Note 9 - Fair Value Measurements - Reconciliation of Note Payable (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2023	Jun. 30, 2023
Notes Payable to Banks [Member]
Balance	$ 15,640
Initial Transaction Fair Value - May 17		15,000
Accrued Paid-in-Kind (PIK) Interest	0	0
Fair Value Adjustment	3,832	640
Accrued Paid-in-Kind (PIK) Interest added to Principal	185
Fair Value Adjustment	(3,832)	(640)
Balance	11,993	15,640
Credit Risk Change [Member]
Balance	0
Initial Transaction Fair Value - May 17		0
Accrued Paid-in-Kind (PIK) Interest	0	0
Fair Value Adjustment	1,208	0
Accrued Paid-in-Kind (PIK) Interest added to Principal	0
Fair Value Adjustment	(1,208)	(0)
Balance	(1,208)	0
Accrued Interest [Member]
Balance	185
Initial Transaction Fair Value - May 17		0
Accrued Paid-in-Kind (PIK) Interest	383	185
Fair Value Adjustment	0	0
Accrued Paid-in-Kind (PIK) Interest added to Principal	(185)
Fair Value Adjustment	0	(0)
Balance	383	185
Notes Payable, Including Accrued Interest [Member]
Balance	15,825
Initial Transaction Fair Value - May 17		15,000
Accrued Paid-in-Kind (PIK) Interest	383	185
Fair Value Adjustment	5,040	640
Accrued Paid-in-Kind (PIK) Interest added to Principal	0
Fair Value Adjustment	(5,040)	(640)
Balance	$ 11,168	$ 15,825

ATHERSYS, INC / NEW 10-Q