Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash flows from operating activities:
Net loss	$ (19,319)	$ (17,950)	$ (33,403)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	3,941	8,983	9,183
Stock-based compensation	1,565	2,304	2,744
Allowance for doubtful accounts	(143)	8	(1,154)
Deferred income taxes	583	3,698	691
Other non-cash items	195	(196)	130
Changes in assets and liabilities:
Accounts receivable	9,837	(1,380)	(12,742)
Advance billings	3,351	(1,897)	(2,311)
Inventories	(2,503)	2,265	(10,177)
Prepaid expenses and other current assets	4,616	(3,337)	69
Other assets	252	220	867
Accounts payable	(5,312)	(3,906)	13,305
Accrued liabilities	(4,553)	3,065	(4,807)
Deferred revenue	(6,044)	6,268	2,699
Other liabilities	(2,434)	(539)	(953)
Net cash provided by (used in) operating activities	(15,968)	(2,394)	(35,859)
Cash flows from investing activities:
Purchase of available-for-sale investments	0	0	(11,327)
Maturities of available-for-sale investments	0	2,151	22,125
Decrease in restricted cash	0	2,149	(2,026)
Purchases of property and equipment	(1,487)	(1,928)	(1,526)
Proceeds from Sale of Property, Plant, and Equipment	60	842	0
Net cash provided by (used in) investing activities	(1,427)	3,214	7,246
Cash flows from financing activities:
Proceeds from stock plans, net	366	12,871	415
Net cash provided by financing activities	366	12,871	415
Effect of exchange rate changes on cash and cash equivalents	310	519	(285)
Net increase (decrease) in cash and cash equivalents	(16,719)	14,210	(28,483)
Cash and cash equivalents, beginning of period	31,073	16,863	45,346
Cash and cash equivalents, end of period	14,354	31,073	16,863
Supplemental Disclosure:
Cash paid for (refunded from) income taxes, net	$ 794	$ (479)	$ 1,336