Investments - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Schedule of Investments [Abstract]
Realized gain (loss) on marketable securities	$ 0.1	$ 0.2	$ (0.3)	$ (0.6)