Note 6 - Share-based Compensation - Non-vested Stock (Details) - Common Stock [Member]	Mar. 31, 2022 $ / shares shares
Outstanding (in shares) | shares	12,698
Outstanding (in dollars per share) | $ / shares	$ 42.92
Outstanding (in shares) | shares	12,698
Outstanding (in dollars per share) | $ / shares	$ 42.92