			11.4			0.5			0.7		11.5			12.1
Expected return on assets	(12.9		)	(12.2		)	—			—		(12.9		)	(12.2		)
Amortization of transition obligation	0.1			0.1			—			—		0.1			0.1
Amortization of prior service credit	(1.0		)	(1.1		)	—			0.1		(1.0		)	(1.0		)
Recognized actuarial losses	6.9			6.2			(0.5		)	—		6.4			6.2
Net periodic benefit cost	$	11.4		$	11.1		$	0.8		$	1.8	$	12.2		$	12.9