CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ 4,275	$ (2,579)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Amortization of deferred revenue	(2,685)	(2,234)
Depreciation	1,449	1,092
Amortization of acquired technology	2,126	34
Amortization of premium and discount on investments, net	(612)	(483)
Stock-based employee compensation	3,111	3,270
Stock-based non-employee compensation		3
Non-cash expense under a materials agreement		9
Stock-based compensation to Board of Directors and Scientific Advisory Board	648	1,252
Loss on stock warrant liability		4,190
Retirement plan benefit expense	1,165	1,145
Increase (decrease) in assets:
Accounts receivable	2,856	(4,513)
Inventory	(5,608)	(2,228)
Other current assets	(2,745)	271
Other assets	37	(96)
Increase in liabilities:
Accounts payable and accrued expenses	1,538	5,307
Other current liabilities	(3)	25
Deferred revenue	1,627	3,330
Net cash provided by operating activities	7,179	7,795
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property and equipment	(2,278)	(2,208)
Purchase of acquired technology	(109,102)	(440)
Purchase of investments	(209,244)	(290,269)
Proceeds from sale of investments	278,412	72,726
Net cash provided by (used in) investing activities	(42,212)	(220,191)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from the issuance of common stock	244	249,867
Proceeds from the exercise of common stock options and warrants	1,323	13,283
Payment of withholding taxes related to stock-based employee compensation	(4,136)	(3,999)
Net cash (used in) provided by financing activities	(2,569)	259,151
(DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	(37,602)	46,755
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	111,795	20,369
CASH AND CASH EQUIVALENTS, END OF PERIOD	74,193	67,124
The following non-cash activities occurred:
Unrealized (loss) gain on available-for-sale securities	16	9
Common stock issued to Board of Directors and Scientific Advisory Board that was earned in a previous period	328	300
Common stock issued to employees that was accrued for in a previous period, net of shares withheld for taxes	252	1,113
Fair value of stock warrant liability reclassified to shareholders' equity upon exercise		$ 14,850