Note 10 - Cash, Cash Equivalents, Investments and Restricted Cash - Unrealized Gains and Losses on Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Amortized Cost	$ 1,049,303	$ 718,024
Unrealized Gains	515	331
Unrealized Losses	(305)	(1,641)
Total Fair Value	1,049,513	716,714
Money Market Funds [Member]
Amortized Cost	282,883	135,514
Unrealized Gains	0	0
Unrealized Losses	0	0
Total Fair Value	282,883	135,514
Certificates of Deposit [Member]
Amortized Cost	171,065	127,123
Unrealized Gains	0	0
Unrealized Losses	0	0
Total Fair Value	171,065	127,123
Corporate Debt Securities [Member]
Amortized Cost	14,522	96,636
Unrealized Gains	0	4
Unrealized Losses	(286)	(1,539)
Total Fair Value	14,236	95,101
US Government Agencies Short-Term Debt Securities [Member]
Amortized Cost	580,658	358,177
Unrealized Gains	515	327
Unrealized Losses	(17)	(95)
Total Fair Value	581,156	358,409
Auction Rate Securities [Member]
Amortized Cost	175	574
Unrealized Gains	0	0
Unrealized Losses	(2)	(7)
Total Fair Value	$ 173	$ 567