Selected Quarterly Data (Unaudited) (Details 1 ) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Dec. 31, 2010	Dec. 31, 2009
Current assets:
Cash and cash equivalents	$ 34,875	$ 13,938	$ 14,357	$ 58,559	$ 28,759	$ 35,672	$ 44,620	$ 87,929	$ 24,844
Restricted cash	2,500	2,500	2,500	2,500	5,000	5,000	5,000
Accounts receivable	10,577	7,250	10,017	9,065	11,371	7,981	9,447
Inventories, net	5,311	5,017	5,483	6,946	6,323	5,948	5,649
Other current assets	3,039	2,631	2,456	2,463	2,499	2,715	2,508
Total current assets	56,302	31,336	34,813	79,533	53,952	57,316	67,224
Property and equipment, net	36,798	36,861	34,446	22,802	15,611	11,208	6,712
Restricted cash	0	1,600	3,200	3,200	3,200	0	0
Other long term assets	676	269	276	283	509	463	602
Total assets	93,776	70,066	72,735	105,818	73,272	68,987	74,538
Current liabilities:
Accounts payable	7,573	4,517	5,597	9,232	8,543	4,566	5,316
Accrued expenses	5,693	4,442	547	6,226	6,627	5,447	5,403
Deferred revenue	1,929	1,806	1,813	2,240	4,137	3,894	3,499
Accrued restructuring	61				396	587	1,047
Convertible debt, at face value	0	0	0	34,851	34,851	34,851	48,242
Current portion of long-term debt	(217)
Other current liabilities	428	402	291	363	692	603	587
Total current liabilities	15,623	11,167	13,148	52,912	54,850	50,132	64,094
Long term debt, at carrying value, net of current portion (face value of $25.2 million at December 31, 2012)	24,861	2,705	0	0	0	5,232	3,029
Lease financing obligation, net of current portion		21,352	19,962	11,357	7,135	968	930
Other long term liabilities	619	909	816	1,874	1,160	65	134
Total liabilities	63,123	36,133	33,926	66,143	63,145	56,397	68,187
Stockholders' equity:
Common stock	13	13	13	12	12	12	12
Additional paid-in capital	612,884	612,542	612,205	610,819	610,572	610,139	609,969
Accumulated deficit	(582,244)	(578,622)	(573,409)	(571,156)	(600,457)	(597,561)	(603,630)
Total stockholders' equity	30,653	33,933	38,809	39,675	10,127	12,590	6,351	3,170	30,202
Total liabilities and stockholders' equity	93,776	70,066	72,735	105,818	73,272	68,987	74,538
Previously Reported [Member]
Current assets:
Cash and cash equivalents		13,938	14,357	58,559	28,759	35,672	44,620	87,929
Restricted cash		2,500	2,500	2,500	5,000	5,000	5,000
Accounts receivable		7,250	10,017	9,065	11,371	7,981	9,447
Inventories, net		5,017	5,483	6,946	6,323	5,948	5,649
Other current assets		2,700	2,560	3,101	2,396	2,715	2,508
Total current assets		31,405	34,917	80,171	53,849	57,316	67,224
Property and equipment, net		14,346	13,502	10,468	7,806	5,513	3,645
Restricted cash		1,600	3,200	3,200	3,200	0	0
Other long term assets		653	692	283	482	463	602
Total assets		48,004	52,311	94,122	65,337	63,292	71,471
Current liabilities:
Accounts payable		4,517	5,597	9,232	8,543	4,566	5,316
Accrued expenses		4,363	5,341	6,127	6,519	5,572	5,387
Deferred revenue		1,806	1,813	2,037	4,137	3,894	3,499
Accrued restructuring						587	1,047
Convertible debt, at face value		0	0	34,851	34,851	34,851	48,242
Other current liabilities		402	291	363		458	549
Total current liabilities		11,088	13,042	52,610	54,486	49,928	64,040
Long term debt, at carrying value, net of current portion (face value of $25.2 million at December 31, 2012)		2,705	0	0		0	0
Lease financing obligation, net of current portion		0	0	0	0	980	946
Other long term liabilities		653	792	1,198	906	65	134
Total liabilities		14,446	13,834	53,808	55,392	50,973	65,120
Stockholders' equity:
Common stock		13	13	12	12	12	12
Additional paid-in capital		612,007	611,669	611,028	610,781	610,139	609,969
Accumulated deficit		(578,462)	(573,205)	(570,726)	(600,848)	(597,832)	(603,630)
Total stockholders' equity		33,558	38,477	40,314	9,945	12,319	6,351
Total liabilities and stockholders' equity		48,004	52,311	94,122	65,337	63,292	71,471
Adjustments [Member]
Current assets:
Cash and cash equivalents		0	0	0	0	0	0	0
Restricted cash		0	0	0	0	0	0
Accounts receivable		0	0	0	0	0	0
Inventories, net		0	0	0	0	0	0
Other current assets		(69)	(104)	(638)	103	0	0
Total current assets		(69)	(104)	(638)	103	0	0
Property and equipment, net		22,515	20,944	12,334	7,805	5,695	3,067
Restricted cash		0	0	0	0	0	0
Other long term assets		(384)	(416)	0	27	0	0
Total assets		22,062	20,424	11,696	7,935	5,695	3,067
Current liabilities:
Accounts payable		0	0	0	0	0	0
Accrued expenses		79	106	99	108	59	16
Deferred revenue		0	0	203	0	0	0
Accrued restructuring						0	0
Convertible debt, at face value		0	0	0	0	0	0
Other current liabilities		0	0	0		145	38
Total current liabilities		79	106	302	364	204	54
Long term debt, at carrying value, net of current portion (face value of $25.2 million at December 31, 2012)		0	0	0		5,232	3,029
Lease financing obligation, net of current portion		21,352	19,962	11,357	7,135	(12)	(16)
Other long term liabilities		256	24	676	254	0	0
Total liabilities		21,687	20,092	12,335	7,753	5,424	3,067
Stockholders' equity:
Common stock		0	0	0	0	0	0
Additional paid-in capital		535	536	(209)	(209)	0	0
Accumulated deficit		(160)	(204)	(430)	391	271	0
Total stockholders' equity		375	332	(639)	182	271	0
Total liabilities and stockholders' equity		$ 22,062	$ 20,424	$ 11,696	$ 7,935	$ 5,695	$ 3,067