Balance Sheet Account Detail (Property and Equipment) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	$ 36,475	$ 36,210
Accumulated depreciation	(17,263)	(12,945)
Property and equipment, net	19,212	23,265
Depreciation expense	5,000	5,300	$ 4,600
Production equipment, molds, and office furniture
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	12,118	11,714
Computer hardware and software
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	8,115	8,162
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	15,499	15,495
Construction in progress (software and related implementation, production equipment, and leasehold improvements)
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	$ 743	$ 839