Postretirement Medical Plan (Tables)

6 Months Ended

Jun. 30, 2013

Postretirement Medical Plan

Schedule of components of net periodic postretirement benefit cost

Net periodic postretirement benefit costs included the following components (in thousands):

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2013		2012		2013		2012
Service Cost	$	1,238	$	1,053	$	2,475	$	2,106
Interest Cost	418		356		837		712
Amortization of prior service cost	444		394		888		788
Net periodic benefit cost	$	2,100	$	1,803	$	4,200	$	3,606