Business Acquisition - Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 06, 2018	Dec. 31, 2018	Dec. 31, 2017	[1]	Dec. 31, 2016
Business Acquisition [Line Items]
Goodwill		$ 63,452	$ 62,030		$ 61,888
Paofit
Business Acquisition [Line Items]
Inventories	$ 8
Intangible assets	1,140
Identifiable assets acquired	1,148
Goodwill	1,602
Total assets acquired	$ 2,750
Weighted-average amortization period (years)	5 years 8 months 12 days
Definite-lived trademarks | Paofit
Business Acquisition [Line Items]
Intangible assets	$ 250
Weighted-average amortization period (years)	5 years
Patents | Paofit
Business Acquisition [Line Items]
Intangible assets	$ 410
Weighted-average amortization period (years)	7 years
Developed technology | Paofit
Business Acquisition [Line Items]
Intangible assets	$ 480
Weighted-average amortization period (years)	5 years

[1] See Note 4.