CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) (USD $)	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (8,568,156)	$ (7,414,426)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Amortization of deferred revenue	(1,479,453)	(3,653,330)
Depreciation	733,597	944,798
Amortization of intangibles	19,539	847,536
Amortization of premium and discount on investments, net	(166,491)	(80,168)
Stock-based employee compensation	2,150,898	1,191,701
Stock-based non-employee compensation	1,934	43,308
Non-cash expense under a materials agreement	9,181	557,223
Stock-based compensation to Board of Directors and Scientific Advisory Board	718,117	384,665
Loss on stock warrant liability	4,429,845	1,869,185
Retirement plan benefit expense	763,436	342,081
Decrease (increase) in assets:
Accounts receivable	706,641	(541,125)
Other current assets	(853,695)	(44,828)
Other assets	(106,706)	(43,656)
Increase in liabilities:
Accounts payable and accrued expenses	1,836,456	1,464,055
Deferred revenue	1,645,000	1,375,000
Net cash provided by (used in) operating activities	1,840,143	(2,757,981)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property and equipment	(1,510,331)	(144,376)
Purchase of intangibles	(439,644)
Purchase of short-term investments	(253,903,705)	(51,910,640)
Proceeds from sale of short-term investments	45,499,654	38,784,983
Net cash used in investing activities	(210,354,026)	(13,270,033)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from the issuance of common stock	249,821,785	129,650
Proceeds from the exercise of common stock options and warrants	7,542,784	6,083,944
Payment of withholding taxes related to stock-based employee compensation	(3,979,473)	(1,132,421)
Net cash provided by financing activities	253,385,096	5,081,173
INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	44,871,213	(10,946,841)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	20,368,852	22,701,126
CASH AND CASH EQUIVALENTS, END OF PERIOD	65,240,065	11,754,285
The following non-cash activities occurred:
Unrealized loss on available-for-sale securities	206,361	40,141
Common stock issued to Board of Directors and Scientific Advisory Board that was earned in a previous period	299,943	314,181
Common stock issued to employees that was accrued for in a previous period, net of shares withheld for taxes	1,113,483	929,552
Common stock issued for royalties that was earned in a previous period		81,273
Fair value of stock warrant liability reclassified to shareholders' equity upon exercise	$ 10,501,422