Income taxes (Details) (USD $)	1 Months Ended	12 Months Ended
	Dec. 28, 2012	Dec. 28, 2012	Dec. 30, 2011	Dec. 31, 2010
Loss from continuing operations before income taxes [Abstract]
Domestic		$ (138,770,000)	$ (14,242,000)	$ 1,293,000
Non-U.S.		113,999,000	(10,413,000)	(26,339,000)
Total		(24,771,000)	(24,655,000)	(25,046,000)
Current [Abstract]
Federal		602,000	655,000	0
State and local		102,000	36,000	88,000
Non-U.S.		8,234,000	(1,971,000)	3,765,000
Total current income tax expense		8,938,000	(1,280,000)	3,853,000
Deferred [Abstract]
Federal		124,000	10,912,000	(245,000)
State and local		0	5,777,000	(37,000)
Non-U.S.		(2,083,000)	7,834,000	(880,000)
Total deferred income tax expense		1,959,000	24,523,000	(1,162,000)
Net tax expense		6,979,000	23,243,000	2,691,000
Discontinued operations income tax expense (benefit)		0	300,000	800,000
Effective Income Tax Rate Reconciliation [Abstract]
U.S. statutory federal income tax rate (in hundredths)		35.00%	35.00%	35.00%
Decrease (increase) resulting from [Abstract]
State and local income taxes, net of federal tax effect (in hundredths)		(1.00%)	4.00%	0.00%
Non-deductible expenses and other (in hundredths)		(62.00%)	(20.00%)	(16.00%)
Withholding Taxes (in hundredths)		(9.00%)	(5.00%)	(2.00%)
Non-U.S. income subject to U.S. income tax (in hundredths)		0.00%	5.00%	(8.00%)
Tax Credits (in hundredths)		62.00%	16.00%	15.00%
Tax effect of intangible impairment (in hundredths)		0.00%	0.00%	(35.00%)
Tax effect of valuation allowance and Section 382/383 limitations (in hundredths)		(214.00%)	(129.00%)	0.00%
Lower foreign tax rates (in hundredths)		161.00%	0.00%	0.00%
Effective tax rate (in hundredths)		(28.00%)	(94.00%)	(11.00%)
Unrecognized tax benefits in other long-term liabilities	4,100,000	4,100,000	8,000,000
Unrecognized tax benefits that would impact effective tax rate	2,500,000	2,500,000
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Unrecognized tax benefits at the beginning of the year		17,300,000	17,686,000	23,237,000
Additions to tax positions related to current year		1,415,000	6,558,000	1,555,000
Reductions to tax positions related to prior years		(7,090,000)	(1,846,000)	(5,005,000)
Lapses in statutes of limitation		(3,745,000)	(5,098,000)	(2,101,000)
Unrecognized tax benefits at the end of the year	7,880,000	7,880,000	17,300,000	17,686,000
Accrued interest and /or penalties related to uncertain income tax position	300,000	300,000
Income tax expense benefit and effective income tax rate [Abstract]
Income tax (expense) benefit		(6,979,000)	(23,243,000)	(2,691,000)
Open tax years range, minimum		2 years
Open tax years range, maximum		10 years
Potential audit settlement		1,000,000
Taxes on foreign earnings		(500,000)	200,000	700,000
Assets [Abstract]
Inventories	1,132,000	1,132,000	794,000
Plant and equipment	6,155,000	6,155,000	6,189,000
Vacation pay and other compensation	218,000	218,000	498,000
Pension expense	928,000	928,000	613,000
Stock awards	68,000	68,000	77,000
Accrued liabilities	1,522,000	1,522,000	1,788,000
Net operating losses - federal, state and foreign	22,216,000	22,216,000	40,130,000
Tax credits	10,780,000	10,780,000	20,770,000
Acquired intangibles	4,120,000	4,120,000	8,800,000
Other	8,246,000	8,246,000	124,000
Total deferred tax assets	55,385,000	55,385,000	79,783,000
Valuation allowance	(44,697,000)	(44,697,000)	(67,556,000)
Net deferred tax assets	10,688,000	10,688,000	12,227,000
Liabilities [Abstract]
Foreign earnings not permanently invested	9,535,000	9,535,000	11,494,000
Restructuring	1,551,000	1,551,000	1,551,000
Acquired intangibles	529,000	529,000	461,000
Other	3,282,000	3,282,000	1,309,000
Total deferred tax liabilities	14,897,000	14,897,000	14,815,000
Net deferred tax assets	(4,209,000)	(4,209,000)	(2,588,000)
Short-term deferred tax assets	1,056,000	1,056,000	1,332,000
Short-term deferred tax liabilities	(92,000)	(92,000)	(3,816,000)
Long-term deferred tax assets	2,443,000	2,443,000	8,549,000
Long-term deferred tax liabilities	(7,616,000)	(7,616,000)	(8,653,000)
Net deferred tax assets	(4,209,000)	(4,209,000)	(2,588,000)
Previously unremitted foreign earnings	40,000,000	40,000,000
Indefinitely reinvested foreign earnings	13,600,000	13,600,000
Accumulated and undistributed earnings in foreign subsidiaries	134,800,000	134,800,000
Unrecognized taxes on undistributed earnings		$ 28,400,000