Balance Sheet Information - Property and equipment, net (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property, equipment, and software development, at cost	$ 33,785	$ 30,467
Accumulated depreciation and amortization	(27,887)	(24,205)
Property, equipment, and software development, net	5,898	6,262
Automobiles
Property, Plant and Equipment [Line Items]
Property, equipment, and software development, at cost	13	13
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, equipment, and software development, at cost	171	171
Computer, communications, and network equipment
Property, Plant and Equipment [Line Items]
Property, equipment, and software development, at cost	17,535	17,450
Construction in Progress
Property, Plant and Equipment [Line Items]
Property, equipment, and software development, at cost	105	0
Software
Property, Plant and Equipment [Line Items]
Property, equipment, and software development, at cost	4,159	4,150
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Property, equipment, and software development, at cost	25	131
Software development
Property, Plant and Equipment [Line Items]
Property, equipment, and software development, at cost	$ 11,777	$ 8,552

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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