Supplemental Cash Flow Information (Tables)

12 Months Ended

Dec. 31, 2018

Supplemental Cash Flow Elements [Abstract]

Supplemental Cash Flow Information

	Years Ending December 31,
	2018		2017		2016
Supplemental disclosures:	(in thousands)
Interest paid	$	6	$	—	$	—
Income taxes paid, net	14,979		16,951		27,353
Non-cash investing and financing activities:
Non-cash capital expenditures	481		832		270