Note 5 - Debt - Carrying Amounts of Long-term Debt (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 30, 2017
Unamortized debt issuance costs	$ (5,184)	$ (4,881)
Total debt	697,598	495,611
Less: Current maturities	10,060	6,250
Total long-term debt	687,538	489,361
Line of Credit [Member]
Debt, carrying amount
Unsecured Debt [Member]
Debt, carrying amount	157,500	122,500
Euro Senior Notes, Series A [Member]
Debt, carrying amount	135,335	139,623
Euro Senior Notes, Series B [Member]
Debt, carrying amount	109,887	113,369
US Senior Notes, Series A Due 2022 [Member]
Debt, carrying amount	25,000	25,000
US Senior Notes, Series B Due 2027 [Member]
Debt, carrying amount	100,000	100,000
US Senior Notes, Series A Due 2025 [Member]
Debt, carrying amount	50,000
US Senior Notes, Series B Due 2030 [Member]
Debt, carrying amount	125,000
Notes Payable, Other Payables [Member]
Debt, carrying amount	$ 60

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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