BALANCE SHEET COMPONENTS Balance Sheet Components (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and Cash Equivalents, at Carrying Value	$ 126,953	$ 125,921	$ 114,500	$ 104,914
Accrued Sales Returns	574	1,632
Accrued Employee Benefits, Current	6,236	10,541
Accrued Warehousing And Inventory Related Expense	1,735	2,816
Other Accrued Liabilities, Current	8,545	14,989
Cash Equivalents [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and Cash Equivalents, at Carrying Value	73,417	73,468
Cash [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and Cash Equivalents, at Carrying Value	$ 53,536	$ 52,453