Summary of Significant Accounting Policies (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 25, 2011	Jun. 26, 2010	Jun. 25, 2011	Jun. 26, 2010	Dec. 25, 2010
Inventories
Inventory valued at the lower of cost, determined on the last-in, first-out (LIFO) method, or market (as a percent)	37.00%		37.00%
Excess of replacement cost of inventories over the LIFO value	$ 54,400		$ 54,400		$ 42,500
Raw materials and purchased parts	187,897		187,897		133,380
Work-in-process	33,529		33,529		25,891
Finished goods and manufactured goods	199,155		199,155		163,511
Subtotal	420,581		420,581		322,782
LIFO reserve	54,396		54,396		42,559
Net inventory	366,185		366,185		280,223
Stock Plans
Shares of common stock available for issuance under the plans (in shares)	856,165		856,165
Vesting period, minimum			First anniversary from date of grant
Vesting period, maximum			Fifth anniversary from date of grant
Ratable amount vesting annually, low end of the range (in years)			3
Ratable amount vesting annually, high end of the range (in years)			6
Expiration period, low end of the range (in years)			6
Expiration period, high end of the range (in years)			10
Stock-based compensation plans expenses and income tax benefits
Compensation expense	1,215	1,229	2,467	2,457
Income tax benefits	$ 468	$ 467	$ 950	$ 934