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.

In 2005, benefit accruals for our Chemicals Hourly Plan participants ceased upon the sale of our Chemicals business. Effective July 2007, we amended our defined benefit pension plans to no longer accept new participants. Future benefit accruals for participants in our salaried defined benefit pension plans ceased on December 31, 2013, while salaried participants’ earnings considered for benefit calculations were frozen on December 31, 2015.

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



PENSION BENEFITS	Three Months Ended		Nine Months Ended
	September 30		September 30
in thousands	2019	2018	2019	2018
Components of Net Periodic Benefit Cost
Service cost	$ 1,248	$ 1,429	$ 3,746	$ 4,287
Interest cost	9,410	8,876	28,230	26,627
Expected return on plan assets	(11,938)	(14,797)	(35,813)	(44,391)
Amortization of prior service cost	335	335	1,005	1,005
Amortization of actuarial loss	1,358	2,457	4,074	7,370
Net periodic pension benefit cost (credit)	$ 413	$ (1,700)	$ 1,242	$ (5,102)
Pretax reclassifications from AOCI included in
net periodic pension benefit cost	$ 1,693	$ 2,792	$ 5,079	$ 8,375

The contributions to pension plans for the nine months ended September 30, 2019 and 2018, as reflected on the Condensed Consolidated Statements of Cash Flows, pertain to benefit payments under nonqualified plans for both periods and a discretionary qualified plan contribution of $100,000,000 in the first quarter of 2018.

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		Nine Months Ended
	September 30		September 30
in thousands	2019	2018	2019	2018
Components of Net Periodic Benefit Cost
Service cost	$ 329	$ 339	$ 988	$ 1,018
Interest cost	347	310	1,041	930
Amortization of prior service credit	(980)	(991)	(2,939)	(2,972)
Amortization of actuarial gain	(327)	(324)	(981)	(973)
Net periodic postretirement benefit credit	$ (631)	$ (666)	$ (1,891)	$ (1,997)
Pretax reclassifications from AOCI included in
net periodic postretirement benefit credit	$ (1,307)	$ (1,315)	$ (3,920)	$ (3,945)

In addition to our pension and postretirement plans, we sponsor two defined contribution plans. Substantially all salaried and nonunion hourly employees are eligible to be covered by one of these plans. Under these plans, we match employees’ eligible contributions at established rates. Expense recognized in connection with these matching obligations totaled $13,646,000 and $10,376,000 for the three months ended September 30, 2019 and 2018, respectively, and totaled $41,246,000 and $30,521,000 for the nine months ended September 30, 2019 and 2018, respectively.