Balance Sheets and Statements of Operations Details (Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 24,876	$ 24,876
Accumulated Amortization	(15,316)	(11,942)
Net Carrying Amount	9,560	12,934
Weighted- Average Amortization Period (years)	6 years
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,098	3,098
Accumulated Amortization	(3,098)	(3,098)
Net Carrying Amount	0	0
Weighted- Average Amortization Period (years)	5 years
Developed and core technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,534	1,534
Accumulated Amortization	(1,534)	(1,534)
Net Carrying Amount	0	0
Weighted- Average Amortization Period (years)	5 years
Maxygen intellectual property [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	20,244	20,244
Accumulated Amortization	(10,684)	(7,310)
Net Carrying Amount	$ 9,560	$ 12,934
Weighted- Average Amortization Period (years)	6 years