EMPLOYEE BENEFIT PLANS

Net periodic pension and postretirement benefit cost for the Company’s defined pension and postretirement benefit plans for the three months ended September 30, 2017 and 2016 are set forth below (in millions):



	Three Months Ended September 30,
Pension benefits	2017			2016
Service cost	$	4.2		$	4.1
Interest cost	5.1			6.2
Expected return on plan assets	(8.9		)	(9.8		)
Amortization of net actuarial losses	3.2			2.5
Amortization of prior service cost	0.3			0.3
Net periodic pension cost	$	3.9		$	3.3



	Three Months Ended September 30,
Postretirement benefits	2017		2016
Interest cost	$	0.4	$	0.3
Net periodic postretirement benefit cost	$	0.4	$	0.3

Net periodic pension and postretirement benefit cost for the Company’s defined pension and postretirement benefit plans for the nine months ended September 30, 2017 and 2016 are set forth below (in millions):



	Nine Months Ended September 30,
Pension benefits	2017			2016
Service cost	$	12.8		$	12.3
Interest cost	15.3			19.0
Expected return on plan assets	(26.7		)	(30.2		)
Amortization of net actuarial losses	9.3			7.8
Amortization of prior service cost	0.9			0.8
Net periodic pension cost	$	11.6		$	9.7



	Nine Months Ended September 30,
Postretirement benefits	2017		2016
Service cost	$	0.1	$	—
Interest cost	1.2		1.1
Amortization of prior service cost	0.1		0.1
Net periodic postretirement benefit cost	$	1.4	$	1.2

The following table summarizes the activity in accumulated other comprehensive loss related to the Company’s defined pension and postretirement benefit plans during the nine months ended September 30, 2017 (in millions):



	Before-Tax Amount			Income Tax			After-Tax Amount
Accumulated other comprehensive loss as of December 31, 2016	$	(404.8	)	$	(100.3	)	$	(304.5	)
Amortization of net actuarial losses	9.3			1.4			7.9
Amortization of prior service cost	1.0			—			1.0
Accumulated other comprehensive loss as of September 30, 2017	$	(394.5	)	$	(98.9	)	$	(295.6	)

During the nine months ended September 30, 2017, approximately $22.5 million of contributions had been made to the Company’s defined pension benefit plans. The Company currently estimates its minimum contributions for 2017 to its defined pension benefit plans will aggregate approximately $29.1 million.

During the nine months ended September 30, 2017, the Company made approximately $1.3 million of contributions to its postretirement health care and life insurance benefit plans. The Company currently estimates that it will make approximately $1.5 million of contributions to its postretirement health care and life insurance benefit plans during 2017.