Business Acquisitions - Dextro, Inc. Acquisition (Details) - USD ($)	Feb. 08, 2017	Dec. 31, 2018	Dec. 31, 2017
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Goodwill		$ 24,981,000	$ 14,927,000
Dextro, Inc.
Business Acquisition [Line Items]
Total purchase price	$ 7,500,000
Payments to acquire businesses, net	7,500,000
Contingent liability	1,000,000
Business combination, liabilities arising from contingencies, amount recognized		$ 600,000.0
Additional contingent consideration arrangements	$ 1,400,000
Intangible assets, weighted average useful life	3 years 4 months 24 days
Incurred and expensed costs	$ 200,000
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Accounts receivable	12,000
Property and equipment	46,000
Goodwill	2,703,000
Deferred income tax liabilities, net	(1,074,000)
Total purchase price	(7,487,000)
Developed technology | Dextro, Inc.
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Developed technology	$ 5,800,000