Postretirement Medical Plan

9 Months Ended

Sep. 30, 2015

Postretirement Medical Plan

Pension and Other Postretirement Benefits Disclosure [Text Block]

14. Postretirement Medical Plan

We maintain an unfunded postretirement medical plan to provide certain postretirement medical benefits to eligible employees. Net periodic postretirement benefit costs included the following components (in thousands):

		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2015		2014		2015		2014
Service cost		$	1,229	$	1,038	$	3,687	$	3,113
Interest cost			482		464		1,446		1,393
Amortization of prior service cost			313		247		939		741
	Net periodic benefit cost	$	2,024	$	1,749	$	6,072	$	5,247