CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Cash flows from operating activities
Net loss	$ (6,613)	$ (10,611)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	3,377	3,224
Share-based compensation	6,737	4,747
Non-cash interest expense and other expenses related to debt		62
Net accretion of discount and amortization of premium on available-for-sale securities		95
Provision for bad debt	228	47
Deferred income taxes	(4)	14
Others	17	11
Changes in assets and liabilities:
Accounts receivable	(6,689)	(3,968)
Inventory	1,414	(343)
Prepaid expenses and other current assets	(970)	(754)
Other assets	452	614
Accounts payable	(2,430)	485
Accrued liabilities	6,927	2,812
Deferred revenue	2,375	2,739
Other liabilities	(12)	139
Net cash provided by (used in) operating activities	4,809	(687)
Cash flows from investing activities
Proceeds from the maturity of available-for-sale securities		6,780
Purchases of property and equipment	(2,023)	(2,859)
Capitalized internal-use software	(439)	(439)
Proceeds from the maturity of restricted investments		100
Net cash provided by (used in) investing activities	(2,462)	3,582
Cash flows from financing activities
Proceeds from issuance of stock in connection with stock plans	281	1,482
Repayment of debt	(938)	(3,330)
Repayment of capital lease obligations	(87)	(216)
Net cash used in financing activities	(744)	(2,064)
Effect of exchange rate changes on cash and cash equivalents	(117)	139
Net increase in cash and cash equivalents	1,486	970
Cash and cash equivalents
Beginning of period	137,588	113,182
End of period	139,074	114,152
Supplemental disclosure of cash flow data
Cash paid for interest	169	1,267
Cash paid for income taxes	123	47
Non-cash investing and financing activities
Change in liability for unvested exercised options	3	9
Equipment and capitalized software purchased and unpaid at period end	$ 496	2,236
Unrealized loss on available-for-sale securities		$ 50