Subsequent Events - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended			9 Months Ended
	Oct. 31, 2019	Dec. 31, 2019	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Subsequent Event [Line Items]
Proceeds from sales of equity securities					$ 589	$ 217
Gain on equity securities			$ (3,068)	$ (7,287)	$ 2,634	$ (27,565)
AquaBounty Technologies, Inc. | Forecast
Subsequent Event [Line Items]
Gain on equity securities		$ 5,267
Affiliate of Third Security, LLC | AquaBounty Technologies, Inc. | Subsequent Event
Subsequent Event [Line Items]
Proceeds from sales of equity securities	$ 21,587