Note 10: Benefit Plans

We sponsor three qualified, noncontributory defined benefit pension plans. These plans cover substantially all employees hired before July 2007, other than those covered by union-administered plans. Normal retirement age is 65, but the plans contain provisions for earlier retirement. Benefits for the Salaried Plan and the Chemicals Hourly Plan are generally based on salaries or wages and years of service; the Construction Materials Hourly Plan provides benefits equal to a flat dollar amount for each year of service. In addition to these qualified plans, we sponsor three unfunded, nonqualified pension plans.

Effective July 2007, we amended our defined benefit pension plans to no longer accept new participants. Effective December 2013, we amended our defined benefit pension plans to freeze future benefit accruals for salaried pension participants. Effective December 31, 2015, we amended our defined benefit pension plans to freeze earnings for salaried pension participants.

The following table sets forth the components of net periodic pension benefit cost:



PENSION BENEFITS	Three Months Ended		Six Months Ended
	June 30		June 30
in thousands	2018	2017	2018	2017
Components of Net Periodic Benefit Cost
Service cost	$ 1,429	$ 1,654	$ 2,858	$ 3,308
Interest cost	8,875	9,058	17,751	18,115
Expected return on plan assets	(14,797)	(12,096)	(29,594)	(24,192)
Amortization of prior service cost	335	335	670	670
Amortization of actuarial loss	2,456	1,823	4,913	3,647
Net periodic pension benefit cost (credit)	$ (1,702)	$ 774	$ (3,402)	$ 1,548
Pretax reclassifications from AOCI included in
net periodic pension benefit cost	$ 2,791	$ 2,158	$ 5,583	$ 4,317

The contributions to pension plans for the six months ended June 30, 2018 and 2017, as reflected on the Condensed Consolidated Statements of Cash Flows, pertain to benefit payments under nonqualified plans and a first quarter 2018 discretionary qualified plan contribution of $100,000,000.

In addition to pension benefits, we provide certain healthcare and life insurance benefits for some retired employees. In 2012, we amended our postretirement healthcare plan to cap our portion of the medical coverage cost at the 2015 level. Substantially all our salaried employees and, where applicable, certain of our hourly employees may become eligible for these benefits if they reach a qualifying age and meet certain service requirements. Generally, Company-provided healthcare benefits end when covered individuals become eligible for Medicare benefits, become eligible for other group insurance coverage or reach age 65, whichever occurs first.

The following table sets forth the components of net periodic other postretirement benefit cost:



OTHER POSTRETIREMENT BENEFITS	Three Months Ended		Six Months Ended
	June 30		June 30
in thousands	2018	2017	2018	2017
Components of Net Periodic Benefit Cost
Service cost	$ 340	$ 291	$ 679	$ 583
Interest cost	310	315	620	630
Amortization of prior service credit	(990)	(1,059)	(1,981)	(2,118)
Amortization of actuarial gain	(325)	(396)	(649)	(793)
Net periodic postretirement benefit credit	$ (665)	$ (849)	$ (1,331)	$ (1,698)
Pretax reclassifications from AOCI included in
net periodic postretirement benefit credit	$ (1,315)	$ (1,455)	$ (2,630)	$ (2,911)

We present the service cost component of net periodic benefit cost in cost of revenues and selling, administrative and general expense consistent with employee compensation costs. The other components of net periodic benefit cost (credit) are reported within other nonoperating income in our accompanying Condensed Consolidated Statements of Comprehensive Income.