Note D - Leases (Details Textual) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2021	Dec. 31, 2020
Lessee, Lease, Termination Period (Year)		1 year
Finance Lease, Right-of-Use Asset, after Accumulated Amortization, Total		$ 908	$ 957
Operating Lease, Right-of-Use Asset		23,282	23,793
Finance Lease, Right-of-Use Asset, Accumulated Depreciation		600	$ 500
Lessor, Operating Lease, Payment to be Received, Remainder of Fiscal Year		647
Lessor, Operating Lease, Payment to be Received, Year One		540
Lessor, Operating Lease, Payment to be Received, Year Two		154
Sublease Fullerton, Jacksonville and Manila Facilities [Member]
Lessor, Operating Lease, Payment to be Received, Remainder of Fiscal Year	[1]	647
Lessor, Operating Lease, Payment to be Received, Year One	[1]	540
Lessor, Operating Lease, Payment to be Received, Year Two	[1]	$ 154
Minimum [Member]
Lessee, Lease Remaining Lease Term (Year)		1 year
Minimum [Member] | Sublease Fullerton, Jacksonville and Manila Facilities [Member]
Lessee, Operating Sublease, Lease Term (Month)		150 days
Maximum [Member]
Lessee, Lease Remaining Lease Term (Year)		6 years
Lessee, Lease, Renewal Term (Year)		5 years
Maximum [Member] | Sublease Fullerton, Jacksonville and Manila Facilities [Member]
Lessee, Operating Sublease, Lease Term (Month)		2 years 330 days

[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 $647k, $540k, and $154k, respectively, are not included in the table above.