Balance Sheet Account Detail (Property and Equipment) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	$ 36,919		$ 36,919		$ 36,475
Accumulated depreciation	(20,024)		(20,024)		(17,263)
Property and equipment, net	16,895		16,895		19,212
Depreciation expense	900	$ 1,200	2,800	$ 3,900
Production equipment, molds, and office furniture
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	12,051		12,051		12,118
Computer hardware and software
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	8,270		8,270		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	$ 1,063		$ 1,063		$ 743