Workers' Compensation Expense (Tables)

6 Months Ended

Jun. 30, 2013

Workers' Compensation Expense [Abstract]

Workers' Compensation Expense

	Three Months Ended June 30,					Six Months Ended June 30,
	2013		2012			2013		2012
	(In thousands)
Service cost	$	505	$	71		$	1,010	$	1,039
Interest cost	657		399			1,313		1,079
Net amortization	235		(851		)	469		(574		)
Curtailments	—		1,933			—		1,933
Total occupational disease	1,397		1,552			2,792		3,477
Traumatic injury claims and assessments	4,791		6,423			12,149		11,599
Total workers’ compensation expense	$	6,188	$	7,975		$	14,941	$	15,076