Revenue (Tables)

6 Months Ended

Jun. 30, 2019

Revenue from Contract with Customer [Abstract]

Revenue from External Customers by Geographic Areas

The following table summarizes net sales by end market:

(in thousands)	For the Three Months Ended June 30,				For the Six Months Ended June 30,
End Market	2019		2018		2019		2018
Industrial	54,660		48,051		105,247		93,770
Energy	52,245		52,014		97,893		90,581
Transportation	31,779		27,008		51,331		37,135
Total	$	138,684	$	127,073	$	254,471	$	221,486

The following table summarizes net sales by geographic area:

(in thousands)	For the Three Months Ended June 30,				For the Six Months Ended June 30,
Geographic Area	2019		2018		2019		2018
North America	$	119,943	$	111,444	$	217,622	$	191,391
Pacific Rim	10,804		11,516		23,429		21,855
Europe	5,006		3,621		8,383		6,936
Other	2,931		492		5,037		1,304
Total	$	138,684	$	127,073	$	254,471	$	221,486

Schedule of Contract Balances

(in thousands)	As of
	June 30, 2019			December 31, 2018
Short-term contract assets (included in Prepaid expenses and other current assets)	$	2,558		$	2,926
Short-term contract liabilities (included in Other accrued liabilities)	(4,689		)	(4,897		)
Long-term contract liabilities (included in Noncurrent contract liabilities)	(13,950		)	(14,611		)
Net contract liabilities	$	(16,081	)	$	(16,582	)