Shareholders' Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended					12 Months Ended
	Dec. 31, 2017	Jan. 31, 2017	Aug. 31, 2015	Jun. 30, 2015	Jan. 31, 2015	Dec. 31, 2017	Dec. 31, 2015
Class of Stock [Line Items]
Shares issued in public or private offerings, net of issuance costs, shares	1,207,980		5,609,756		4,312,500
Value of shares issued in public or private offerings	$ 13,686		$ 218,193		$ 110,041	$ 13,686	$ 328,234
Underwriting discounts and commissions			11,500		6,086
Capitalized offering expenses			$ 306		$ 311
Noncash dividend to shareholders						$ 0	172,419
Affiliates Of Third Security
Class of Stock [Line Items]
Shares issued in public or private offerings, net of issuance costs, shares					555,556
AquaBounty Technologies, Inc.
Class of Stock [Line Items]
Noncash dividend, shares		1,776,557
Noncash dividend to shareholders		$ 22,385
ZIOPHARM Oncology, Inc.
Class of Stock [Line Items]
Noncash dividend, shares				17,830,305
Realized investment gain							$ 81,401
Intrexon Stock Option Plans
Class of Stock [Line Items]
Adjustment due to dividend (in shares)						46,766	312,795
Adjustment due to dividend (in usd per share)						$ 31.11	$ 25.40