Property, Plant and Equipment, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
Property, Plant and Equipment, Net
Total property, plant, and equipment, gross	$ 280,391	$ 276,288
Less: accumulated depreciation and amortization	(196,334)	(186,799)
Total property, plant, and equipment, net	84,057	89,489		$ 81,421
Depreciation expense	30,600	29,700	$ 29,700
Land
Property, Plant and Equipment, Net
Total property, plant, and equipment, gross	634	644
Buildings
Property, Plant and Equipment, Net
Total property, plant, and equipment, gross	4,110	24,558
Furniture and fixtures
Property, Plant and Equipment, Net
Total property, plant, and equipment, gross	13,835	13,121
Machinery and equipment
Property, Plant and Equipment, Net
Total property, plant, and equipment, gross	25,438	27,452
Equipment leased to third parties under operating leases
Property, Plant and Equipment, Net
Total property, plant, and equipment, gross	29,217	30,093
Less: accumulated depreciation and amortization	(12,972)	(14,712)
Net book value	16,245	15,381
Leasehold improvements
Property, Plant and Equipment, Net
Total property, plant, and equipment, gross	131,617	111,247
Computers and software
Property, Plant and Equipment, Net
Total property, plant, and equipment, gross	$ 75,540	$ 69,173