Balance Sheet Account Detail (Property and Equipment) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	$ 36,836		$ 36,836		$ 36,475
Accumulated depreciation	(19,133)		(19,133)		(17,263)
Property and equipment, net	17,703		17,703		19,212
Depreciation expense	1,000	$ 1,300	1,900	$ 2,700
Production equipment, molds, and office furniture
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	12,086		12,086		12,118
Computer hardware and software
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	8,274		8,274		8,115
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	15,535		15,535		15,499
Construction in progress (software and related implementation, production equipment, and leasehold improvements)
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	$ 941		$ 941		$ 743