Balance Sheet Account Detail (Property and Equipment) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	$ 36,337		$ 36,337		$ 36,617
Accumulated depreciation	(21,842)		(21,842)		(20,584)
Property and equipment, net	14,495		14,495		16,033
Depreciation expense	900	$ 1,000	1,800	$ 1,900
Production equipment, molds, and office furniture
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	11,469		11,469		11,854
Computer hardware and software
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	8,356		8,356		8,235
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	15,535		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	$ 977		$ 977		$ 993