Note 10 - Income Taxes (Details Textual) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 30, 2017	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016	Dec. 30, 2016
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			35.00%	35.00%	35.00%
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability	$ 47,000
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability, Toll Charge	49,000		$ 49,000
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability, Other Than Toll Charge	(2,000)		(1,962)
Effective Income Tax Rate Reconciliation, Tax Credit, Foreign, Amount			13,000
Income Tax Expense (Benefit)			84,518	18,786	26,082
Income Taxes Paid			31,800	35,600	23,300
Proceeds from Income Tax Refunds			13,700
Undistributed Earnings of Foreign Subsidiaries	680,000		680,000
Deferred Tax Liabilities, Undistributed Foreign Earnings	12,000		12,000	1,750		$ 1,800
Income Tax Examination, Interest Expense			900	900	200
Income Tax Examination, Interest Accrued	3,300		3,300	2,400	1,500
Unrecognized Tax Benefits	7,660		7,660	8,617	3,532
CHINA
Income Tax Holiday, Aggregate Dollar Amount			$ 5,700
Income Tax Holiday Expense (Benefit) Amount Per Diluted Share			$ 0.25
Foreign Tax Authority [Member]
Deferred Tax Liabilities, Undistributed Foreign Earnings	11,800		$ 11,800
Foreign Tax Authority [Member] | Federal Ministry of Finance, Germany [Member] | Earliest Tax Year [Member]
Income Tax Examination, Year under Examination			2011
Foreign Tax Authority [Member] | Federal Ministry of Finance, Germany [Member] | Latest Tax Year [Member]
Income Tax Examination, Year under Examination			2014
Domestic Tax Authority [Member]
Deferred Tax Liabilities, Undistributed Foreign Earnings	200		$ 200
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Earliest Tax Year [Member]
Income Tax Examination, Year under Examination			2015
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Latest Tax Year [Member]
Income Tax Examination, Year under Examination			2016
Accumulated Defined Benefit Plans Adjustment Attributable to Noncontrolling Interest [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Income Tax Expense (Benefit)					$ (11,700)
Carry-back of U.S. Federal Net Operating Loss [Member]
Income Tax Expense (Benefit)				$ (3,000)
Other Long-term Liabilities [Member]
Accrued Income Taxes, Noncurrent	$ 32,000		$ 32,000
Scenario, Forecast [Member]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%