Note C - Significant Customers - Schedules of Concentration of Risk, by Risk Factor (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Accounts receivable, net of allowance of $1,151 in 2024 and $1,065 in 2023	$ 205,740	$ 215,581
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Do D [Member]
Accounts receivable, net of allowance of $1,151 in 2024 and $1,065 in 2023	50,319	56,848
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Amazon [Member]
Accounts receivable, net of allowance of $1,151 in 2024 and $1,065 in 2023	76,798	74,509
Accounts Receivable [Member] | Customer Concentration Risk [Member] | DHL [Member]
Accounts receivable, net of allowance of $1,151 in 2024 and $1,065 in 2023	$ 13,520	$ 8,040