Business Segment and Geographic Region Information - Revenue and Long-Lived Assets (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue and long-lived assets by geographic region
Revenue	$ 474,560	$ 342,958	$ 442,575
Long-Lived Assets	68,303	68,084	70,982
United States.
Revenue and long-lived assets by geographic region
Revenue	351,069	256,092	342,802
Long-Lived Assets	67,521	67,336	70,022
Europe
Revenue and long-lived assets by geographic region
Revenue	28,977	28,743	29,417
Long-Lived Assets	235
Asia Pacific
Revenue and long-lived assets by geographic region
Revenue	94,514	58,123	70,356
Long-Lived Assets	547	748	960
International \| Revenue \| Geographic concentration risk
Revenue and long-lived assets by geographic region
Revenue	$ 423,700	$ 306,600	$ 388,300
Percentage of revenue	89.30%	89.40%	87.70%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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