Note 7 - Shareholders' Equity - Activity in Shareholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Apr. 01, 2018
Balance	$ 354,663
Net income	7,059	$ 15,084
Pension liability adjustment	(91)	(2,216)
Foreign currency translation adjustment	(5,203)	8,830
Cash flow hedge unrealized gain (loss)	(3,306)	$ 1,632
Balance	$ 349,659
Common Stock [Member]
Balance (in shares)	59,508,000	59,806,000
Balance	$ 5,951	$ 5,981
Net income	$ 0	$ 0
Stock issuances under employee plans (in shares)	509,000	175,000
Stock issuances under employee plans	$ 51	$ 17
Other issuances of common stock (in shares)	224,000	187,000
Other issuances of common stock	$ 22	$ 19
Unamortized stock compensation expense related to restricted stock awards	0	0
Cash dividends paid	$ 0	$ 0
Forfeitures and compensation expense related to stock awards (in shares)	(225,000)	(55,000)
Forfeitures and compensation expense related to stock awards	$ (22)	$ (6)
Share Repurchases	0	(61)
Pension liability adjustment	0	0
Foreign currency translation adjustment	0	0
Cash flow hedge unrealized gain (loss)	$ 0	$ 0
Share Repurchases (in shares)	0	(615,000)
Balance (in shares)	60,016,000	59,498,000
Balance	$ 6,002	$ 5,950
Additional Paid-in Capital [Member]
Balance	270,269	271,271
Net income	0	0
Stock issuances under employee plans	379	102
Other issuances of common stock	3,900	4,769
Unamortized stock compensation expense related to restricted stock awards	(3,922)	(4,788)
Cash dividends paid	0	0
Forfeitures and compensation expense related to stock awards	29	3,185
Share Repurchases	0	(14,424)
Pension liability adjustment	0	0
Foreign currency translation adjustment	0	0
Cash flow hedge unrealized gain (loss)	0	0
Balance	270,655	260,115
Retained Earnings [Member]
Balance	222,214	187,433
Net income	7,059	15,084
Stock issuances under employee plans	0	0
Other issuances of common stock	0	0
Unamortized stock compensation expense related to restricted stock awards	0	0
Cash dividends paid	(3,900)	(3,868)
Forfeitures and compensation expense related to stock awards	0	0
Share Repurchases	0	0
Pension liability adjustment	0	0
Foreign currency translation adjustment	0	0
Cash flow hedge unrealized gain (loss)	0	0
Balance	225,373	198,649
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Balance	(43,610)	(56,554)
Net income	0	0
Stock issuances under employee plans	0	0
Other issuances of common stock	0	0
Unamortized stock compensation expense related to restricted stock awards	0	0
Cash dividends paid	0	0
Forfeitures and compensation expense related to stock awards	0	0
Share Repurchases	0	0
Pension liability adjustment	(91)	(2,216)
Foreign currency translation adjustment	0	0
Cash flow hedge unrealized gain (loss)	0	0
Balance	(43,701)	(58,770)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Balance	(101,487)	(78,943)
Net income	0	0
Stock issuances under employee plans	0	0
Other issuances of common stock	0	0
Unamortized stock compensation expense related to restricted stock awards	0	0
Cash dividends paid	0	0
Forfeitures and compensation expense related to stock awards	0	0
Share Repurchases	0	0
Pension liability adjustment	0	0
Foreign currency translation adjustment	(5,203)	8,830
Cash flow hedge unrealized gain (loss)	0	0
Balance	(106,690)	(70,113)
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Balance	1,326	904
Net income	0	0
Stock issuances under employee plans	0	0
Other issuances of common stock	0	0
Unamortized stock compensation expense related to restricted stock awards	0	0
Cash dividends paid	0	0
Forfeitures and compensation expense related to stock awards	0	0
Share Repurchases	0	0
Pension liability adjustment	0	0
Foreign currency translation adjustment	0	0
Cash flow hedge unrealized gain (loss)	(3,306)	1,632
Balance	$ (1,980)	$ 2,536