Derivative financial instruments and fair value measurements (Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis ) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended							9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended					9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended					9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended						9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended
	Sep. 29, 2012	Oct. 01, 2011	Sep. 29, 2012	Oct. 01, 2011	Sep. 29, 2012 Edner Of Nevada [Member]	Sep. 29, 2012 Babco [Member]	Feb. 10, 2012 Babco [Member]	Sep. 29, 2012 Fair Value, Inputs, Level 1 [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 1 [Member]	Sep. 29, 2012 Fair Value, Inputs, Level 1 [Member] Interest Rate Swap [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 1 [Member] Interest Rate Swap [Member]	Sep. 29, 2012 Fair Value, Inputs, Level 1 [Member] Foreign Exchange Forward [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 1 [Member] Foreign Exchange Forward [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 1 [Member] Other Current [Member] Future And Forward Contracts [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 1 [Member] Other Long Term [Member] Future And Forward Contracts [Member]	Sep. 29, 2012 Fair Value, Inputs, Level 2 [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 2 [Member]	Sep. 29, 2012 Fair Value, Inputs, Level 2 [Member] Interest Rate Swap [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 2 [Member] Interest Rate Swap [Member]	Sep. 29, 2012 Fair Value, Inputs, Level 2 [Member] Foreign Exchange Forward [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 2 [Member] Foreign Exchange Forward [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 2 [Member] Other Current [Member] Future And Forward Contracts [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 2 [Member] Other Long Term [Member] Future And Forward Contracts [Member]	Sep. 29, 2012 Fair Value, Inputs, Level 3 [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 3 [Member]	Sep. 29, 2012 Fair Value, Inputs, Level 3 [Member] Interest Rate Swap [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 3 [Member] Interest Rate Swap [Member]	Sep. 29, 2012 Fair Value, Inputs, Level 3 [Member] Foreign Exchange Forward [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 3 [Member] Foreign Exchange Forward [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 3 [Member] Other Current [Member] Future And Forward Contracts [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 3 [Member] Other Long Term [Member] Future And Forward Contracts [Member]	Sep. 29, 2012 Fair Value, Measurements, Recurring [Member]		Dec. 31, 2011 Fair Value, Measurements, Recurring [Member]	Sep. 29, 2012 Fair Value, Measurements, Recurring [Member] Interest Rate Swap [Member]	Dec. 31, 2011 Fair Value, Measurements, Recurring [Member] Interest Rate Swap [Member]	Sep. 29, 2012 Fair Value, Measurements, Recurring [Member] Foreign Exchange Forward [Member]	Dec. 31, 2011 Fair Value, Measurements, Recurring [Member] Foreign Exchange Forward [Member]	Sep. 29, 2012 Fair Value, Measurements, Recurring [Member] Other Current [Member] Future And Forward Contracts [Member]		Dec. 31, 2011 Fair Value, Measurements, Recurring [Member] Other Current [Member] Future And Forward Contracts [Member]	Sep. 29, 2012 Fair Value, Measurements, Recurring [Member] Other Long Term [Member] Future And Forward Contracts [Member]		Dec. 31, 2011 Fair Value, Measurements, Recurring [Member] Other Long Term [Member] Future And Forward Contracts [Member]	Sep. 29, 2012 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 1 [Member]		Sep. 29, 2012 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 1 [Member] Other Current [Member] Future And Forward Contracts [Member]		Sep. 29, 2012 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 1 [Member] Other Long Term [Member] Future And Forward Contracts [Member]		Sep. 29, 2012 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 2 [Member]		Sep. 29, 2012 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 2 [Member] Other Current [Member] Future And Forward Contracts [Member]		Sep. 29, 2012 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 2 [Member] Other Long Term [Member] Future And Forward Contracts [Member]		Sep. 29, 2012 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 3 [Member]		Sep. 29, 2012 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 3 [Member] Other Current [Member] Future And Forward Contracts [Member]		Sep. 29, 2012 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 3 [Member] Other Long Term [Member] Future And Forward Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unrealized Derivative Gain														$ 34	$ 0							$ 2,091	$ 271							$ 0	$ 0								$ 5,382	[1]	$ 2,125	$ 262	[1]	$ 271			$ 0	[1]	$ 0	[1]			$ 5,382	[1]	$ 262	[1]			$ 0	[1]	$ 0	[1]
Unrealized Derivative Loss														0	0							(1,410)	(70)							0	0								(3,540)	[1]	(1,410)	(10)	[1]	(70)			(891)	[1]	0	[1]			(2,649)	[1]	(10)	[1]			0	[1]	0	[1]
Inventories Carried At Market									0								12,685								0							18,625	[2]	12,685											0	[2]					18,625	[2]					0	[2]
Unrealized Gain (Loss) on Derivatives	(3,075)	646	(1,178)	(3,272)						0	0	0	0					(497)	(256)	304	(149)					0	0	0	0						(497)	(256)	304	(149)
Business Acquisition, Contingent Consideration, at Fair Value						617	615	0	0							0	0							4,487	4,456							4,487		4,456
Business Acquisition Contingent Consideration Payments					$ 388

[1] Unrealized short-term derivative gain is included in prepaid expenses and other current assets, unrealized long-term derivative gain is included in other assets, unrealized short-term derivative loss is included in other current liabilities and unrealized long-term derivative loss is included in long-term liabilities on the consolidated balance sheets.

[2] Inventories carried at market are included in inventories on the consolidated balance sheets.