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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Long-lived assets other than financial instruments, long-term customer relationships of a financial institution, mortgage and other servicing rights, deferred policy acquisition costs, and deferred tax assets.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

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Business Segment and Geographic Region Information - Revenue and Long-Lived Assets (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue and long-lived assets by geographic region
Revenue	$ 116,396	$ 104,482	$ 102,790	$ 86,893	$ 69,358	$ 65,650	$ 64,451	$ 67,521	$ 410,561	$ 266,980	$ 301,495
Long-Lived Assets	56,796				52,523				56,796	52,523	42,063
United States.
Revenue and long-lived assets by geographic region
Revenue									313,916	191,261	226,890
Long-Lived Assets	56,089				52,006				56,089	52,006	41,729
Europe
Revenue and long-lived assets by geographic region
Revenue									26,936	25,436	24,209
Asia Pacific
Revenue and long-lived assets by geographic region
Revenue									69,709	50,283	50,396
Long-Lived Assets	$ 707				$ 517				707	517	334
International \| Revenue \| Geographic concentration risk
Revenue and long-lived assets by geographic region
Revenue									$ 348,500	$ 213,800	$ 256,500
Percentage of revenue									84.90%	80.00%	85.10%