Income Taxes (Details) (USD $)	3 Months Ended	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Current
Federal			$ 14,090,000
State			2,155,000
Deferred
Federal				399,000
Total			16,245,000	399,000
Reconciliation of the expected income tax benefit computed using the federal statutory income tax rate to the Company's effective income tax rate
Income tax (benefit) computed at federal statutory tax rate		(16,270,000)	(13,419,000)	(13,421,000)
Permanent items		396,000	57,000	61,000
State taxes		(2,487,000)	(2,155,000)	(2,142,000)
Change in valuation allowance		18,754,000		16,144,000
Uncertain tax position		(64,000)	129,000	190,000
Research and development credits			(857,000)	(1,267,000)
Other		(329,000)		36,000
Income tax benefit			(16,245,000)	(399,000)
Pre-tax income from discontinued operations			93,300,000
Income tax expense from discontinued operations			36,800,000
Income tax benefit generated from the loss from continuing operations	(16,200,000)	0	(16,245,000)	(399,000)
NOL carryforwards		80,800,000
Research and development credit carryforwards		3,900,000
Deferred tax assets:
Net operating loss carryforward	14,809,000	32,714,000	14,809,000
Deferred rent credit	514,000	477,000	514,000
Accrued compensation and non-qualified stock options	48,000	60,000	48,000
Deferred financing costs	35,000		35,000
Depreciation and amortization	98,000	282,000	98,000
Research and development credits	5,018,000	3,901,000	5,018,000
Other	9,000	788,000	9,000
Net deferred tax asset before valuation allowance	20,531,000	38,222,000	20,531,000
Valuation allowance	(20,531,000)	(38,222,000)	(20,531,000)
Net change in total valuation allowance due to the tax attributes utilized by discontinued operations		17,700,000
Reconciliation of the beginning and ending amount of gross unrecognized tax benefits
Balance at the beginning of the period		752,000	642,000
Gross increases related to prior-year tax positions				452,000
Gross increases (decrease) related to current-year tax positions		(64,000)	110,000	190,000
Balance at the end of the period	$ 752,000	$ 688,000	$ 752,000	$ 642,000