Organization and Business (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) segment	Sep. 30, 2019 USD ($)
Revenues from External Customers and Long-Lived Assets [Line Items]
Number of reportable segments | segment			1
Revenues (2)	$ 267,864	$ 250,014	$ 791,558	$ 747,948
Long-Lived Assets	109,432	127,570	$ 109,432	127,570
Warranty period for international agreements			24 months
UNITED STATES
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues (2)	172,286	166,284	$ 517,914	501,783
Long-Lived Assets	98,049	114,595	98,049	114,595
UNITED KINGDOM
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues (2)	34,387	28,446	98,768	86,494
Long-Lived Assets	2,578	3,586	2,578	3,586
Outside the United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues (2)	61,191	55,284	174,876	159,671
Long-Lived Assets	$ 8,805	$ 9,389	$ 8,805	$ 9,389
Minimum
Revenues from External Customers and Long-Lived Assets [Line Items]
Warranty period			90 days
Maximum
Revenues from External Customers and Long-Lived Assets [Line Items]
Warranty period			180 days