Note D - Leases - Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Sep. 30, 2021		Dec. 31, 2020
Right-of-use Assets, operating leases	$ 19,569		$ 23,793
Right-of-use Assets, finance leases	810		957
Right-of-use Assets, total	20,379		24,750
Short-term lease liabilities, total	6,615		6,663
Long-term lease liabilities, total	17,546		21,295
Total Lease Liabilities, finance leases	462
Short-term Lease Liabilities [Member]
Short-term lease liabilities, operating leases	6,410		6,436
Short-term lease liabilities, finance leases	205		227
Short-term lease liabilities, total	6,615		6,663
Long-term Lease Liabilities [Member]
Long-term lease liabilities, operating leases	17,289		20,892
Long-term lease liabilities, finance leases	257		403
Long-term lease liabilities, total	17,546		21,295
Short-term Lease Liabilities and Long-term Lease Liabilities [Member]
Total Lease Liabilities, operating leases	23,699	[1]	27,328
Total Lease Liabilities, finance leases	462		630
Total Lease Liabilities, total	$ 24,161		$ 27,958

[1] Non-cancelable sublease proceeds for the remainder of the fiscal year ending December 31, 2021 and the fiscal years ending December 31, 2022 and 2023 of $0.2 million, $0.6 million, and $0.2 million, respectively, are not included in the table above.