Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash flows from operating activities:
Net loss	$ (17,950)	$ (33,403)	$ (67,042)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Allowance for doubtful accounts	8	(1,154)	(2,440)
Depreciation and amortization	8,983	9,183	13,618
Deferred income taxes	3,698	691	(8,504)
Stock-based compensation	2,304	2,744	2,944
Other non-cash items	(196)	130	348
Changes in assets and liabilities:
Accounts receivable	(1,380)	(12,742)	6,479
Advance billings	(1,897)	(2,311)	(765)
Inventories	2,265	(10,177)	17,784
Prepaid expenses and other current assets	(3,337)	69	1,034
Other assets	220	867	(291)
Accounts payable	(3,906)	13,305	202
Accrued liabilities	3,065	(4,807)	(3,568)
Deferred revenue	6,268	2,699	(2,548)
Income taxes payable, non-current	(3,076)	(593)	0
Other liabilities	2,537	(360)	435
Net cash used in operating activities	(2,394)	(35,859)	(42,314)
Cash flows from investing activities:
Purchases of available-for-sale investments	0	(11,327)	(28,771)
Maturities of available-for-sale investments	2,151	22,125	41,500
Decrease (increase) in restricted cash	2,149	(2,026)	(2,000)
Purchases of property and equipment	(1,928)	(1,526)	(1,409)
Proceeds from sales of property and equipment	842	0	0
Net cash from investing activities	3,214	7,246	9,320
Cash flows from financing activities:
Proceeds from issuance of common stock, net	12,871	415	208
Net cash from financing activities	12,871	415	208
Effect of exchange rate changes on cash and cash equivalents	519	(285)	1,025
Net increase (decrease) in cash and cash equivalents	14,210	(28,483)	(31,761)
Cash and cash equivalents, beginning of period	16,863	45,346	77,107
Cash and cash equivalents, end of period	31,073	16,863	45,346
Supplemental disclosures:
Cash paid for (refunded from) income taxes, net	$ (479)	$ 1,336	$ 266