Note 10—Benefit Plans and Other Postretirement Benefits

The Company and certain of its domestic subsidiaries have defined benefit pension plans (the “U.S. Plans”), which cover certain U.S. employees and which represent the majority of the plan assets and benefit obligations of the aggregate defined benefit plans of the Company. The U.S. Plans’ benefits are generally based on years of service and compensation and are generally noncontributory. Certain U.S. employees not covered by the U.S. Plans are covered by defined contribution plans. Certain foreign subsidiaries have defined benefit plans covering their employees (the “International Plans” and, together with the U.S. Plans, the “Plans”). The following is a summary, based on the most recent actuarial valuations of the Company’s net cost for pension benefits, of the Plans and other postretirement benefits for the three and nine months ended September 30, 2018 and 2017:


					Other Postretirement
	Pension Benefits				Benefits
Three Months Ended September 30:	2018		2017		2018		2017
Service cost	$	1.8	$	2.5	$	—	$	—
Interest cost		4.9		5.0		0.1		0.1
Expected return on plan assets		(9.6)		(7.8)		—		—
Amortization of prior service cost		0.6		0.7		—		—
Amortization of net actuarial losses		5.8		5.8		0.1		0.2
Net pension expense	$	3.5	$	6.2	$	0.2	$	0.3

Nine Months Ended September 30:
Service cost	$	5.6	$	7.3	$	—	$	—
Interest cost		14.7		14.9		0.3		0.3
Expected return on plan assets		(28.9)		(23.2)		—		—
Amortization of prior service cost		1.8		2.1		—		—
Amortization of net actuarial losses		17.5		17.2		0.3		0.5
Net pension expense	$	10.7	$	18.3	$	0.6	$	0.8

As a result of the adoption of ASU 2017‑07, the Company records service costs in the same line item as the respective employee compensation costs and within operating income, while all other pension-related costs including interest cost, expected return on plan assets, amortization of prior service cost and amortization of net actuarial losses are reported separately within Other income, net in the Condensed Consolidated Statements of Income.

In January 2018, the Company made a voluntary cash contribution of approximately $81.0 to fully fund the U.S. Plans, and estimates that, based on current actuarial calculations, cash contributions to the Plans will aggregate approximately $90.0 in 2018. The timing and amount of cash contributions in subsequent years will depend on a number of factors, including the investment performance of the Plans’ assets. This voluntary cash contribution made in the first quarter of 2018 is reflected as cash used in operating activities within Net change in accrued pension and postretirement benefits in the Condensed Consolidated Statements of Cash Flow.

The Company offers various defined contribution plans for certain U.S. and foreign employees. Participation in these plans is based on certain eligibility requirements. The Company matches the majority of employee contributions to the U.S. defined contribution plans with cash contributions up to a maximum of 5% of eligible compensation. During the nine months ended September 30, 2018 and 2017, the Company provided matching contributions to the U.S. defined contribution plans of approximately $6.2 and $5.0, respectively.