Balance Sheet Account Details - Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	$ 144,260	$ 121,309
Less: accumulated depreciation and amortization	82,675	70,451
Property, Plant and Equipment, Net	61,585	50,858
Equipment, furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	75,728	61,972
Building and improvements
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	34,994	34,243
Leased instruments
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	32,458	24,014
Land
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	$ 1,080	$ 1,080