Note 6 - Share-based Compensation - Non-vested Stock (Details) - Common Stock [Member]	6 Months Ended
	Jun. 30, 2022 $ / shares shares
Outstanding (in shares) | shares	12,698
Outstanding (in dollars per share) | $ / shares	$ 42.92
Granted (in shares) | shares	0
Granted (in dollars per share) | $ / shares	$ 0
Vested (in shares) | shares	0
Vested (in dollars per share) | $ / shares	$ 0
Forfeited (in shares) | shares	0
Forfeited (in dollars per share) | $ / shares	$ 0
Outstanding (in shares) | shares	12,698
Outstanding (in dollars per share) | $ / shares	$ 42.92