Marketable Securities - Available for Sale (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Short-term AFS securities
Amortized cost, short-term AFS securities	$ 189,198	$ 164,612
Gross unrealized gains, short-term AFS securities	10	61
Gross unrealized losses, short-term AFS securities	(772)	(2,579)
Fair value, short-term AFS securities	188,436	162,094
Long-term AFS securities
Amortized cost, long-term AFS securities	313,165	255,796
Gross unrealized gains, long-term AFS securities	229	1,909
Gross unrealized losses, long-term AFS securities	(801)	(72)
Fair value, long-term AFS securities	312,593	257,633
U.S. Treasury securities
Short-term AFS securities
Amortized cost, short-term AFS securities	122,999	48,721
Gross unrealized gains, short-term AFS securities	1	55
Gross unrealized losses, short-term AFS securities	(417)	(667)
Fair value, short-term AFS securities	122,583	48,109
Long-term AFS securities
Amortized cost, long-term AFS securities	144,705	148,878
Gross unrealized gains, long-term AFS securities	39	1,023
Gross unrealized losses, long-term AFS securities	(417)	(42)
Fair value, long-term AFS securities	144,327	149,859
Corporate debt securities
Short-term AFS securities
Amortized cost, short-term AFS securities	61,284	109,891
Gross unrealized gains, short-term AFS securities	9	6
Gross unrealized losses, short-term AFS securities	(306)	(1,828)
Fair value, short-term AFS securities	60,987	108,069
Long-term AFS securities
Amortized cost, long-term AFS securities	168,460	103,061
Gross unrealized gains, long-term AFS securities	190	886
Gross unrealized losses, long-term AFS securities	(384)	(5)
Fair value, long-term AFS securities	168,266	103,942
U.S. governmental agency securities
Short-term AFS securities
Amortized cost, short-term AFS securities	4,915	6,000
Gross unrealized gains, short-term AFS securities	0	0
Gross unrealized losses, short-term AFS securities	(49)	(84)
Fair value, short-term AFS securities	$ 4,866	5,916
Long-term AFS securities
Amortized cost, long-term AFS securities		3,857
Gross unrealized gains, long-term AFS securities		0
Gross unrealized losses, long-term AFS securities		(25)
Fair value, long-term AFS securities		$ 3,832