Equipment and Leasehold Improvements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Property, plant and equipment
Total cost	$ 88,630	$ 80,404
Less accumulated depreciation and amortization	65,188	58,293
Equipment and leasehold improvements, net	23,442	22,111
Depreciation and amortization	6,896	7,526	$ 5,166
Software
Property, plant and equipment
Total cost	57,463	50,988
Computer equipment
Property, plant and equipment
Total cost	15,425	13,734
Leasehold improvements
Property, plant and equipment
Total cost	8,264	8,264
Other equipment
Property, plant and equipment
Total cost	3,132	3,132
Furniture and fixtures
Property, plant and equipment
Total cost	$ 4,346	$ 4,286