Mergers and Acquisitions - Pro Forma Financial Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Loss before income taxes	$ (53,862)	$ 14,991	$ (103,525)	$ (27,890)
Net income (loss)	(53,862)	14,991	(103,548)	(27,890)
Net loss attributable to the noncontrolling interests	1,137	507	2,895	1,114
Accretion of dividends on redeemable convertible preferred stock	0	(4,044)	0	(18,391)
Undistributed earnings allocated to preferred shareholders	0	(3,132)	0	0
Net income (loss) attributable to common shareholders	(52,725)	8,322	(100,653)	(45,167)
Medistem and Trans Ova | Pro Forma
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Revenues	31,506	22,335	88,628	65,822
Loss before income taxes	(51,858)	15,453	(98,745)	(27,303)
Net income (loss)	(51,858)	15,453	(98,768)	(27,303)
Net loss attributable to the noncontrolling interests	1,192	721	3,246	1,667
Net loss attributable to Intrexon	(50,666)	16,174	(95,522)	(25,636)
Accretion of dividends on redeemable convertible preferred stock	0	(4,044)	0	(18,391)
Undistributed earnings allocated to preferred shareholders	0	(3,132)	0	0
Net income (loss) attributable to common shareholders	$ (50,666)	$ 8,998	$ (95,522)	$ (44,027)