Other Noncurrent Liabilities (Tables)

12 Months Ended

Dec. 31, 2018

Other Liabilities Disclosure [Abstract]

Summary of Other Noncurrent Liabilities

	December 31,
	2017		2018
	(in thousands)
Reserve for uncertain tax positions	$	7,312	$	7,312
Insurance claims and expenses		620		621
OPEB		1,846		1,519
Other		560		463
Total	$	10,338	$	9,915