v3.7.0.1
Consolidated Statements of Cash Flows - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2017
Mar. 31, 2016
Cash flows from operating activities    
Net loss $ (9,019) $ (12,523)
Adjustments to reconcile net loss to net cash used in operating activities:    
Depreciation and amortization 842 896
Stock-based compensation 3,553 4,896
Other (15) 123
Changes in operating assets and liabilities:    
Accounts receivable, net 4,562 1,940
Inventories 961 (714)
Prepaid expenses and other current assets (638) (3,636)
Other assets (58) (350)
Accounts payable (885) (684)
Accrued liabilities 144 5,713
Other liabilities (6) 7
Deferred revenue (997) 1,010
Net cash used in operating activities (1,556) (3,322)
Cash flows from investing activities    
Purchases of property and equipment (223) (337)
Maturities of short-term investments 4,200 4,200
Purchases of short-term investments (7,709) (2,406)
Investment in privately held company 0 (1,500)
Net cash used in investing activities (3,732) (43)
Cash flows from financing activities    
Proceeds from exercise of vested stock options 218 108
Payment for shares withheld for tax withholdings on vesting of restricted stock units (326) (311)
Payment to repurchase common stock 0 (785)
Repayments of Long-term Capital Lease Obligations (43)  
Net cash used in financing activities (151) (988)
Net decrease in cash and cash equivalents (5,439) (4,353)
Cash and cash equivalents at beginning of period 34,346 45,741
Cash and cash equivalents at end of period 28,907 41,388
Supplemental disclosure of cash flow information    
Income taxes paid 99 249
Interest paid 126 139
Supplemental disclosure of noncash investing and financing activities    
Unpaid property and equipment purchases $ 22 $ 97