Marketable Securities - Amortized Cost and Fair Value of Debt Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Fair Value to Amortized Cost
Amortized Cost	$ 436,014	$ 192,971
Allowance for Credit Losses	0	0
Net Amortized Cost	436,014	192,971
Gross Unrealized Gains	3	1
Gross Unrealized Losses	(2,607)	(324)
Fair Value	433,410	192,648
Corporate bonds - U.S.
Fair Value to Amortized Cost
Amortized Cost	290,201	130,388
Allowance for Credit Losses	0	0
Net Amortized Cost	290,201	130,388
Gross Unrealized Gains	2	1
Gross Unrealized Losses	(1,969)	(234)
Fair Value	288,234	130,155
Corporate bonds - Foreign
Fair Value to Amortized Cost
Amortized Cost	47,106	20,643
Allowance for Credit Losses	0	0
Net Amortized Cost	47,106	20,643
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(426)	(82)
Fair Value	46,680	20,561
Government related obligations - U.S.
Fair Value to Amortized Cost
Amortized Cost	98,707	41,939
Allowance for Credit Losses	0	0
Net Amortized Cost	98,707	41,939
Gross Unrealized Gains	1	0
Gross Unrealized Losses	(212)	(8)
Fair Value	$ 98,496	$ 41,931