Balance Sheet Account Detail (Property and Equipment) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	$ 36,201		$ 36,617
Accumulated depreciation	(20,965)		(20,584)
Property and equipment, net	15,236		16,033
Depreciation expense	900	$ 1,000
Production equipment, molds, and office furniture
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	11,451		11,854
Computer hardware and software
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	8,252		8,235
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	15,535		15,535
Construction in progress (software and related implementation, production equipment, and leasehold improvements)
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	$ 963		$ 993