Note 4 - Equity - Common Stock Purchase Warrant Activity (Details) - $ / shares	3 Months Ended						9 Months Ended		12 Months Ended
	Sep. 30, 2025	Jun. 30, 2025	Mar. 31, 2025	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Outstanding (in shares)	39,633	39,633	39,633	55,214	67,176	3,052	39,633	3,052	3,052
Outstanding (in dollars per share)	$ 503.75	$ 503.75	$ 503.75	$ 361.6	$ 297.21	$ 4,054.81	$ 503.75	$ 4,054.81	$ 4,054.81
Warrants issued (in shares)			0			64,124
Warrants issued (in dollars per share)			$ 0			$ 118.37
Warrants exercised (in shares)	0	0		15,580	11,962
Warrants exercised (in dollars per share)	$ 0	$ 0		$ 0.01	$ 0.01
Warrants cancelled or expired (in shares)	25			0
Warrants cancelled or expired (in dollars per share)	$ 7,620			$ 0
Outstanding (in shares)	39,608	39,633	39,633	39,634	55,214	67,176	39,608	39,634	39,633