Disclosure - Pro Forma Financial Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Income (loss) before tax	$ 3,555	$ (36,362)
Net income (loss)	3,249	(36,362)
Net loss attributable to the noncontrolling interests	866	51
Accretion of dividends on redeemable convertible preferred stock		(6,405)
Net income (loss) attributable to common shareholders	4,115	(42,716)
Medistem, Inc. | Pro Forma
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Revenues	7,837	3,976
Income (loss) before tax	2,973	(36,631)
Net income (loss)	2,667	(36,631)
Net loss attributable to the noncontrolling interests	866	51
Net income (loss) attributable to Intrexon	3,533	(36,580)
Accretion of dividends on redeemable convertible preferred stock		(6,405)
Net income (loss) attributable to common shareholders	$ 3,533	$ (42,985)