Investments - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Investments
Investments, realized gains or losses	$ 0	$ 0	$ 0	$ 0
Marketable securities, gross unrealized loss position	66,400,000		66,400,000
Marketable securities, continuous unrealized loss position, greater than 12 months	0		0
Marketable securities, continuous unrealized loss position, less than 12 months	$ 41,800,000		$ 41,800,000