Goodwill (Tables)

12 Months Ended

Dec. 31, 2017

Goodwill and Intangible Assets Disclosure [Abstract]

Changes in Carrying Value of Goodwill

Goodwill consists of the following:

	As of December 31,
	2017		2016
	(in thousands)
Balance, January 1	$	208,186	$	209,024
Foreign currency translation adjustments	9,551		(838		)
Balance, December 31	$	217,737	$	208,186