Balance Sheet Components (Other assets and Accrued liabilities) (Details) - USD ($)
$ in Thousands
Dec. 31, 2016
Dec. 31, 2015
Other assets    
Deposits $ 656 $ 933
Prepaid licensing 417 664
Deferred tax asset 935  
Other   53
Other assets total 2,008 1,650
Accrued liabilities    
Sales returns and current portion of warranty accruals 2,892 2,508
Compensation accruals 4,445 2,331
Other accrued liabilities 1,575 1,041
Total accrued liabilities $ 8,912 $ 5,880