Investments in Joint Ventures - Intrexon T1D Partners - Additional Information (Details)	1 Months Ended
	Mar. 31, 2016 USD ($)	Dec. 31, 2017 USD ($) board_seat	Dec. 31, 2016 USD ($)
Schedule Of Investments In Joint Venture [Line Items]
Investment		$ 18,870,000	$ 23,655,000
Intrexon T1D Partners, LLC
Schedule Of Investments In Joint Venture [Line Items]
Membership interest	50.00%
Maximum additional capital contributions committed	$ 5,000,000
Additional capital contributions committed, remaining commitment		$ 2,900,000
Total number of seats on the joint venture's governing board | board_seat		5
Total number of seats on the joint venture's governing board, internally selected | board_seat		2
Total number of seats on the joint venture's governing board, externally selected | board_seat		3
Upfront | Intrexon T1D Partners, LLC | Upfront and Milestone Payments
Schedule Of Investments In Joint Venture [Line Items]
Collaborative agreement, consideration received, value	$ 10,000,000
Investor | Intrexon T1D Partners, LLC
Schedule Of Investments In Joint Venture [Line Items]
Membership interest	50.00%
Capital contribution	$ 10,000,000
Maximum additional capital contributions committed	$ 5,000,000
Investments in affiliates | Intrexon T1D Partners, LLC
Schedule Of Investments In Joint Venture [Line Items]
Investment			$ 806,000
Other accrued liabilities | Intrexon T1D Partners, LLC
Schedule Of Investments In Joint Venture [Line Items]
Investment		$ (943,000)