Goodwill

The following is a summary of the goodwill balance for each reportable segment as of March 31, 2018 (in thousands):



	North America			International		Total
Net goodwill as of December 31, 2017	$	170,685		$	29,262	$	199,946
Foreign exchange impact	(32		)	828		796
Net goodwill as of March 31, 2018	$	170,653		$	30,090	$	200,743

Goodwill represents the excess of purchase price and related costs over the value assigned to the net tangible and identifiable intangible assets of businesses acquired. In accordance with ASC 350, Intangibles – Goodwill and Other, goodwill is not amortized, but instead is tested for impairment annually, or more frequently if circumstances indicate a possible impairment may exist.

The fair value estimates used in the goodwill impairment analysis require significant judgment. The Company's fair value estimates for purposes of performing the analysis are considered Level 3 fair value measurements. The fair value estimates were based on assumptions that management believes to be reasonable, but that are inherently uncertain, including estimates of future revenues and operating margins and assumptions about the overall economic climate and the competitive environment for the business.

Absent any interim indicators of impairment, the Company tests for goodwill impairment as of the first day of the fourth fiscal quarter of each year. The Company does not believe that goodwill is impaired as of March 31, 2018.