Business Segments (Schedule Of Reportable Segments) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
Oct. 01, 2011	Oct. 02, 2010	Oct. 01, 2011	Oct. 02, 2010	Jan. 01, 2011	Jan. 02, 2010
Segment Reporting Information [Line Items]
Net Sales	$ 736,885	$ 590,801	$ 2,081,325	$ 1,682,300
Income from Operations	78,144	69,883	197,073	199,447
Goodwill at end of period	1,135,702	711,243	1,135,702	711,243	775,371	663,920
Mechanical Segment [Member]
Segment Reporting Information [Line Items]
Net Sales	69,435	63,012	208,271	174,476
Income from Operations	8,769	7,845	27,273	22,232
% of Net Sales	12.60%	12.40%	13.10%	12.70%
Goodwill at end of period	11,942	11,261	11,942	11,261	12,236
Electrical Segment [Member]
Segment Reporting Information [Line Items]
Net Sales	667,450	527,789	1,873,054	1,507,824
Income from Operations	69,375	62,038	169,800	177,215
% of Net Sales	10.40%	11.80%	9.10%	11.80%
Goodwill at end of period	$ 1,123,760	$ 699,982	$ 1,123,760	$ 699,982	$ 763,135	$ 663,920

Carrying amount as of the balance sheet date, which is the cumulative amount paid and (if applicable) the fair value of any noncontrolling interest in the acquiree, adjusted for any amortization recognized prior to the adoption of any changes in generally accepted accounting principles (as applicable) and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions.

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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