Supplemental Cash Flow Information (Tables)

12 Months Ended

Dec. 31, 2017

Supplemental Cash Flow Elements [Abstract]

Supplemental Cash Flow Information

Supplemental disclosures of cash flow information are as follows:

	Year ended December 31,
	2017		2016		2015
	(in thousands)
Cash paid for income taxes, net	$	3,146	$	4,231	$	4,792