CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (1,221)	$ (11,881)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Amortization of deferred revenue	(917)	(705)
Depreciation	418	372
Amortization of intangibles	15	5
Amortization of premium and discount on investments, net	(238)	(64)
Stock-based employee compensation	800	1,039
Non-cash expense under a materials agreement		9
Stock-based compensation to Board of Directors and Scientific Advisory Board	213	529
Loss on stock warrant liability		8,926
Retirement plan benefit expense	388	382
Decrease (increase) in assets:
Accounts receivable	2,019	1,263
Inventory	(1,731)	(89)
Other current assets	(827)	394
Other assets	15	(116)
(Decrease) increase in liabilities:
Accounts payable and accrued expenses	(1,987)	253
Other current liabilities	(1)
Deferred revenue	1,042	1,300
Net cash (used in) provided by operating activities	(2,012)	1,617
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property and equipment	(1,802)	(475)
Purchase of intangibles		(440)
Purchase of investments	(139,512)	(37,346)
Proceeds from sale of investments	178,638	23,396
Net cash provided by (used in) investing activities	37,324	(14,865)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from the issuance of common stock	71	249,803
Proceeds from the exercise of common stock options and warrants	541	5,120
Payment of withholding taxes related to stock-based employee compensation	(3,473)	(3,938)
Net cash (used in) provided by financing activities	(2,861)	250,985
INCREASE IN CASH AND CASH EQUIVALENTS	32,451	237,737
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	111,795	20,369
CASH AND CASH EQUIVALENTS, END OF PERIOD	144,246	258,106
The following non-cash activities occurred:
Unrealized (loss) gain on available-for-sale securities	(104)	11
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		$ 6,476