Enterprise-Wide Disclosures (Tables)

12 Months Ended

Dec. 31, 2018

Segment Reporting [Abstract]

Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas

Financial Information About Geographic Areas	2018		2017		2016
(amounts in thousands)
Revenue from External Customers:
United States	$	232,178	$	219,886	$	253,955
Belgium (1)		48,585		39,347		35,995
Luxembourg (1)		44,660		36,954		31,441
Other countries		33,346		5,023		3,502
Total foreign revenue		126,591		81,324		70,938
Total revenue	$	358,769	$	301,210	$	324,893
Long-lived Assets:
United States	$	3,715	$	5,206	$	4,280
France (2)		6,042		—		—
United Kingdom (3)		840		1,005		792
Other countries		995		785		791
Total long-lived assets	$	11,592	$	6,996	$	5,863
Deferred Tax Assets, Net of Valuation Allowance:
United States	$	—	$	3,810	$	6,886
Europe		767		51		—
Total deferred tax assets, net	$	767	$	3,861	$	6,886

(1) Revenue for our Belgium and Luxembourg operations has been disclosed separately as it exceeds 10% of consolidated revenue in at least one of the years presented.

(2) Long-lived assets for our France operations has been disclosed separately as it exceeds 10% of consolidated long-lived assets in at least one of the years presented.

(3) Long-lived assets for our United Kingdom operations has been disclosed separately as it exceeds 10% of consolidated long-lived assets in at least one of the years presented.