Note 9 - Income Taxes - Components of Deferred Income Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
State tax credits	$ 757	$ 1,046
Unfunded pension liability	1,840	1,102
Reserves and accruals	3,181	2,721
Federal, state and foreign net operating loss and credit carryforwards	7,744	8,042
Depreciation	604	686
Amortization	142	698
Lease accounting	3,217	3,961
Other accruals	5,452	5,079
Total deferred tax assets	22,937	23,335
Depreciation	1,992	1,901
Amortization	6,541	6,973
Lease accounting	3,110	3,871
Other accruals	330	370
Total deferred tax liabilities	11,973	13,115
Valuation allowance	6,289	8,216
Net deferred tax assets	$ 4,675	$ 2,004