The following table shows components of our pension and other post-retirement benefits expense for the three months ended September 30, 2017 and 2016 (in millions):



	2017 Pension Benefits			2016 Pension Benefits			2017 Retiree Health and Life		2016 Retiree Health and Life
Service cost	$	1.6		$	1.5		$	—	$	0.1
Interest cost	3.8			3.9			0.2		0.2
Expected return on plan assets	(5.9		)	(6.5		)	—		—
Settlement expense	—			5.7			—		—
Amortization of (1):
Unrecognized prior service credit	—			(0.2		)	—		(0.1		)
Unrecognized net actuarial loss	2.2			2.6			—		—
Net expense	$	1.7		$	7.0		$	0.2	$	0.2

The following table shows components of our pension and other post-retirement benefits expense for the nine months ended September 30, 2017 and 2016 (in millions):



	2017 Pension Benefits			2016 Pension Benefits			2017 Retiree Health and Life			2016 Retiree Health and Life
Service cost	$	4.9		$	4.5		$	0.1		$	0.2
Interest cost	11.5			11.8			0.7			0.7
Expected return on plan assets	(17.9		)	(19.5		)	—			—
Settlement expense	0.1			5.7			—			—
Amortization of (1):
Unrecognized prior service credit	—			(0.7		)	(0.1		)	(0.2		)
Unrecognized net actuarial loss (gain)	6.9			7.7			(0.2		)	(0.2		)
Net expense	$	5.5		$	9.5		$	0.5		$	0.5

________

(1) Amounts reclassified from accumulated other comprehensive loss.

During the third quarter of 2016, we recorded a settlement accounting adjustment of $5.7 million attributable to lump sum payments elected by eligible retirees as part of a voluntary early retirement program offered in 2015.