Note 8 - Stock-based Compensation - Summary of Restricted Common Stock Activity (Details) - $ / shares		6 Months Ended
		Jun. 30, 2023	Jun. 30, 2022
Restricted Stock [Member]
Outstanding, Shares (in shares)	[1]	997,745	1,035,728
Outstanding, Weighted average grant date fair value (in dollars per share)		$ 20.62	$ 19.69
Granted, Shares (in shares)		1,007,921	400,927
Granted, Weighted average grant date fair value (in dollars per share)		$ 8.15	$ 21.68
Vested, Shares (in shares)		(461,953)	(341,918)
Vested, Weighted average grant date fair value (in dollars per share)		$ 20.27	$ 19.03
Outstanding, Shares (in shares)		1,543,713	1,094,737
Outstanding, Weighted average grant date fair value (in dollars per share)		$ 12.58	$ 20.62
Restricted Stock [Member] | Common Class A [Member]
Outstanding, Shares (in shares)		677,238	720,421
Outstanding, Weighted average grant date fair value (in dollars per share)		$ 19.36	$ 18.22
Granted, Shares (in shares)		738,854	250,448
Granted, Weighted average grant date fair value (in dollars per share)		$ 8.34	$ 20.52
Vested, Shares (in shares)		(203,986)	(229,758)
Vested, Weighted average grant date fair value (in dollars per share)		$ 18.76	$ 16.99
Outstanding, Shares (in shares)		1,212,106	741,111
Outstanding, Weighted average grant date fair value (in dollars per share)		$ 12.74	$ 19.38
Restricted Stock Units (RSUs) [Member]
Outstanding, Shares (in shares)		274,145	125,247
Outstanding, Weighted average grant date fair value (in dollars per share)		$ 23.60	$ 19.02
Granted, Shares (in shares)		587,168	259,079
Granted, Weighted average grant date fair value (in dollars per share)		$ 11.50	$ 23.87
Vested, Shares (in shares)		(247,953)	(108,921)
Vested, Weighted average grant date fair value (in dollars per share)		$ 23.64	$ 19.03
Forfeited, Shares (in shares)		(26,192)	(1,260)
Forfeited, Weighted average grant date fair value (in dollars per share)		$ 23.15	$ 19.05
Outstanding, Shares (in shares)		587,168	274,145
Outstanding, Weighted average grant date fair value (in dollars per share)		$ 11.50	$ 23.60

[1] For awards subject to future performance conditions, amounts assume target performance.