Note 4 - Fair Value Measurements - Fair Value Measurements (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Assets, fair value	$ 61	$ 59
Guaranteed Investment Certificates [Member]
Assets, fair value	61	59
Fair Value, Inputs, Level 1 [Member]
Assets, fair value	0	0
Fair Value, Inputs, Level 1 [Member] | Guaranteed Investment Certificates [Member]
Assets, fair value	0	0
Fair Value, Inputs, Level 2 [Member]
Assets, fair value	61	59
Fair Value, Inputs, Level 2 [Member] | Guaranteed Investment Certificates [Member]
Assets, fair value	61	59
Fair Value, Inputs, Level 3 [Member]
Assets, fair value	0	0
Fair Value, Inputs, Level 3 [Member] | Guaranteed Investment Certificates [Member]
Assets, fair value	$ 0	$ 0