Workers Compensation Expense

The Company is liable under the Federal Mine Safety and Health Act of 1969, as subsequently amended, to provide for pneumoconiosis (occupational disease) benefits to eligible employees, former employees and dependents. The Company currently provides for federal claims principally through a self-insurance program. The Company is also liable under various state workers’ compensation statutes for occupational disease benefits. The occupational disease benefit obligation represents the present value of the actuarially computed present and future liabilities for such benefits over the employees’ applicable years of service.

In addition, the Company is liable for workers’ compensation benefits for traumatic injuries which are calculated using actuarially-based loss rates, loss development factors and discounted based on a risk free rate. Traumatic workers’ compensation claims are insured with varying retentions/deductibles, or through state-sponsored workers’ compensation programs.

Workers’ compensation expense consists of the following components:



	Three Months Ended March 31,
	2018		2017
	(In thousands)
Self-insured occupational disease benefits:
Service cost	$	1,860	$	1,558
Interest cost⁽¹⁾	1,195		1,169
Total occupational disease	$	3,055	$	2,727
Traumatic injury claims and assessments	3,011		2,878
Total workers’ compensation expense	$	6,066	$	5,605

(1) In accordance with the adoption of ASU 2017-07, “Compensation-Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost,” these costs are recorded within Nonoperating expenses in the Condensed Consolidated Income Statements on the line item “Non-service related pension and postretirement benefit costs.” For additional information about the adoption of the standard, see Note 2, “Accounting Policies” in the Condensed Consolidated Financial Statements.