Represents the portion of the difference, between total income tax expense or benefit as reported in the income statement for the period and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations, that is attributable to federal alternative minimum tax income tax expense or benefit.

No definition available.

Income Taxes (Details 2) (USD $)	12 Months Ended				3 Months Ended
Income Taxes (Details 2) (USD $)	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Federal	Mar. 31, 2013 Federal Subsequent event	Dec. 31, 2012 Research and development Federal	Dec. 31, 2012 Research and development California
Tax credit carryforwards
Tax credit carryforwards with expiration						$ 4,600,000
Tax credit carryforwards without expiration							4,400,000
Foreign tax credit carryforward that begin to expire in 2014				1,100,000
Increase in tax credit carryforward					1,000,000
Reconciliation of income taxes provided at the federal statutory rate (35%) to actual income tax provision (benefit)
Federal statutory rate	35.00%
Income tax benefit computed at U.S. statutory rate	(9,626,000)	4,040,000	(8,054,000)
Federal alternative minimum tax		247,000
State income tax (net of federal benefit)	2,000	2,000	2,000
Foreign income tax at rate different from U.S. statutory rate	(13,000)	(9,000)	(90,000)
Research and development credits	(691,000)	(1,254,000)	(1,239,000)
Foreign tax credit		(17,000)	(21,000)
Stock-based compensation	252,000	292,000	607,000
Amortization of intangible assets	(100,000)	(657,000)
Valuation allowance changes affecting tax provision	10,526,000	(2,363,000)	8,979,000
Other	(240,000)	7,000	(133,000)
Total	110,000	288,000	51,000
Domestic and foreign components of income (loss) before income tax provision (benefit)
U.S.	(27,737,000)	11,363,000	(23,499,000)
Non-U.S.	233,000	181,000	488,000
Income (loss) before income taxes	$ (27,504,000)	$ 11,544,000	$ (23,011,000)